We conducted eye tracking experiments on naturalistic stereo images presented through a haploscope, and found that fixated
luminance contrast and luminance gradient were generally higher than randomly selected luminance contrast and luminance gradient, which agrees with previous literature. However we also found that the fixated disparity contrast and disparity gradient were generally lower than randomly selected disparity contrast and disparity gradient. We discuss the implications of this remarkable
result.
Shadow Removal of Individual Tree Crowns in a High Resolution Satellite ImageryIJMTST Journal
Satellite image processing involves many techniques for enhancement/segmentation of raw (Raster)
images acquired from cameras or sensors placed on satellites, space probes and aircrafts. These pictures
have numerous applications in regular day to day life. Remote sensing is a process of creating thematic maps
as spatial sharing of exacting information and is used to discover and isolate the coherent parts of the
surface objects (trees/buildings) and the water bodies.
Shadow detection and removal is an main preprocessing for improving act of such (segmentation, thing
recognition, view study, tracking, etc) vision tasks. Shadow removal of individual tree top in a coniferous
vegetation test zone involves complex procedures. For extracting vegetation zone from a satellite, a pair of
spectral indices called Normalized Difference Vegetation Index(NDVI) and Saturation Index(SI) are available.
The difficulty of shadows occurring in satellite images need to be addressed while segmenting the tree
crowns. In the object slanting shadow detection and deletion or removal method, shadow features are taken
into deliberation during image segmentation, and then, according to the statistical features of the images,
assumed shadows are extracted. In addition to, some dim objects which could be incorrect for shadows are
lined out according to object properties and spatial bond between objects. The retrieved image can be
obtained by considering the cross projection advance or approach for shadow free image.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Droege Pupil Center Detection In Low Resolution ImagesKalle
In some situations, high quality eye tracking systems are not affordable. This generates the demand for inexpensive systems built upon non-specialized, off the shelf devices. Investigations show that algorithms developed for high resolution systems do not perform satisfactorily on such lowcost and low resolution systems. We investigate
algorithms specifically tailored to such low resolution input devices, based on combination of different strategies. An approach called gradient direction consensus is introduced and compared to image based correlation with adaptive templates as well as other known methods. The results are compared using synthetic input data with known ground truth.
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.
“Trade-Off between Detection and Resolution of Two Point Objects Under Variou...IOSR Journals
It is a well-experienced fact that whenever one tries to detect a weak object point in the vicinity of an intense point object, viz., a binary star-SIRUS and its companion weak satellite star, there is always loss of resolution of the optical system. In other words, one wants to improve the defectively of the system, there is always a loss of resolution capabilities of the system. Thus, there is a trade-off between Detection and Resolution of optical systems under various imaging situations. In this first paper of discussion of this trade-off, we have derived the Fourier analytical formulation of this problem. This formulation will be used to find out a compatible trade-off between Detection and Resolution in our further publications
Jarodzka A Vector Based, Multidimensional Scanpath Similarity MeasureKalle
A great need exists in many fields of eye-tracking research for a robust and general method for scanpath comparisons. Current measures either quantize scanpaths in space (string editing measures like the Levenshtein distance) or in time (measures based on attention maps). This paper proposes a new pairwise scanpath similarity measure. Unlike previous measures that either use AOI sequences or forgo temporal order, the new measure defines scanpaths as a series of geometric vectors and compares temporally aligned scanpaths across several dimensions: shape, fixation position, length, direction, and fixation duration. This approach offers more multifaceted insights to how similar two scanpaths are. Eight fictitious scanpath pairs are tested to elucidate the strengths of the new measure, both in itself and compared to two of the currently most popular measures - the Levenshtein distance and attention map correlation.
Shadow Removal of Individual Tree Crowns in a High Resolution Satellite ImageryIJMTST Journal
Satellite image processing involves many techniques for enhancement/segmentation of raw (Raster)
images acquired from cameras or sensors placed on satellites, space probes and aircrafts. These pictures
have numerous applications in regular day to day life. Remote sensing is a process of creating thematic maps
as spatial sharing of exacting information and is used to discover and isolate the coherent parts of the
surface objects (trees/buildings) and the water bodies.
Shadow detection and removal is an main preprocessing for improving act of such (segmentation, thing
recognition, view study, tracking, etc) vision tasks. Shadow removal of individual tree top in a coniferous
vegetation test zone involves complex procedures. For extracting vegetation zone from a satellite, a pair of
spectral indices called Normalized Difference Vegetation Index(NDVI) and Saturation Index(SI) are available.
The difficulty of shadows occurring in satellite images need to be addressed while segmenting the tree
crowns. In the object slanting shadow detection and deletion or removal method, shadow features are taken
into deliberation during image segmentation, and then, according to the statistical features of the images,
assumed shadows are extracted. In addition to, some dim objects which could be incorrect for shadows are
lined out according to object properties and spatial bond between objects. The retrieved image can be
obtained by considering the cross projection advance or approach for shadow free image.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Droege Pupil Center Detection In Low Resolution ImagesKalle
In some situations, high quality eye tracking systems are not affordable. This generates the demand for inexpensive systems built upon non-specialized, off the shelf devices. Investigations show that algorithms developed for high resolution systems do not perform satisfactorily on such lowcost and low resolution systems. We investigate
algorithms specifically tailored to such low resolution input devices, based on combination of different strategies. An approach called gradient direction consensus is introduced and compared to image based correlation with adaptive templates as well as other known methods. The results are compared using synthetic input data with known ground truth.
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.
