This document proposes a novel method for medical image denoising that combines contourlet thresholding, bilateral filtering, and non-local means filtering. Specifically, it introduces scaling factors to the universal threshold for wavelet and contourlet transforms. It then uses the contourlet-based thresholding as a pre-processing step before bilateral or non-local means filtering for denoising. Simulation results show the combined approach achieves better PSNR and perceptual quality than using bilateral or non-local means filtering alone.
Image Denoising Using Earth Mover's Distance and Local HistogramsCSCJournals
In this paper an adaptive range and domain filtering is presented. In the proposed method local histograms are computed to tune the range and domain extensions of bilateral filter. Noise histogram is estimated to measure the noise level at each pixel in the noisy image. The extensions of range and domain filters are determined based on pixel noise level. Experimental results show that the proposed method effectively removes the noise while preserves the details. The proposed method performs better than bilateral filter and restored test images have higher PSNR than those obtained by applying popular Bayesshrink wavelet denoising method.
An Image Enhancement Approach to Achieve High Speed using Adaptive Modified B...TELKOMNIKA JOURNAL
For real time application scenarios of image processing, satellite imaginary has grown more interest by researches due to the informative nature of image. Satellite images are captured using high quality cameras. These images are captured from space using on-board cameras. Wrong ISO setting, camera vibrations or wrong sensory setting causes noise. The degraded image can cause less efficient results during visual perception which is a challenging issue for researchers. Another reason is that noise corrupts the image during acquisition, transmission, interference or dust particles on the scanner screen of image from satellite to the earth stations. If quality degraded images are used for further processing then it may result in wrong information extraction. In order to cater this issue, image filtering or denoising approach is required.
Since remote sensing images are captured from space using on-board camera which requires high speed operating device which can provide better reconstruction quality by utilizing lesser power consumption. Recently various approaches have been proposed for image filtering. Key challenges with these approaches are reconstruction quality, operating speed, image quality by preserving information at edges on image.
Proposed approach is named as modified bilateral filter. In this approach bilateral filter and kernel schemes are combined. In order to overcome the drawbacks, modified bilateral filtering by using FPGA to perform the parallelism process for denoising is implemented.
A common goal of the engineering field of signal processing is to reconstruct a signal from a series of sampling measurements. In general, this task is impossible because there is no way to reconstruct a signal during the times
that the signal is not measured. Nevertheless, with prior knowledge or assumptions about the signal, it turns out to
be possible to perfectly reconstruct a signal from a series of measurements. Over time, engineers have improved their understanding of which assumptions are practical and how they can be generalized. An early breakthrough in signal processing was the Nyquist–Shannon sampling theorem. It states that if the signal's highest frequency is less than half of the sampling rate, then the signal can be reconstructed perfectly. The main idea is that with prior knowledge about constraints on the signal’s frequencies, fewer samples are needed to reconstruct the signal. Sparse sampling (also known as, compressive sampling, or compressed sampling) is a signal processing technique for efficiently acquiring and reconstructing a signal, by finding solutions tounder determined linear systems. This is based on the principle that, through optimization, the sparsity of a signal can be exploited to recover it from far fewer samples than required by the Shannon-Nyquist sampling theorem. There are two conditions under which recovery is possible.[1] The first one is sparsity which requires the signal to be sparse in some domain. The second one is incoherence which is applied through the isometric property which is sufficient for sparse signals Possibility
of compressed data acquisition protocols which directly acquire just the important information Sparse sampling (CS) is a fast growing area of research. It neglects the extravagant acquisition process by measuring lesser values to reconstruct the image or signal. Sparse sampling is adopted successfully in various fields of image processing and proved its efficiency. Some of the image processing applications like face recognition, video encoding, Image encryption and reconstruction are presented here.
Image Denoising Using Earth Mover's Distance and Local HistogramsCSCJournals
In this paper an adaptive range and domain filtering is presented. In the proposed method local histograms are computed to tune the range and domain extensions of bilateral filter. Noise histogram is estimated to measure the noise level at each pixel in the noisy image. The extensions of range and domain filters are determined based on pixel noise level. Experimental results show that the proposed method effectively removes the noise while preserves the details. The proposed method performs better than bilateral filter and restored test images have higher PSNR than those obtained by applying popular Bayesshrink wavelet denoising method.
An Image Enhancement Approach to Achieve High Speed using Adaptive Modified B...TELKOMNIKA JOURNAL
For real time application scenarios of image processing, satellite imaginary has grown more interest by researches due to the informative nature of image. Satellite images are captured using high quality cameras. These images are captured from space using on-board cameras. Wrong ISO setting, camera vibrations or wrong sensory setting causes noise. The degraded image can cause less efficient results during visual perception which is a challenging issue for researchers. Another reason is that noise corrupts the image during acquisition, transmission, interference or dust particles on the scanner screen of image from satellite to the earth stations. If quality degraded images are used for further processing then it may result in wrong information extraction. In order to cater this issue, image filtering or denoising approach is required.
Since remote sensing images are captured from space using on-board camera which requires high speed operating device which can provide better reconstruction quality by utilizing lesser power consumption. Recently various approaches have been proposed for image filtering. Key challenges with these approaches are reconstruction quality, operating speed, image quality by preserving information at edges on image.
Proposed approach is named as modified bilateral filter. In this approach bilateral filter and kernel schemes are combined. In order to overcome the drawbacks, modified bilateral filtering by using FPGA to perform the parallelism process for denoising is implemented.
A common goal of the engineering field of signal processing is to reconstruct a signal from a series of sampling measurements. In general, this task is impossible because there is no way to reconstruct a signal during the times
that the signal is not measured. Nevertheless, with prior knowledge or assumptions about the signal, it turns out to
be possible to perfectly reconstruct a signal from a series of measurements. Over time, engineers have improved their understanding of which assumptions are practical and how they can be generalized. An early breakthrough in signal processing was the Nyquist–Shannon sampling theorem. It states that if the signal's highest frequency is less than half of the sampling rate, then the signal can be reconstructed perfectly. The main idea is that with prior knowledge about constraints on the signal’s frequencies, fewer samples are needed to reconstruct the signal. Sparse sampling (also known as, compressive sampling, or compressed sampling) is a signal processing technique for efficiently acquiring and reconstructing a signal, by finding solutions tounder determined linear systems. This is based on the principle that, through optimization, the sparsity of a signal can be exploited to recover it from far fewer samples than required by the Shannon-Nyquist sampling theorem. There are two conditions under which recovery is possible.[1] The first one is sparsity which requires the signal to be sparse in some domain. The second one is incoherence which is applied through the isometric property which is sufficient for sparse signals Possibility
of compressed data acquisition protocols which directly acquire just the important information Sparse sampling (CS) is a fast growing area of research. It neglects the extravagant acquisition process by measuring lesser values to reconstruct the image or signal. Sparse sampling is adopted successfully in various fields of image processing and proved its efficiency. Some of the image processing applications like face recognition, video encoding, Image encryption and reconstruction are presented here.
An Ultrasound Image Despeckling Approach Based on Principle Component AnalysisCSCJournals
An approach based on principle component analysis (PCA) to filter out multiplicative noise from ultrasound images is presented in this paper. An image with speckle noise is segmented into small dyadic lengths, depending on the original size of the image, and the global covariance matrix is found. A projection matrix is then formed by selecting the maximum eigenvectors of the global covariance matrix. This projection matrix is used to filter speckle noise by projecting each segment into the signal subspace. The approach is based on the assumption that the signal and noise are independent and that the signal subspace is spanned by a subset of few principal eigenvectors. When applied on simulated and real ultrasound images, the proposed approach has outperformed some popular nonlinear denoising techniques such as 2D wavelets, 2D total variation filtering, and 2D anisotropic diffusion filtering in terms of edge preservation and maximum cleaning of speckle noise. It has also showed lower sensitivity to outliers resulting from the log transformation of the multiplicative noise.
