A minimax tree is similar to a Huffman tree except that, instead of minimizing the weighted average of the leaves’ depths, it minimizes the maximum of any leaf’s weight plus its depth. Golumbic (1976) introduced minimax trees and gave a Huffman-like, O(n log n)-time algorithm for building them. Drmota and Szpankowski (2002) gave another O(n log n)-time algorithm, which takes linear time when th...

Given a probability vector, Huffman coding finds a corresponding prefix-free binary code that minimizes the mean codeword length. In this paper we explore situations in which the goals are different from those in Huffman coding. We explore a family of penalties (generalized means) proposed by Campbell [8], finding redundancy bounds for a common subfamily. We generalize an efficient algorithm fo...

image data require huge amounts of disk space and large bandwidths for transmission. hence, imagecompression is necessary to reduce the amount of data required to represent a digital image. thereforean efficient technique for image compression is highly pushed to demand. although, lots of compressiontechniques are available, but the technique which is faster, memory efficient and simple, surely...

Consider a discrete finite source with N symbols, and with the probability distribution p := (u1, u2, . . . , uN). It is well-known that the Huffman encoding algorithm [1] provides an optimal prefix code for this source. A D-ary Huffman code is usually represented using a D-ary tree T , whose leaves correspond to the source symbols; The D edges emanating from each intermediate node of T are lab...

Given an tilphabet C = (al! . . . , a,) and a corresponding list of weights [WI, . . . , w,], a Huffman code for this alphabet is a prefix code that minimizes the weighted length of a code string, defined to be Cr.., wili, where li is the length of the code assigned to ai. A. Huffman code can be generated in O(n log n) time for an unsorted list of weights alld in Cl(n) time if the weights are a...

This research paper proposes a method for the compression of medical images using an efficient hybrid algorithm. The objective of this hybrid (DWT,DCT and Huffman quantization) scheme is to calculate the compression ratio, peak signal to noise ratio and mean square error by changing the DWT level and Huffman quantization factor. The goal is to achieve higher compression ratio by applying differ...

In every system of security, to keep important data confidential, we need a high degree protection. Steganography can be defined as way sending confidential texts through secure medium communications well protecting the information during process transmission. is technology that used protect users' security and privacy. Communication majorly achieved using network SMS, e-mail, so on. The presen...

In compressed data a single bit error propagates because of the corruption of the decoder’s state. This work is a study of error resilience in compressed data and, in particular, of the recovery of as much data as possible after a bit error. It is focused on Huffman codes. In a message encoded with a Huffman code a bit error causes the decoder to lose synchronization with the coder. The error p...

In this paper, Compression and improving the Quality of images during the transmission using SPIHT algorithm combined with Huffman encoding over OFDM channel has been proposed. Initially decompose the image in to different level, the compressed coefficients are arranged in descending order of priority and mapped over the channels. The coefficients with lower importance level, which are likely t...