“Trade-Off between Detection and Resolution of Two Point Objects Under Variou...IOSR Journals
It is a well-experienced fact that whenever one tries to detect a weak object point in the vicinity of an intense point object, viz., a binary star-SIRUS and its companion weak satellite star, there is always loss of resolution of the optical system. In other words, one wants to improve the defectively of the system, there is always a loss of resolution capabilities of the system. Thus, there is a trade-off between Detection and Resolution of optical systems under various imaging situations. In this first paper of discussion of this trade-off, we have derived the Fourier analytical formulation of this problem. This formulation will be used to find out a compatible trade-off between Detection and Resolution in our further publications
Jarodzka A Vector Based, Multidimensional Scanpath Similarity MeasureKalle
A great need exists in many fields of eye-tracking research for a robust and general method for scanpath comparisons. Current measures either quantize scanpaths in space (string editing measures like the Levenshtein distance) or in time (measures based on attention maps). This paper proposes a new pairwise scanpath similarity measure. Unlike previous measures that either use AOI sequences or forgo temporal order, the new measure defines scanpaths as a series of geometric vectors and compares temporally aligned scanpaths across several dimensions: shape, fixation position, length, direction, and fixation duration. This approach offers more multifaceted insights to how similar two scanpaths are. Eight fictitious scanpath pairs are tested to elucidate the strengths of the new measure, both in itself and compared to two of the currently most popular measures - the Levenshtein distance and attention map correlation.
Effect of kernel size on Wiener and Gaussian image filteringTELKOMNIKA JOURNAL
In this paper, the effect of the kernel size of Wiener and Gaussian filters on their image restoration qualities has been studied and analyzed. Four sizes of such kernels, namely 3x3, 5x5, 7x7 and 9x9 were simulated. Two different types of noise with zero mean and several variances have been used: Gaussian noise and speckle noise. Several image quality measuring indices have been applied in the computer simulations. In particular, mean absolute error (MAE), mean square error (MSE) and structural similarity (SSIM) index were used. Many images were tested in the simulations; however the results of three of them are shown in this paper. The results show that the Gaussian filter has a superior performance over the Wiener filter for all values of Gaussian and speckle noise variances mainly as it uses the smallest kernel size. To obtain a similar performance in Wiener filtering, a larger kernel size is required which produces much more blur in the output mage. The Wiener filter shows poor performance using the smallest kernel size (3x3) while the Gaussian filter shows the best results in such case. With the Gaussian filter being used, similar results of those obtained with low noise could be obtained in the case of high noise variance but with a higher kernel size.
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.
Dorr Space Variant Spatio Temporal Filtering Of Video For Gaze Visualization ...Kalle
We introduce an algorithm for space-variant filtering of video based on a spatio-temporal Laplacian pyramid and use this algorithm to render videos in order to visualize prerecorded eye movements. Spatio-temporal contrast and colour saturation are reduced as a function of distance to the nearest gaze point of regard, i.e. nonfixated, distracting regions are filtered out, whereas fixated image regions remain unchanged. Results of an experiment in which the eye movements of an expert on instructional videos are visualized with this algorithm, so that the gaze of novices is guided to relevant
image locations, show that this visualization technique facilitates the novices’ perceptual learning.
Despeckling of Ultrasound Imaging using Median Regularized Coupled PdeIDES Editor
This paper presents an approach for reducing speckle
in ultrasound images using Coupled Partial Differential
Equation (CPDE) which has been obtained by uniting secondorder
and the fourth-order partial differential equations. Using
PDE to reduce the speckle is the noise-smoothing methods
which is getting attention widely, because PDE can keep the
edge well when it reduces the noise. We also introduced a
median regulator to guide energy source to boost the features
in the image and regularize the diffusion. The proposed
method is tested in both simulated and real medical
ultrasound images. The proposed method is compared with
SRAD, Perona Malik diffusion and Non linear coherent
diffusion methods, our method gives better result in terms of
CNR, SSIM and FOM.
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.
Texture Classification based on Gabor Wavelet IJORCS
This paper presents the comparison of Texture classification algorithms based on Gabor Wavelets. The focus of this paper is on feature extraction scheme for texture classification. The texture feature for an image can be classified using texture descriptors. In this paper we have used Homogeneous texture descriptor that uses Gabor Wavelets concept. For texture classification, we have used online texture database that is Brodatz’s database and three advanced well known classifiers: Support Vector Machine, K-nearest neighbor method and decision tree induction method. The results shows that classification using Support vector machines gives better results as compare to the other classifiers. It can accurately discriminate between a testing image data and training data.
Multiweld heeft een groot assortiment lastvoegmaterialen zoals lasdraad, laslectroden en lasstaven. Multiweld is onder andere distributeur van Lincoln Electric en Böhler, maar ook voor overige merken lastoevoegmaterialen kunt u bij ons terecht.
Intern prosjektpresentasjon (kulturbygging) ved NTNU Universitetsbiblioteket. Målet var å informere de ansatte om prosjektet og holde de oppdatert på arbeidet som var gjort så langt.
Effect of kernel size on Wiener and Gaussian image filteringTELKOMNIKA JOURNAL
In this paper, the effect of the kernel size of Wiener and Gaussian filters on their image restoration qualities has been studied and analyzed. Four sizes of such kernels, namely 3x3, 5x5, 7x7 and 9x9 were simulated. Two different types of noise with zero mean and several variances have been used: Gaussian noise and speckle noise. Several image quality measuring indices have been applied in the computer simulations. In particular, mean absolute error (MAE), mean square error (MSE) and structural similarity (SSIM) index were used. Many images were tested in the simulations; however the results of three of them are shown in this paper. The results show that the Gaussian filter has a superior performance over the Wiener filter for all values of Gaussian and speckle noise variances mainly as it uses the smallest kernel size. To obtain a similar performance in Wiener filtering, a larger kernel size is required which produces much more blur in the output mage. The Wiener filter shows poor performance using the smallest kernel size (3x3) while the Gaussian filter shows the best results in such case. With the Gaussian filter being used, similar results of those obtained with low noise could be obtained in the case of high noise variance but with a higher kernel size.
