ABSTRACT
This paper is concerned with the design and implementation of a compression method for
color image. This method based on Differential Pulse Code Modulation (DPCM), Discrete Cosine
Transform (DCT) , Discrete Wavelet Transform (DWT) and Quadtree Coding Scheme. As a first
step the DPCM technique is used to isolate blocks of an image into correlated and uncorrelated
blocks. The isolated correlated blocks have been compressed using DCT based compression method
then each block has been embedded with zeros on the original image. Each uncorrelated block has
been compressed using DWT based method and put the compressed block in its location on the
original image. Then, the result (i.e., the zeros blocks and compressed blocks with DWT) coded
using Quadtree spatial coding. The output from DWT based and DCT based passed through shift
coding stage to gain a possible further compression. The performance results of proposed hybrid
algorithms produces better quality of image in terms of Peak-Signal-to-Noise Ratio (PSNR) with a
higher Compression Ratio (CR) compared to standalone DCT or DWT. The PSNR values of the
reconstructed images after applying proposed system are ranged from 30.62 to 40.95dB and CR on
average, have been reduced to be around 1:19.6 of the size of the original image.