It seems obvious that the number of keypoints of any image should equal the number of keypoints of the mirror image of that image. The following is a simple function to test this assumption:?
keypointsanitycheck[arg_Image] := Module[{q1},
q1 = Image@Transpose@Reverse@Transpose@ImageData@arg;
q1 = Length /@ ImageKeypoints /@ {arg, q1};
q1[[1]] == q1[[2]]]
It is very easy to find images that flunk this simple test. In particular the image of the girl in the hat included in the Mathematica documentation yields False when the above is appled to it. This example can be found at
Import["ExampleData/lena.tif"]
Any comments that could help clarify this situation would be appreciated.
Thank you