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The issue of backwards compatible image and video coding gained some attention in both MPEG and JPEG, let it be as extension for HEVC, let it be as the JPEG XT standardization initiative of the SC29WG1 committee. The coding systems work all on the principle of a base layer operating in the low-dynamic range regime, using a tone-mapped version of the HDR material as input, and an extension layer invisible...
Compressed sensing (CS) is the theory and practice of sub-Nyquist sampling of sparse signals of interest. Perfect reconstruction may then be possible with much fewer than the Nyquist required number of data. In this paper, we consider a distributed multi-view imaging system where each camera at a different location performs independent compressed sensing acquisition of the target scene. At the decoder,...
We propose a compression scheme for still images, by exploiting the theory of Distributed Coding of correlated multi-sources. Two corrupted versions of an image are encoded separately but decoding jointly. Our approach results in twofold. i) use of decomposition of low-pass wavelet co-efficients for creating the Side Information, and ii) variable-length coset creation by estimating the bit-rate of...
This paper proposes an efficient lossless coding scheme for still images. The scheme employs a block-adaptive prediction technique to remove spatial redundancy in a given image. The resulting prediction errors are encoded using context-adaptive arithmetic coding. Several coding parameters, which must be sent to a decoder as side information, are iteratively optimized for each image so that the number...
A wavelet-based video coder built on the principles of distributed source coding is described. The encoder employs a syndrome-based encoding strategy for intercoded coefficients while other coefficients are intracoded using an embedded wavelet-based coder designed for the coding of arbitrarily shaped image objects. The decoder uses a reference frame in the domain of a redundant wavelet transform to...
This paper illustrates an algorithm specifically designed for encoding multiple views of the same scene taken from calibrated cameras. The assumption here is that these views are strongly correlated as they represent the same content viewed from different perspectives. In order to keep the encoding complexity low, the proposed algorithm builds on PRISM (Power-efficient, Robust, hIgh compression, Syndrome-based...
The paper defines the conditions for the coefficients of a linear color transformation that guarantee that after one cycle of transformation and inverse transformation all further cycles of transformation do not introduce rounding errors to sample values. Moreover, the upper limits of the rounding error can be calculated according to the formulas given in the paper. The results are very important...
This paper presents a full codec for a distributed video surveillance system. It is based on a new method called LAR, mixing both spatial and spectral approaches. The spatial coder provides a low resolution image but preserving objects boundaries, whereas the spectral coder can add the local texture information. The encoding scheme is progressive, providing large flexibility for rate/quality trade-off.
In this paper we propose novel strategies for reducing the practical limitations of the Singular Value Decomposition (SVD) for image compression. First, the computational cost is reduced by computing only a limited number of eigenvectors. Second, an online Adaptive Vector Quantization (AVQ) method is used to achieve a low bit rate. Simulation results show that the proposed algorithm is better than...
This paper is concerned with the problem of error detection and correction of MPEG-4 video streams transmitted over lossy networks. The problem is first defined and some relevant detail of the MPEG-4 syntax is presented. The difficulties encountered in articulating this problem within a unified Bayesian framework are explored and two separate frameworks for dealing with error detection and error correction...
The upcoming still image compression standard, called JPEG2000, has defined modes for encoding and decoding parts of the image that are considered of particular importance (Regions of Interest — ROFs), with better quality than the rest of the image. The ROI coding modes are based in the "scaling based method" and the generation of the ROI mask. In this paper we describe a fast method for...
Image-based rendering is a powerful and promising approach for 3D object representation. This approach considers 3D object or scene as a collection of images called key frames taken from the reference viewpoints and generates arbitrary views of the object using these key frames. In this paper, we present an object-based encoding scheme for the multi-view sequences (key frames) of 3D object and a view...
In this paper, we present a subsampling method for color video sequences using feedforward artificial neural networks. In our method, subsampling of the high detail and smooth regions of the video chrominance frames is performed using pattern matching, by extracting different geometrical information for each region. Experimental results show that our method outperforms spatial subsampling obtained...
In this work we present and evaluate new architectures for the arithmetic encoding and decoding of multilevel images. Arithmetic coding is of great interest due to the excellent results that it gives. On the other hand, the complexity of its implementation has always gone against it and its different applications usually suffer from a high computational cost, slowness or both. By introducing a new...
This paper proposes a data-hiding scheme for quality access control of digital images using a new model of quantization index modulation (QIM). An encoded binary watermark is embedded over N-mutually orthogonal signal points using QIM but without complete self-noise suppression. It is well known that due to insertion of external information, there will be degradation in visual quality of the host...
Vector Quantization is an effective and simple method for lossy image compression. Codebook generation acts as important phase in Vector Quantization (VQ). The codebook is used to encode the image blocks for image compression. The codebook generation algorithm is generally preferred to have minimum distortion between the original image and obtained the reconstructed image. The paper presents an effective...
E-commerce websites rely heavily on JPEG images for product presentation. We describe a new coding scheme and file format that is tailored to the presentation of single-color products with multiple color choices: Instead of using multiple files of the same product at different colors, the new file format allows the transmission of all color choices in one file. On the decoder side images of the same...
Efficient lossless compression using decimation and interpolation algorithms with low complexity and high quality is an important goal for multi-media distribution over the internet. This is because content is consumed at different sizes and over networks with different bandwidths. It is also because informational content, large screen advertisements, professional video and high quality computer animation...
Performing a compression over massive video files in any network is one essential task from network and traffic management viewpoint. In the most recent times, HEVC (High Efficiency Video Coding) has stood up as new signaling protocol for performing video compression. Unfortunately, owing to the novelty in HEVC, there is less evidence of effective traffic management in prior studies. Therefore, the...
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