Analysis of Various Image De-Noising Techniques: A Perspective Viewijtsrd
A critical issue in the image restoration is the problem of de noising images while keeping the integrity of relevant image information. A large number of image de noising techniques are proposed to remove noise. Mainly these techniques are depends upon the type of noise present in images. So image de noising still remains an important challenge for researchers because de noising techniques remove noise from images but also introduces some artifacts and cause blurring. In this paper we discuss about various image de noising and their features. Some of these techniques provide satisfactory results in noise removal and also preserving edges with fine details present in images. Noise modeling in images is greatly affected by capturing instruments, data transmission media, image quantization and discrete sources of radiation. Different algorithms are used depending on the noise model. Most of the natural images are assumed to have additive random noise which is modeled as a Gaussian. Speckle noise is observed in ultrasound images whereas Rician noise affects MRI images. The scope of the paper is to focus on noise removal techniques for natural images. Bhavna Kubde | Prof. Seema Shukla "Analysis of Various Image De-Noising Techniques: A Perspective View" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-1 , December 2019, URL: https://www.ijtsrd.com/papers/ijtsrd29629.pdfPaper URL: https://www.ijtsrd.com/computer-science/other/29629/analysis-of-various-image-de-noising-techniques-a-perspective-view/bhavna-kubde
Performance Analysis and Optimization of Nonlinear Image Restoration Techniqu...CSCJournals
Abstract: This paper is concerned with critical performance analysis of spatial nonlinear restoration techniques for continuous tone images from various fields (Medical images, Natural images, and others images).The performance of the nonlinear restoration methods is provided with possible combination of various additive noises and images from diversified fields. Efficiency of nonlinear restoration techniques according to difference distortion and correlation distortion metrics is computed.Tests performed on monochrome images, with various synthetic and real-life degradations, without and with noise, in single frame scenarios, showed good results, both in subjective terms and in terms of the increase of signal to noise ratio(ISNR) measure. The comparison of the present approach with previous individual methods in terms of mean square error, peak signal-to-noise ratio, and normalised absolute error is also provided. In comparisons with other state of art methods, our approach yields better to optimization, and shows to be applicable to a much wider range of noises. We discuss how experimental results are useful to guide to select the effective combination. Promising performance analysed through computer simulation and compared to give critical analysis.
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity
Learning Based Single Frame Image Super-resolution Using Fast Discrete Curvel...CSCJournals
High-resolution (HR) images play a vital role in all imaging applications as they offer more details. The images captured by the camera system are of degraded quality due to the imaging system and are low-resolution (LR) images. Image super-resolution (SR) is a process, where HR image is obtained from combining one or multiple LR images of same scene. In this paper, learning based single frame image super-resolution technique is proposed by using Fast Discrete Curvelet Transform (FDCT) coefficients. FDCT is an extension to Cartesian wavelets having anisotropic scaling with many directions and positions, which forms tight wedges. Such wedges allow FDCT to capture the smooth curves and fine edges at multiresolution level. The finer scale curvelet coefficients of LR image are learnt locally from a set of high-resolution training images. The super-resolved image is reconstructed by inverse Fast Discrete Curvelet Transform (IFDCT). This technique represents fine edges of reconstructed HR image by extrapolating the FDCT coefficients from the high-resolution training images. Experimentation based results show appropriate improvements in MSE and PSNR.
Novel adaptive filter (naf) for impulse noise suppression from digital imagesijbbjournal
In general, it is known that an adaptive filter adjusts its parameters iteratively such as size of the working
window, decision threshold values used in two stage detection-estimation based switching filters, number of
iterations etc. It is also known that nonlinear filters such as median filters and its several variants are
popularly known for their ability in dealing with the unknown circumstances. In this paper an efficient and
simple adaptive nonlinear filtering scheme is presented to eliminate the impulse noise from the digital images with an impulsive noise detection and reduction scheme based on adaptive nonlinear filter techniques. The proposed scheme employs image statistics based dynamically varying working window and an adaptive threshold for noise detection with a Noise Exclusive Median (NEM) based restoration. The intensity value of the Noise Exclusive Median (NEM) is derived from the processed pixels in local
neighborhood of a dynamically adaptive window. In the proposed scheme use of an adaptive threshold value derived from the noisy image statistics returns more precise results for the noisy pixel detection. The
proposed scheme is simple and can be implemented as either a single pass or a multi-pass with a maximum
of three iterations with a simple stopping criterion. The goodness of the proposed scheme is evaluated with respect to the qualitative and quantitative measures obtained by MATLAB simulations with standard images added with impulsive noise of varying densities. From the comparative analysis it is evident that the proposed scheme out performs the state-of-art schemes, preferably in cases of high-density impulse noise
Medical Images are regularly of low contrast and boisterous/Noisy (absence of clarity) because of
the circumstances they are being taken. De-noising these pictures is a troublesome undertaking as they
ought to exclude any antiquities or obscuring of edges in the pictures. The Bayesian shrinkage strategy has
been chosen for thresholding in light of its sub band reliance property. The spatial space and Wavelet
based de-noising systems utilizing delicate thresholding strategy are contrasted and the proposed technique
utilizing GA (Genetic Algorithm) is used. The GA procedure is proposed in view of PSNR and results are
contrasted and existing spatial space and wavelet based de-noising separating strategies. The proposed
calculation gives improved visual clarity to diagnosing the restorative pictures. The proposed strategy in
view of GA surveys the better execution on the premise of the quantitative metric i.e PSNR (Peak Signal
to Noise-Ratio) and visual impacts. Reenactment results demonstrate that the GA based proposed
technique beats the current de-noising separating strategies.
Analysis PSNR of High Density Salt and Pepper Impulse Noise Using Median Filterijtsrd
In this paper a new method for the enhancement of gray scale images is introduced, when images are corrupted by fixed valued impulse noise salt and pepper noise . The proposed methodology ensures a better output for low and medium density of fixed value impulse noise as compare to the other famous filters like Standard Median Filter SMF , Decision Based Median Filter DBMF and Modified Decision Based Median Filter MDBMF etc. The main objective of the proposed method was to improve peak signal to noise ratio PSNR , visual perception and reduction in blurring of image. The proposed algorithm replaced the noisy pixel by trimmed mean value. When previous pixel values, 0's and 255's are present in the particular window and all the pixel values are 0's and 255's then the remaining noisy pixels are replaced by mean value. The gray-scale image of mandrill and Lena were tested via proposed method. The experimental result shows better peak signal to noise ratio PSNR , mean square error MSE and mean absolute error MAE values with better visual and human perception. Sonali Malviya | Prof. Anshuj Jain "Analysis PSNR of High Density Salt and Pepper Impulse Noise Using Median Filter" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-1 , December 2018, URL: http://www.ijtsrd.com/papers/ijtsrd19086.pdf
http://www.ijtsrd.com/engineering/computer-engineering/19086/analysis-psnr-of-high-density-salt-and-pepper-impulse-noise-using-median-filter/sonali-malviya
An Efficient Image Denoising Approach for the Recovery of Impulse NoisejournalBEEI
Image noise is one of the key issues in image processing applications today. The noise will affect the quality of the image and thus degrades the actual information of the image. Visual quality is the prerequisite for many imagery applications such as remote sensing. In recent years, the significance of noise assessment and the recovery of noisy images are increasing. The impulse noise is characterized by replacing a portion of an image’s pixel values with random values Such noise can be introduced due to transmission errors. Accordingly, this paper focuses on the effect of visual quality of the image due to impulse noise during the transmission of images. In this paper, a hybrid statistical noise suppression technique has been developed for improving the quality of the impulse noisy color images. We further proved the performance of the proposed image enhancement scheme using the advanced performance metrics.
In this paper, an attempt has been made to extract texture
features from facial images using an improved method of
Illumination Invariant Feature Descriptor. The proposed local
ternary Pattern based feature extractor viz., Steady Illumination
Local Ternary Pattern (SIcLTP) has been used to extract texture
features from Indian face database. The similarity matching
between two extracted feature sets has been obtained using Zero
Mean Sum of Squared Differences (ZSSD). The RGB facial images
are first converted into the YIQ colour space to reduce the
redundancy of the RGB images. The result obtained has been
analysed using Receiver Operating Characteristic curve, and is
found to be promising. Finally the results are validated with
standard local binary pattern (LBP) extractor.
