This document presents a paper that proposes an image registration algorithm using log-polar transform and FFT-based correlation. The algorithm first estimates the angle, scale, and translation between two images by converting them to the log-polar domain, where rotation and scaling appear as translation. It then recovers the residual translation using gradient correlation in the spatial domain. The algorithm is tested on various images related by similarity transformations and is shown to accurately recover scales up to 5.85 times while being robust to noise. It provides a computationally efficient way to register images using properties of the Fourier transform and log-polar mappings.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
COMPLEMENTARY VISION BASED DATA FUSION FOR ROBUST POSITIONING AND DIRECTED FL...ijaia
The present paper describes an improved 4 DOF (x/y/z/yaw) vision based positioning solution for fully 6
DOF autonomous UAVs, optimised in terms of computation and development costs as well as robustness
and performance. The positioning system combines Fourier transform-based image registration (Fourier
Tracking) and differential optical flow computation to overcome the drawbacks of a single approach. The
first method is capable of recognizing movement in four degree of freedom under variable lighting conditions, but suffers from low sample rate and high computational costs. Differential optical flow computation, on the other hand, enables a very high sample rate to gain control robustness. This method, however, is limited to translational movement only and performs poor in bad lighting conditions. A reliable positioning system for autonomous flights with free heading is obtained by fusing both techniques. Although the vision system can measure the variable altitude during flight, infrared and ultrasonic sensors are used for robustness. This work is part of the AQopterI8 project, which aims to develop an autonomous
flying quadrocopter for indoor application and makes autonomous directed flight possible.
ANALYSIS OF INTEREST POINTS OF CURVELET COEFFICIENTS CONTRIBUTIONS OF MICROS...sipij
This paper focuses on improved edge model based on Curvelet coefficients analysis. Curvelet transform is
a powerful tool for multiresolution representation of object with anisotropic edge. Curvelet coefficients
contributions have been analyzed using Scale Invariant Feature Transform (SIFT), commonly used to study
local structure in images. The permutation of Curvelet coefficients from original image and edges image
obtained from gradient operator is used to improve original edges. Experimental results show that this
method brings out details on edges when the decomposition scale increases.
Improved Characters Feature Extraction and Matching Algorithm Based on SIFTNooria Sukmaningtyas
According to SIFT algorithm does not have the property of affine invariance, and the high
complexity of time and space, it is difficult to apply to real-time image processing for batch image
sequence, so an improved SIFT feature extraction algorithm was proposed in this paper. Firstly, the MSER
algorithm detected the maximally stable extremely regions instead of the DOG operator detected extreme
point, increasing the stability of the characteristics, and reducing the number of the feature descriptor;
Secondly, the circular feature region is divided into eight fan-shaped sub-region instead of 16 square subregion
of the traditional SIFT, and using Gaussian function weighted gradient information field to construct
the new SIFT features descriptor. Compared with traditional SIFT algorithm, The experimental results
showed that the algorithm not only has translational invariance, scale invariance and rotational invariance,
but also has affine invariance and faster speed that meet the requirements of real-time image processing
applications.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
COMPLEMENTARY VISION BASED DATA FUSION FOR ROBUST POSITIONING AND DIRECTED FL...ijaia
The present paper describes an improved 4 DOF (x/y/z/yaw) vision based positioning solution for fully 6
DOF autonomous UAVs, optimised in terms of computation and development costs as well as robustness
and performance. The positioning system combines Fourier transform-based image registration (Fourier
Tracking) and differential optical flow computation to overcome the drawbacks of a single approach. The
first method is capable of recognizing movement in four degree of freedom under variable lighting conditions, but suffers from low sample rate and high computational costs. Differential optical flow computation, on the other hand, enables a very high sample rate to gain control robustness. This method, however, is limited to translational movement only and performs poor in bad lighting conditions. A reliable positioning system for autonomous flights with free heading is obtained by fusing both techniques. Although the vision system can measure the variable altitude during flight, infrared and ultrasonic sensors are used for robustness. This work is part of the AQopterI8 project, which aims to develop an autonomous
flying quadrocopter for indoor application and makes autonomous directed flight possible.
ANALYSIS OF INTEREST POINTS OF CURVELET COEFFICIENTS CONTRIBUTIONS OF MICROS...sipij
This paper focuses on improved edge model based on Curvelet coefficients analysis. Curvelet transform is
a powerful tool for multiresolution representation of object with anisotropic edge. Curvelet coefficients
contributions have been analyzed using Scale Invariant Feature Transform (SIFT), commonly used to study
local structure in images. The permutation of Curvelet coefficients from original image and edges image
obtained from gradient operator is used to improve original edges. Experimental results show that this
method brings out details on edges when the decomposition scale increases.
