A high performance digital multi-window quadtree video (MWQTVideo) compression encoding system

The evolution of communications technology to digital formats is upon us today. Digital transmission is now cheaper and better suited for the transfer of digital data since it offers additional capacity for the same analog channel cost. This dissertation specifically addresses the problem of video transmission over existing digital communication links. The transmission of digital video hinges on digital video compression since digital video signals require approximately 74 megabits per second and existing T-1 or ISDN digital communication links operate at 1.5 megabits per second or p {dollar}times{dollar} 64 kilobits per second respectively. "p" is an integer that ranges from 1 to 32.; In order to solve this particular problem, we present the development of a high performance digital Multi-Window Quadtree Video (MWQTVideo) compression encoding system. First, we develop the MWQTVideo algorithm, a video version of the MWQT algorithm, that has the ability to process many images per second without sacrificing either simplicity or ease of use. This is accomplished by extending MWQT algorithm to video through the exploitation of "inter-frame" redundancy. It should be noted that still frame compression methods exploit "intra-frame" redundancy, which means that individual picture elements (pixels) can often be predicted from their neighbors. One should also keep in mind that video coding exploits intra-frame redundancy, but additional compression is achieved by exploiting frame to frame correlation in video sequences. Second, we use an inter-frame coding scheme which forms a difference image by subtracting the previous image from the current image.; Third, we present a digital MWQTVideo compression encoding system which allows the MWQTVideo coder to compress the difference image. It switches over to compress the original image when it reaches a region with significant changes. The MWQTVideo compression encoding system test results show the ease with which MWQTVideo coder can change its characteristics from region to region for different types and sizes of images while providing good performance. We believe this high performance digital MWQTVideo compression encoding system will be as good as or better than other methods. It produces digital video that can be transmitted over standard T-1 phone line operating at 1.5 megabits per second or ISDN channel operating at p {dollar}times{dollar} 64 kilobits per second without the need for expensive hardware.