Hough Transform, alternative

[Richard Stockham]

Although there are obviously many ways that this library could work and base itself on, several other libraries use other methods, such as Hough transform to detect lines, which they then assemble into shapes or blobs. My question is not critical, but simply cerebral. Why the current method, and not others, such as line detection?

[Sean Owen]

1. Because I barely have any background in image processing now, and had none 5 years ago
2. The theory was this is best solved in hardware by auto-focus, and this was Android-only to start, and Android was going to be auto-focus-only
3. Basic image processing was too expensive relative to benefits of just taking another frame; probably not so now

The Hough transform is overkill and probably still too slow to pull its weight, but I say that without having tried it. A specialization to vertical line edge detection might be just the thing.

I have had good luck with a Canny edge detector. Quite cheap but improves things moderately.