Given nonnegative weights (wr, . . . , w,,), the well-known algorithm of Huffman [2] can be used to construct a binary tree with n external nodes and n 1 internal nodes, where the external nodes are labeled with the weights (wr, . . . , w,) in some order. Huffman’s tree has the minimum value of WJ, + * * . + w,,l, over all such binary trees, where lj is the level at which wj occurs in the tree....

A new method for constructing minimum-redundancy prefix codes is described. This method does not explicitly build a Huffman tree; instead it uses a property of optimal codes to find the codeword length of each weight. The running time of the algorithm is shown to be O(nk), which is asymptotically faster than Huffman’s algorithm when k = o(log n), where n is the number of weights and k is the nu...

Multimedia transmission over time-varying channels such as wireless channels has recently motivated the research on the joint source-channel technique. In this paper, we present a method for joint source-channel soft decision decoding of Huffman encoded multiple sources. By exploiting the a priori bit probabilities in multiple sources, the decoding performance is greatly improved. Compared with...

Image steganography is the art of hiding information into a cover image. This paper presents a novel technique for Image steganography based on Block-DCT, where DCT is used to transform original image (cover image) blocks from spatial domain to frequency domain. Firstly a gray level image of size M × N is divided into no joint 8 × 8 blocks and a two dimensional Discrete Cosine Transform(2-d DCT...

Images include information about human body which is used for different purposes such as medical, security and other plans. Compression of images is used in some applications such as profiling data and transmission systems. Regard to importance of images information, lossless or lossy compression is preferred. Lossless compressions are JPEG, JPEG-LS and JPEG 2000 is few well-known methods for l...

ABSTRACT Huffman Compression, also known as Huffman Coding, is one of many compression techniques in use today. The two important features of Huffman coding are instantaneousness that is the codes can be interpreted as soon as they are received and variable length that is a most frequent symbol has length smaller than a less frequent symbol. The traditional Huffman coding has two procedures: co...

Efficient bit-representation or compression of documents is an important issue in many applications. The amount of compression depends on the document contents such as written scripts, diagrams, tables, etc. The contents of the document determine the limit of this compression. In the CCITI" Recommendation T.4, 'Standardization of group 3 apparatus for document transmission', a modified Huffman ...

The construction of optimal prefix codes plays a significant and influential role in applications concerning information processing and communication. For decades, different algorithms were proposed treating the issue of Huffman codes construction and various optimizations were introduced. In this paper we propose a detailed practical time-efficient parallel algorithm for generating Huffman cod...