Effective segmentation of sclera, iris and pupil in noisy eye imagesTELKOMNIKA JOURNAL
In today’s sensitive environment, for personal authentication, iris recognition is the most attentive
technique among the various biometric technologies. One of the key steps in the iris recognition system is
the accurate iris segmentation from its surrounding noises including pupil and sclera of a captured
eye-image. In our proposed method, initially input image is preprocessed by using bilateral filtering.
After the preprocessing of images contour based features such as, brightness, color and texture features
are extracted. Then entropy is measured based on the extracted contour based features to effectively
distinguishing the data in the images. Finally, the convolution neural network (CNN) is used for
the effective sclera, iris and pupil parts segmentations based on the entropy measure. The proposed
results are analyzed to demonstrate the better performance of the proposed segmentation method than
the existing methods.
Rician Noise Reduction with SVM and Iterative Bilateral Filter in Different T...IJMERJOURNAL
ABSTRACT: Parallel magnetic resonance imaging (pMRI) techniques can speed up MRI scan through a multi-channel coil array receiving signal simultaneously. Nevertheless, noise amplification and aliasing artifacts are serious in pMRI reconstructed images at high accelerations. Image Denoising is one of the most challenging task because image denoising techniques not only poised some technical difficulties, but also may result in the destruction of the image (i.e. making it blur) if not effectively and adequately applied to image. This study presents a patch-wise de-noising method for pMRI by exploiting the rank deficiency of multi-Channel coil images and sparsity of artifacts. For each processed patch, similar patches a researched in spatial domain and through-out all coil elements, and arranged in appropriate matrix forms. Then, noise and aliasing artifacts are removed from the structured Matrix by applying sparse and low rank matrix decomposition method. The proposed method has been validated using both phantom and in vivo brain data sets, producing encouraging results. Specifically, the method can effectively remove both noise and residual aliasing artifact from pMRI reconstructed noisy images, and produce higher peak signal noise rate (PSNR) and structural similarity index matrix (SSIM) than other state-of-the-art De-noising methods. We propose image de-noising using low rank matrix decomposition (LMRD) and Support vector machine (SVM). The aim of Low Rank Matrix approximation based image enhancement is that it removes the various types of noises in the contaminated image simultaneously. The main contribution is to explore the image denoising low-rank property and the applications of LRMD for enhanced image Denoising, Then support vector machine is applied over the result.
Computationally Efficient Methods for Sonar Image Denoising using Fractional ...CSCJournals
Sonar images produced due to the coherent nature of scattering phenomenon inherit a multiplicative component called speckle and contain almost homogeneous as well as textured regions with relatively rare edges. Speckle removal is a pre-processing step required in applications like the detection and classification of objects in the sonar image. In this paper computationally efficient Fractional Integral Mask algorithms to remove the speckle noise from sonar images is proposed. Riemann- Liouville definition of fractional calculus is used to create Fractional integral masks in eight directions. The use of a mask incorporated with the significant coefficients from the eight directional masks and a single convolution operation required in such case helps in obtaining the computational efficiency. The sonar image heterogeneous patch classification is based on a new proposed naive homogeneity index which depends on the texture strength of the patches and despeckling filters can be adjusted to these patches. The application of the mask convolution only to the selected patches again reduce the computational complexity. The non-homomorphic approach used in the proposed method avoids the undesired bias occurring in the traditional homomorphic approach. Experiments show that the mask size required directly depends on the fractional order. Mask size can be reduced for lower fractional orders thus ensuring the computation complexity reduction for lower orders. Experimental results substantiate the effectiveness of the despeckling method. The different non reference image performance evaluation criterion are used to evaluate the proposed method.
An Ultrasound Image Despeckling Approach Based on Principle Component AnalysisCSCJournals
An approach based on principle component analysis (PCA) to filter out multiplicative noise from ultrasound images is presented in this paper. An image with speckle noise is segmented into small dyadic lengths, depending on the original size of the image, and the global covariance matrix is found. A projection matrix is then formed by selecting the maximum eigenvectors of the global covariance matrix. This projection matrix is used to filter speckle noise by projecting each segment into the signal subspace. The approach is based on the assumption that the signal and noise are independent and that the signal subspace is spanned by a subset of few principal eigenvectors. When applied on simulated and real ultrasound images, the proposed approach has outperformed some popular nonlinear denoising techniques such as 2D wavelets, 2D total variation filtering, and 2D anisotropic diffusion filtering in terms of edge preservation and maximum cleaning of speckle noise. It has also showed lower sensitivity to outliers resulting from the log transformation of the multiplicative noise.
Analysis of Various Image De-Noising Techniques: A Perspective Viewijtsrd
A critical issue in the image restoration is the problem of de noising images while keeping the integrity of relevant image information. A large number of image de noising techniques are proposed to remove noise. Mainly these techniques are depends upon the type of noise present in images. So image de noising still remains an important challenge for researchers because de noising techniques remove noise from images but also introduces some artifacts and cause blurring. In this paper we discuss about various image de noising and their features. Some of these techniques provide satisfactory results in noise removal and also preserving edges with fine details present in images. Noise modeling in images is greatly affected by capturing instruments, data transmission media, image quantization and discrete sources of radiation. Different algorithms are used depending on the noise model. Most of the natural images are assumed to have additive random noise which is modeled as a Gaussian. Speckle noise is observed in ultrasound images whereas Rician noise affects MRI images. The scope of the paper is to focus on noise removal techniques for natural images. Bhavna Kubde | Prof. Seema Shukla "Analysis of Various Image De-Noising Techniques: A Perspective View" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-1 , December 2019, URL: https://www.ijtsrd.com/papers/ijtsrd29629.pdfPaper URL: https://www.ijtsrd.com/computer-science/other/29629/analysis-of-various-image-de-noising-techniques-a-perspective-view/bhavna-kubde
Performance Analysis and Optimization of Nonlinear Image Restoration Techniqu...CSCJournals
Abstract: This paper is concerned with critical performance analysis of spatial nonlinear restoration techniques for continuous tone images from various fields (Medical images, Natural images, and others images).The performance of the nonlinear restoration methods is provided with possible combination of various additive noises and images from diversified fields. Efficiency of nonlinear restoration techniques according to difference distortion and correlation distortion metrics is computed.Tests performed on monochrome images, with various synthetic and real-life degradations, without and with noise, in single frame scenarios, showed good results, both in subjective terms and in terms of the increase of signal to noise ratio(ISNR) measure. The comparison of the present approach with previous individual methods in terms of mean square error, peak signal-to-noise ratio, and normalised absolute error is also provided. In comparisons with other state of art methods, our approach yields better to optimization, and shows to be applicable to a much wider range of noises. We discuss how experimental results are useful to guide to select the effective combination. Promising performance analysed through computer simulation and compared to give critical analysis.
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity
Learning Based Single Frame Image Super-resolution Using Fast Discrete Curvel...CSCJournals
High-resolution (HR) images play a vital role in all imaging applications as they offer more details. The images captured by the camera system are of degraded quality due to the imaging system and are low-resolution (LR) images. Image super-resolution (SR) is a process, where HR image is obtained from combining one or multiple LR images of same scene. In this paper, learning based single frame image super-resolution technique is proposed by using Fast Discrete Curvelet Transform (FDCT) coefficients. FDCT is an extension to Cartesian wavelets having anisotropic scaling with many directions and positions, which forms tight wedges. Such wedges allow FDCT to capture the smooth curves and fine edges at multiresolution level. The finer scale curvelet coefficients of LR image are learnt locally from a set of high-resolution training images. The super-resolved image is reconstructed by inverse Fast Discrete Curvelet Transform (IFDCT). This technique represents fine edges of reconstructed HR image by extrapolating the FDCT coefficients from the high-resolution training images. Experimentation based results show appropriate improvements in MSE and PSNR.
