Efficient Image Compression Scheme for Still Images

Abstract

The raw image files take a large amount of disk space and it can be a huge disadvantage while storing or transmitting, and for this reason an efficient image compression technique is required. Image compression has been a widely addressed research area since many years. Many compression standards have been proposed. But there is still a scope for high compression with better quality reconstruction. Discrete Cosine Transform (DCT) is used for compression in a very popular standard called JPEG. First section of this paper aims at the analysis of compression using DCT transform method, and results obtained from certain experiments and execution of programs in MATLAB have been shown. There are many compression techniques, but still a technique which is better, simple to implement and with a good efficiency is suitable for user requirements. In the second section of this paper a new lossless variable length coding method is proposed for image comp¬ression and decompression which is inspired by a popular coding technique called Huffman coding. This new variable length coding technique is simple in implementation and the resulting compressed file utilizes comparatively less memory than the actual image. By using the new variable length coding technique a software algorithm has been written and implemented for compression and decompression of an image in a MATLAB platform.