A New Method of Image Compression using Irreducible Covers of Maximum Rectangles

In recent years there has been a tremendous spurt in research and activity in finding efficient compression techniques for image processing applications. Particularly when an image is structured over a nonrectangular region, it is always advantageous to define a method of covering a region by minimal numbers of maximal rectangles. Towards this objective, we analyze the binary image compression problem using irreducible cover of maximal rectangles. We also give a bound on the minimum rectangular cover problem for image compression under certain conditions that previously have not been analyzed. I t is demonstrated that for a simply connected image, the irreducible cover proposed here uses less than four times the number of the rectangles in a minimum cover. With n pixels in a square, the parallel algorithm of obtaining the irreducible cover presented in the paper uses ( I I /log n ) concurrent-read-exclusive-write (CREW) processors in