Novel adaptive filter (naf) for impulse noise suppression from digital imagesijbbjournal
In general, it is known that an adaptive filter adjusts its parameters iteratively such as size of the working
window, decision threshold values used in two stage detection-estimation based switching filters, number of
iterations etc. It is also known that nonlinear filters such as median filters and its several variants are
popularly known for their ability in dealing with the unknown circumstances. In this paper an efficient and
simple adaptive nonlinear filtering scheme is presented to eliminate the impulse noise from the digital images with an impulsive noise detection and reduction scheme based on adaptive nonlinear filter techniques. The proposed scheme employs image statistics based dynamically varying working window and an adaptive threshold for noise detection with a Noise Exclusive Median (NEM) based restoration. The intensity value of the Noise Exclusive Median (NEM) is derived from the processed pixels in local
neighborhood of a dynamically adaptive window. In the proposed scheme use of an adaptive threshold value derived from the noisy image statistics returns more precise results for the noisy pixel detection. The
proposed scheme is simple and can be implemented as either a single pass or a multi-pass with a maximum
of three iterations with a simple stopping criterion. The goodness of the proposed scheme is evaluated with respect to the qualitative and quantitative measures obtained by MATLAB simulations with standard images added with impulsive noise of varying densities. From the comparative analysis it is evident that the proposed scheme out performs the state-of-art schemes, preferably in cases of high-density impulse noise
Medical Images are regularly of low contrast and boisterous/Noisy (absence of clarity) because of
the circumstances they are being taken. De-noising these pictures is a troublesome undertaking as they
ought to exclude any antiquities or obscuring of edges in the pictures. The Bayesian shrinkage strategy has
been chosen for thresholding in light of its sub band reliance property. The spatial space and Wavelet
based de-noising systems utilizing delicate thresholding strategy are contrasted and the proposed technique
utilizing GA (Genetic Algorithm) is used. The GA procedure is proposed in view of PSNR and results are
contrasted and existing spatial space and wavelet based de-noising separating strategies. The proposed
calculation gives improved visual clarity to diagnosing the restorative pictures. The proposed strategy in
view of GA surveys the better execution on the premise of the quantitative metric i.e PSNR (Peak Signal
to Noise-Ratio) and visual impacts. Reenactment results demonstrate that the GA based proposed
technique beats the current de-noising separating strategies.
Analysis PSNR of High Density Salt and Pepper Impulse Noise Using Median Filterijtsrd
In this paper a new method for the enhancement of gray scale images is introduced, when images are corrupted by fixed valued impulse noise salt and pepper noise . The proposed methodology ensures a better output for low and medium density of fixed value impulse noise as compare to the other famous filters like Standard Median Filter SMF , Decision Based Median Filter DBMF and Modified Decision Based Median Filter MDBMF etc. The main objective of the proposed method was to improve peak signal to noise ratio PSNR , visual perception and reduction in blurring of image. The proposed algorithm replaced the noisy pixel by trimmed mean value. When previous pixel values, 0's and 255's are present in the particular window and all the pixel values are 0's and 255's then the remaining noisy pixels are replaced by mean value. The gray-scale image of mandrill and Lena were tested via proposed method. The experimental result shows better peak signal to noise ratio PSNR , mean square error MSE and mean absolute error MAE values with better visual and human perception. Sonali Malviya | Prof. Anshuj Jain "Analysis PSNR of High Density Salt and Pepper Impulse Noise Using Median Filter" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-1 , December 2018, URL: http://www.ijtsrd.com/papers/ijtsrd19086.pdf
http://www.ijtsrd.com/engineering/computer-engineering/19086/analysis-psnr-of-high-density-salt-and-pepper-impulse-noise-using-median-filter/sonali-malviya
An Efficient Image Denoising Approach for the Recovery of Impulse NoisejournalBEEI
Image noise is one of the key issues in image processing applications today. The noise will affect the quality of the image and thus degrades the actual information of the image. Visual quality is the prerequisite for many imagery applications such as remote sensing. In recent years, the significance of noise assessment and the recovery of noisy images are increasing. The impulse noise is characterized by replacing a portion of an image’s pixel values with random values Such noise can be introduced due to transmission errors. Accordingly, this paper focuses on the effect of visual quality of the image due to impulse noise during the transmission of images. In this paper, a hybrid statistical noise suppression technique has been developed for improving the quality of the impulse noisy color images. We further proved the performance of the proposed image enhancement scheme using the advanced performance metrics.
In this paper, an attempt has been made to extract texture
features from facial images using an improved method of
Illumination Invariant Feature Descriptor. The proposed local
ternary Pattern based feature extractor viz., Steady Illumination
Local Ternary Pattern (SIcLTP) has been used to extract texture
features from Indian face database. The similarity matching
between two extracted feature sets has been obtained using Zero
Mean Sum of Squared Differences (ZSSD). The RGB facial images
are first converted into the YIQ colour space to reduce the
redundancy of the RGB images. The result obtained has been
analysed using Receiver Operating Characteristic curve, and is
found to be promising. Finally the results are validated with
standard local binary pattern (LBP) extractor.
Effective segmentation of sclera, iris and pupil in noisy eye imagesTELKOMNIKA JOURNAL
In today’s sensitive environment, for personal authentication, iris recognition is the most attentive
technique among the various biometric technologies. One of the key steps in the iris recognition system is
the accurate iris segmentation from its surrounding noises including pupil and sclera of a captured
eye-image. In our proposed method, initially input image is preprocessed by using bilateral filtering.
After the preprocessing of images contour based features such as, brightness, color and texture features
are extracted. Then entropy is measured based on the extracted contour based features to effectively
distinguishing the data in the images. Finally, the convolution neural network (CNN) is used for
the effective sclera, iris and pupil parts segmentations based on the entropy measure. The proposed
results are analyzed to demonstrate the better performance of the proposed segmentation method than
the existing methods.
Rician Noise Reduction with SVM and Iterative Bilateral Filter in Different T...IJMERJOURNAL
ABSTRACT: Parallel magnetic resonance imaging (pMRI) techniques can speed up MRI scan through a multi-channel coil array receiving signal simultaneously. Nevertheless, noise amplification and aliasing artifacts are serious in pMRI reconstructed images at high accelerations. Image Denoising is one of the most challenging task because image denoising techniques not only poised some technical difficulties, but also may result in the destruction of the image (i.e. making it blur) if not effectively and adequately applied to image. This study presents a patch-wise de-noising method for pMRI by exploiting the rank deficiency of multi-Channel coil images and sparsity of artifacts. For each processed patch, similar patches a researched in spatial domain and through-out all coil elements, and arranged in appropriate matrix forms. Then, noise and aliasing artifacts are removed from the structured Matrix by applying sparse and low rank matrix decomposition method. The proposed method has been validated using both phantom and in vivo brain data sets, producing encouraging results. Specifically, the method can effectively remove both noise and residual aliasing artifact from pMRI reconstructed noisy images, and produce higher peak signal noise rate (PSNR) and structural similarity index matrix (SSIM) than other state-of-the-art De-noising methods. We propose image de-noising using low rank matrix decomposition (LMRD) and Support vector machine (SVM). The aim of Low Rank Matrix approximation based image enhancement is that it removes the various types of noises in the contaminated image simultaneously. The main contribution is to explore the image denoising low-rank property and the applications of LRMD for enhanced image Denoising, Then support vector machine is applied over the result.
Computationally Efficient Methods for Sonar Image Denoising using Fractional ...CSCJournals
Sonar images produced due to the coherent nature of scattering phenomenon inherit a multiplicative component called speckle and contain almost homogeneous as well as textured regions with relatively rare edges. Speckle removal is a pre-processing step required in applications like the detection and classification of objects in the sonar image. In this paper computationally efficient Fractional Integral Mask algorithms to remove the speckle noise from sonar images is proposed. Riemann- Liouville definition of fractional calculus is used to create Fractional integral masks in eight directions. The use of a mask incorporated with the significant coefficients from the eight directional masks and a single convolution operation required in such case helps in obtaining the computational efficiency. The sonar image heterogeneous patch classification is based on a new proposed naive homogeneity index which depends on the texture strength of the patches and despeckling filters can be adjusted to these patches. The application of the mask convolution only to the selected patches again reduce the computational complexity. The non-homomorphic approach used in the proposed method avoids the undesired bias occurring in the traditional homomorphic approach. Experiments show that the mask size required directly depends on the fractional order. Mask size can be reduced for lower fractional orders thus ensuring the computation complexity reduction for lower orders. Experimental results substantiate the effectiveness of the despeckling method. The different non reference image performance evaluation criterion are used to evaluate the proposed method.
