Multidimensional Incremental Parsing for Universal Source Coding

The article considers the relevance of the development of lossless image compression and transmission algorithms and their application for creating transport video surveillance systems. A brief overview of lossless transport image compression methods is provided. We propose a method for compressing transport plots based on the pyramid-recursive method of splitting the source image into polygons of various shapes and sizes. We consider two new algorithms for implementing the proposed method that are fundamentally different from each other: with a transition to the spectral region and without a transition to the spectral region of the original signal to ensure lossless compression. The results of testing various well-known lossless compression algorithms are analyzed: series length, Huffman, and arithmetic encoding, and compared with the proposed algorithms. It is shown that the proposed algorithms are more efficient in terms of compression ratio (2—3 times) compared to the known ones, while the computational complexity increases approximately by more than 3-4 times.

In this article we report on a study of how to use the context tree weighting (CTW) algorithm for lossless image compression. This algorithm has been shown to perform optimally, in terms of redundancy, for a wide class of data sources. Our study shows that this algorithm can successfully be applied to image compression even in its basic form. We also report on possible modifications of the basic CTW algorithm to let it work more efficiently for image data. Our research is briefly focussed on the compression of medical gray scale images.

Problem statement: Identifying the new lossless image compression algorithm for high performance applications like medical and satellite imaging; a high quality lossless image is most important when reproduction which leads to classify the data for decision making. Approach: A new lossless hybrid algorithm based on simple selective scan order with Bit Plane Slicing method is presented for lossless Image compression of limited bits/pixel images, such as medical images, satellite images and other still images common in the world. Efficient coding is achieved by run length and modified Huffman coding. This approach is combined with efficient selective scan order for entire image in one pass through. Results: The new hybrid algorithm achieves good compression rate, compared to the existing schemes of coding with different test images. Conclusion: Compared to the existing standards JPEG-LS and CALIC, the compression rate is reduced with our proposed algorithm for different standard test images.

Although subband and wavelet coding have been proved to be very efficient for lossy image compression, it is generally not possible to represent the output of most subband/wavelet filters by a limited number of bits and yet guarantee perfect reconstruction. This is a fundamental problem when applying subband and wavelet coding to lossless image compression. This paper presents a solution to this problem by an investigation of interpolative subband coding. Based on an evaluation of the decorrelation performance of some typical image interpolation techniques, a new interpolative coding algorithm has been proposed. The new algorithm has been shown to be superior to two related algorithms, the hierarchical interpolation algorithm and the recently published minimum entropy pyramid algorithm.

Diabetic retinopathy is the leading cause of blindness in the adult population. Mass-screening efforts, during which high resolution images of the retina are captured, are therefore underway in order to detect the disease in its early stages. In this paper we evaluate the compression performance of several lossless image compression algorithms that could be employed in a retina Picture Archiving and Communications System to lessen the demand on computing resources. The algorithms we analyse are TIFF PackBits, Lossless JPEG, JPEG-LS, and JPEG2000 all of which are incorporated in the current DICOM standard together with the non-standard CALIC algorithm for benchmark comparison. Compression performance is evaluated in terms of compression ratio, compression speed, and decompression speed. Based on a large dataset of more than 800 colour retinal images, divided into groups according to retinal region (nasal, posterior, and temporal) and image size, JPEG-LS is found to be the most suitable compression algorithm, offering good compression ratios combined with high compression and decompression speed. Compression ratios can be further improved through the application of a reversible colour space transformation prior to compression as a second set of experiments show.

As medical imaging facilities move towards film-less imaging technology, robust image compression systems are starting to play a key role. Conventional storage and transmission of large-scale raw medical image datasets can be very expensive and time-consuming. Recently, we proposed a memory-assisted lossless image compression algorithm based on Principal Component Analysis(PCA). In this paper, we further improve the performance of the algorithm in two different directions: Firstly, we replace PC A with NMF (Non Negative Matrix Factorization). NMF has several advantages in representing images with an image-like basis, results in sparse factors, and provides better user control over iterations. Secondly, we expand the single-level model with a new multilevel decomposition/projection framework to further reduce entropy of residual images. Our experimental results on X-ray images confirm that both modifications provide significant improvements over the single level PCA based algorithm as well as existing non-memory based techniques.

