Nonhomogeneous image coding for progressive transmission

In this paper a new progressive image transmission scheme which emploies the eye perception is described. The algorithm apply a very fast quantiźation technique to images represtented in a pyramidal form. The pyramidal data structure has relatively low equivalent entropy and suitable to Progressive transmission. To gain further compression a very fast vector quantization is applied to the pyramidal representation of the images on a level-by-level basis. This fast vector quantization technique is based on the Mini-max error criterion, such that the quantization error will be within a prespecified bound. It is an adaptive technique which can force the quantization errors to be within a prespecified range. However, the error due to the quantization at a certain level may be delivered to the next level allowing us to gain a lossless transmission up to the bottom levels wherever, selective areas well be given a smaller quantization error threshold. Simulation results recommanded the use of nonhomogeneous image coding to obtain comparable quality with a lower bit rate than for other complex techniques.