Fractal image Compression encodes the image at low bitrates with acceptable image quality but, the time taken for encoding is large in most of the proposals. In this paper, a Fast Search Strategy using visual-based Pa...
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ISBN:
(纸本)9781479933587
Fractal image Compression encodes the image at low bitrates with acceptable image quality but, the time taken for encoding is large in most of the proposals. In this paper, a Fast Search Strategy using visual-based Particle Swarm Optimization (CPSO) with Chaos searching is proposed to enhance the speed of fractal image encoding. The search for near best match utilizes the visual based optimization with k-restrictions and intuitive move. The evaluated suboptimum value is close to that of best match. Though the strategy is according to edge property it preserves better visual quality. Thus the CPSO-kI technique speeds up the fractal encoder by 128 times and preserves better image quality.
One of the main problem of the optical imaging systems is limited depth of field which prevent from obtaining an all-in-focus image of the environment. This paper proposes a novel pixel-based multi-focus image fusion ...
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ISBN:
(纸本)9781509064946
One of the main problem of the optical imaging systems is limited depth of field which prevent from obtaining an all-in-focus image of the environment. This paper proposes a novel pixel-based multi-focus image fusion method making use of a series of multi-focus images to obtain an all-in-focus image. The proposed method, firstly, generate a focus map over the edges. Then, a full focus map is obtained by propagating the focus values at edge locations to the entire image. The proposed method and the state-of-the-art methods are compared in terms of both quantitative and visual evaluation. Based on the results, the proposed method outperforms the other ones.
An algorithm for image compression, based on local histogram analysis, is presented. A given image is compressed by dividing the image into nonoverlapping square blocks and coding the edge information in each block. T...
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ISBN:
(纸本)0819424358
An algorithm for image compression, based on local histogram analysis, is presented. A given image is compressed by dividing the image into nonoverlapping square blocks and coding the edge information in each block. The edge information is extracted by first differentiating the original image, quantising the differential image, then invistigated the local histogarm of small blocks of the differential image. Depending on the behaviour of the local histograms in the differential image, the corresponding blocks in the original image are classified into visually active and visually continuous blocks. The visually continous blocks are coded using the mean value only. A visually active block is coded using the location and orientation of the edge within the block. As a result, the compression ratio of the proposed algorithm depends on the behaviour of the local histogram, which in turn depends heavely on the quantisation process of the differential image. In this paper, the effect of the quantisation of the differential image on the compression ratio and the image quality is discussed.
An experiment quantifying human sensitivity to supra-threshold compression artifacts in wavelet-compressed images allows a computation and comparison of mean-squared errors producing equivalent visual distortion, and ...
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ISBN:
(纸本)0780367251
An experiment quantifying human sensitivity to supra-threshold compression artifacts in wavelet-compressed images allows a computation and comparison of mean-squared errors producing equivalent visual distortion, and demonstrates that common assumptions used in wavelet image compression do not necessarily hold for low-rate images The resulting MSE in the image is constant for a spatial frequency and is independent of orientation Because the quantizers are not operating in the granular region, however, equal MSE does not imply equal quantizer step sizes Computed threshold elevations for the second and third visible degradations are predicted well by the constant MSE model Supra-threshold distortions in complex stimuli do not therefore behave according to subthreshold assumptions, which suggest that quantizer step size should be constant for a spatial frequency.
The application of computer technology has also brought many conveniences to people. As an important part of computer technology, the application of imageprocessing technology in visual transmission system has create...
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Global motion estimation and compensation are important research issues in video compression. The main difficulty in global motion estimation resides in the disturbance of independently moving objects. The algorithm p...
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ISBN:
(纸本)0819424358
Global motion estimation and compensation are important research issues in video compression. The main difficulty in global motion estimation resides in the disturbance of independently moving objects. The algorithm presented in this paper exploits global motion information not only from stationary objects and the image background, but also from independently moving objects. Simulation results show that the new algorithm is more robust to the disturbance of independently moving objects, and computationally faster than an algorithm based on least-square approximation.
In the present work, we will first show that 3G wireless multimedia systems adopting scalable video encoding can achieve higher overall network utilization. Moreover, the problems of both packet loss and player rebuff...
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ISBN:
(纸本)0780367251
In the present work, we will first show that 3G wireless multimedia systems adopting scalable video encoding can achieve higher overall network utilization. Moreover, the problems of both packet loss and player rebuffering can degrade wireless streaming performance if the streaming video is non-scalable due to fading/retransmission and multi-user sharing. We will demonstrate that these problems can be mitigated using a scalable video with rate control. The results indicate that, MPEG-4 Simple Scalable visual Profile is more suitable for wireless video applications than Simple visual Profile.
High Efficiency Video Coding (HEVC), not only provides a much better coding efficiency than previous video coding standards, but also shows significantly superior performance than other image coding schemes when appli...
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ISBN:
(纸本)9781479902880
High Efficiency Video Coding (HEVC), not only provides a much better coding efficiency than previous video coding standards, but also shows significantly superior performance than other image coding schemes when applied to image coding. However, the improvement is at the cost of significant increase of encoding complexity. In this paper, we focus on retaining the high coding efficiency provided by HEVC while largely reducing its encoding complexity for image coding. By applying various techniques including optimized coding structure parameters, coding unit early termination, fast intra prediction and transform skip mode decision, we significantly reduce the complexity of HEVC intra coding while keeping most of its coding efficiency. Experimental results show that our light-weight HEVC encoder can save about 82% coding time compared with original HEVC encoder. With a slight loss to the HEVC reference software, the proposed scheme still gains about 19% in BD-BR compared with H.264/AVC.
In this paper we present a novel framework for compressing images using saliency maps and KAZE features. The method involves adapting the quality factor in JPEG compression scheme for each block instead of using the s...
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ISBN:
(纸本)9781509017461
In this paper we present a novel framework for compressing images using saliency maps and KAZE features. The method involves adapting the quality factor in JPEG compression scheme for each block instead of using the same quality factor for the entire image. This is achieved by adapting JPEG quality parameter based on visual saliency and KAZE keypoints. Subsequently, a piecewise function is used to compress the least important image blocks with higher compression ratio while maintaining the overall perceptual quality and avoiding blocking artifacts. This work introduces use of KAZE keypoints for image compression for the first time in literature. We show that the proposed method outperforms the JPEG compression using PSNR and FSIMc evaluation measures especially at high compression ratios.
In this paper we propose an image coding scheme based on the polynomial transform and multiresolution analysis. The polynomial transform is an image representation model that mimics some properties of the human visual...
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ISBN:
(纸本)0819424358
In this paper we propose an image coding scheme based on the polynomial transform and multiresolution analysis. The polynomial transform is an image representation model that mimics some properties of the human visual system, and which we use in order to model edges in terms of their characteristic parameters. Based on the polynomial transform, we build a pyramidal hierarchical predictive scheme for image coding. The feature parameters that we encode are: local average, edge orientation, edge position and edge magnitude.
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