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Is "-colorspace" usage changed again in IM 6.7.6-5 Q16?
Posted: 2012-04-09T08:10:09-07:00
by henrywho
Okay -> convert test.jpg -distort Resize 25% -quality 95% test_out1.jpg
Okay -> convert test.jpg -gamma 0.4545454545454545 -distort Resize 25% -gamma 2.2 -quality 95% test_out2.jpg
Too dark -> convert test.jpg -colorspace RGB -distort Resize 25% -colorspace sRGB -quality 95% test_out3.jpg
.... tested using Win32 Portable and Win64 DLL versions.
Re: Is "-colorspace" usage changed again in IM 6.7.6-5 Q16?
Posted: 2012-04-09T11:53:58-07:00
by fmw42
RGB and sRGB were swapped as far as I know only at IM 6.7.5.5
But I will defer to the IM developers in case it accidentally got switched back.
Re: Is "-colorspace" usage changed again in IM 6.7.6-5 Q16?
Posted: 2012-04-09T15:49:32-07:00
by henrywho
Also too dark -> convert test.jpg -colorspace sRGB -distort Resize 25% -colorspace RGB -quality 95% test_out4.jpg
Re: Is "-colorspace" usage changed again in IM 6.7.6-5 Q16?
Posted: 2012-04-10T20:32:00-07:00
by anthony
henrywho wrote:Also too dark -> convert test.jpg -colorspace sRGB -distort Resize 25% -colorspace RGB -quality 95% test_out4.jpg
With the current IM, This devolves into the operations...
Code: Select all
convert {input} -distort Resize 25% -colorspace RGB {result}
In other words you resize in sRGB and saved after converting from sRGB to RGB. Whcih would be too dark.
the right way to do colorspace corrected resize is now...
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convert {input} -colorspace RGB -distort Resize 25% -colorspace sRGB {result}
The gamma correctly resize has not changed.
See the updated IM Examples, Reszie with corrections
http://www.imagemagick.org/Usage/resize ... colorspace
Re: Is "-colorspace" usage changed again in IM 6.7.6-5 Q16?
Posted: 2012-04-11T01:49:00-07:00
by henrywho
That's case (3) in my first post, where I got a dark image.
Actually, I suspect that it is a bug in the (various) Windows build of 6.7.6-5 Q16.