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.
Dorr Space Variant Spatio Temporal Filtering Of Video For Gaze Visualization ...Kalle
We introduce an algorithm for space-variant filtering of video based on a spatio-temporal Laplacian pyramid and use this algorithm to render videos in order to visualize prerecorded eye movements. Spatio-temporal contrast and colour saturation are reduced as a function of distance to the nearest gaze point of regard, i.e. nonfixated, distracting regions are filtered out, whereas fixated image regions remain unchanged. Results of an experiment in which the eye movements of an expert on instructional videos are visualized with this algorithm, so that the gaze of novices is guided to relevant
image locations, show that this visualization technique facilitates the novices’ perceptual learning.
Despeckling of Ultrasound Imaging using Median Regularized Coupled PdeIDES Editor
This paper presents an approach for reducing speckle
in ultrasound images using Coupled Partial Differential
Equation (CPDE) which has been obtained by uniting secondorder
and the fourth-order partial differential equations. Using
PDE to reduce the speckle is the noise-smoothing methods
which is getting attention widely, because PDE can keep the
edge well when it reduces the noise. We also introduced a
median regulator to guide energy source to boost the features
in the image and regularize the diffusion. The proposed
method is tested in both simulated and real medical
ultrasound images. The proposed method is compared with
SRAD, Perona Malik diffusion and Non linear coherent
diffusion methods, our method gives better result in terms of
CNR, SSIM and FOM.
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.
Texture Classification based on Gabor Wavelet IJORCS
This paper presents the comparison of Texture classification algorithms based on Gabor Wavelets. The focus of this paper is on feature extraction scheme for texture classification. The texture feature for an image can be classified using texture descriptors. In this paper we have used Homogeneous texture descriptor that uses Gabor Wavelets concept. For texture classification, we have used online texture database that is Brodatz’s database and three advanced well known classifiers: Support Vector Machine, K-nearest neighbor method and decision tree induction method. The results shows that classification using Support vector machines gives better results as compare to the other classifiers. It can accurately discriminate between a testing image data and training data.
Multiweld heeft een groot assortiment lastvoegmaterialen zoals lasdraad, laslectroden en lasstaven. Multiweld is onder andere distributeur van Lincoln Electric en Böhler, maar ook voor overige merken lastoevoegmaterialen kunt u bij ons terecht.
Intern prosjektpresentasjon (kulturbygging) ved NTNU Universitetsbiblioteket. Målet var å informere de ansatte om prosjektet og holde de oppdatert på arbeidet som var gjort så langt.
Automated Diagnosis of Glaucoma using Haralick Texture FeaturesIOSR Journals
Abstract : Glaucoma is the second leading cause of blindness worldwide. It is a disease in which fluid
pressure in the eye increases continuously, damaging the optic nerve and causing vision loss. Computational
decision support systems for the early detection of glaucoma can help prevent this complication. The retinal
optic nerve fibre layer can be assessed using optical coherence tomography, scanning laser polarimetry, and
Heidelberg retina tomography scanning methods. In this paper, we present a novel method for glaucoma
detection using an Haralick Texture Features from digital fundus images. K Nearest Neighbors (KNN)
classifiers are used to perform supervised classification. Our results demonstrate that the Haralick Texture
Features has Database and classification parts, in Database the image has been loaded and Gray Level Cooccurrence
Matrix (GLCM) and thirteen haralick features are combined to extract the image features, performs
better than the other classifiers and correctly identifies the glaucoma images with an accuracy of more than
98%. The impact of training and testing is also studied to improve results. Our proposed novel features are
clinically significant and can be used to detect glaucoma accurately.
Keywords: Glaucoma, Haralick Texture features, KNN Classifiers, Feature Extraction
The project aims at development of efficient segmentation method for the CBIR system. Mean-shift segmentation generates a list of potential objects which are meaningful and then these objects are clustered according to a predefined similarity measure. The method was tested on benchmark data and F-Score of .30 was achieved.
High Resolution Mri Brain Image Segmentation Technique Using Holder Exponent ijsc
Image segmentation is a technique to locate certain objects or boundaries within an image. Image segmentation plays a crucial role in many medical imaging applications. There are many algorithms and techniques have been developed to solve image segmentation problems. Spectral pattern is not sufficient in high resolution image for image segmentation due to variability of spectral and structural information. Thus the spatial pattern or texture techniques are used. Thus the concept of Holder Exponent for segmentation of high resolution medical image is an efficient image segmentation technique. The proposed method is implemented in Matlab and verified using various kinds of high resolution medical images. The experimental results shows that the proposed image segmentation system is efficient than the existing segmentation systems.
HIGH RESOLUTION MRI BRAIN IMAGE SEGMENTATION TECHNIQUE USING HOLDER EXPONENTijsc
Image segmentation is a technique to locate certain objects or boundaries within an image. Image
segmentation plays a crucial role in many medical imaging applications. There are many algorithms and
techniques have been developed to solve image segmentation problems. Spectral pattern is not sufficient in
high resolution image for image segmentation due to variability of spectral and structural information.