Improved Characters Feature Extraction and Matching Algorithm Based on SIFTNooria Sukmaningtyas
According to SIFT algorithm does not have the property of affine invariance, and the high
complexity of time and space, it is difficult to apply to real-time image processing for batch image
sequence, so an improved SIFT feature extraction algorithm was proposed in this paper. Firstly, the MSER
algorithm detected the maximally stable extremely regions instead of the DOG operator detected extreme
point, increasing the stability of the characteristics, and reducing the number of the feature descriptor;
Secondly, the circular feature region is divided into eight fan-shaped sub-region instead of 16 square subregion
of the traditional SIFT, and using Gaussian function weighted gradient information field to construct
the new SIFT features descriptor. Compared with traditional SIFT algorithm, The experimental results
showed that the algorithm not only has translational invariance, scale invariance and rotational invariance,
but also has affine invariance and faster speed that meet the requirements of real-time image processing
applications.
Image similarity using symbolic representation and its variationssipij
This paper proposes a new method for image/object retrieval. A pre-processing technique is applied to
describe the object, in one dimensional representation, as a pseudo time series. The proposed algorithm
develops the modified versions of the SAX representation: applies an approach called Extended SAX
(ESAX) in order to realize efficient and accurate discovering of important patterns, necessary for retrieving
the most plausible similar objects. Our approach depends upon a table contains the break-points that
divide a Gaussian distribution in an arbitrary number of equiprobable regions. Each breakpoint has more
than one cardinality. A distance measure is used to decide the most plausible matching between strings of
symbolic words. The experimental results have shown that our approach improves detection accuracy.
Image Registration Methode in Radar Interferometryijeei-iaes
This article presents a methodology for the determination of the registration of an Interferometric Synthetic radar (InSAR) pair images with half pixel precision. Using the two superposed radar images Single Look complexes (SLC) [1-4], we developed an iterative process to superpose these two images according to their correlation coefficient with a high coherence area. This work concerns the exploitation of ERS Tandem pair of radar images SLC of the Algiers area acquired on 03 January and 04 January 1994. The former is taken as a master image and the latter as a slave image.
Time Multiplexed VLSI Architecture for Real-Time Barrel Distortion Correction...ijsrd.com
A low-cost very large scale integration (VLSI) implementation of real-time correction of barrel distortion for video- endoscopic images is presented in this paper. The correcting mathematical model is based on least-squares estimation. To decrease the computing complexity, we use an odd-order polynomial to approximate the back-mapping expansion polynomial. By algebraic transformation, the approximated polynomial becomes a monomial form which can be solved by Hornor's algorithm. With the iterative characteristic of Hornor's algorithm, the hardware cost and memory requirement can be conserved by time multiplexed design. In addition, a simplified architecture of the linear interpolation is used to reduce more computing resource and silicon area. The VLSI architecture of this paper contains 13.9-K gates by using a 0.18 μm CMOS process. Compared with some existing distortion correction techniques, this paper reduces at least 69% hardware cost and 75% memory requirement.
Modification on Energy Efficient Design of DVB-T2 Constellation De-mapperIJERA Editor
The second generation of terrestrial digital video broadcasting standard (DVB-T2) offers several advantages for greater efficiency. Signal Space Diversity (SSD) contains rotated constellation and Q-Delay (RQD), which is one of advantage that offered to improve the performance over fading channels compared to the non-rotated modulation. In this journal, the proposed low-power de-mapper design of this work attempts to employ the introduced SSD to reduce power through replacing LLR calculations by a significantly less complex projection-based de-mapping whenever possible. It benefits from an algorithm that applies projection-based de-mapping to significantly reduce LLR computations without deteriorating performance. Two versions are introduced for hard de-mapping and soft de-mapping. The design uses several techniques simultaneously to be even more energy efficient without affecting the performance. Prototype results indicate significant reduction of LLR calculations as Eb/N0 increases with no performance degradation. The idea and energy saving techniques can be easily applied to any rotated constellation de-mapper.
International Refereed Journal of Engineering and Science (IRJES) is a peer reviewed online journal for professionals and researchers in the field of computer science. The main aim is to resolve emerging and outstanding problems revealed by recent social and technological change. IJRES provides the platform for the researchers to present and evaluate their work from both theoretical and technical aspects and to share their views.
www.irjes.com
Fractal Image Compression of Satellite Color Imageries Using Variable Size of...CSCJournals
Fractal image compressions of Color Standard Lena and Satellite imageries have been carried out for the variable size range block method. The image is partitioned by considering maximum and minimum size of the range block and transforming the RGB color image into YUV form. Affine transformation and entropy coding are applied to achieve fractal compression. The Matlab simulation has been carried out for three different cases of variable range block sizes. The image is reconstructed using iterative functions and inverse transforms. The results indicate that both color Lena and Satellite imageries with R max = 16 and R min = 8, shows higher Compression ratio (CR) and good Peak Signal to Noise Ratios (PSNR). For the color standard Lena image the achievable CR~13.9 and PSNR ~25.9 dB, for Satellite rural image of CR~ 16 and PSNR ~ 23 and satellite urban image CR~16.4 and PSNR~16.5. The results of the present analysis demonstrate that, for the fractal compression scheme with variable range method applied to both color and gray scale Lena and satellite imageries, show higher CR and PSNR values compared to fixed range block size of 4 and 4 iterations. The results are presented and discussed in the paper.