KNOWMATICS AND THE RELATED FIELDS OF STUDY- EDUCATION, PSYCHOLOGY, BRAIN RESE...Dr. Raju M. Mathew
Knowmatics, Mathematics and Engineering of Knowledge, has a multi-disciplinary foundations, such as Cybernetics, Brain Research, Psycholinguistics, Education and Cognitive Science. It can be considered as a Post-Information Technology Discipline that forms the basis of Modern Knowledge Industry. It is capable of bring a Revolution in Education, Scientific Research, Decision-Making, Professional Practices and all Social Production Processes in making them Knowledge- Intensive.
TechBook: DB2 for z/OS Using EMC Symmetrix Storage Systems EMC
This EMC Engineering TechBook provides a general description of EMC products that can be used for DB2 administration on z/OS. Using EMC products to manage DB2 environments can reduce database and storage management administration, reduce CPU resource consumption, and reduce the time required to clone, back up, or recover DB2 systems
White Paper: Mobile Banking: How to Balance Opportunities and ThreatsEMC
This brief discusses the top security considerations when rolling out a mobile strategy, the truth about mobile malware and other fraud threats, and emerging trends in mobile payments, authentication and regulation.
Pivotal: Virtualize Big Data to Make the Elephant DanceEMC
Big Data and virtualization are two of the hottest trends in the industry today, yet the full potential for bringing the two together has not been fully realized. In this session, learn how virtualization brings the advantages of greater elasticity, stronger isolation for multi-tenancy, and a click HA protection to Hadoop, while maintaining the comparable performance to Hadoop on physical machines.
Objective 1: Understand the benefits of virtualizing Hadoop.
After this session you will be able to:
Objective 2: Understand how to get started with Pivotal HD Hadoop .
Objective 3: Understand where to find more information.
EMC Isilon Multitenancy for Hadoop Big Data AnalyticsEMC
This white paper discusses the EMC Isilon scale-out storage platform, which provides multitenancy through access zones that segregate tenants and their data sets for a scalable, multitenant storage solution for Hadoop and other analytics applications.
Image Denoising Based On Wavelet for Satellite Imagery: A ReviewIJMER
In this paper studied the use of wavelet and their family to denoising images. Satellite images
are extensively used in the field of RS and GIS for land possession, mapping use for planning and
decision support. As of many Satellite image having common problem i.e. noise which hold unwanted
information in an images. Different types of noise are addressing different techniques to denoising
remotely sense images. Noise within the remote sensing images identifying and denoising them is big
challenge before the researcher. Therefore we review wavelet for denoising of the remote sensing
images. Thus implementing wavelet is essential to get much higher quality denoising image. However,
they are usually too computationally demanding. In order to reduce the
Contourlet Transform Based Method For Medical Image DenoisingCSCJournals
Noise is an important factor of the medical image quality, because the high noise of medical imaging will not give us the useful information of the medical diagnosis. Basically, medical diagnosis is based on normal or abnormal information provided diagnose conclusion. In this paper, we proposed a denoising algorithm based on Contourlet transform for medical images. Contourlet transform is an extension of the wavelet transform in two dimensions using the multiscale and directional filter banks. The Contourlet transform has the advantages of multiscale and time-frequency-localization properties of wavelets, but also provides a high degree of directionality. For verifying the denoising performance of the Contourlet transform, two kinds of noise are added into our samples; Gaussian noise and speckle noise. Soft thresholding value for the Contourlet coefficients of noisy image is computed. Finally, the experimental results of proposed algorithm are compared with the results of wavelet transform. We found that the proposed algorithm has achieved acceptable results compared with those achieved by wavelet transform.
An Efficient Thresholding Neural Network Technique for High Noise Densities E...CSCJournals
Medical images when infected with high noise densities lose usefulness for diagnosis and early detection purposes. Thresholding neural networks (TNN) with a new class of smooth nonlinear function have been widely used to improve the efficiency of the denoising procedure. This paper introduces better solution for medical images in noisy environments which serves in early detection of breast cancer tumor. The proposed algorithm is based on two consecutive phases. Image denoising, where an adaptive learning TNN with remarkable time improvement and good image quality is introduced. A semi-automatic segmentation to extract suspicious regions or regions of interest (ROIs) is presented as an evaluation for the proposed technique. A set of data is then applied to show algorithm superior image quality and complexity reduction especially in high noisy environments.
Intensify Denoisy Image Using Adaptive Multiscale Product ThresholdingIJERA Editor
This Paper presents a wavelet-based multiscale products thresholding scheme for noise suppression of magnetic resonance images. This paper proposed a method based on image de-noising and edge enhancement of noisy multidimensional imaging data sets. Medical images are generally suffered from signal dependent noises i.e. speckle noise and broken edges. Most of the noises signals appear from machine and environment generally not contribute to the tissue differentiation. But, the noise generated due to above mentioned reason causes a grainy appearance on the image, hence image enhancement is required. For the intent of image denoising, Adaptive Multiscale Product Thresholding based on 2-D wavelet transform is used. In this method, contiguous wavelet sub bands are multiplied to improve edge structure while reducing noise. In multiscale products, boundaries can be successfully distinguished from noise. Adaptive threshold is designed and forced on multiscale products as an alternative of wavelet coefficients or recognize important features. For the edge enhancement. Canny Edge Detection Algorithm is used with scale multiplication technique. Simulation results shows that the planned technique better suppress the Poisson noise among several noises i.e. salt & pepper, speckle noise and random noise. The Performance of Image Intesification can be estimate by means of PSNR, MSE.
Intensify Denoisy Image Using Adaptive Multiscale Product ThresholdingIJERA Editor
This Paper presents a wavelet-based multiscale products thresholding scheme for noise suppression of magnetic resonance images. This paper proposed a method based on image de-noising and edge enhancement of noisy multidimensional imaging data sets. Medical images are generally suffered from signal dependent noises i.e. speckle noise and broken edges. Most of the noises signals appear from machine and environment generally not contribute to the tissue differentiation. But, the noise generated due to above mentioned reason causes a grainy appearance on the image, hence image enhancement is required. For the intent of image denoising, Adaptive Multiscale Product Thresholding based on 2-D wavelet transform is used. In this method, contiguous wavelet sub bands are multiplied to improve edge structure while reducing noise. In multiscale products, boundaries can be successfully distinguished from noise. Adaptive threshold is designed and forced on multiscale products as an alternative of wavelet coefficients or recognize important features. For the edge enhancement. Canny Edge Detection Algorithm is used with scale multiplication technique. Simulation results shows that the planned technique better suppress the Poisson noise among several noises i.e. salt & pepper, speckle noise and random noise. The Performance of Image Intesification can be estimate by means of PSNR, MSE.
Survey Paper on Image Denoising Using Spatial Statistic son PixelIJERA Editor
The classical non-local means image denoising approach, the value of a pixel is determined based on the weighted average of other pixels, where the weights are determined based on a fixed isotropic ally weighted similarity function between the local neighbourhoods. It is demonstrate that noticeably improved perceptual quality can be achieved through the use of adaptive anisotropic ally weighted similarity functions between local neighbourhoods. This is accomplished by adapting the similarity weighing function in an anisotropic manner based on the perceptual characteristics of the underlying image content derived efficiently based on the Mexican Hat wavelet. Experimental results show that the it can be used to provide improved perceptual quality in the denoised image both quantitatively and qualitatively when compared to existing methods.