With the success of deep learning in computer vision applications, deep learning based algorithms have also been proposed for image processing applications. One such application is lossless image compression. Most traditional lossless image compression algorithms use pixel-by-pixel processing algorithms. In the pixel-by-pixel algorithms, each pixel is predicted from the previously coded neighbor pixels and the prediction error is compressed without loss. Deep learning based lossless image compression algorithms can be categorized into two categories, namely prior based algorithms and pixel-by-pixel (or masked convolution based) algorithms. In the pixel-by-pixel algorithms, each pixel's probability distribution is obtained by processing the previously coded neighboring pixels with a neural network, which is then used by an arithmetic coder for lossless compression. This paper explores a deep learning based architecture, which utilizes masked convolutions, to model probability distributions of pixels and also presents a method to improve the parallelization of the algorithms. The obtained compression performance is competitive and is compared to both state-of-the art traditional and deep learning based methods.

Objectives. The widespread use of systems for capturing light fields is due to the high quality of the reproduced image. This type of capture, although qualitatively superior to traditional methods to capturing volumetric images, generates a huge amount of data needed to reconstruct the original captured 4D light field. The purpose of the work is to consider traditional and extended to four-dimensional image compression algorithms, to perform a comparative analysis and determine the most suitable.Methods. Mathematical methods of signal processing and methods of statistical analysis are used.Results. Algorithms are compared and analyzed in relation to the compression of four-dimensional light fields using the PSNR metric. The selected evaluation criterion is affected not only by the dimension of the compression algorithm, but also by the distance of the baseline of the capture setting, since the difference between images increases with the distance between the optical centers of each camera matrix. Thus, for installations consisting of an array of machine vision cameras located on racks and placed in a room, the obvious choice would be to use conventional image compression methods. Furthermore, based on the assessment of the arbitrariness of video compression methods, it should be noted that the XVC algorithm remains undervalued, although its results are higher. Algorithm AV1 can be considered the next in order of importance. It has been established that the latest compression algorithms show higher performance if compared to their predecessors. It has also been shown that with a small distance between the optical centers of the captured images, the use of video compression algorithms is preferable to the use of image compression algorithms, since they show better results in both three-dimensional and four-dimensional versions.Conclusions. A comparison of the results obtained shows the need to use algorithms from the video compression family (XVC, AV1) on installations with a long baseline (mounted on camera stands). When working with integrated light field cameras (Lytro) and setting the capture with a short baseline, it is recommended to use image compression algorithms (JPEG). In general, video compression algorithms are recommended, in particular XVC, since on average it shows an acceptable level of PSNR in both the case of a short and long installation baseline.

Improving the ground resolution of SPOT 5 compared with SPOT 4 involves multiplying the data rate by 4. This made it necessary to seek a new image compression algorithm able to significantly increase the compression ratio while complying with the image quality requirements of SPOT users. We finally selected a DCT based algorithm embedded in a regulation loop in order to obtain a constant rate at the compressor output. This algorithm was first tested using simulated images. Quantitative and qualitative analyses were carried out at different development stages. Finally, a wide range of images chosen from the SPOT image database was used for validation purpose. This led us to propose several optimizations which have now been thoroughly tested. The result is an almost lossless compression algorithm, which will be used on both SPOT5 and HELIOS II, the French space agency's forthcoming Earth observation missions.