Wireless Positioning using Ellipsoidal ConstraintsGiovanni Soldi
This master's thesis presents a new approach for indoor positioning, based on the notion of separating ellipsoids. In order to improve the position estimation algorithm, the technique is combined with the algorithm A*, being applied to binary maps of the examined buildings to take into account obstacles such as walls.
The combination of separating ellipsoids and A seems to promise an improvement over previous algorithms based on a probabilistic approaches.
Application of Image Retrieval Techniques to Understand Evolving Weatherijsrd.com
Multispectral satellite images provide valuable information to understand the evolution of various weather systems such as tropical cyclones, shifting of intra tropical convergence zone, moments of various troughs etc., accurate prediction and estimation will save live and property. This work will deal with the development of an application which will enable users to search an image from database using either gray level, texture and shape features for meteorological satellite image retrieval .Gray level feature is extracted using histogram method. The Texture feature is extracted using gray level co-occurrence method and wavelet approach. The shape feature vector is extracted using morphological operations. The similarity between query image and database images is calculated using Euclidian distance. The performance of the system is evaluated using precision
In this paper, we analyze and compare the performance of fusion methods based on four different
transforms: i) wavelet transform, ii) curvelet transform, iii) contourlet transform and iv) nonsubsampled
contourlet transform. Fusion framework and scheme are explained in detail, and two different sets of
images are used in our experiments. Furthermore, eight different performancemetrics are adopted to
comparatively analyze the fusion results. The comparison results show that the nonsubsampled contourlet
transform method performs better than the other three methods, both spatially and spectrally. We also
observed from additional experiments that the decomposition level of 3 offered the best fusion performance,
anddecomposition levels beyond level-3 did not significantly improve the fusion results.
A lossless color image compression using an improved reversible color transfo...eSAT Journals
Abstract In case of the conventional lossless color image compression methods, the pixels are interleaved from each color component, and they are predicted and finally encoded. In this paper, we propose a lossless color image compression method using hierarchical prediction of chrominance channel pixels and encoded with modified Huffman coding. An input image is chosen and the R, G and B color channel is transform into YCuCv color space using an improved reversible color transform. After that a conventional lossless image coder like CALIC is used to compress the luminance channel Y. The chrominance channel Cu and Cv are encoded with hierarchical decomposition and directional prediction. The effective context modeling for prediction residual is adopted finally. It is seen from the experimental result the proposed method improves the compression performance than the existing method. Keywords: Lossless color image compression, hierarchical prediction, reversible color transform, modified Huffman coding.
DTAM: Dense Tracking and Mapping in Real-Time, Robot vision GroupLihang Li
This is the slides about DTAM for my group meeting report, hope it does help to anyone who will want to implement DTAM and need to understand it deeply.
Image similarity using symbolic representation and its variationssipij
This paper proposes a new method for image/object retrieval. A pre-processing technique is applied to
describe the object, in one dimensional representation, as a pseudo time series. The proposed algorithm
develops the modified versions of the SAX representation: applies an approach called Extended SAX
(ESAX) in order to realize efficient and accurate discovering of important patterns, necessary for retrieving
the most plausible similar objects. Our approach depends upon a table contains the break-points that
divide a Gaussian distribution in an arbitrary number of equiprobable regions. Each breakpoint has more
than one cardinality. A distance measure is used to decide the most plausible matching between strings of
symbolic words. The experimental results have shown that our approach improves detection accuracy.
Image Registration Methode in Radar Interferometryijeei-iaes
This article presents a methodology for the determination of the registration of an Interferometric Synthetic radar (InSAR) pair images with half pixel precision. Using the two superposed radar images Single Look complexes (SLC) [1-4], we developed an iterative process to superpose these two images according to their correlation coefficient with a high coherence area. This work concerns the exploitation of ERS Tandem pair of radar images SLC of the Algiers area acquired on 03 January and 04 January 1994. The former is taken as a master image and the latter as a slave image.
Time Multiplexed VLSI Architecture for Real-Time Barrel Distortion Correction...ijsrd.com
A low-cost very large scale integration (VLSI) implementation of real-time correction of barrel distortion for video- endoscopic images is presented in this paper. The correcting mathematical model is based on least-squares estimation. To decrease the computing complexity, we use an odd-order polynomial to approximate the back-mapping expansion polynomial. By algebraic transformation, the approximated polynomial becomes a monomial form which can be solved by Hornor's algorithm. With the iterative characteristic of Hornor's algorithm, the hardware cost and memory requirement can be conserved by time multiplexed design. In addition, a simplified architecture of the linear interpolation is used to reduce more computing resource and silicon area. The VLSI architecture of this paper contains 13.9-K gates by using a 0.18 μm CMOS process. Compared with some existing distortion correction techniques, this paper reduces at least 69% hardware cost and 75% memory requirement.
