Abstract: In present paper we proposed a simple and effective method to compress an image. Here we found success in size reduction of an image without much compromising with it’s quality. Here we used Haar Wavelet Transform to transform our original image and after quantization and thresholding of DWT coefficients Run length coding and Huffman coding schemes have been used to encode the image. DWT is base for quite populate JPEG 2000 technique. Keywords—lossy compression, DWT, quantization, Run length coding, Huffman coding, JPEG2000

Abstract: Data compression has been playing an important role in the areas of data transmission. Many great contributions have been made in this area, such as Huffman coding, LZW algorithm, run length coding, and so on. These methods only focus on the data compression. On the other hand, it is very important for us to encrypt our data to against malicious theft and attack during transmission. A novel algorithm named Swapped Huffman code Table (SHT algorithm) which joints compression and encryption based on the Huffman coding is proposed in this paper. This algorithm is a enhanced Huffman coding with encryption for wireless data broadcasting system. The application example and evaluation results show its feasibility and efficiency.

Abstract: Distributed video coding (DVC), a new video coding paradigm based on Slepian-Wolf and Wyner-Ziv theories, is a promising solution for implementing low-power and low-cost distributed wireless video sensors since most of the computation load is moved from the encoder to the decoder. It has been showed that there is still room to improve the coding efficiency of the current DVC codec. In this paper, we propose a hybrid coding structure with frame-level coding mode selection (CMS) to allow the DVC encoder to flexibly choose channel coding or entropy coding to code each band. The experimental results show the significant improvement on the rate-distortion (R-D) performance with only slight increase in the encoding complexity compared to the DISCOVER codec. The proposed DVC system performs comparably to H.264 No Motion with much lower encoding complexity.

Abstract: Problem statement: Identifying the new lossless image compression alg orithm 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, satelli te 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 dif ferent 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.

Abstract: Encoding and decoding methods for single and multiple layered video coding systems are provided. Specifically, video information provided to a base layer and one or more enhancement layers can be coded using a picture coding mode and/or a residual coding mode. Selection between coding modes can be performed on a region-by -region basis.

Abstract: In H.264/advanced video coding (AVC), lossless coding and lossy coding share the same entropy coding module. However, the entropy coders in the H.264/AVC standard were original designed for lossy video coding and do not yield adequate performance for lossless video coding. In this paper, we analyze the problem with the current lossless coding scheme and propose a mode-dependent template (MD-template) based method for intra lossless coding. By exploring the statistical redundancy of the prediction residual in the H.264/AVC intra prediction modes, more zero coefficients are generated. By designing a new scan order for each MD-template, the scanned coefficients sequence fits the H.264/AVC entropy coders better. A fast implementation algorithm is also designed. With little computation increase, experimental results confirm that the proposed fast algorithm achieves about 7.2% bit saving compared with the current H.264/AVC fidelity range extensions high profile.

Abstract: In this paper we have proposed an image crypto-compression system that guarantees a secure storage and transfer while preserving the performance of the used compression method. Regarding compression, we have chosen to use the discrete cosine transformation (DCT), Huffman coding and RLE because of their efficiency and their use in most current cryptocompression systems. As for encryption, we have made the choice to use the chaos for its good cryptographic properties. Experimental results confirm that our system is efficient, secure and greatly improve the compression ratio of the image while maintaining the performance of the encryption algorithm.

Abstract: Adaptive version of loss-less Region Based Huffman compression techniques are proposed where a proposed region formation algorithm is used to divide the input file into a number of regions that adapts region size depending on the ASCII value difference of symbols. Huffman codes are obtained for entire file after formation of regions. Code interchanging between the maximum frequency element of a region and maximum frequency element of entire file is done before symbols of that region are compressed. Another variation of the technique where region wise interchanging of code is done based on an additional condition. Comparisons are made among these two compression techniques with Region Based Huffman compression technique, Size Adaptive Region Based Huffman compression technique and classical Huffman technique. The proposed techniques offer better results for most of the files.

Abstract: This paper presents a software JPEG decoder with extremely small memory footprint, which is suitable for embedded systems. It is achieved by decoding one MCU at a time and storing it immediately in frame buffer, instead of processing full image strip, so consequently the memory usage is independent on image size. Due to efficient Huffman table processing and fast IDCT calculations, this software could be ported even to lower range microcontrollers. It also provides the auto scaling and auto rotation functionality.

Abstract: In this paper we propose an efficient approach to the compressed string matching problem on Huffman encoded texts, based on the BOYER-MOORE strategy. Once a candidate valid shift has been located, a subsequent verification phase checks whether the shift is codeword aligned by taking advantage of the skeleton tree data structure. Our approach leads to algorithms that exhibit a sublinear behavior on the average, as shown by extensive experimentation.

