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This paper presents an efficient codec which is based on an optimal spline wavelet transform and an improved Set Partitioning in Hierarchical Trees algorithm. A comparative study of the proposed codec with the existing works using the polynomial spline based transform and the biorthogonal B9/7 which is frequently used in image compression is done. Peak signal-to-noise ratio (PSNR), structural similarity...
Evolving video applications impose requirements for high image quality, low bitrate, and/or small computational cost. This paper combines state-of-the-art coding and superresolution (SR) techniques to improve video compression both in terms of coding efficiency and complexity. The proposed approach improves a generic decimation–quantization compression scheme by introducing low complexity single-image...
This papers deals with an efficient image compression technique for images having low dynamic range. The images with low dynamic range generally have low intensity variations. By considering this fundamental characteristic into account we can go for image compression at higher ratio with small modifications to the existing block based EZW algorithm. To achieve the improvement in compression ratio,...
With many observations, we find that there exists a logarithmic relationship between the average collage error (ACER) and the quality of decoded images. By making use of the ACER in the encoding process, the quality of decoded images can be predicted without fractal decoding. In order to shorten the prediction process further, an accelerated version of the prediction method is proposed. By theoretical...
If a region is semantically more important than others, it is appropriate that a image compression scheme is capable of handling the regional semantic difference because the information loss of the interested region is more severe. We propose the quality scalable coding with its model by introducing the quality scale parameter. It is more extended and generalized image compression philosophy than...
Dealing with lossy compression of medical images requires particular attention whether for still images, video or volumetric slice-sets. In this work we propose an approach based on a selective allocation of coding resources that is directly related to the diagnostic task. We introduce the concepts of Region of Diagnostic Interest (RODI) and Diagnostic Quality as key links between the radiological...
The paper reports research on original techniques for compression of chrominance data in video sequences transmitted at very low bit rates. Two chrominance components are converted into one scalar chrominance signal using vector quantization in chrominance plane. Three methods for scalar chrominance compression based on transform and predictive coding are described. The important issue is that presented...
In this work, two new design techniques for matched (adaptive) orthogonal block transforms (BT) based partly on Vector Quantization (VQ) are presented. Both techniques start from reference vectors that are adapted to the characteristics of the signal to be coded. Then the corresponding orthogonal block transform is obtained in the first technique via signed permutations of the reference vector, while...
Fractal coding is a promising technique for image compression. However, one of the challenges for cost effective implementation is to reduce the huge computational complexity of the encoder. In this paper, we propose a novel algorithm to address this issue, Firstly, we replace mean square error with mean absolute error as distortion measure to reduce multiplication. Secondly, we use statistical normalization...
A new class of error resilient source code - Multiplexed Code was recently introduced. It takes advantage of the fact that real multimedia signals, such as images, audios and videos, contain heterogeneous information that can be grouped at different priority levels. High priority information is assigned to fixed length codewords; the inherent redundancy is exploited to represent low priority information...
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...
An algorithm for optimal selection of wavelet packet transforms for object-based coding is presented in this paper. The method exploits the object statistics at each GOP or scene period and estimate an optimal wavelet packet tree and an optimal quantizer for each object so that a) objects of importance (e.g., foreground) are transmitted with higher bit rate (quality) than the background objects, while...
In this paper, a parametric texture based video coding scheme is proposed for multi-view videos. The proposed scheme exploits the perceptual redundancy of the textured region in a statistical manner which is ignored in the multi-view video coding scheme of H.264/MVC. This statistical nature of texture is independent of the 3D scene structure. The set of most similar texture macroblocks over different...
In this paper, two compression mechanisms based on 3D-Discrete Wavelet Transform (DWT) and 2D Embedded Zero Wavelet (EZW) are compared depending on the mathematical parameters Peak Signal-to-Noise Ratio (PSNR) and compression ratio(CR). In this paper, we are using Haar wavelet decomposition for compression, as it has shown improved compression in recent years when used with the techniques like EZW,...
There are more and more systems using mobile devices to perform sensing task, but it increases the risk of leakage of personal privacy and data. Data hiding is one of the important ways for information security. Even many data hiding algorithms have worked on providing more hiding capacity or higher PSNR, there are few algorithms that can achieve effective control on PSNR while ensuring hiding capacity...
A lossy hyperspectral image compression method is proposed using online learning based sparse coding. The least number of coefficients are obtained to represent hyperspectral images by applying the sparse coding algorithm which is based on a dicriminative online dictionary learning method. Results indicate that a pre-analysis of the number of non-zero dictionary elements may help in improving the...
Scalable video coding (SVC) allows to encode videos in a unique bit stream at several operating points corresponding to different quality, spatial resolution and temporal frame rate. In this paper, we apply the allpass-based wavelet filters to wavelet-based scalable video coding (WSVC) for improving the coding performance, in particular, at reduced spatial resolutions. The allpass-based wavelet filters...
In order to improve the performance of no-search fractal coding further, a two order fitting surface is proposed to approximate the range blocks and domain blocks. In our research, a novel gray-level transform with a fitting surface is introduced. On one hand, the fitting surface we propose can approximate the range and domain blocks better than the previous fitting planes, this can lead to smaller...
A new scheme is proposed which uses the features of Discrete Cosine Transform (DCT) for the embedding of the watermark coefficients and uses a pseudo-random sequence for selection of the DCT coefficients to embed the watermark. These coefficients are different in different watermarked images so there is no chance of collusion of the watermarked images to detect the watermark illegally. The scheme...
In this paper, we propose a content-adaptive pre-processing for downsampling depth map for 3D multiview plus depth video coding. The proposed scheme takes advantage of spatially varying content of depth maps and targets improved encoding performance. The key idea is to divide the video frames into several horizontal and vertical stripes and downsample each of them with an appropriate downsampling...
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