New Noise Reduction Technique for Medical Ultrasound Imaging using Gabor Filt...CSCJournals
Ultrasound (US) imaging is an important medical diagnostic method, as it allows the examination of several internal body organs. However, its usefulness is diminished by signal dependent noise known as speckle noise. Speckle noise degrades target detectability in ultrasound images and reduces contrast and resolution, affecting the ability to identify normal and pathological tissue. For accurate diagnosis, it is important to remove this noise from ultrasound images. In this study, a new filtering technique is proposed for removing speckle noise from medical ultrasound images. It is based on Gabor filtering. Specifically, a preprocessing step is added before applying the Gabor filter. The proposed technique is applied to various ultrasound images, and certain measurement indexes are calculated, such as signal to noise ratio, peak signal to noise ratio, structure similarity index, and root mean square error, which are used for comparison. In particular, five widely used image enhancement techniques were applied to three types of ultrasound images (kidney, abdomen and ortho). The main objective of image enhancement is to obtain a highly detailed image, and in that respect, the proposed technique proved superior to other widely used filters.
A Novel Multiple-kernel based Fuzzy c-means Algorithm with Spatial Informatio...CSCJournals
Fuzzy c-means (FCM) algorithm has proved its effectiveness for image segmentation. However, still it lacks in getting robustness to noise and outliers, especially in the absence of prior knowledge of the noise. To overcome this problem, a generalized a novel multiple-kernel fuzzy cmeans (FCM) (NMKFCM) methodology with spatial information is introduced as a framework for image-segmentation problem. The algorithm utilizes the spatial neighborhood membership values in the standard kernels are used in the kernel FCM (KFCM) algorithm and modifies the membership weighting of each cluster. The proposed NMKFCM algorithm provides a new flexibility to utilize different pixel information in image-segmentation problem. The proposed algorithm is applied to brain MRI which degraded by Gaussian noise and Salt-Pepper noise. The proposed algorithm performs more robust to noise than other existing image segmentation algorithms from FCM family.
AN EFFICIENT WAVELET BASED FEATURE REDUCTION AND CLASSIFICATION TECHNIQUE FOR...ijcseit
This research paper proposes an improved feature reduction and classification technique to identify mild and severe dementia from brain MRI data. The manual interpretation of changes in brain volume based on visual examination by radiologist or a physician may lead to missing diagnosis when a large number of MRIs are analyzed. To avoid the human error, an automated intelligent classification system is proposed
which caters the need for classification of brain MRI after identifying abnormal MRI volume, for the diagnosis of dementia. In this research work, advanced classification techniques using Support Vector Machines based on Particle Swarm Optimisation and Genetic algorithm are compared. Feature reduction
by wavelets and PCA are analysed. From this analysis, it is observed that the proposed classification of SVM based PSO is found to be efficient than SVM trained with GA and wavelet based feature reduction technique yields better results than PCA.
AN EFFICIENT WAVELET BASED FEATURE REDUCTION AND CLASSIFICATION TECHNIQUE FOR...ijcseit
This research paper proposes an improved feature reduction and classification technique to identify mild
and severe dementia from brain MRI data. The manual interpretation of changes in brain volume based on
visual examination by radiologist or a physician may lead to missing diagnosis when a large number of
MRIs are analyzed. To avoid the human error, an automated intelligent classification system is proposed
which caters the need for classification of brain MRI after identifying abnormal MRI volume, for the
diagnosis of dementia. In this research work, advanced classification techniques using Support Vector
Machines based on Particle Swarm Optimisation and Genetic algorithm are compared. Feature reduction
by wavelets and PCA are analysed. From this analysis, it is observed that the proposed classification of
SVM based PSO is found to be efficient than SVM trained with GA and wavelet based feature reduction
technique yields better results than PCA.
Performance Comparison of Hybrid Haar Wavelet Transform with Various Local Tr...CSCJournals
A novel image compression using hybrid Haar wavelet transform has been proposed in this paper. Hybrid wavelet transform is generated using two different orthogonal transforms. Haar transform acts as a base transform and other sinusoidal transforms like DCT, DST, Hartley and Real-DFT are paired with Haar transform to generate hybrid Haar wavelet. Among these four pairs Haar-DCT hybrid wavelet gives lower error as compared to Haar-DST, Haar-Hartley and Haar-Real-DFT. Performance of Haar-DCT hybrid wavelet is further analyzed using multi resolution hybrid wavelet and Haar-DCT hybrid transform. Experimental results show that hybrid wavelet with component size 16-16 gives lower error at higher compression ratios than multi resolution analysis and hybrid transform performance. Performance is measured using RMSE which is traditional parameter to measure error. Lowest RMSE obtained is 9.77 at compression ratio 32 using Haar-DCT Hybrid Wavelet with component size 16-16. Various other error metrics like MAE, AFCPV and SSIM are used to measure error. Lowest MAE and AFCPV are observed at compression ratio 32 are in Haar (16x16) –DCT (16x16) hybrid wavelet having values 6.86 and 0.31 respectively. When blocked SSIM is applied on 16-16 Haar-DCT hybrid wavelet it gives value 0.993 at compression ratio 32 which is closer to one indicating that good quality of compressed image is obtained.
FusIon - On-Field Security and Privacy Preservation for IoT Edge Devices: Con...jamesinniss
FusIon - On-Field Security and Privacy Preservation for IoT Edge Devices: Concurrent Defense Against Multiple types of Hardware Trojan Attacks
Get more info here:
>>> https://bit.ly/38FXJav
Abstract: These days analysing patient data in the form of medical images to perform diagnose while doing detection
and prediction of a disease has emerged as a biggest research challenge. All these medical images can be in the form of
X-RAY, CT scan, MRI, PET and SPECT. These images carry minute information about heart, brain, nerves etc within
themselves. It may happen that these images get corrupted due to noise while capturing them. This makes the complete
image interpretation process very difficult and inaccurate. It has been found that the accuracy rate of existing method is
very less so improvement is required to make them more accurate. This paper proposes a Machine Learning Model based
on Convolutional Neural Network (CNN) that will contain all the filters required to de-noise MRI or USI Images. This
model will have same error rate efficiency like those of data mining techniques which radiologists were interested in. The
filters used in the proposed work are namely Weiner Filter, Gaussian Filter, Median Filter that are capable of removing
most common noises such as Salt and Pepper, Poisson, Speckle, Blurred, Gaussian existing in MRI images in Grey Scale
and RGB Scale.
Keywords: Convolution Neural Network, Denoising, Machine Learning, Deep Learning, Image Noise, Filters
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
Connector Corner: Automate dynamic content and events by pushing a buttonDianaGray10
Here is something new! In our next Connector Corner webinar, we will demonstrate how you can use a single workflow to:
Create a campaign using Mailchimp with merge tags/fields
Send an interactive Slack channel message (using buttons)
Have the message received by managers and peers along with a test email for review
But there’s more:
In a second workflow supporting the same use case, you’ll see:
Your campaign sent to target colleagues for approval
If the “Approve” button is clicked, a Jira/Zendesk ticket is created for the marketing design team
But—if the “Reject” button is pushed, colleagues will be alerted via Slack message
Join us to learn more about this new, human-in-the-loop capability, brought to you by Integration Service connectors.
And...
Speakers:
Akshay Agnihotri, Product Manager
Charlie Greenberg, Host
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
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After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
Encryption in Microsoft 365 - ExpertsLive Netherlands 2024Albert Hoitingh
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Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
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My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on the notifications, alerts, and approval requests using Slack for Bonterra Impact Management. The solutions covered in this webinar can also be deployed for Microsoft Teams.
Interested in deploying notification automations for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024Tobias Schneck
As AI technology is pushing into IT I was wondering myself, as an “infrastructure container kubernetes guy”, how get this fancy AI technology get managed from an infrastructure operational view? Is it possible to apply our lovely cloud native principals as well? What benefit’s both technologies could bring to each other?
Let me take this questions and provide you a short journey through existing deployment models and use cases for AI software. On practical examples, we discuss what cloud/on-premise strategy we may need for applying it to our own infrastructure to get it to work from an enterprise perspective. I want to give an overview about infrastructure requirements and technologies, what could be beneficial or limiting your AI use cases in an enterprise environment. An interactive Demo will give you some insides, what approaches I got already working for real.