Thus the spatial pattern or texture techniques are used. Thus the concept of Holder Exponent for
segmentation of high resolution medical image is an efficient image segmentation technique. The proposed
method is implemented in Matlab and verified using various kinds of high resolution medical images. The
experimental results shows that the proposed image segmentation system is efficient than the existing
segmentation systems.
COMPUTATIONALLY EFFICIENT TWO STAGE SEQUENTIAL FRAMEWORK FOR STEREO MATCHINGijfcstjournal
Almost all the existing stereo algorithms fall under a common assumption that corresponding color or
intensity values will be similar like one another. On the other hand, it is also not that true in practice
where the image color or intensity values are regularly affected by different radiometric factors like
illumination direction, change in image device, illuminant color and so on. For this issue, the information
about the raw color of the images which is recorded by the camera should not depend on it totally, and
also the common assumptions on color consistency doesn’t influence good (great) between the stereo
images in real scenario. Therefore, most of the conventional stereo algorithms can be seriously degraded
in terms of performance under radiometric variations. In this work, we intend to develop a new stereo
matching algorithm which will be insensitive to change in radiometric conditions between stereo pairs i.e.
left image as well as right image. Unlike the other stereo algorithms, we propose a computationally
efficient two stage sequential framework for stereo matching which can handle the various radiometric
variations between the stereo pairs.Experimental results proves that the proposed method outperforms
extremely well compare to other state of the art stereo methods under change in various radiometric
conditions for a given stereo pair and it is also found from the results that the execution time is less
compare to existing methods.
Hyperspectral Data Compression Using Spatial-Spectral Lossless Coding TechniqueCSCJournals
Hyperspectral imaging is widely used in many applications; especially in vegetation, climate changes, and desert studies. Such kind of imaging has a huge amount of data, which requires transmission, processing, and storage resources especially for space borne imaging. Compression of hyperspectral data cubes is an effective solution for these problems. Lossless compression of the hyperspectral data usually results in low compression ratio, which may not meet the available resources; on the other hand, lossy compression may give the desired ratio, but with a significant degradation effect on object identification performance of the hyperspectral data. Moreover, most hyperspectral data compression techniques exploits the similarities in spectral dimensions; which requires bands reordering or regrouping, to make use of the spectral redundancy. In this paper, we analyze the spectral cross correlation between bands for Hyperion hyperspectral data; spectral cross correlation matrix is calculated, assessing the strength of the spectral matrix, and finally, we propose new technique to find highly correlated groups of bands in the hyperspectral data cube based on "inter band correlation square", from the resultant groups of bands we propose a new predictor that can predict efficiently the whole bands within data cube based on weighted combination of spectral and spatial prediction, the results are evaluated versus other state of the art predictor for lossless compression.
DOMAIN SPECIFIC CBIR FOR HIGHLY TEXTURED IMAGEScseij
It is A Challenging Task To Build A Cbir System Which Primarily Works On Texture Values As There
Meaning And Semantics Needs A Special Care To Be Mapped With Human Based Languages. We Have
Consider Highly Textured Images Having Properties(Entropy, Homogeneity, Contrast, Cluster Shade, Auto
Correlation)And Have Mapped Using A Fuzzy Minmax Scale W.R.T. Their Degree(High, Low,
Medium)And Technical Interpetation.This Developed System Is Performing Well In Terms Of Precision
And Recall Value Showing That Semantic Gap Has Been Reduced For Highly Textured Images Based Cbir.
Image Denoising Based On Sparse Representation In A Probabilistic FrameworkCSCJournals
Image denoising is an interesting inverse problem. By denoising we mean finding a clean image, given a noisy one. In this paper, we propose a novel image denoising technique based on the generalized k density model as an extension to the probabilistic framework for solving image denoising problem. The approach is based on using overcomplete basis dictionary for sparsely representing the image under interest. To learn the overcomplete basis, we used the generalized k density model based ICA. The learned dictionary used after that for denoising speech signals and other images. Experimental results confirm the effectiveness of the proposed method for image denoising. The comparison with other denoising methods is also made and it is shown that the proposed method produces the best denoising effect.
The accurate determination of the sex and age of human skull is a critical challenge in skeleton anthropology and crime department. In the forensic
laboratory they determine both the sex and age of skeleton using carbon content of the bones. The teeth, pelvis and skull are the most widely used sites
for determination of sex and age of the skeleton. This paper introduces a technique for objective qualification of age and sexual dimorphic features
using wavelet transformation, it is a multiscale mathematical technique that allows determination of shape variation that are hide at various scale of
resolution. We use a 2D discrete wavelet transform in the proposed method. In the skull the supraorbital margin is consider to determine sex of skull
and the area occupation of upper part of skull is used to estimate the age of the skull. SVM is a classifier used for classification. We used both
supervised and unsupervised SVM for both sex and age detection of the skull.
Maximizing Strength of Digital Watermarks Using Fuzzy Logicsipij
In this paper, we propose a novel digital watermarking scheme in DCT domain based fuzzy inference system and the human visual system to adapt the embedding strength of different blocks. Firstly, the original image is divided into some 8×8 blocks, and then fuzzy inference system according to different textural features and luminance of each block decide adaptively different embedding strengths. The watermark detection adopts correlation technology. Experimental results show that the proposed scheme has good imperceptibility and high robustness to common image processing operators.
These are the slides from the 3rd talk of our series on 19th July 2018, presented by Dr. Matt Edgar. This presents an overview of the research conducted within the Optics group in the School of Physics and Astronomy at the University of Glasgow.
