A Study on an Efficient Compression Algorithm for Digital Images

Presents two discre tewavelet transform based methods for coding digital image. In the first, an original image is divided into one lowpass or blurred subimage and three highpass or detai directional subimages by discrete orthogonal wavelet transform after subsampling. The compression strategies used for the subimages is put forward to analyse the statistical performance of every subimage considering the human visual system. A better reconstructed image is attained by inverse wavelet transform and bilinear interpolation. In the second, the image is divided into one low resolution lowpass subimage and several highpass subimages having different resolution.By pro gressive transmission of the decomposed images, reconstructed high resolution image can be obtained.Simulation results are given.