2. weakened. This phenomenon is referred as propagation of
noise (PoN) [11].
As an extension of bilateral filtering, Buades et al.[12] had
put forward Non-Local means image denoising which utilizes
structural similarity. Generally speaking, the information in a
natural image is redundant to some extent. NL means image
denoising algorithm takes full advantage of image redundancy.
The basic idea is that images contain repeated structures, and
averaging them will reduce the (random) noise. It is an efficient
denoising method with the ability to result in proper restoration
of the slowly varying signals in homogeneous tissue regions
while strongly preserving the tissue boundaries. NLm has been
used in medical image denoising in many works [13].
However, the NLM filter may suffer from potential limitations
since the calculation for similarity weights is performed in a
full-space of neighborhood. Specifically, the accuracy of the
similarity weights will be affected by noise.
Donoho and Johnstone proposed an innovative nonlinear
denoising scheme in transform domain VisuShrink [14] which
thresholds the wavelet detail coefficients for one dimension (1-
D) signals. This scheme is simple and efficient. More recently,
wavelet based filters have been applied successfully to MR
image denoising [15,10,4]. Donoho and Johnstone have shown
that VisuShrink results in an estimate asymptotically optimal in
the minimax sense. When images are denoised by VisuShrink,
in many cases it can outperform the classic linear Wiener
filtering, especially for the images with a low peak signal-to-
noise ratio (PSNR). However, it is also well known that
universal thresholding yields overly smoothed images. This is
because its threshold choice can be unwarrantedly large due to
its dependence on the number of samples. Many researchers
have made claim that the universal threshold is not the perfect
threshold and performance can vary around this threshold [4,6].
Minh N. Do and Martin Vetterli put forward a new
dimension in image transform named contourlet
transform[16,17],which proved to be much better than the
wavelet transform in conserving edges and line details. The
improvement in approximation by contourlets based on
keeping the most significant coefficients will directly lead to
improvements in denoising. A simple thresholding scheme
applied on the contourlet transform is more effective in
removing the noise than it is for the wavelet transform[17]. A
number of works have been proposed in image denoising using
contourlet transform recently. Atif et al.[18] used the same
thresholding scheme which is used in wavelets to contourlet
denoising, to substantiate the claim made in paper[17]. The
problem is that directly using the universal threshold which
suites well in wavelet domain is not suitable in contourlet
domain, since the number of elements in transform coefficients
for contourlet is much higher than wavelet coefficients.
In this paper we propose a novel technique to medical
images corrupted by AWGN. This paper puts forward three
contributions
• As the universal thresholding is an estimate which is
asymptotically optimal in the minmax sense, we
introduce a scaling parameter to the universal threshold
by extensive simulation and regression of data with
wide range of standard medical images as well as
natural images of different size and corrupted by
different noise variances.
• We have also extended this idea to contourlet
transformation with a new scaling factor and the same
universal thresholding.
• Proposed contourlet thresholding is performed as a
pre-processing step prior to bilateral and NLm
filtering, which can give significant improvement in
PSNR as well as visual quality from bilateral and NLm
filter used alone.
The paper is organized as follows. Section II introduces
Bilateral filtering, Non Local mean filtering, wavelet shrinkage
and contourlet transform. In Section III, Proposed Method is
discussed. The Section IV presents the experimental results and
discussion. The concluding remarks are given in Section V.
II. BACKGROUND
A. Bilateral Filtering
The bilateral ¿lter is a nonlinear ¿lter proposed by Tomasi
and Manduchi to smooth images[11].The key idea of the
bilateral ¿lter is that for a pixel to inÀuence another pixel, it
should not only occupy a nearby location but also have a
similar value. The idea underlying bilateral ¿ltering is to do in
the range of an image what traditional ¿lters do in its domain.
Two pixels can be close to one another, that is, occupy nearby
spatial location, or they can be similar to one another, that is,
have nearby values, possibly in a perceptually meaningful
fashion. Closeness refers to vicinity in the domain, similarity to
vicinity in the range. Traditional ¿ltering is domain ¿ltering,
and enforces closeness by weighting pixel values with
coef¿cients that fall off with distance. Similarly, range ¿ltering
is defined, which averages image values with weights that
decay with dissimilarity. Range ¿lters are nonlinear because
their weights depend on image intensity or color. The bilateral
¿lter is also non-iterative, i.e. it achieves satisfying results with
only a single pass. This makes the ¿lter’s parameters relatively
intuitive since their action does not depend on the cumulated
eơects of several iterations. Computationally, they are no more
complex than standard non-separable ¿lters. Most importantly,
they preserve edges.
The weight assigned to each neighbour decreases with both
the distance in the image plane (the spatial domain S) and the
distance on the intensity axis (the range domain R). Using a
Gaussian Gı as a decreasing function, and considering a gray
level image I, the BF[I] of the bilateral ¿lter is de¿ned by:
( ) ( )¦∈
−−=
S
IIIGG
W
IBF
q
qqp
p
p qp ||||||
1
][ rs σσ (1)
• Ip = value of image I at position: p = ( px , py )
• F [ I ] = output of filter F applied to image I
The parameter ıs defines the size of the spatial
neighborhood used to filter a pixel, and ır controls how much
an adjacent pixel is down weighted because of the intensity
difference. Wp normalizes the sum of the weights.
187187
3. On the other hand, the bilateral filter is nonlinear and its
evaluation is computationally expensive since traditional
acceleration, such as performing convolution after an FFT, are
not applicable. Many fast algorithm have been formulated for
bilateral filtering [19,20], one of the recent algorithm is
formulated by Choudhary et al. [21] .
B. Non-Local Mean filtering
Buades et al. [12] developed a Non-Local means (NLm)
image denoising algorithm which takes full advantage of
image redundancy. The basic idea is that images contain
repeated structures, and averaging them will reduce the
(random) noise. The NL-means filter is an evolution of the
Yaroslavsky filter [22] which averages similar image pixels
defined according to their local intensity similarity. The main
difference between the NLmeans and this filter is that the
similarity between pixels has been made more robust to noise
by using a region comparison, rather than pixel comparison and
also that matching patterns are not restricted to be local. That
is, pixels far from the pixel being filtered are not penalized.
Given an image Y the filtered value at a point i using the NL-
means method is computed as a weighted average of
neighbouring pixels Ni in the image following this formula:
¦∈
=
Nij
jYjiwiYNL )(),()]([ p (2)
1),(0 ≤≤ jiw and 1),( =¦∈Nij
jiw
where i is point being filtering and j represents any other
image pixel. The weights w(i, j) are based on the similarity
between the neighborhoods Ni and Nj of pixels i and j. Ni is
defined as a square neighbourhood window indices centered
around pixel i. Theoretically, noise filtering performed must be
considered as an estimation task. Since the estimation task of
weights w(i,j) are computationally expensive, a large number
of fast methods have been developed[23,24].
C. Wavelet shrinkage
Wavelet transform shows localization in both time and
frequency and hence it has proved itself to be an efficient tool
for a number of image processing applications including noise
removal[14,15].The methods based on wavelet representations
yield very simple algorithms that are often more powerful and
easy to work with than traditional methods of function
estimation. Visushrink consists of decomposing the observed
signal into wavelets and use thresholds to select the
coefficients, from which a signal is synthesized. The idea
behind wavelet shrinkage is that Wavelet is such a basis
because exceptional event generates identifiable exceptional
coefficients due to its good localization property in both spatial
and frequency domain [5]. But considering noise, as long as it
does not generate exceptions, additive white Gaussian noise
after applying WT is still AWGN. A large fraction of any L
number of random data array with zero mean and variance ı2
,
will be smaller than the universal threshold T with high
probability; the probability approaching 1 as L increases to
infinity[14] where
LT elog2σ= (3)
However, VisuShrink yields overly smoothed images. This
is because its threshold choice can be unwarrantedly large due
to its dependence on the number of samples and universal
thresholding is an estimate which is asymptotically optimal in
the minmax sense.
