This paper proposes a merge mode decision algorithm while maintaining the accuracy of a diamond search (DS) in motion estimation and compensation. In High Efficiency Video Coding (HEVC), the merge mode is used to redu...
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ISBN:
(纸本)9781479902880
This paper proposes a merge mode decision algorithm while maintaining the accuracy of a diamond search (DS) in motion estimation and compensation. In High Efficiency Video Coding (HEVC), the merge mode is used to reduce the bit rate in order to carry motion information. The rate-distortion (RD) cost of the merge mode is compared with the RD cost of the inter-prediction mode in the course of the motion estimation which can be terminated early when the merge cost is smaller than the estimated cost of the inter-prediction mode. To this end, this paper proposes a fast merge mode prediction algorithm when the DS is used for motion estimation. The main purpose of this work is to estimate the RD cost of the merge mode in advance by utilizing the distortion information of the RD cost of the motion vector prediction (MVP) so as to early terminate the motion search operation. Experimental results show that the proposed fast merge mode estimation achieves a comparable RD performance but reduces the amount of computation by 16.6% on the average when compared to the fast motion estimation with the diamond search implemented in the HM 8.0 reference software.
In this work, a new VPR approach that uses the features extracted from a Convolutional Neural Network (CNN) architecture that will be encoded by the Fisher Vector (FV) is introduced. As the main aim of this work is to...
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ISBN:
(纸本)9781728172064
In this work, a new VPR approach that uses the features extracted from a Convolutional Neural Network (CNN) architecture that will be encoded by the Fisher Vector (FV) is introduced. As the main aim of this work is to develop a robust approach that can meet real-life challenges, the deep features are encoded with FV, which as shown in the experiments section, can lead to getting more robust features. Our approach was evaluated using two classifiers, Dynamic Time Warping (DTW) and Support Vector Machine (SVM) in particular. Using both classifiers, the FV-based encoded features have outperformed the non-encoded features.
Lossless image coding is a crucial task especially in the medical area, e.g., for volumes from Computed Tomography or Magnetic Resonance Tomography. Besides lossless coding, compensated wavelet lifting offers a scalab...
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ISBN:
(纸本)9781479961399
Lossless image coding is a crucial task especially in the medical area, e.g., for volumes from Computed Tomography or Magnetic Resonance Tomography. Besides lossless coding, compensated wavelet lifting offers a scalable representation of such huge volumes. While compensation methods increase the details in the lowpass band, they also vary the characteristics of the wavelet coefficients, so an adaption of the coefficient coder should be considered. We propose a simple invertible extension for JPEG 2000 that can reduce the filesize for lossless coding of the highpass band by 0.8% on average with peak rate saving of 1.1%.
In this paper we assess the independence of the optimization of source and channel coding parameters. We propose a method to separate the source and channel coding optimization as much as possible while maintaining th...
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ISBN:
(纸本)0819437034
In this paper we assess the independence of the optimization of source and channel coding parameters. We propose a method to separate the source and channel coding optimization as much as possible while maintaining the possibility of joint optimization. We theoretically derive key parameters that must be passed through an interface between source and channel coding. This separation greatly reduces the complexity of the optimization problem and enhances the flexibility.
To replicate human visual perception, we analyze processingimages with optical illusion using edge preserving filters and smoothed local histogram equalization (LHE). images with the optical illusions are good models...
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ISBN:
(纸本)9781538644584
To replicate human visual perception, we analyze processingimages with optical illusion using edge preserving filters and smoothed local histogram equalization (LHE). images with the optical illusions are good models for gradual/rapid changes in contrast and strong edges, which are good cases for assessing the robustness of image filters. Here, we study and analyze the performance of smoothed LHE filters while processing perceptual illusion. Our studies conclude that, smoothed LHEs are useful in retaining actual edge forms in these images as they can operate using large kernel sizes. These large kernel size filters can construct sawtooth like edge and it corresponds to adequately wide halos. We also demonstrate the usefulness of smoothed LHE like tone mapping techniques in preserving naturalness, and we confirmed it by performing subjective visual test.