Modification on Energy Efficient Design of DVB-T2 Constellation De-mapperIJERA Editor
The second generation of terrestrial digital video broadcasting standard (DVB-T2) offers several advantages for greater efficiency. Signal Space Diversity (SSD) contains rotated constellation and Q-Delay (RQD), which is one of advantage that offered to improve the performance over fading channels compared to the non-rotated modulation. In this journal, the proposed low-power de-mapper design of this work attempts to employ the introduced SSD to reduce power through replacing LLR calculations by a significantly less complex projection-based de-mapping whenever possible. It benefits from an algorithm that applies projection-based de-mapping to significantly reduce LLR computations without deteriorating performance. Two versions are introduced for hard de-mapping and soft de-mapping. The design uses several techniques simultaneously to be even more energy efficient without affecting the performance. Prototype results indicate significant reduction of LLR calculations as Eb/N0 increases with no performance degradation. The idea and energy saving techniques can be easily applied to any rotated constellation de-mapper.
International Refereed Journal of Engineering and Science (IRJES) is a peer reviewed online journal for professionals and researchers in the field of computer science. The main aim is to resolve emerging and outstanding problems revealed by recent social and technological change. IJRES provides the platform for the researchers to present and evaluate their work from both theoretical and technical aspects and to share their views.
www.irjes.com
Fractal Image Compression of Satellite Color Imageries Using Variable Size of...CSCJournals
Fractal image compressions of Color Standard Lena and Satellite imageries have been carried out for the variable size range block method. The image is partitioned by considering maximum and minimum size of the range block and transforming the RGB color image into YUV form. Affine transformation and entropy coding are applied to achieve fractal compression. The Matlab simulation has been carried out for three different cases of variable range block sizes. The image is reconstructed using iterative functions and inverse transforms. The results indicate that both color Lena and Satellite imageries with R max = 16 and R min = 8, shows higher Compression ratio (CR) and good Peak Signal to Noise Ratios (PSNR). For the color standard Lena image the achievable CR~13.9 and PSNR ~25.9 dB, for Satellite rural image of CR~ 16 and PSNR ~ 23 and satellite urban image CR~16.4 and PSNR~16.5. The results of the present analysis demonstrate that, for the fractal compression scheme with variable range method applied to both color and gray scale Lena and satellite imageries, show higher CR and PSNR values compared to fixed range block size of 4 and 4 iterations. The results are presented and discussed in the paper.
Wireless Positioning using Ellipsoidal ConstraintsGiovanni Soldi
This master's thesis presents a new approach for indoor positioning, based on the notion of separating ellipsoids. In order to improve the position estimation algorithm, the technique is combined with the algorithm A*, being applied to binary maps of the examined buildings to take into account obstacles such as walls.
The combination of separating ellipsoids and A seems to promise an improvement over previous algorithms based on a probabilistic approaches.
Application of Image Retrieval Techniques to Understand Evolving Weatherijsrd.com
Multispectral satellite images provide valuable information to understand the evolution of various weather systems such as tropical cyclones, shifting of intra tropical convergence zone, moments of various troughs etc., accurate prediction and estimation will save live and property. This work will deal with the development of an application which will enable users to search an image from database using either gray level, texture and shape features for meteorological satellite image retrieval .Gray level feature is extracted using histogram method. The Texture feature is extracted using gray level co-occurrence method and wavelet approach. The shape feature vector is extracted using morphological operations. The similarity between query image and database images is calculated using Euclidian distance. The performance of the system is evaluated using precision
In this paper, we analyze and compare the performance of fusion methods based on four different
transforms: i) wavelet transform, ii) curvelet transform, iii) contourlet transform and iv) nonsubsampled
contourlet transform. Fusion framework and scheme are explained in detail, and two different sets of
images are used in our experiments. Furthermore, eight different performancemetrics are adopted to
comparatively analyze the fusion results. The comparison results show that the nonsubsampled contourlet
transform method performs better than the other three methods, both spatially and spectrally. We also
observed from additional experiments that the decomposition level of 3 offered the best fusion performance,
anddecomposition levels beyond level-3 did not significantly improve the fusion results.
A lossless color image compression using an improved reversible color transfo...eSAT Journals
Abstract In case of the conventional lossless color image compression methods, the pixels are interleaved from each color component, and they are predicted and finally encoded. In this paper, we propose a lossless color image compression method using hierarchical prediction of chrominance channel pixels and encoded with modified Huffman coding. An input image is chosen and the R, G and B color channel is transform into YCuCv color space using an improved reversible color transform. After that a conventional lossless image coder like CALIC is used to compress the luminance channel Y. The chrominance channel Cu and Cv are encoded with hierarchical decomposition and directional prediction. The effective context modeling for prediction residual is adopted finally. It is seen from the experimental result the proposed method improves the compression performance than the existing method. Keywords: Lossless color image compression, hierarchical prediction, reversible color transform, modified Huffman coding.