In technological developments, it also affects the size of the data from a file, especially in transmitting JPEG images or images. Digital images have a size or capacity that is large enough so that the image transmission process often experiences problems due to its large enough capacity. Large data sizes also require large storage space, therefore additional solutions are needed to save space on storage media, such as reducing the size of the data to be stored. Knowing the value of the speed and efficiency of the JPEG image compression process needs to remember so many compression methods that exist today, one of which is the FELICS method. Image compression is carried out on images aimed at reducing the redundancy of existing data in the image so that it can be stored or transmitted efficiently. The FELICS method, which stands for Fast Compression & Lossless Image System, is a lossless image compression algorithm that performs 5 times faster than the original lossless JPEG codec and produces a compression ratio of the same value. So through this research the writer wants to carry out the analysis process of the FELICS method. The Fast Compression & Lossless Image System method works very well on images and produces high ratio values. Keywords : Analysis, Image, Compression, FELICS Method

This paper presents a new lossless image compression algorithm which uses Joint Photographic Expert Group-Lossless (JPEG-LS) prediction technique and the concept of the seed number for compression. Image is processed in blocks of size 4*4. Pixels of the blocks are placed in a table of size 16*16. The span across which the pixels of each block are spread in the table is determined which forms a rectangle. Seed number for that block is computed. Using the JPEG-LS prediction technique in regular mode, the pixels are predicted and their position in the rectangle is found. Huffman encoded seed number, rectangle position and the positions of the pixels constitute the compressed files. Image is decompressed by Huffman decoding the files and reconstructing the pixels with the help of the pixel position, rectangle position and the seed number. This approach gives a new technique to compress the image, It is a simple approach and though the compression ratio is slightly lesser compared to JPEG-LS, it can be improved by Iterative approach.

We present a novel lossless image compression algorithm. It achieves better compression than popular lossless image formats like PNG and lossless JPEG 2000. Existing image formats have specific strengths and weaknesses: e.g. JPEG works well for photographs, PNG works well for line drawings or images with few distinct colors. For any type of image, our method performs as good or better (on average) than any of the existing image formats for lossless compression. Interlacing is improved compared to PNG, making the format suitable for progressive decoding and responsive web design.

The invention of Fountain codes is a major advance in the field of error correcting codes. The goal of this work is to study and develop algorithms for source and channel coding using a family of Fountain codes known as Raptor codes. From an asymptotic point of view, the best currently known sum-product decoding algorithm for non binary alphabets has a high complexity that limits its use in practice. For binary channels, sum-product decoding algorithms have been extensively studied and are known to perform well. In the first part of this work, we develop a decoding algorithm for binary codes on non-binary channels based on a combination of sum-product and maximum-likelihood decoding. We apply this algorithm to Raptor codes on both symmetric and non-symmetric channels. Our algorithm shows the best performance in terms of complexity and error rate per symbol for blocks of finite length for symmetric channels. Then, we examine the performance of Raptor codes under sum-product decoding when the transmission is taking place on piecewise stationary memoryless channels and on channels with memory corrupted by noise. We develop algorithms for joint estimation and detection while simultaneously employing expectation maximization to estimate the noise, and sum-product algorithm to correct errors. We also develop a hard decision algorithm for Raptor codes on piecewise stationary memoryless channels. Finally, we generalize our joint LT estimation-decoding algorithms for Markov-modulated channels. In the third part of this work, we develop compression algorithms using Raptor codes. More specifically we introduce a lossless text compression algorithm, obtaining in this way competitive results compared to the existing classical approaches. Moreover, we propose distributed source coding algorithms based on the paradigm proposed by Slepian and Wolf.

In machine learning problems, there are two main algorithms: supervised learning and unsupervised learning. Supervised learning algorithms can be used to classify data for tagged data; non-supervised learning algorithms can be used to cluster data for unlabeled data. This paper discusses the basic principles of clustering algorithm and selection of key parameters of clustering algorithm. The application of clustering algorithm in image compression is also analyzed. This paper also emphasizes the problems that should be paid attention to when using clustering. Finally, a practical case of image compression with K-means is given.

The bi-directional reading processes in DNA replication and gene expression together with the similarities between the so-called alternative splicing and Lempel-Ziv (LZ) algorithms has motivated us to incorporate bi-directional readings into LZ algorithms. LZ77, LZ78, and LZW84 are universal lossless data compression algorithms. A modified version of these algorithms that takes into account both forward and reverse readings is presented in this work. It is shown that bi-directional reading can improve the compression ratio at the expense of slight modifications in LZ algorithms provided that there exists some symmetry in the information content. Results are presented for text, image, and audio files.