Reversible compression of industrial radiographs using multiresolution decorrelation

An improved method for the reversible compression of industrial radiographs is described. The method uses one of the multiresolution decorrelation techniques, viz., hierarchical interpolation (HINT), to decorrelate a given image. However, instead of encoding the decorrelated image pixels at each resolution level using a memoryless source as in the traditional HINT method, a statistical source model with multiple contexts is employed and the pixels are encoded using the appropriate contextual statistics. Experiments on industrial x-ray images show that the improved method achieves about 19% more compression on the average than the traditional method.