DTAM: Dense Tracking and Mapping in Real-Time, Robot vision GroupLihang Li
This is the slides about DTAM for my group meeting report, hope it does help to anyone who will want to implement DTAM and need to understand it deeply.
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.
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.
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.
MULTIPLE REGION OF INTEREST TRACKING OF NON-RIGID OBJECTS USING DEMON'S ALGOR...cscpconf
In this paper we propose an algorithm for tracking multiple ROI (region of interest) undergoing non-rigid transformations. Demon's algorithm based on the idea of Maxwell's demon, has been applied here to estimate the displacement field for tracking of multiple ROI. This algorithm works on pixel intensities of the sequence of images thus making it suitable for tracking objects/regions undergoing non-rigid transformations. We have incorporated a pyramid-based approach for demon's algorithm computations of displacement field, which leads to significant reduction in the convergence speed and improvement in the accuracy. This algorithm is applied for tracking non-rigid objects in laproscopy videos which would aid surgeons in Minimal Invasive Surgery (MIS).
Multiple region of interest tracking of non rigid objects using demon's algor...csandit
In this paper we propose an algorithm for tracking multiple ROI (region of interest) undergoing
non-rigid transformations. Demon's algorithm based on the idea of Maxwell's demon, has been
applied here to estimate the displacement field for tracking of multiple ROI. This algorithm
works on pixel intensities of the sequence of images thus making it suitable for tracking
objects/regions undergoing non-rigid transformations. We have incorporated a pyramid-based
approach for demon's algorithm computations of displacement field, which leads to significant
reduction in the convergence speed and improvement in the accuracy. This algorithm is applied
for tracking non-rigid objects in laproscopy videos which would aid surgeons in Minimal
Invasive Surgery (MIS).
The usage of a fused image and compressed model in a VLSI implementation is demonstrated. In this study, distortion correction is also considered. In distortion correction models, least-squares estimate is utilized. The technique of picture fusion is widely employed in medical imaging. Many pictures are obtained from various sensors (or) multiple images are captured at different times by one sensor in the image fusion approach. CT scans give useful information on denser tissue with the least amount of distortion. The information obtained from a magnetic resonance imaging (MRI) of soft tissue with significant distortion is useful. The DWT-based image fusion approach employs discrete wavelet transforms, a novel multi-resolution analytic tool. Back mapping expansion polynomial is used to reduce computer complexity. Using 0.18um technology, the suggested VLSI design achieves 218MHz with 1480 logical components.
Efficient 3D stereo vision stabilization for multi-camera viewpointsjournalBEEI
In this paper, an algorithm is developed in 3D Stereo vision to improve image stabilization process for multi-camera viewpoints. Finding accurate unique matching key-points using Harris Laplace corner detection method for different photometric changes and geometric transformation in images. Then improved the connectivity of correct matching pairs by minimizing
the global error using spanning tree algorithm. Tree algorithm helps to stabilize randomly positioned camera viewpoints in linear order. The unique matching key-points will be calculated only once with our method.
Then calculated planar transformation will be applied for real time video rendering. The proposed algorithm can process more than 200 camera viewpoints within two seconds.
Shot Boundary Detection using Radon Projection MethodIDES Editor
The detection of shot boundaries provides a base for
nearly all video abstraction and high-level video segmentation
approaches. Therefore solving the problem of shot boundary
detection is one of the major prerequisites for revealing
higher level video content structure. As a crucial step in video
indexing and retrieval, accurate shot boundary detection plays
an important role to organize and summarize video content
into meaningful shots for further scene analysis. Many
algorithms have been proposed for detecting video shot
boundaries and classifying shots and shot transition types. In
this paper we propose a novel technique for shot boundary
detection using radon transform. We first removed the effect
of illumination using DCT and DWT. Then shot boundary is
detected using radon transform. Radon transform is based on
projection of image intensity along a radial line oriented at a
specific angle. Projection of image intensity for current frame
is different than that of projection of the previous frame, where
shot boundary is detected. In order to verify the performance
of algorithm, experiments have been carried out with news,
documentary and movie. Experimental result demonstrates
efficiency of proposed shot boundary detection technique.
Data-Driven Motion Estimation With Spatial AdaptationCSCJournals
The pel-recursive computation of 2-D optical flow raises a wealth of issues, such as the treatment of outliers, motion discontinuities and occlusion. Our proposed approach deals with these issues within a common framework. It relies on the use of a data-driven technique called Generalised Cross Validation to estimate the best regularisation scheme for a given pixel. In our model, the regularisation parameter is a general matrix whose entries can account for different sources of error. The motion vector estimation takes into consideration local image properties following a spatially adaptive approach where each moving pixel is supposed to have its own regularisation matrix. Preliminary experiments indicate that this approach provides robust estimates of the optical flow.