Abstract: This Paper considers the design of lossless image and data compression methods dedicated to still images and text data. For Images, after a preprocessing step (RGB to gray transformation, resizing) and for text after a preprocessing step (ASCII conversion), dynamic Huffman and Run Length Encoding (RLE) is applied. The dynamic Huffman coding involves computing an approximation to the probabilities of occurrence “on the fly”, as the ensemble is being transmitted with the aim to obtain the best possible compression ratio CR and Time Elapsed to compress. The additional parameters of evaluation in case of images are PSNR and MSE. The efficiency of the proposed methods is verified by applying these techniques to variety of data and images. Motivation behind this work is to provide a detail analysis of lossless compression methods which can be best suited in cognitive radio environment.

Abstract: In this paper, the comparative studies of Adaptive Region Based Huffman compression techniques are done. All these techniques use a region formation algorithm that is also discussed. This algorithm is used to form regions whose size is adjusted depending on the ASCII value difference of elements in the file. One of the techniques is Size Adaptive Region Based Huffman Compression (SARBH) where Huffman codes for entire file are obtained after formation of regions to encode elements of the files. Another technique known as Size Adaptive Region Based Huffman Compression with code interchanging (SARBHI) where interchanging of codes are done between the maximum frequency element of a region and maximum frequency element of entire file before elements of that region are compressed. Another variation of the technique is Size Adaptive Region Based Huffman Compression with selective code interchanging (SARBHS) where region wise interchanging of code is done based on an additional condition. Comparisons in terms of compression ratios and compression times are made among these three techniques and also with Region Based Huffman compression technique and classical Huffman technique. The proposed techniques offer better rates of compression for most of the files. Among these techniques, SARBHS is more effective for all most all types of files.

Abstract: Generally, data mining is the process of analyzing data from different perspectives and summarizing it into useful information information that can be used to increase revenue, cuts costs, or both. Data mining software is one of a number of analytical tools for analyzing data. It allows users to analyze data from many different dimensions or angles, categorize it, and summarize the relationships identified. Technically, data mining is the process of finding correlations or patterns among dozens of fields in large relational databases.

Abstract: This article presents several hardware architectures of Advanced Audio Coding (AAC) Huffman noiseless encoder, its optimisations and working implementation. Much attention has been paid to optimise the demand of hardware resources especially memory size. The aim of design was to get as short binary stream as possible in this standard. The Huffman encoder with whole audio-video system has been implemented in FPGA devices.

Abstract: A system and method combine an entropy coding algorithm like Huffman or arithmetic coding with a fixed length coding scheme and can improve the compression performance in a fixed rate compression scheme. The fixed length code assigns codes with a fixed length to symbols that have the highest probability of occurrence. Therefore, fixed length coding is used if all symbols in the sequence are from the set of symbols that have the highest probability values. Otherwise an entropy coding algorithm (e.g. Huffman coding) is used to encode quantized symbols.

Abstract: This paper presents the video compression techniques used for the processing of image sequences which are based on time based video. The temporal redundancies among the images are used for efficient code motion. Here, a simple method to increase the accuracy of most interframe predictions is to account for the frame-to-frame motion of objects. Using an interframe predictor, the compression has been increased to 2.085. In linear predictive coding and variable length Huffman coding, the compression is loss less and due to the fact that the entropy of the resulting prediction residuals is lowers than the entropy of the frame.

Abstract: JPEG coder is still the most attractive compression scheme for still image. Using Huffman coding makes the JPEG coder very sensitive to communication error. In this paper we propose a simple modification to JPEG coder by using reversible variable length code designed for the DC coefficients of each block. The results show great improvement in error resilience in a binary symmetric channel transmission with an average reduction of 5---10% in compression ratio.

Abstract: A coding device and method, which can suppress degradation of image data while guaranteeing a target compression ratio, a decoding device and method, which decode the data coded by the coding device and method, and a coding/decoding system including the coding device and the decoding device are provided. The coding device includes a predictive value data generator that sequentially generates predictive value data, a predictive error data generator that sequentially generates predictive error data, which is a difference between pixel data and the predictive value data, a coder that sequentially codes the predictive error data to sequentially generate variable-length coded data, and a coding controller that sequentially controls the coder. The coding controller sequentially calculates an accumulated value by accumulating a difference between a code length and a target code length of the variable-length coded data, and controls the coder such that the final accumulated value is 0 or lower.

Abstract: In this paper, a performance comparison of an embedded zero tree wavelet (EZW) based codec is done on the basis of Huffman and arithmetic coding The sub-band decomposition coefficients are coded into multilayer bit stream and then it is entropy coded using Huffman and arithmetic code The comparison results shows that the arithmetic coded bit stream results in improved bit rate than Huffman coding at the same threshold

Abstract: This article presents a novel method for exploiting inter/intra-block redundancies for JPEG image coding. It first expands the given image by duplicating certain rows and columns so that if f is a 8 by 8 pixel block and g and h are blocks to its immediate left and above, resp., adjacent pixels at the common boundary of f and g and at the boundary of f with h in the expanded image match. We show that the first column (row) DCT coefficients of f can be predicted without incurring any loss from the remaining DCT coefficients of f and from the DCT coefficients of g (h), assuming that the DCT is reversible. Our experiment shows that on average, we can save about 14.6% of JPEG Huffman code bits just by not coding the first row/column DCT coefficients.

