The use of the Hilbert scan is relatively new in image compression. This scan is guided by the Hilbert space filling curve. A Hilbert image, thus produced by this scan of a gray level image provides better compression rate than that of a raster scanned image. Since a Hilbert image is a 1D image, an efficient 1D algorithm based on a Bezier-Bernstein polynomial has been developed to simultaneously separate out and and approximate homogeneous segments of pixels depending on some absolute error based criteria. The approximation parameters are then encoded by a Huffman coding scheme. Investigation shows that better performance on image compression can be achieved using the Hilbert scan. Comparison with an existing algorithm shows also better performance of the proposed algorithm.
['S. Biswas']
Hilbert scan and image compression