A Novel Super Resolution Algorithm Using Interpolation and LWT Based Denoisin...CSCJournals
Image capturing technique has some limitations and due to that we often get low resolution(LR) images. Super Resolution(SR) is a process by which we can generate High Resolution(HR) image from one or more LR images. Here we have proposed one SR algorithm which take three shifted and noisy LR images and generate HR image using Lifting Wavelet Transform(LWT) based denoising method and Directional Filtering and Data Fusion based Edge-Guided Interpolation Algorithm.
APPLYING R-SPATIOGRAM IN OBJECT TRACKING FOR OCCLUSION HANDLINGsipij
Object tracking is one of the most important problems in computer vision. The aim of video tracking is to extract the trajectories of a target or object of interest, i.e. accurately locate a moving target in a video sequence and discriminate target from non-targets in the feature space of the sequence. So, feature descriptors can have significant effects on such discrimination. In this paper, we use the basic idea of many trackers which consists of three main components of the reference model, i.e., object modeling, object detection and localization, and model updating. However, there are major improvements in our system. Our forth component, occlusion handling, utilizes the r-spatiogram to detect the best target candidate. While spatiogram contains some moments upon the coordinates of the pixels, r-spatiogram computes region-based compactness on the distribution of the given feature in the image that captures richer features to represent the objects. The proposed research develops an efficient and robust way to keep tracking the object throughout video sequences in the presence of significant appearance variations and severe occlusions. The proposed method is evaluated on the Princeton RGBD tracking dataset considering sequences with different challenges and the obtained results demonstrate the effectiveness of the proposed method.
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.
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
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.
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.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
Encryption in Microsoft 365 - ExpertsLive Netherlands 2024Albert Hoitingh
In this session I delve into the encryption technology used in Microsoft 365 and Microsoft Purview. Including the concepts of Customer Key and Double Key Encryption.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
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N045077984
1. MR. Divyang Patel et al Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 5( Version 7), May 2014, pp.79-84
www.ijera.com 79 | P a g e
Image Registration Using Log Polar Transform and Fft Based
Scale Invariant
Mr. Divyang Patel, Ass Prof. Vaibhav Gandhi, Miss. Vrutti Patel
Department of Computer Engineering, Parul Institute of Engineering & Technology, Baroda.
Department of Computer Science & Engineering, Parul Institute of Engineering & Technology, Baroda.
Department of E & C Engineering, Vishwakarma Government Engineering College Chandkheda, Gandhinagar.
ABSTRACT
Image registration is the fundamental task used to match two or more partially overlapping images taken, for
example, at different times, from different sensors, or from different viewpoints and stitch these images into one
panoramic image comprising the whole scene. It is a fundamental image processing technique and is very useful
in integrating information from different sensors, finding changes in images taken at different times, inferring
three-dimensional information from stereo images, and recognizing model-based objects. Some techniques are
proposed to find a geometrical transformation that relates the points of an image to their corresponding points of
another image. To register two images, the coordinate transformation between a pair of images must be found.
In this paper, we have proposed an algorithm that is based on Log-Polar Transform and first we roughly
estimate the angle, scale and translation between two images. The proposed algorithm can recover scale value
up to 5.85. The robustness of this algorithm is verified on different images with similarity transformation and in
the presence of noise.
Keywords— Image Registration, Log-Polar Transform (LPT), Fast Fourier Transform
I. INTRODUCTION
The estimation of the relative motions
between two or more images is probably at the heart
of any autonomous system which aims at the efficient
processing of visual information. Motions in images
are induced due to camera displacements or
displacements of the individual objects composing
the scene. Image registration techniques for global
motion estimation address the problem of
compensating for the camera ego-motion and finally
aligning the images. Practical applications are
numerous: from global scene representation and
image mosaicing to object detection / tracking and
video compression.
We propose a robust correlation-based
scheme which operates in the Fourier domain for the
estimation of translations, rotations and scaling in
images. For the class of similarity transforms, a
frequency domain approach has several advantages.
First, through the use of correlation, it enables an
exhaustive search for the unknown motion
parameters. Second, the approach is global which
equips the algorithm with robustness to noise [1].
Third, the method is computationally efficient. This
comes from the shift property of the Fourier
Transform (FT) and the use of Fast Fourier
Transform (FFT) routines for the rapid computation
of correlations.
The work in [2] introduces the basic
principles for translation, rotation and scale-invariant
image registration in the frequency domain. Given
two images related by a similarity transform, the
translational displacement does not affect the
magnitudes of the FTs of the two images. Re-
sampling the Fourier magnitudes on the log-polar
grid reduces the problem of estimating the rotation
and scaling to one of estimating a 2D translation.
