On 2020-07-04 23:19 -0400, Andriy Gelman wrote: > On Sun, 05. Jul 09:37, lance.lmw...@gmail.com wrote: > > On Sat, Jul 04, 2020 at 01:03:48PM -0400, Andriy Gelman wrote: > > > On Mon, 29. Jun 09:26, Valery Kot wrote: > > > > On Sun, Jun 28, 2020 at 12:03 AM Andriy Gelman > > > > <andriy.gel...@gmail.com> wrote: > > > > > > > > > > lgtm. I saw a small improvement when testing. > > > > > > > > > > Would be nice to allow weak edges that become strong to trigger > > > > > neighboring weak > > > > > edges in the future. > > > > > > > > Thanks for the comment. > > > > > > > > You are right, ideally double_threshold should be recursive (seed from > > > > each "high" peak and spread over "low" peaks). But then potentially we > > > > may end up with width*height/2 recursion depth, which may lead to > > > > stack overflow. So probably some recursion limit is needed, and hence > > > > suboptimal solution. > > > > > > > > Or iterative approach, running through the complete image again and > > > > again checking if "low" peaks are touching already selected edge > > > > pixels. Stop when no new pixels can be added to the edge. Better, but > > > > still potentially width*height/2 iterations with width*height > > > > operations each, completely killing performance. > > > > > > > > Maybe later I'll try to implement it in a generic way, but this is out > > > > of scope for this patch. > > > > > > > > Regards, > > > > > > > > Valery Kot > > > > > > Any objections if I apply this patch? > > > > > The patch look fine to me, but no sign-off? > > > > Thanks, will add one.
I guess it's OK to push. In my few tests for some cases it looked a bit better. I didn't understand why this doesn't make things worse for the outermost frame of pixels, but Valery commented it wouldn't make any difference because of the surrounding code. I just looked at that function and because it checks all the eight surrounding pixels, I thought we might now miss cases that wouldn't have been missed before. Should of course be usually be better for most pictures. Anyway I couldn't get around to build a mental model for this call, so I might well be missing context. Alexander _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
