The patch to follow adds a new selector to ant that allows images files to be selected based on the size of the image. The original usecase has been to create thumbnail images only for images over a certain size, and then just copy the rest rather than scale them up to "thumbnail" size. Unfortunately I've yet to get to grips with the bed making and mirror cleaning of the selector tests so there's no testcase as yet.
Created attachment 8273 [details] zip file including build.xml/default.properties patch + new class
sorry to see this six years to late: your zip is missing the actual selector, it only contains the testcase