Similar to Liu Natural Scene Statistics At Stereo Fixations (20)
Blignaut Visual Span And Other Parameters For The Generation Of HeatmapsKalle
Although heat maps are commonly provided by eye-tracking and visualization tools, they have some disadvantages and caution must be taken when using them to draw conclusions on eye tracking results. It is motivated here that visual span is an essential component of visualizations of eye-tracking data and an algorithm is proposed to allow the analyst to set the visual span as a parameter prior to generation of a heat map.
Although the ideas are not novel, the algorithm also indicates how transparency of the heat map can be achieved and how the color gradient can be generated to represent the probability for an object to be observed within the defined visual span. The optional addition of contour lines provides a way to visualize separate intervals in the continuous color map.
Zhang Eye Movement As An Interaction Mechanism For Relevance Feedback In A Co...Kalle
Relevance feedback (RF) mechanisms are widely adopted in Content-Based Image Retrieval (CBIR) systems to improve image retrieval performance. However, there exist some intrinsic problems: (1) the semantic gap between high-level concepts and low-level features and (2) the subjectivity of human perception of visual contents. The primary focus of this paper is to evaluate the possibility of inferring the relevance of images based on eye movement data. In total, 882 images from 101 categories are viewed by 10 subjects to test the usefulness of implicit RF, where the relevance of each image is known beforehand. A set of measures based on fixations are thoroughly evaluated which include fixation duration, fixation count, and the number of revisits. Finally, the paper proposes a decision tree to predict the user’s input during the image searching tasks. The prediction precision of the decision tree is over 87%, which spreads light on a promising integration of natural eye movement into CBIR systems in the future.
Yamamoto Development Of Eye Tracking Pen Display Based On Stereo Bright Pupil...Kalle
The intuitive user interfaces of PCs and PDAs, such as pen display and touch panel, have become widely used in recent times. In this study, we have developed an eye-tracking pen display based on the stereo bright pupil technique. First, the bright pupil camera was developed by examining the arrangement of cameras and LEDs for pen display. Next, the gaze estimation method was proposed for the stereo bright pupil camera, which enables one point calibration. Then, the prototype of the eyetracking pen display was developed. The accuracy of the system was approximately 0.7° on average, which is sufficient for human interaction support. We also developed an eye-tracking tabletop as an application of the proposed stereo bright pupil technique.
Wastlund What You See Is Where You Go Testing A Gaze Driven Power Wheelchair ...Kalle
Individuals with severe multiple disabilities have little or no opportunity to express their own wishes, make choices and move independently. Because of this, the objective of this work has been to develop a prototype for a gaze-driven device to manoeuvre powered wheelchairs or other moving platforms. The prototype has the same capabilities as a normal powered wheelchair, with two exceptions. Firstly, the prototype is controlled by eye movements instead of by a normal joystick. Secondly, the prototype is equipped with a sensor that stops all motion when the machine approaches an obstacle. The prototype has been evaluated in a preliminary clinical test with two users. Both users clearly communicated that they appreciated and had mastered the ability to control a powered wheelchair with their eye movements.
Vinnikov Contingency Evaluation Of Gaze Contingent Displays For Real Time Vis...Kalle
The visual field is the area of space that can be seen when an observer fixates a given point. Many visual capabilities vary with position in the visual field and many diseases result in changes in the visual field. With current technology, it is possible to build very complex real-time visual field simulations that employ gaze-contingent displays. Nevertheless, there are still no established techniques to evaluate such systems. We have developed a method to evaluate a system’s contingency by employing visual blind spot localization as well as foveal fixation. During the experiment, gaze-contingent and static conditions were compared. There was a strong correlation between predicted results and gaze-contingent trials. This evaluation method can also be used with patient populations and for the evaluation of gaze-contingent display systems, when there is need to evaluate a visual field outside of the foveal region.
Urbina Pies With Ey Es The Limits Of Hierarchical Pie Menus In Gaze ControlKalle
Pie menus offer several features which are advantageous especially for gaze control. Although the optimal number of slices per pie
and of depth layers has already been established for manual control, these values may differ in gaze control due to differences in spatial accuracy and congitive processing. Therefore, we investigated the layout limits for hierarchical pie menu in gaze control. Our user study indicates that providing six slices in multiple depth layers guarantees fast and accurate selections. Moreover, we compared two different methods of selecting a slice. Novices performed well with both, but selecting via selection borders produced better performance for experts than the standard dwell time selection.
Urbina Alternatives To Single Character Entry And Dwell Time Selection On Eye...Kalle
Eye typing could provide motor disabled people a reliable method of communication given that the text entry speed of current interfaces can be increased to allow for fluent communication. There are two reasons for the relatively slow text entry: dwell time selection requires waiting a certain time, and single character entry limits the maximum entry speed. We adopted a typing interface based on hierarchical pie menus, pEYEwrite [Urbina and Huckauf 2007] and included bigram text entry with one single pie iteration. Therefore, we introduced three different bigram building strategies.
Moreover, we combined dwell time selection with selection by borders, providing an alternative selection method and extra functionality. In a longitudinal study we compared participants performance during character-by-character text entry with bigram entry and with
text entry with bigrams derived by word prediction. Data showed large advantages of the new entry methods over single character text entry in speed and accuracy. Participants preferred selecting by
borders, which allowed them faster selections than the dwell time method.
Tien Measuring Situation Awareness Of Surgeons In Laparoscopic TrainingKalle
The study of surgeons’ eye movements is an innovative way of assessing skill and situation awareness, in that a comparison of eye movement strategies between expert surgeons and novices may show differences that can be used in training. Our preliminary study compared eye movements of 4 experts and
4 novices performing a simulated gall bladder removal task on a
dummy patient with an audible heartbeat and simulated vital signs displayed on a secondary monitor. We used a head-mounted Locarna PT-Mini eyetracker to record fixation locations during the operation. The results showed that novices concentrated so hard on the surgical
display that they were hardly able to look at the patient’s vital signs, even when heart rate audibly changed during the procedure. In comparison, experts glanced occasionally at the vitals monitor, thus being able to observe the patient condition.