D. Contourlet Transform
The contourlet transform is a new geometrical image-based
transform, which is recently introduced by Do and Vetterli
[17]. In contourlet transform, the Laplacian pyramid [25] is
first used to capture the point discontinuities, then it is followed
by a directional filter bank [26] to link point discontinuities
into linear structures. The overall result is an image expansion
using elementary images like contour segments, called
contourlet transform, which is implemented by a pyramidal
directional filter bank. The Laplacian pyramid (LP) is used to
decompose an image into a number of radial subbands, and the
directional filter banks (DFB) decomposes each LP detail sub-
band into a number of directional subbands.
Figure 1. Contourlet implementation using directional filterbank and
pyramidal filter banks.
The improvement in approximation by contourlets based on
keeping the most significant coefficients will directly lead to
improvements in applications, including compression,
denoising, and feature extraction. As an example, for image
denoising, random noise will generate significant wavelet
coefficients just like true edges, but is less likely to generate
significant contourlet coefficients. Consequently, a simple
thresholding scheme applied on the contourlet transform is
more effective in removing the noise than it is for the wavelet
transform[17].
III. PROPOSED METHOD
Wavelet thresholding which is a signal estimation
technique that exploits the capabilities of wavelet transform for
signal denoising, removes noise by killing coefficients that are
insignificant relative to some threshold. It turns out to be
simple and effective, depends heavily on the choice of a
thresholding parameter and the choice of this threshold
determines, to a great extent, the efficacy of denoising.
Researchers have developed various techniques for choosing
denoising parameters and so far there is no “best” universal
threshold determination technique. As the universal
thresholding is an estimate which is asymptotically optimal in
the minmax sense and universal threshold as derived by
Donoho is hundred percent effective only when number of
pixels in an image tends to infinity, which is an impractical
situation. Considering this delicate argument we introduce a
scaling parameter to the universal threshold which is suitable
188188
4. for medical images whose number of pixels are finite, by
extensive simulation and tabulation with different standard
medical images of different size and corrupted by different
noise variances. The experimental procedure we adopted is
taking an arbitrary image of known size and corrupted by a
known noise variance. Then we introduced scaling factors for
the universal threshold and selected the scaling factor
corresponding to the highest PSNR. This procedure is repeated
for large set of images of different size and corrupted by
different noise variance. The compact equation of scaling
parameter is obtained by linear regression of the best scaling
parameter as a function of noise variance and image size.
For wavelet thresholding, tabulation and regression with
different sets of medical images as well as natural images give
the threshold Ȝw to be
Ȝw =3.944°10-11
S2
– 5.5285°10-6
S+0.6022 (4)
where S is a function of noise variance and number of image
pixels, which is given as
NS ×=σ
N is the number of pixels of the image under consideration
and ı is the standard deviation of noise. So the new threshold
is Tw = Ȝw °T.
Same set of experiments done on wavelet thresholding is
performed with contourlet transformation. For contourlet
thresholding experimental measurements gives the threshold
Ȝc to be
Ȝc =3.944°10-11
S2
– 5.5285°10-6
S+0.5522 (5)
where S is a function of noise variance and number of image
pixels, which is given as
NS ×= σ
N is the number of pixels of the image under
consideration and ı is the standard deviation of noise. So the
new threshold is Tc= Ȝc°T. The reason for the reduction in
scaling factor is that, in contourlet transform, number of
transform coefficients are large compared to the wavelet(in
which number of transform coefficients equal to image
pixels), a similar reduction in weight of coefficients take place
in contourlet domain, so as to distribute values over all
contourlet coefficients. Simulation results show that proposed
contourlet thresholding and wavelet thresholding outperforms
the standard Visushrink.
Bilateral filtering in which real homogeneous gray levels
corrupted by noise is polluted significantly, and fails to
efficiently remove noise in regions of homogeneous physical
properties. In homogeneous regions in which noise strike,
bilateral filtering most likely perform range filtering much
greater than spatial filtering. So the effect of noise is retained
as if it were an edge information of the image. If contourlet
denoising which is computationally efficient and having
negligible execution time is done before bilateral filtering,
noise in homogeneous regions which is present as un-
exceptions can be removed efficiently retaining the edge
information as well as texture. Simulation results show that
preprocessing with proposed contourlet denoising is superior
to proposed wavelet thresholding. The reason is that the only
aim of the denoising prior to bilateral filtering is to remove
discrepancies in homogeneous regions, but retaining edge
information and texture details as such. But wavelet transform
using Visushrink smoothens the image[15] thereby degrading
performance of bilateral filtering. But contourlet thresholding
is good in retaining directions and edge features.
The NLM filter may suffer from potential limitations since
the calculation for similarity weights is performed in a full-
space of neighborhood. Specifically, the accuracy of the
similarity weights will be affected by noise. Performing
contourlet denoising prior to NLM filtering can compensate
noise, which can increase the accuracy of similarity weights in
the full space of neighbourhood and hence increase the
performance of NLM filtering. Preprocessing with proposed
contourlet thresholding give better results compared to
proposed wavelet thresholding because contourlet denoising
is much efficient in retaining edges and texture information
and hence similarity weights after thresholding.
IV. SIMULATION RESULTS
A set of two gray scale images, MRI image of human brain
and CT image of abdomen, shown in Fig. 2, were selected for
our simulations. Each image has a size of 512 x 512 and 1024
x 1024 pixels respectively with 256 shades of gray, i.e. 8 bits
per pixel. The evaluation criteria are based upon quantitative
measure of Peak signal to noise ratio. These measures, as
such, do not represent human perception of the images,
i.e.visual quality of the images. It is very difficult to guage
denoised images mathematically on visual quality as human
vision system is not only highly subjective but also exhibit
different tolerance levels to various types of noises. Thus
authentication of denoising method requires both quantitative
measure and qualitative inspection of image. In our work, we
apply both criteria; first the PSNR and the image is also
viewed for visual acceptance.
a b
Fig. 2 (a) CT image of abdomen(CT) (b) MRI image of human brain(MRI).
Table I gives the comparison of calculated PSNR of images
reconstructed utilizing various thresholding. Fig. 3 gives the
corresponding images.
Table II gives PSNR comparison of image denoising using
standard Bilateral filtering, standard non local mean filtering,
and the proposed methods. Fig. 4 gives the corresponding
images.
189189
6. It can be seen that, there is a significant improvement in
PSNR values in the proposed threshold compared to the
universal thresholding. Also by incorporating proposed
contourlet thresholding prior to bilateral filtering and non-local
mean filtering gives improved PSNR. Visually it’s evident that
the Proposed preprocessing with NLm filtering gives much
more visual information, than with bilateral filtering even
though pre-processing with bilateral filtering give good PSNR.
The reason is that bilateral filtering incorporates a spatial filter
apart from range filter which gives a smoothing effect.
V. CONCLUSION AND FURTHER WORKS
In this work we propose a novel preprocessing scheme for
bilateral filtering and NLm filtering for medical image
denoisning. We used contourlet transform, as a directional non-
separable transform, to retain image textures and edges even
after thresholding. A new threshold for denoising is devised
using simulation results both in contourlet and wavelet space.
The method is tested on CT abdomen and brain MR images. It
is also compared with universal threshold. It is shown that for
many noisy images, universal threshold based on wavelet is not
a proper choice. Instead we can use contourlet based methods
which can retain edges in the image much better than wavelet
thresholding. We have shown that by using contourlet
thresholding as a preprocessing step prior to bilateral filtering
and Non local means filtering we can effectively denoise the
image and also significantly increase the PSNR and perceptual
quality.
In general as a future forethought any denoising scheme
whose performance very much depend on spatial or structural
features, preprocessing with proposed contourlet thresholding
happens to be a better candidate in retaining the spatial or
structural features and hence enhance the performance of
aforementioned denosing scheme. Also it is also possible to
device a similar thresholding scheme related with a particular
application by simulation and regression with large sets of data.
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