We provide a comprehensive trade-off analysis of major compression algorithms as applied to multispectral imagery. Our goal is to identify a real-time, low cost codec for multispectral imagery. Hence the major criteri...
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We provide a comprehensive trade-off analysis of major compression algorithms as applied to multispectral imagery. Our goal is to identify a real-time, low cost codec for multispectral imagery. Hence the major criteria used for performance and ranking of various algorithms emphasize implementation complexity in addition to compression performance and robustness. Multispectral imagery codecs are designed by suitably extending and modifying the state-of-art still image codecs so that the resultant codec simultaneously benefits from the spatial and spectral correlations inherent in multispectral imagery. In particular, two different approaches of interest which emerge are vector quantization (VQ) and transform coding (TC). This paper describes and analyzes some recently developed multispectral imagery codecs utilizing the above two approaches. For completeness, a brief overview of alternate approaches is also included.< >
A classified context quantization (CCQ) technique is proposed to code basic image VQ indexes in the setting of high order context models. The context model of an index is first classified into one of three classes acc...
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ISBN:
(纸本)0780388747
A classified context quantization (CCQ) technique is proposed to code basic image VQ indexes in the setting of high order context models. The context model of an index is first classified into one of three classes according to the smoothness of the image area they represent. Then the index is coded with a context quantizer designed for that class. Experimental results show that CCQ achieves about three percent improvement over the previous best results of image VQ by conditional entropy coding of VQ indexes (CECOVI), and does so at a lower computational cost.
Television reception is the next challenge mobile handheld terminals will face, which already receive FM radio and can access to Internet. User cases include relaxation at idle times during travels, video information ...
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Television reception is the next challenge mobile handheld terminals will face, which already receive FM radio and can access to Internet. User cases include relaxation at idle times during travels, video information services for business users, entertainment clips and cartoons. This paper introduces two different wireless technologies, DVB-H and MBMS, which can be used to receive digital television in handheld devices. The paper presents both technologies as feasible solutions for the video broadcasting scenario, compares their performance, and it finally tells about their limitations.
Image compression has emerged as a major research area due to the phenomenal growth of applications that generate process and transmit images. Image compression can be sequential or progressive. Natural images contain...
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Image compression has emerged as a major research area due to the phenomenal growth of applications that generate process and transmit images. Image compression can be sequential or progressive. Natural images contain edges, geometry, texture and other discontinuities (details that are oriented in various directions). In this paper, a comparative analysis of four images compression techniques (JPEG, Wavelets, Bandelets and Ridgelets) applied to images of chromosomes is proposed. The interest of this study is to measure the sensitivity to the noise of these techniques when dealing with contour and texture of different forms of objects in the image. This synthesis and from results, proves that the studied factors (compression ratio, processing duration, coding error and signal noise ratio) have a characteristic influence on each other. This indicates that the choice of the result converges to an optimal compromise. Promising results are obtained.
A comparative study of lossless compression algorithms is presented. The following algorithms are considered: UNIX compress, gzip, LZW, CCITT Group 3 and Group 4, JBIG, old lossless JPEG, JPEG-LS based on LOCO, CALIC,...
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ISBN:
(纸本)0780362977
A comparative study of lossless compression algorithms is presented. The following algorithms are considered: UNIX compress, gzip, LZW, CCITT Group 3 and Group 4, JBIG, old lossless JPEG, JPEG-LS based on LOCO, CALIC, FELICS, S+P transform, and PNG. In cases where the algorithm under consideration may only be applied to binary data, the bit planes of the gray scale image are separated, with and without Gray encoding, and the compression is applied to individual bit planes. Testing is done using a set of document images obtained by gray scale scanning of prints of the eight standard CCITT images and a set of nine gray scale pictorial images. The results show that the highest compression is obtained using the CALIC and JPEG-LS algorithms.
In the paper influence of segments size on the efficiency of SA DCT is analyzed. Namely, it is shown that typical in image compression 8times8-pixel blocks are usually too small for obtaining the best PSNR values. Opt...
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In the paper influence of segments size on the efficiency of SA DCT is analyzed. Namely, it is shown that typical in image compression 8times8-pixel blocks are usually too small for obtaining the best PSNR values. Optimal block size depends on compression ratio, it grows from 12times12 pixels for low compression (more than 1 bit per pixel) up to 32times32 pixels or natural (non-rectangular) segmentation for less than 0.5 bits per pixel. The explanation is obvious, it is required that for a segment at least its DC component should be computed, while the number of blocks is inversely proportional to their size. The difference is also clearly seen when evaluating images subjectively
The integer wavelet transform (IWT) is dealt with. For for image compression performance, it is known that the IWT has a worse performance than the discrete wavelet transform (DWT). We analyse the IWT signal represent...
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The integer wavelet transform (IWT) is dealt with. For for image compression performance, it is known that the IWT has a worse performance than the discrete wavelet transform (DWT). We analyse the IWT signal representation mechanism with respect to the DWT one, in order to explain this difference. Insight into this mechanism suggests a simple, computationally efficient yet very effective way to improve the IWT compression performance up to the DWT level. Simulation results are presented for both natural and synthetic images, these latter being more critical for the IWT; it is shown that the proposed method permits one to fill the gap between the IWT and the DWT performance.
This paper presents a three-dimensional television (3DTV) trial broadcasting service that has been recently launched in Korea. The 3DTV trial broadcasting service employs a delivery mechanism of 3D content, called as ...
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ISBN:
(纸本)9781612841618
This paper presents a three-dimensional television (3DTV) trial broadcasting service that has been recently launched in Korea. The 3DTV trial broadcasting service employs a delivery mechanism of 3D content, called as dual stream method that delivers left and right images over each encoded stream based on MPEG-2 system technology, guaranteeing backward-compatibility. Specifically, this dual stream method is regarded as a proper solution for providing higher image quality both 2D and 3D video. This paper also presents a service mechanism along with signaling method, which enables 2D and 3D service to broadcast in a time-scheduled manner. Finally, we summarize the results of high-definition (HD) 3D trial broadcasting service.
The Wireless Sensor Network (WSN) has limitations in bandwidth and computational resources as they have limited communication and storage capabilities. WSN consists of cameras, which have some local image processing a...
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The Wireless Sensor Network (WSN) has limitations in bandwidth and computational resources as they have limited communication and storage capabilities. WSN consists of cameras, which have some local image processing and one or more central computers, where image data from multiple cameras is further processed and fused. Because of these limitations, the encoding techniques used for transmitting the image data should be efficient in order to make use of the available resources properly. A new sampling method is also introduced in the Image/video encoder of the WSN called Compressed Sensing (CS), which is the process of acquiring and reconstructing a signal that is supposed to be sparse or compressible, thus reducing the computational complexity. The image is divided into dense and sparse components by applying 2 levels of wavelet transform. The dense component uses the standard encoding procedure such as JPEG and the sparse measurements obtained from the sparse components are encoded by the techniques such as Exponential Golomb coding followed by Run-length encoding and arithmetic coding and the performances in terms of compression ratio and bits per pixel are compared. The recovery algorithm may be anyone supporting the compressed sensing technique such as OMP, POCS etc. In this work, the measurements (used in CS) and the predicted sparse components as the initial values, the projection onto convex set (POCS) recovery algorithm is used to get back the original sparse components of two levels and hence the original image by applying the inverse of transform to the dense and recovered sparse components.
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