Space communication performance of progressive turbo coding

This paper describes a method, that allows progressively image transfer over space communication channel, in which the quality of the image passed to the receiver can be adjusted. Images are converted into the appropriate format - bit plane sliced and turbo coded- on the transmitter side. With the desired image quality specified, the transmitter sends coded bit planes of image through the channel. The receiver cumulatively builds the coded data for the image while applying additional error correction -MAP (Maximum A posteriori Probability) algorithm- operations on the data obtained so far. The ability to specify desired image quality allows the receiver to satisfy constraints imposed by line bandwidth and response time. This method is illustrated with 4 bit gray scale images for simulation and can be extended for color images. The Progressive Transmission and compression of Turbo Coded Image procedure is based on the idea that only partial information from the original image is provided to the receiver at each iteration -i.e. bit plane iteration-. The receiver will use the limited information it has obtained, perform enhancement if desired or necessary, and displays the image. In the next iteration, additional information about the image will be sent to the receiver (like WWW browsers). The new data, together with data already on the receiver side, is used to build a new and more complete image at the receiver, achieving a better image representation. As the procedure is iterated, for more enhancement, the receiver gathers more image data so that eventually it is able to recreate the image in its original form.