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False colors converting J2C -> XYZ-TIFF-12 -> RGB-BMP-8
Posted: 2010-05-10T12:51:14-07:00
by uvw
Hi all,
recently I installed ImageMagick 6.6.1-5 on a SUSE LINUX 11.2.
Executing
convert infile.tif -set colorspace XYZ -colorspace RGB -depth 8 outfile.bmp
results in inadequate colors of the output file. But executing the same command on a windows machine with the same version of ImageMagick or on another Linux Machine with version 6.5.6-8, both work perfectly fine.
Here's a link to a folder with two examples:
www.adca-content.de\downloads\samples.zip
I have no idea what causes this. Any help in solving this issue would be sincerly appreciated.
Re: False colors converting J2C -> XYZ-TIFF-12 -> RGB-BMP-8
Posted: 2010-05-10T14:13:33-07:00
by snibgo
www.adca-content.de\downloads\samples.zip: Host not found.
Re: False colors converting J2C -> XYZ-TIFF-12 -> RGB-BMP-8
Posted: 2010-05-10T14:25:52-07:00
by fmw42
snibgo wrote:http://www.adca-content.de\downloads\samples.zip: Host not found.
try
www.adca-content.de/downloads/samples.zip
Re: False colors converting J2C -> XYZ-TIFF-12 -> RGB-BMP-8
Posted: 2010-05-10T14:28:19-07:00
by fmw42
convert infile.tif -set colorspace XYZ -colorspace RGB -depth 8 outfile.bmp
\
What are you trying to do here? Seems to me to be wrongly stated? Are you trying to go from XYZ to RGB or RGB to XYZ.
If the former:
convert infile.tif -colorspace XYZ -depth 8 outfile.bmp
if the latter
convert infile.tif -colorspace RGB -depth 8 outfile.bmp
Perhaps I am misunderstanding your intentions here?
Re: False colors converting J2C -> XYZ-TIFF-12 -> RGB-BMP-8
Posted: 2010-05-11T11:11:54-07:00
by uvw
Hi all,
first of all, thank you for your prompt replies to my question here.
I did this:
Pictures extracted from a Digital Cinema Package were transcoded with
for file in $J2C_FRAMES
do
NewFile=${file: -16)
NewFile=${NewFile:0:12}
j2k_to_image -i $file -o ./dcp_workspace/tiff/$NewFile.tif
done
expecting the result to be a XYZ TIFF with a bit depth of 12.
Next step was converting these files using
convert anyinfile.tif -set colorspace XYZ -colorspace RGB -depth 8 anyoutfile.bmp
expecting the result to be a RGB BMP with a bit depth of 8.
And that it was, but there were color deviations which i figured were caused through changing the bit depth in ImageMagick.
This assumption was wrong. The colors were already messed up in the first step, while transcoding from j2c to tif.
The reason for this was, that an older version of openjpeg, not capable of exporting tif file format, was installed on the machine.
Strangely it wrote tif files without reporting any errors. But the bit depth of these files was inappropriately changed to 8 bits,
leaving nothing to do for the correct bit depth change with ImageMagick.
Sorry guys, looks like I've stressed your brains in vain. I should have looked more closely right at the beginning.
Maybe it's because I'd rather be in sunny California.
Thanks again, uwe.