File: https://github.com/Itseez/opencv/blob/master/modules/shape/src/sc_dis.cpp
Line: 235
In function computeDistance(InputArray contour1, InputArray contour2) the following line seems to be a potential bug. The computation of shape context descriptor of the first shape is fine since it uses its own mean distance for distance noramlisation. However, the second shape is using he mean distance of first shape. The two shapes can be different in the scales so they should use their own mean distance to normalise themselves.
set2SCE.extractSCD(set2, set2SCD, inliers2, set1SCE.getMeanDistance());