Blind image compression history determination using dynamic thresholding

In certain situations, a software application or even a hardware processing unit receives image data in a raster format, such as in a bitmap file, without any knowledge of what, if any, prior processing has occurred to it. If further processing is intended, it can be helpful or even necessary to know of an image’s processing history. Using a directional edge detector with a dynamic thresholding technique, an algorithm as been developed that can determine an image’s compression history using only the raster bitmap information. By accentuating an image’s block boundaries and then subsequently comparing the edge count at the block boundary with the edge count the pixel row right below, the compression history of images compressed up to a Quality Factor of 100 can be determined.