An attraction-repulsion expectation-maximization (AREM) algorithm for density estimation is proposed in this paper. We introduce a Gibbs distribution function for attraction and inverse Gibbs distribution for repulsio...
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ISBN:
(纸本)9780819469946
An attraction-repulsion expectation-maximization (AREM) algorithm for density estimation is proposed in this paper. We introduce a Gibbs distribution function for attraction and inverse Gibbs distribution for repulsion as an augmented penalty function in order to determine equilibrium between over-smoothing and over-fitting. The logarithm of the likelihood function augmented the Gibbs density mixture is solved under expectation-maximization (EM) method. We demonstrate the application of the proposed attraction-repulsion expectation-maximization algorithm to image reconstruction and sensor field estimation problem using computer simulation. We show, that the proposed algorithm improves the performance considerably.
Traditional objective metrics for the quality measure of coded images such as the mean squared error (MSE) and the peak signal-to-noise ratio (PSNR) do not correlate with the subjective human visual experiences well, ...
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ISBN:
(纸本)0819424358
Traditional objective metrics for the quality measure of coded images such as the mean squared error (MSE) and the peak signal-to-noise ratio (PSNR) do not correlate with the subjective human visual experiences well, since they do not take human perception into account. Quantification of artifacts resulted from lossy image compression techniques is studied based on a human visual system (HVS) model and the time-space localization property of the wavelet transform is exploited to simulate HVS in this research. As a result of our research, anew image quality measure by using the wavelet basis function is proposed. This new metric works for a wide variety of compression artifacts. Experimental results are given to demonstrate that it is more consistent with human subjective ranking.
Inspired by the recent image quality assessment (IQA) studies which indicate that the image gradient data reflects the visual information more reliably than the image pixels, gradient based transmission scheme was rec...
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ISBN:
(纸本)9781479961399
Inspired by the recent image quality assessment (IQA) studies which indicate that the image gradient data reflects the visual information more reliably than the image pixels, gradient based transmission scheme was recently proposed to pursue better perceptual quality for wireless visual communication. This paper develops an effective method to reconstruct high quality image from the received noisy gradient data. The proposed method utilizes both local correlation and non-local similarity within the image signal to regularize the reconstruction image. Principle component analysis (PCA) is employed to learn signal-adaptive two-dimensional (2D) transform basis, and 3D transform is performed on grouped similar patches to further decorrelate the coefficients. In this way, distortions can be effectively suppressed via adaptive collaborative shrinkage on the transform coefficients. Experimental results demonstrate that the proposed method improves the reconstruction performance remarkably compared with the existing schemes.
In an image Quality Assessment (IQA) scenario, the Human Vision System (HVS) always acts as the ultimate receiver and valuator of generated images. As an important feature of HVS, the visual attention data has been de...
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ISBN:
(纸本)9781538644584
In an image Quality Assessment (IQA) scenario, the Human Vision System (HVS) always acts as the ultimate receiver and valuator of generated images. As an important feature of HVS, the visual attention data has been demonstrated to be able to effectively improve the performance of existing objective quality metrics. However, this feature has not yet been well explored in the IQA of image interpolation. In this paper, we conduct an eye-tracking test on an interpolated image database and investigate the impact of visual attention on IQA of image interpolation. Two visual attention models, saliency map and Region Of Interest (ROI), are then obtained from the eye-tracking data. We further incorporate these models into non-integer interpolated IQA metric and examine their performances. Experiments show that the introduction of eye-tracking features obviously improves the conventional IQA metric for non-integer image interpolation.
The anisotropic wavelet packet transform is an extension of the conventional wavelet (packet) transform where the basis can have different scales in different dimensions. As there are certain kinds of images with diff...
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ISBN:
(纸本)0819450235
The anisotropic wavelet packet transform is an extension of the conventional wavelet (packet) transform where the basis can have different scales in different dimensions. As there are certain kinds of images with different behaviour in horizontal and vertical direction, anisotropic wavelet packet bases can be adapted more precisely to these images. Zero-tree image compression has already proved its efficiency on conventional wavelet transformed data as well as for wavelet packets. In this work, zero-tree methods are extended to work with anisotropic wavelet packets and coding results are shown for several types of images.
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