how to find hough lines in gradient image ?

I want to use gradient image as the representative of edges and outlines of the normal image to find lines by hough transformation. Hough function needs edge map to find lines while gradient magnitude generated by imgradient function is not binary.

[Gmag, Gdir] = imgradient(ImgResamp2,'sobel'); [H,T,R] = hough(Gmag); %here Gmag is not binary image

[Bilal]

I want to use as a gradient image as the representative of edges, not the thresholded one

Answer 1

[Image Analyst]

Try edge() - it uses imgradient() and then thresholds it to get a binary image. See the demo where they start out with the gantry crane image.