Enhanced approach of Entropy Coding in Image Compression

Abstract

In transmission applications, multimedia systems and computer communications, compression techniques are constrained by real time and on-line considerations that are due to limiting size and complexity of the hardware. The reasons for multimedia systems to compress the data, large storage is required to save the compressed data, the storage devices are relatively slow that do not allow playing multimedia data in real-time, and the network bandwidth, which does not allow real-time data transmission. In the present research work an enhanced approach of entropy coding has been proposed. The compression of data at source encoding and decompression at its destination decoding, achieves larger compression by using this approach. JPEG image compression standard is used in this research work to show the effectiveness of the proposed run length coding. This standard is flexible and gives user the choice for selecting retrieved image quality. This scheme represents the occurrence of repeated zeros by RUN, and a non-zero coefficient by LEVEL. It removes the value of RUN, as for the sequence of non-zero coefficients it is zero for most of the time and unintended RUN, LEVEL (1, 0) pair used for the zero present between non-zero coefficients is replaced by ‘0’ which results in larger compression. This scheme has been tested on various images and results confirmed that it produces effective results.