Study of the coding in the progressive image transmission

Direction coding is a new method of image coding. The human visual model is used to make direction filters and high compression ratios are obtained. Direction coding not only deals with the continuous component of an image by subsampling it with high compression ratio, but also does some things with the discontinuous component of the image. We apply the direction coding method to narrowband image transmission in a progressive way. Experiments were made on normal telephone lines.