For image processing developments I'm interested in a descriptor (or rather: a routine) that characterizes the structuring of a displayed object in a sensible manner, if possible by a smaller number of single values - e.g. some numbers describing maxima in spatial frequency occurrences or the like. The numbers describing the image structure should not be sensitive to the objects orientation in the image.
For clarification: if you have an ordered set of matches (to be considered as a combined object) displayed in the image, the desired descriptor should show the same values regardless of the orientation of the set of matches in the image. But in case the matches are evenly and chaotically spread across the scene the descriptor should yield different value(s), as the structure of the image has changed.
An answer would be most helpful if based on/related to the available routines of the open source image processing library ImageMagick. But any answer is greatly appreciated.