Bugfix: Correct pointer arithmetic when storing score

[jschornick]

The Scores cv::Mat has elements of integer size. The pointer arithmetic should be based on simple row/col offset calculation. It should definitely not be using the stride of the source image.

This worked in the past since this method is only meant to be called with grayscale images, where one byte per element meant (stride == cols).

[ethzasl-jenkins]

Can one of the admins verify this patch?

[jschornick]

@simonlynen

Accidentally discovered this when doing something silly in an unrelated test. I believe the fix is correct, but you should definitely double check my interpretation of what's going on.

[simonlynen]

lgtm

[simonlynen]

test this please