[JAI] Should I be basing my new OpImage on UntiledOpImage?
I'm new to JAI and am trying to write a Canny edge detector.
I have half implemented an AreaOpImage derivative to do the job, but
have just realised that AreaOpImage may not be appropriate - I now need
to verify my understanding of JAI is correct...
With the Canny algorithm (http://www.cee.hw.ac.uk/hipr/html/canny.html),
I need to first perform edge detection, before computing "non maximal
suppression" which involves tracking along the edges. I think that the
edge detection must be completed across the entire image before the
tracking begins, because the tracker should not be allowed to reach into
areas of the image for which edges have not been computed yet. I
suspect I should be using an UntiledOpImage instead for the following
1) AreaOpImage doesn't seem to give me the ability to perform a second
pass over the source once the first pass is complete.
2) Tracking is a recursive process that follows lines, so I cannot
implement mapDestRect(), because there is no prior knowledge about how
far the tracker will reach outside of the dest rect.
Is this reasoning in line with JAI's design? (note that I cannot
separate the two steps into different OpImages, because the second step
relies on computed artefacts from the first step)