Documentation of SGBM Stereo is not exact (Bug #1937)

In the Documentation of

StereoSGBM::StereoSGBM()

it says:

"speckleRange – Maximum disparity variation within each connected component. If you do speckle filtering, set the parameter to a positive value, multiple of 16. Normally, 16 or 32 is good enough."

In fact there is no need that this param is multiple of 16. May be in an older version it was necessary but now it is not.

The call to the relevant function in 2.4.0 is:
filterSpeckles(disp, (minDisparity - 1)*DISP_SCALE, speckleWindowSize, DISP_SCALE*speckleRange, buffer);
and I guess that DISP_SCALE is 16.

The unit of speckleRange, as it is in the code now, I think that it is "pixels of disparity", and may be this should be reflected in the documentation. Normal values, should be 1 or 2.