yes i forgot to turn off the sharpening when i took the picture, it was just for a test
the reason I am interested in LineSegmentDetector is because it might be more robust in certain situations, like uneven lighting conditions
ideally there is something similar to the ‘bucket fill tool’ in Paint etc, where it fills an area of the image bounded by some defined constraints, such as a sharp transition in colour (such as in Paint) or the presence of a line