1. A system for lossless progressive streaming of images over a communication network, comprising: an image storage device for storing a digital image; a client computer coupled to the communication network, wherein said client computer generates and transmits across said communication network a request list containing the coordinates of data blocks required for rendering a region of interest (ROI) within said digital image, wherein said request list is ordered in accordance with a selected progressive mode; a server computer coupled to said communication network and said image storage device, said server computer adapted to perform the steps of: preprocessing said digital image through a lossless wavelet transformation; receiving said request list from said client computer; and progressively transmitting to said client computer data blocks corresponding to said region of interest in the order they were requested.