Indeed. That was my first reaction too. But then why doesn't this work: oiiotool test.png --ch "R=R,B=R,G=R" -o out.png
oiiotool test.png --ch "R=R,B=R,G=R,A=1.0" -o out.png I figured it was user error. On Fri, Feb 8, 2019 at 2:39 PM Larry Gritz <[email protected]> wrote: > Doesn't the fact that everything interesting ends up in out-0.png tell us > that the alpha was black all along, and it was the red channel that you're > after? > > > On Feb 8, 2019, at 2:03 PM, Stephen Parker <[email protected]> > wrote: > > ... actually, disregard the -swap as -separate is all that's needed. > > convert test.png -separate out.png > > On Fri, Feb 8, 2019 at 1:51 PM Stephen Parker <[email protected]> > wrote: > >> Try: >> >> convert test.png -separate -swap 4,0 out.png >> >> You should get an image written out for each channel. "out-0.png" can be >> opened in Preview.app. >> >> -s >> >> >> On Fri, Feb 8, 2019 at 1:38 PM Larry Gritz <[email protected]> wrote: >> >>> On my mac, ImageMagick "convert test.png test.tif" also results in what >>> appears to be a black image. >>> >>> And using ImageMagick's "identify -verbose", I see these stats: >>> >>> Alpha: >>> min: 0 (0) >>> max: 0 (0) >>> mean: 0 (0) >>> standard deviation: 0 (0) >>> kurtosis: -3 >>> skewness: 0 >>> entropy: 0 >>> >>> Are you *sure* that the alpha channel isn't really 0 everywhere? >>> >>> >>> >>> On Feb 8, 2019, at 11:55 AM, Larry Gritz <[email protected]> wrote: >>> >>> Hmmm... it's not just "--ch", that image looks "black" (all 0.0 values) >>> in all channels to all OIIO tools. (For example, `oiiotool -stats >>> test.png`) I'm suspecting something in the reader rather than an issue with >>> channel selection. >>> >>> Looking into it. >>> >>> -- lg >>> >>> >>> On Feb 8, 2019, at 11:31 AM, Stephen Parker <[email protected]> >>> wrote: >>> >>> Hi Larry, >>> >>> I'm on the release branch. Here is the PNG in question (attached). >>> >>> thanks >>> >>> On Fri, Feb 8, 2019 at 11:12 AM Larry Gritz <[email protected]> wrote: >>> >>>> Which version of OIIO? >>>> And I don't suppose you can send me an example PNG that has the >>>> problem? Or is it weird for every png you try? >>>> >>>> >>>> >>>> On Feb 8, 2019, at 10:59 AM, Stephen Parker <[email protected]> >>>> wrote: >>>> >>>> Hello, >>>> >>>> I'm having some trouble using oiiotool's copy channel operator. It >>>> might be user error but I wanted to check and see if it's intended >>>> behavior. I've only glanced at the code so far. >>>> >>>> My test image is a PNG (4-channel RGBA), but only has information in >>>> the Alpha. When attempting to copy the Alpha into the other 3 channels and >>>> write out an RGB image (no Alpha), I get black. Imagemagick's 'convert' did >>>> what I expected. >>>> >>>> invoked as: >>>> >>>> oiiotool input.png --ch "R=A,G=A,B=A" -o output.png >>>> >>>> I also tried using the numeric channel labels to no avail. >>>> >>>> -sp >>>> _______________________________________________ >>>> Oiio-dev mailing list >>>> [email protected] >>>> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org >>>> >>>> >>>> -- >>>> Larry Gritz >>>> [email protected] >>>> >>>> >>>> >>>> >>>> _______________________________________________ >>>> Oiio-dev mailing list >>>> [email protected] >>>> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org >>>> >>> <test.png>_______________________________________________ >>> Oiio-dev mailing list >>> [email protected] >>> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org >>> >>> >>> -- >>> Larry Gritz >>> [email protected] >>> >>> >>> >>> >>> _______________________________________________ >>> Oiio-dev mailing list >>> [email protected] >>> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org >>> >>> >>> -- >>> Larry Gritz >>> [email protected] >>> >>> >>> >>> >>> _______________________________________________ >>> Oiio-dev mailing list >>> [email protected] >>> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org >>> >> _______________________________________________ > Oiio-dev mailing list > [email protected] > http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org > > > -- > Larry Gritz > [email protected] > > > > > _______________________________________________ > Oiio-dev mailing list > [email protected] > http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org >
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