Takemura Estimating 3 D Point Of Regard And Visualizing Gaze Trajectories Und...Kalle
The portability of an eye tracking system encourages us to develop a technique for estimating 3D point-of-regard. Unlike conventional methods, which estimate the position in the 2D image coordinates of the mounted camera, such a technique can represent richer gaze information of the human moving in the larger area. In this paper, we propose a method for estimating the 3D point-of-regard and a visualization technique of gaze trajectories under natural head movements for the head-mounted device. We employ visual SLAM technique to estimate head configuration and extract environmental information. Even in cases where the head moves dynamically, the proposed method could obtain 3D point-of-regard. Additionally, gaze trajectories are appropriately overlaid on the scene camera image.
Stevenson Eye Tracking With The Adaptive Optics Scanning Laser OphthalmoscopeKalle
Recent advances in high magnification retinal imaging have allowed for visualization of individual retinal photoreceptors, but these systems also suffer from distortions due to fixational eye motion. Algorithms developed to remove these distortions have the added benefit of providing arc second level resolution of the eye movements that produce them. The system also allows for visualization of targets on the retina, allowing for absolute retinal position measures to the level of individual cones. This paper will describe the process used to remove the eye movement artifacts and present analysis of their spectral characteristics. We find a roughly 1/f amplitude spectrum similar to that reported by Findlay (1971) with no evidence for a distinct
tremor component.
Stellmach Advanced Gaze Visualizations For Three Dimensional Virtual Environm...Kalle
Gaze visualizations represent an effective way for gaining fast insights into eye tracking data. Current approaches do not adequately support eye tracking studies for three-dimensional (3D) virtual environments. Hence, we propose a set of advanced gaze visualization techniques for supporting gaze behavior analysis in such environments. Similar to commonly used gaze visualizations for twodimensional
stimuli (e.g., images and websites), we contribute advanced 3D scan paths and 3D attentional maps. In addition, we introduce a models of interest timeline depicting viewed models, which can be used for displaying scan paths in a selected time segment. A prototype toolkit is also discussed which combines an implementation of our proposed techniques. Their potential for facilitating eye tracking studies in virtual environments was supported by a user study among eye tracking and visualization experts.
Skovsgaard Small Target Selection With Gaze AloneKalle
Accessing the smallest targets in mainstream interfaces using gaze
alone is difficult, but interface tools that effectively increase the size of selectable objects can help. In this paper, we propose a conceptual framework to organize existing tools and guide the development of new tools. We designed a discrete zoom tool and conducted a proof-of-concept experiment to test the potential of the framework and the tool. Our tool was as fast as and more accurate than the currently available two-step magnification tool. Our framework shows potential to guide the design, development, and testing of zoom tools to facilitate the accessibility of mainstream
interfaces for gaze users.
San Agustin Evaluation Of A Low Cost Open Source Gaze TrackerKalle
This paper presents a low-cost gaze tracking system that is based on a webcam mounted close to the user’s eye. The performance of the gaze tracker was evaluated in an eye-typing task using two different typing applications. Participants could type between 3.56 and 6.78 words per minute, depending on the typing system used. A pilot study to assess the usability of the system was also carried out in the home of a user with severe motor impairments. The
user successfully typed on a wall-projected interface using his eye movements.
Ryan Match Moving For Area Based Analysis Of Eye Movements In Natural TasksKalle
Analysis of recordings made by a wearable eye tracker is complicated by video stream synchronization, pupil coordinate mapping, eye movement analysis, and tracking of dynamic Areas Of Interest (AOIs) within the scene. In this paper a semi-automatic system is developed to help automate these processes. Synchronization is accomplished
via side by side video playback control. A deformable eye template and calibration dot marker allow reliable initialization via simple drag and drop as well as a user-friendly way to correct the algorithm when it fails. Specifically, drift may be corrected by nudging the detected pupil center to the appropriate coordinates. In a case study, the impact of surrogate nature views on physiological health and perceived well-being is examined via analysis of gaze over images of nature. A match-moving methodology was developed to track AOIs for this particular application but is applicable toward similar future studies.
Rosengrant Gaze Scribing In Physics Problem SolvingKalle
Eye-tracking has been widely used for research purposes in fields such as linguistics and marketing. However, there are many possibilities of how eye-trackers could be used in other disciplines like physics. A part of physics education research deals with the differences between novices and experts, specifi-cally how each group solves problems. Though there has been a great deal of research about these differences there has been no research that focuses on noticing exactly where experts and no-vices look while solving the problems. Thus, to complement the past research, I have created a new technique called gaze scrib-ing. Subjects wear a head mounted eye-tracker while solving electrical circuit problems on a graphics monitor. I monitor both scan patterns of the subjects and combine that with videotapes of their work while solving the problems. This new technique has yielded new information and elaborated on previous studies.
Qvarfordt Understanding The Benefits Of Gaze Enhanced Visual SearchKalle
In certain applications such as radiology and imagery analysis, it is important to minimize errors. In this paper we evaluate a structured inspection method that uses eye tracking information as a feedback mechanism to the image inspector. Our two-phase method starts with a free viewing phase during which gaze data is collected. During the next phase, we either segment the image, mask previously seen areas of the image, or combine the two techniques, and repeat the search. We compare the different methods
proposed for the second search phase by evaluating the inspection method using true positive and false negative rates, and subjective workload. Results show that gaze-blocked configurations reduced the subjective workload, and that gaze-blocking without segmentation showed the largest increase in true positive identifications and the largest decrease in false negative identifications of previously unseen objects.
