Fix testing when scaling factor != 2

[zhaoalex]

When R != 2, running test.py results in an error:

Traceback (most recent call last):
  File "test.py", line 91, in <module>
    predictHR[row-margin,col-margin] = patch.dot(h[angle,strength,coherence,pixeltype])
IndexError: index 4 is out of bounds for axis 3 with size 4

This PR fixes that behavior!