EXTENDED DISCRETE COSINE TRANSFORM

Abstract

Lossy compression is a valuable technique in reducing the file size of an image for storing and transmitting across computer networks. Discrete cosine transform (DCT) has been one of the efficient transforms that is being used in popular compressor like JPEG. For fast compression, transforms with integer coefficients were developed. Few such transforms are integer discrete cosine transform (IntDCT) and integer-based discrete Tchebichef transform (DTT). In this paper, we extend the type II 8 × 8 DCT and produce a transform with integer coefficients. Simulated results show that the proposed method performed better than the other integer-based transforms in terms of the PSNR values and is also competitive with DCT.