Thus, the method relies on correlation twice: once in
the log-polar Fourier domain to estimate the rotation
and scaling and once in the spatial domain to recover
the residual translation. In the usual way, the authors
use phase correlation (PC) [3] instead of standard
correlation while they perform conversion from
Cartesian to log-polar using standard interpolation
schemes (e.g. bilinear interpolation).
In our scheme, we first replace image
functions with complex gray-level edge maps and
then compute the standard Cartesian FFT. Next, we
simply resample the Cartesian FFT on the log-polar
grid using bilinear interpolation. Neither
sophisticated FFT nor over-sampling is employed to
enhance accuracy. To perform robust correlation, we
replace phase correlation with gradient-based
correlation schemes.
II. LOG POLAR TRANSFORM (LPT):
The Log-Polar Transform is used for image
registration for its rotation invariant and scale
invariant properties. The log-polar image geometry is
used because of the fact that scaling and rotation in
Cartesian domain corresponds to pure translation in
log-polar domain Taking logarithm of radial distance
RESEARCH ARTICLE OPEN ACCESS
2. MR. Divyang Patel et al Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 5( Version 7), May 2014, pp.79-84
www.ijera.com 80 | P a g e
ρ, we get log-polar coordinates. The log-polar
transformation is a conformal mapping from the
points on the Cartesian plane (x,y) to points in the
log-polar plane (log(ρ),θ). Considering a polar
coordinate system, where ρ is the radial distance from
the center of the image say (xc, yc) and θ denotes the
angle. Any point (x, y) can be represented in polar
coordinates and is given by
eu (1)
If the polar coordinate transformation is
applied to an image in the Cartesian domain, then the
radial lines in the Cartesian domain maps to
horizontal lines in (ρ,θ) domain.
Fig. 1. Approximate mapping from Cartesian space
to (ρ, θ) space.[4]
Fig.1 shows the approximate mapping from
Cartesian space to polar space or (ρ,θ) space. The
black box shows that the pixels are at a constant
angle with respect to the center. Similarly, the boxes
with cross marks are at a constant radial distance
from the center. It is clear from Fig.1 that if there was
a rotation in the image, the black box will shift its
positions on the theta axis [4]. A similar situation can
be discussed for the scale variation. In log-polar
coordinates, logarithm of the radial axis is taken by
(ρ, θ) = (log(ρ), θ) (2)
Now if the image is scaled by a factor of say
α, then the coordinates (x, y) in Cartesian domain
will become (αx, αy). Introduction of logarithms will
simplify the procedure, the coordinates in log domain
will be reflected as
(log((αx), log((αy) = ((logα + logx), (logα + logy)) (3)
The effects of distortions are expressed by
log-polar image translation on ρ axis and θ axis,
respectively in the log-polar coordinates. However,
when the original image is translated by (△x, △y),
the corresponding logpolar coordinates is represented
by
22
)sin()cos(log' yexe
(4)
xe
ye
cos
sin
tan' 1
(5)
According to above two Equations (4) and (5),
the slight translation produces a modification of the
log-polar image. Therefore, the log-polar image is not
suitable for faithfully extracting translation
parameters of images [5,6, 7].
III. ROBUST FFT-BASED SCALE-
INVARIANT IMAGE
REGISTRATION
To estimate the translational displacement,
we can replace standard correlation with gradient-
based correlation schemes[8]. Gradient correlation
(GC) combines the magnitude and orientation of
image gradients.
)(*)()(
*
21 uGuGuGC
dxuxGxG
2
)(*)(
*
21
Where, )()()( ,, xjGxGxG yixii
iyyiixxi IGIG ,, are the gradients along the
horizontal and vertical direction respectively.
From (6), we can easily derive
)}(*)()(*)({)(*)()(*)()( ,2,1,2,1,2,1,2,1 uGuGuGuGjuGuGuGuGuGC xyyxyyxx
The imaginary part in the above equation is equal to
zero, therefore
)(*)()(*)()( ,2,1,2,1 uGuGuGuGuGC yyxx
(8)
Using the polar representation of complex numbers,
we define
yixii GGR ,
2
,
2
and
)/(tan ,,
1
xiyii GG
(9)
Based on the representation of (8)
dxuxxuxRxRuGC
2
)]()(cos[)()()( 2121
(10)
The magnitudes Ri reward pixel locations
with strong edge responses and suppress the
contribution of areas of constant intensity level which
do not provide any reference points for motion
estimation. Orientation information is embedded in
the cosine kernel. This term is responsible for the
Dirac-like shape of GC and its ability to reject
outliers induced by the presence of dissimilar parts in
the two images.
We assumed Ri = 1, i= 1,2. To optimize the
orientation difference function DF of the image
salient structures solely, we introduce the normalized
gradient correlation:
|)(|*|)(|
)(*)(
)( *
21
*
21
uGuG
uGuG
uNGC
(11)
The above analysis, (11) takes the form:
dxuxRxR
dxxuuxRxR
uNGC
2
2
)()(
),(cos)()(
)(
21
21
(12)
NGC has two interesting properties:
3. MR. Divyang Patel et al Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 5( Version 7), May 2014, pp.79-84
www.ijera.com 81 | P a g e
1. 0 ≤ |NGC(u)| ≤ 1.
