... 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 >> >
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