Bound check fixes

[mlourakis]

I've been testing ELSED on a video sequence and discovered a couple of memory overrun errors. They were all caused by wrong or missing bound checks which I have fixed here.

[iago-suarez]

Dear @mlourakis, thanks a lot for your interest and for the fix. I will try it and if everything runs fine I will integrate it :)

Best,
Iago.

[iago-suarez]

Dear @mlourakis,

Everything runs correctly. Thanks again for your contribution 😃

Best,
Iago.

[mlourakis]

You're welcome, thanks for making your code available.

[h1063135843]

l /= std::sqrt(l[0] * l[0] + l[1] * l[1]);
line 291 in function drawAnchorPoints may also cause segmantion fault due to divide zero.

[iago-suarez]

Hi! Thanks a lot for your interest and your observation.

I am actually not sure. The expression will only be zero if the cross product of the starting and ending points in homogeneous coordinates is zero. This only happens if the starting point and the ending pixels are the same, which is impossible by definition in a line segment.

Have you found any case where this is true? If so, could you provide the instructions to reproduce so?

Best,
Iago.

[h1063135843]

just detect this image to reproduce.