شيماء ضياء الدين
In this paper, an efficient compression system is introduced, it is based on using wavelet transform and two types of 3Dimension (3D) surface representations (i.e., Cubic Bezier Interpolation (CBI)) and 1st order polynomial approximation. Each one is applied on different scales of the image; CBI is applied on the wide area of the image in order to prune the image components that show large scale variation, while the 1st order polynomial is applied on the small area of residue component (i.e., after subtracting the cubic Bezier from the image) in order to prune the local smoothing components and getting better compression gain. Then, the produced cubic Bezier surface is subtracted from the image signal to get the residue component. Then, the bi-orthogonal wavelet transform is applied on the produced Bezier residue component. The resulting transform coefficients are quantized using progressive scalar quantization, and the 1st order polynomial is applied on the quantized LL subband to produce the polynomial surface, then the produced polynomial surface is subtracted from the LL subband to get the residue component (high frequency component). Then, the quantized values are represented using quadtree encoding to prune the sparse blocks, followed by high order shift coding algorithm to handle the remaining statistical redundancy and to attain efficient compression performance. The conducted tests indicated that the introduced system leads to promising compression gain.