Prats Interpretation Of Geometric Shapes An Eye Movement StudyKalle
This paper describes a study that seeks to explore the correlation between eye movements and the interpretation of geometric shapes. This study is intended to inform the development of an eye tracking interface for computational tools to support and enhance the natural interaction required in creative design. A common criticism of computational design tools is that they do not enable manipulation of designed shapes according to all perceived features. Instead the manipulations afforded are limited by formal structures of shapes. This research examines the potential for eye movement data to be used to recognise and make available for manipulation the perceived features in shapes. The objective of this study was to analyse eye movement data with the intention of recognising moments in which an interpretation of shape is made. Results suggest that fixation duration and saccade amplitude prove to be consistent indicators of shape interpretation.
Porta Ce Cursor A Contextual Eye Cursor For General Pointing In Windows Envir...Kalle
Eye gaze interaction for disabled people is often dealt with by designing ad-hoc interfaces, in which the big size of their elements compensates for both the inaccuracy of eye trackers and the instability of the human eye. Unless solutions for reliable eye cursor control are employed, gaze pointing in ordinary graphical operating environments is a very difficult task. In this paper we present an eye-driven cursor for MS Windows which behaves differently according to the “context”. When the user’s gaze is perceived within the desktop or a folder, the cursor can be discretely shifted from one icon to another. Within an application window or where there are no icons, on the contrary, the cursor can be continuously and precisely moved. Shifts in the four directions (up, down, left, right) occur through dedicated buttons. To increase user awareness of the currently pointed spot on the screen while continuously moving the cursor, a replica of the spot is provided within the active direction button, resulting in improved pointing performance.
Pontillo Semanti Code Using Content Similarity And Database Driven Matching T...Kalle
Laboratory eyetrackers, constrained to a fixed display and static (or accurately tracked) observer, facilitate automated analysis of fixation data. Development of wearable eyetrackers has extended environments and tasks that can be studied at the expense of automated analysis. Wearable eyetrackers provide 2D point-of-regard (POR) in scene-camera coordinates, but the researcher is typically interested in some high-level semantic property (e.g., object identity, region, or material) surrounding individual fixation points. The synthesis of POR into fixations and semantic information remains a labor-intensive manual task, limiting the application of wearable eyetracking.
We describe a system that segments POR videos into fixations and allows users to train a database-driven, object-recognition system. A correctly trained library results in a very accurate and semi-automated translation of raw POR data into a sequence of objects, regions or materials.
Park Quantification Of Aesthetic Viewing Using Eye Tracking Technology The In...Kalle
The purpose of this study is to explore how the viewers’ previous training is related to their aesthetic viewing in various interactions with the form and the context, in relation to apparel design. Berlyne’s two types of exploratory behavior, diversive and specific, provided a theoretical framework to this study. Twenty female subjects (mean age=21, SD=1.089) participated. Twenty model images, posed by a male and a female model, were shown on an eye-tracker screen for 10 seconds each. The findings of this study verified Berlyne’s concepts of visual exploration. One of the different findings from Berlyne’s theory was that the untrained viewers’ visual attention tended to be more significantly focused on peripheral areas of visual interest, compared to the trained viewers, while there was no significant difference on the central, foremost areas of visual interest between the two groups. The overall aesthetic viewing patterns were also identified.
2. It could be argued that, since we are only interested in local scene centers of both monitors to help the observers to fuse before the
statistics, why not record the movements of both eyes, and use the presentation of the next stereo pair.
disparity between the recorded left and right fixations to find the
correct match? There are several reasons why this wasn’t practic- This calibration routine was repeated compulsorily every 10 im-
al. First, there are fixation disparities that occur between the right ages, and a calibration test run every 5 images. This was achieved
eye and the left eyes. Most people have a fixation disparity that is by requiring that the observer fixate for 500ms within a 5s time
less than 6 arcmin, but can be as large as 20 arcmin with peripher- limit on a central square region (0.3◦ ×0.3◦) prior to progressing to
al visual targets [Wick, 1985]. When fixation disparity occurs, the next image in the stimulus collection. If the calibration had
the image of an object point that a person is trying to fixate do not drifted, the observer would be unable to satisfy this test, and the
fall on exactly corresponding points. Secondly, each Purkinje eye full calibration procedure was re-run.
tracker has an accuracy about 7 acrmin (the median offset from
real fixations); hence the error between two eye trackers is about Observers who became uncomfortable during the experiment
14 arcmin, which corresponds to about 12 pixels. This is quite a were allowed to take a break of any duration they desired.
large error, considering that the stereo images are only 800×600.
Thirdly, the fixation detection algorithm (associated with eye- The ambient illumination in the experiment room was kept con-
tracking) of the two eye paths can also introduce unwanted noise stant for all observers, with a minimum of 5 minutes luminance
into the corresponding fixation locations; registered stereoscopic adaptation provided while the eye-tracker was calibrated.
eyetracking is difficult to accomplish in practice. Lastly, since we
are interested in disparity features within neighborhoods (not just
points) of the fixations, a dense disparity map is required for all
points in the neighborhood. Hence, local processing of the type
that our disparity algorithm accomplishes would be required any-
way.