2. Invariance to affine changes in illumination.
The first property provides a measure to
assess the correctness of the match. To show the
second property, consider: bxaII )(' 22
with
a and b
IV. PROPOSED ALGORITHM
Inputs: Two images Ii, i = 1;2 related by a
translation t, rotation θ and scaling s.
Step 1: Estimate gradient Gi=Gi(x) + j Gi(y). By
finding the Horizontal and vertical edges using the
standard Cartesian FFT.
Step 2: Resample on the log-polar grid using bilinear
interpolation.
Step 3: Estimate θ and s using NGCorr in the log-
polar domain.
Step 4: Scale down and derotate the zoomed, rotated
image. Resolve the π ambiguity.
Step 5: Find the translation using the Normalized
Gradient Correlation in a spatial domain.
Step 6: Shift the image to the original position as per
the reference image which is obtained in step 5.
Step 7: Find the MSE (mean square error) between
the Reference image and the registered image.
Stpe8: Overlap the Registered image above the
Reference image.
STEP-BY-STEP ALGORITHM-CLOSE LOOK
Inputs
Fig 2. Reference image (input)
Fig 3. Sense image (input)
Step 1: Estimate gradient Gi=Gi(x) + j Gi(y). By
finding the Horizontal and vertical edges using the
standard Cartesian FFT.
Fig 4. Gradient of reference image
Fig 5. Gradient of sense image
Step 2:
Fig 5. Log polar transform if reference image
4. MR. Divyang Patel et al Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 5( Version 7), May 2014, pp.79-84
www.ijera.com 82 | P a g e
Fig 6. Log polar transform of sense image
Step 3:
For finding theta and scale :
θ = (y) * 180 / (N);
base = exp (log(N) / (N));
scale = base ^ ((x));
Where; N is size of Image and (x, y) is peak after
find Normalized Gradient Correlation between
referenced and sense image.
Estimating for given example:
θ = 0.00 , scaling = (1/scale) = 3.2605.
Step 4.
Scale Down and Re-rotate which is estimated above
and Pad it according to reference Image.
Fig 7. Derotated and scale down iamge
Step 5:
Now NGCorr is find between Reference
Image and De-rotated and Scale down image. Peak is
founded which has some co-ordinate (x,y), which is
the point of translation. Remove the Translation.
Estimating for given example:
Translation= (-22, -92)
Step 6 :
Fig 8. Shift the image to the original position
Step 7.
Now, find MSE between the Reference
Image and Registered Image.
Where; I(x,y) is the original image,
I'(x,y) is the approximated version and M,N
are the dimensions of the images.
Estimating for given example:
MSE= 0.2833
Step 8.
Now Overlap the Registered Image on
Reference Image.
Fig 9. Overlap registered and reference image
])),('),(([
1
1 1
2
M
x
N
y
yxIyxI
MN
MSE
5. MR. Divyang Patel et al Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 5( Version 7), May 2014, pp.79-84
www.ijera.com 83 | P a g e
V. EXPERIMENTAL DATA.
Fig 10. building.pgm (a) reference image, (b) sense
image, (c) derotate, downscale and translated
image,(d) registered image
Fig 11. mountain.pgm (a) reference image, (b) sense
image, (c) de rotate, downscale and translated
image,(d) registered image
Fig 12. x-ray.jpg (a) reference image, (b) sense image,
(c) de rotate, downscale and translated image,(d)
registered image
FIG NO. IMAGE RECOVERED
θ
SCALE
10 building -31.64 5.85
11 mountain 0 3.26
12 x-ray -22.85 1.12
FIG NO. IMAGE TRANSLATION MSE
Fig. 10 building (72 , 4) 0.2507
Fig. 11 mountain (-22,-92) 0.2528
Fig. 12 x-ray (53 , 75) 0.0434
VI. CONCLUSION
Mostly image registration algorithm is
presented using Log-Gabor filter, Log-Polar
Transform and Phase Correlation. The rotation and
scale invariant properties of the LPT, along with FT
and phase correlation allow us to develop a robust
algorithm that works faithfully under geometric
distortions like rotation, scale and translation. Hence
this approach is highly effective in registering aerial
images. Any amount of scaling and rotation in
Cartesian domain will be pure translation in log polar
domain. Scale and rotation between images is
recovered by first converting them into Log-Polar
images and then applying FFT-based cross-
correlation.
A key feature of Fourier-based registration
methods is the speed offered by the use of FFT
routines. The proposed scheme estimates large
motions accurately and robustly without the need of
excessive zero padding and over-sampling, thus
without sacrificing part of the computational
efficiency which typifies the frequency domain
formulation. Finally, a further advantage of the FFT-
based image registration methods is that it is able to
find the scaling up to 5.85.
REFRENCES
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