Abstract: We propose an implementation of steganography embedding secret information without degradation of the data quality or increase of data size using Huffman coding. When general digital data are compressed using Huffman coding, the alphabet and the symbol frequency of the source depend on the data. In many cases, the statistics of the data are investigated and code table optimized for the data is constructed and then, encoding is applied with the code table and encoded data are stored together with the coding table. In this paper, we propose an implementation of embedding data using degrees of freedom in Huffman coding. Any digital data can be used as cover data and the quality of data is completely preserved because the compression is lossless. The proposed method contributes to the expansion of the application of steganography and to the improvement of security of digital data.

Abstract: Since advanced 3D video systems employ depth information to support free-viewpoint navigation and comfortable 3D video viewing, efficient depth map coding is necessary for future 3D video systems. Most residual data in depth map coding are generated along abrupt depth discontinuities, represented by near-zero and high-magnitude values. In this paper, we model the residual data with two representative values calculated by the K-means clustering method and send them to the decoder by skipping transformation. After best mode decision, we applied the proposed method to a block containing residual data, and then we send the quantized representative values to decoder if its coding rate is less than the conventional best mode. By conducting INTRA only coding, −20.32% bit saving was achieved.

Abstract: This paper describes an experimental system integration of Digital Rights Management (DRM) architecture and fingerprinting which is composed of an incomplete cryptography scheme using invariant offset huffman code length feature and the user identification mechanism to control the quality of the digital contents. We adopt the AC-coefficent huffman code length feature of the DCT coefficient in the JPEG codec to the implement incomplete cryptography. In the our scheme, the copyright information is embedded into the decoded content while decoding process, and the size of digital contents are invariant in the whole process. Experimental results with simulation confirmed that the modified codes keep compatibility with standard JPEG format, and revealed the proposed method is suitable for DRM in the network distribution system.

Abstract: In order to improve the coding performance of image lossless compression, a hybrid lossless compression scheme based on modified Set Partitioning in Hierarchical Trees (SPIHT) and Huffman coding is proposed. The lower magnitude bit-planes, whose corresponding magnitude thresholds are less than 8, and the sign bit-plane are scanned node by node in the fixed order, and the bit sequence obtained by scanning the bit-planes is further processed by Huffman coder to remove the statistical redundancy. The other bit-planes, namely the higher magnitude bit-planes, are sorted by the modified SPIHT partitioning structure, which could improves the coding efficiency of sorting pass by means of grouping more nodes together. Experimental results show the proposed algorithm has reduced its bit-rate by 0.13bit/pixel-0.35bit/pixel for gray images and by 0.72bit/pixel-1.25bit/pixel for color images as compared with those of the original SPIHT algorithm. Furthermore, the modified scheme retains the progressive transmission property of SPIHT coder. It is concluded that the proposed method efficiently reduces the redundancy existing in the original SPIHT coder and is fit for lossless image compression.

Abstract: This paper proposes an efficient intra-mode coding method using the deviation of neighbor pixels. In HEVC, the number of intra-prediction modes is increased in order to improve coding performance for intra-prediction as compared to H.264/AVC. However, this causes coding inefficiency in intra-mode coding. To improve coding efficiency, we propose a new intra-mode coding method that applies the analysis of the correlation between neighbor pixels and the intra-mode. Experimental results show that coding efficiency is improved by up to 0.80% in intra-mode coding. The proposed method also reduces an average 0.19% of the bitrate in the total codec as compared to HM4.0.

Abstract: . A variation of Huffman coding is presented. This variant not only seeks the frequency of letters, it also seeks the word frecuency, thus minimizing the av-erage number of bits per word (a string of characters). In this case we show the compression of the Bible into text file. Keywords: Compression, codeword, binary tree, code. 1 Introduction As a variable-length coding technique, Huffman coding [4-5] has been shown to be one of the most leading methods being used in various applications dealing with data compression. This compression method is based on frequency of occurrence of the symbols of an alphabet. To encode a text composed of characters from an alpha-bet, each character is assigned a sequence of bits called "codeword".The idea is to assign shorter codewords to the most frequent characters and longer codewords for less common characters. This assignment of codewords is represented by a binary tree. The Huffman method is divided into two main parts [4], 1) codeword's length determination. 2) encoding procedure and codewords as-signment.In the first part the binary tree is built based on the occurrence of each alphabet character in the text. The codeword is assigned to the binary label of the path from the root to a leaf node. The algorithm to construct the tree is shown below. 1. Initialize n trees of a node and label them with the characters of the al-phabet.2. Write the frequency of each character in the root of each tree to indicate the weight of trees.REPEAT1. Find the two trees with lower weights.2. Make left subtree and right subtree of a new tree.3. Write the weight as the sum of the weights in the root of new tree.UNTIL all the trees are in a single tree. The alternative proposed in this paper is located in the first part of the method of Huffman.