2.3 Equipments
Stereo images were displayed on two 17 inch, gamma calibrated Luminance Disparity
monitors. The distance between the monitors and the observer
was 124 cm. Each monitor’s screen resolution was set at 800×600
pixels, corresponding to about 50 pixels per degree of visual an-
gle. The total spatial extent of each display was thus about 16◦ ×
12◦ of visual angle.
A haploscope was placed between the two monitors and the ob-
servers to completely separate the displays from the left and right Luminance gradient Disparity gradient
monitor. Eye movements were recorded by a SRI Generation V
Dual Purkinje eye tracker. This eye tracker has an accuracy of <
10′ of arc, a response time of under 1 ms, and bandwidth of DC to
> 400Hz. The output of the eye tracker (horizontal and vertical
eye position signals) was low-pass filtered in the hardware and
then sampled at 200 hHz by a National Instruments data acquisi-
tion board in a Pentium IV host computer, where the data were
stored for offline data analysis. The observers used a bite bar and
Luminance contrast Disparity contrast
a forehead rest to restrict their head movements.
A viewing session was composed of 48 viewed stereo image Figure 1. The luminance and disparity features
pairs. At the beginning of each session, a 0.3°×0.3° crosshair was
displayed on the centers of both monitors to help the observers to
fuse by fixating on it. When the correct binocular fixation (the
crosshair was perceived single) was achieved, the observer
3 Analysis
pressed a button to start the calibration. Two 3×3 calibration grids
were displayed on the monitors respectively. After the observers 3.1 Computation of scene statistics
visited all 9 dots, a linear interpolation was then done to establish
the transformation between the output voltages of the eye tracker Denote the right image as I, and the dense disparity map as D We
and the position of the subject’s gaze on each computer display. computed the luminance gradient map:
The calibration also accounted for crosstalk between the horizon-
tal and vertical voltage measurements. After correct calibration, a
0.3°×0.3° crosshair was displayed on the centers to force all ob-
servers to start from the same center position. The stereo images
were displayed on two monitors for 10 seconds during which the
eye movements were recorded. Between two consecutive image and the disparity gradient map:
pairs, two identical Gaussian noise images were displayed for 3
seconds on both monitors to help suppress after-images corres-
ponding to the previous stereo pairs that may otherwise have at-
tracted fixations. Then a 0.3°×0.3° crosshair was displayed on the
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3. using the Matlab function gradient(X). Here we define luminance ∑ ,
contrast as the RMS contrast of a luminance patch:
where , is the location of the fixation.
∑ , We also computed the mean patch gradient of the random loca-
tions the image as:
and likewise, disparity contrast as
∑ ,
∑
where , is the location of the random location.
which is the standard deviation of a disparity patch. All of the For each image, we then defined the fixation-to-random lumin-
following analysis is based on these four scene features: lumin- ance contrast ratio / and the fixation-to-random lu-
minance gradient ratio / . If 1, it means that
ance contrast, disparity contrast, luminance gradient, and disparity the fixated patches generally have a larger luminance contrast
gradient. Figure 1 depicts these scene features for one example than randomly selected patches on the image being considered. If
stereo pair. 1, then the meaning is reversed. The same meaning applies
to the luminance gradient ratio.
3.2 Random locations
The same analysis method that was used on the luminance con-
Suppose an observer made fixations for the image. Then, trast and luminance gradient was also applied to for the analysis
the total number of fixations that the observer made during a ses- of disparity. We calculated the mean disparity contrast on the
sion is ∑ . We assume that a random observer also made the fixated patches, and the same quantity on the randomly se-
same number of fixations as the subject did. That is, for the lected patches. The ratio of disparity contrast between the fixated
image, the random observer selected fixations uniformly distri- patches and the randomly selected patches is defined as
buted on the image plane too. For each human observer, we as- / .
sume that there are 100 random observers each making the same
number of fixations in each image as the human observer. For The mean patch disparity gradient at the fixated patches ( ) and
example, the overall fixation that subject LKC made is 486 fixa- the randomly selected patches ( was also calculated. The ratio
tions in 48 images, so each random observer selected 486 random of the disparity gradient between the fixated patches and the ran-
locations too. The total number of random locations is 48,600. We dom patches is defined as / . If the ratios are signif-
wanted to know whether or not there is a statistically significant icantly greater than 1, then fixated patches tend to have a larger
difference between image features at fixations and those at ran- disparity contrast and gradient than randomly picked locations.
domly selected locations by comparing the human observer’s data
and the 100 random observers’ data.
3.3 Fixation/Random ratios
1.1
For the image, we computed the mean luminance contrast at
the fixations as: 1
Ratios
∑ ,
0.9
where , is the location of the fixation, and is the lu-
minance contrast map. 0.8
We also computed the mean luminance contrast at the random
locations as: 0.7
0.4 0.6 0.8 1 1.2 1.4 1.6
∑ ,
Patch size (deg)
Figure 2. Mean luminance gradient ratios (red), and
where , is the location of the random location. mean disparity gradient ratios (blue) of three observers.
We defined patch luminance gradient as the mean gradient of the
patch:
We ran 100 simulations for each image, and plotted the mean
∑ , ⁄ , luminance gradient ratio with 95% confidence intervals (CI),
and the mean disparity gradient ratio with 95% CIs, for all
where is the luminance gradient map. Similarly, we computed subjects as shown in Figure 2. For better comparison, we plotted 1
the mean patch luminance gradient of the fixations for the as a straight horizontal line across all patch sizes. The red curves
image as: show the ratios of luminance gradient, and the blue curves showed
the ratios of disparity gradients. Different markers were used to
represent the observers: LKC (*), CHY (o), JSL (∆). We made a
163
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