Now that I have Octave, here is an actual comparison between gradient_norm (G’MIC) and phasecong3 (Kovesi). phasecong3 also outputs corners. Note that it contains many parameters, so I am sure the output could be optimized better.
canon3.bmp (converted to png using G’MIC)
gradient_norm
phasecong3 edges
phasecong3 corners
