Hi Larry, that's awesome. I still didn't have the chance to test this. Thank you. I will tey to ger to it tomorrow.
Cheers, Sebastian On Monday, March 30, 2015, Larry Gritz <[email protected]> wrote: > As a follow-up, I have implemented the -trim (explicit trim in place) that > I mentioned on this thread would have been convenient. > > https://github.com/OpenImageIO/oiio/pull/1105 > > > On Mar 26, 2015, at 10:13 AM, Larry Gritz <[email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');>> wrote: > > How about this (presuming it's a 4 channel RGBA): > > oiiotool in.exr -dup -mulc 10000 -clamp:min=0:max=1 -ch R=A,G=A,B=A,A -mul > -autorim -o out.exr > > This reads in.exr, duplicates it on the stack, multiplies pixel values > 10000 then clamps to [0,1] (that has the effect of turning all nonzero > alpha into 1.0), replicates the thresholded alpha value into all 4 > channels, multiplies that mask by the original image (still below it on the > stack!) -- now we've squashed all color to 0 in pixels that were original > alpha 0 -- and finally write it out with autotrim! > > I haven't tested this, so take with a grain of salt that I've spelled > everything correctly and whatnot. But I think the overall methodology is > sound. > > If you are using master (so you have expression substitution), another > clever trick might be: > > oiiotool in.exr --ch A -autotrim -o alphatrim.exr > oiiotool alphatrim.exr in.exr -crop {IMG[1].geom} -o out.exr > > This extracts just the alpha channel and saves to a temporary file with > auto-trimming. Then it uses the size of the saved auto-trimmed alpha to > explicitly crop the original. I would prefer to do it in one step, but it > looks like --autotrim only works upon the saved output of "-o", and I > neglected to implement a --trim (trim the outer black "in place" so you can > then use the trimmed image). > > > > On Mar 25, 2015, at 10:42 PM, Jason Iversen <[email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');>> wrote: > > Perhaps you can premultiply (--premult) before autotrimming? > > On Wed, Mar 25, 2015 at 8:48 PM, Sebastian Kral <[email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');>> wrote: > >> Hi, >> >> I was wondering if it's possible to create a DataWindow in an EXR with >> the --autotrim flag which is based purely on the Alpha instead of black >> pixels. >> We have some rather large mattepaintings which I am trying to trim but >> since the background isn't black the autotrim doesn't seem to work. >> >> Perhaps I am missing something and someone can help me out. >> >> The command I am running: >> oiiotool in.exr --scanline --compress zips --autotrim -o out.exr >> >> Thank you. >> >> Cheers, >> Sebastian >> >> _______________________________________________ >> Oiio-dev mailing list >> [email protected] >> <javascript:_e(%7B%7D,'cvml','[email protected]');> >> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org >> >> > > > -- > jason iversen > http://www.odforce.net > _______________________________________________ > Oiio-dev mailing list > [email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');> > http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org > > > -- > Larry Gritz > [email protected] <javascript:_e(%7B%7D,'cvml','[email protected]');> > > > > _______________________________________________ > Oiio-dev mailing list > [email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');> > http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org > > > -- > Larry Gritz > [email protected] <javascript:_e(%7B%7D,'cvml','[email protected]');> > > > > -- Sent from mobile device
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