I tried everything including the Hough Transform with different inputs; Laplacian and Sobel and Canny edge detector were run on filtered image but cv2.HoughLinesP and cv2.HoughLines both give me wrong answers. For example, I am able to get the following image:
However, I can't get the line from this image though HoughLines from cv2. I even tried dilating the image which would make the lines more bolder but nothing.
Source image is: