I've been trying to implement this paper from Boris Epshtein, Eyal Ofek, and Yonatan Wexler, the pioneers of Stroke Width Transform .
Having a simple image with random texts, that underwent gray scaling. Then I have produced two edge maps using two different algorithms for output comparison (for later) , Sobel and Canny (I'm also planning on Prewwit or other edge detection algorithms). I also have gradient maps x and y, using sobel.
Now, up to this point I got lost on the second paragraph of section 3.1 of the paper, which is getting a gradient direction and finding the other point for the ray: " ...then dp must be roughly perpendicular to the orientation of the stroke... " and " ... dp(dq = -dp±π/6) ... ". Does this mean I'll have to take a wild guess as to where the direction of dq is? or have I misinterpreted it?