Ghostscript tiffsep creates CMYK image that is inverted in ImageMagick display? (repost)
Posted: 2017-04-10T04:53:34-07:00
Just posted this: http://stackoverflow.com/questions/4332 ... ck-display, thought it might be a good idea to repost here, as this could be a bug with `display`:
Not sure what to make of this - but let's say we work with this PDF file: https://stlab.adobe.com/wiki/index.php/File:Test.pdf, and I want to obtain separations using Ghostscript's `tiffsep` device:
This generates five files: `testseps(Black).tif`, `testseps(Cyan).tif`, `testseps(Magenta).tif`, `testseps.tif`, `testseps(Yellow).tif`. I open the full-color output (`testseps.tif`) in both Eye of Gnome (`eog`), and ImageMagick's `display`, and this is what I get (Ubuntu 14.04, MATE desktop, ghostscript 9.10, ImageMagick 6.7.7-10 2017-03-14 Q16):
Namely, ImageMagick's `display` (left) shows this file with inverted colors, while Eye of Gnome (right) shows the very same file correctly?!
So how can I get this CMYK tiff to show correctly in both `display` and Eye of Gnome? Can I somehow convert it with ImageMagick's `convert`, and what would the command line be? I've already tried something like:
... and that file again shows the same problem.
EDIT: Also, if I try to combine the individual separations using `convert`:
... then `combined.tif` shows properly in ImageMagick `display` - but is shown as completely black in Eye of Gnome! If I add the `-negate` switch after `-combine`, then I'm back to the previous state (`display` shows inverted, `eog` shows correct)
EDIT2: Tried to use a service http://www.rgb2cmyk.org/, to obtain a CMYK tif of the RGB screenshot posted here, and that one also shows the same bug: it is inverted in `display`, and shown correctly in Eye of Gnome.
Just for reference, here is a bit of info about `testseps.tif`:
Not sure what to make of this - but let's say we work with this PDF file: https://stlab.adobe.com/wiki/index.php/File:Test.pdf, and I want to obtain separations using Ghostscript's `tiffsep` device:
Code: Select all
cd /tmp
wget https://stlab.adobe.com/wiki/images/d/d3/Test.pdf
ghostscript -q -sDEVICE=tiffsep -dNOPAUSE -dBATCH -dSAFER -r72x72 -sOutputFile=testseps.tif -dFirstPage=1 -dLastPage=1 Test.pdf
eog testseps.tif & display testseps.tifNamely, ImageMagick's `display` (left) shows this file with inverted colors, while Eye of Gnome (right) shows the very same file correctly?!
So how can I get this CMYK tiff to show correctly in both `display` and Eye of Gnome? Can I somehow convert it with ImageMagick's `convert`, and what would the command line be? I've already tried something like:
Code: Select all
convert testseps.tif -colorspace CMYK -alpha off -define quantum:polarity=min-is-white -colorspace CMYK testseps2.tifEDIT: Also, if I try to combine the individual separations using `convert`:
Code: Select all
convert \
testseps\(Cyan\).tif \
testseps\(Magenta\).tif \
testseps\(Yellow\).tif \
testseps\(Black\).tif \
-set colorspace CMYK \
-profile /usr/share/ghostscript/9.10/iccprofiles/default_cmyk.icc
-combine
combined.tifEDIT2: Tried to use a service http://www.rgb2cmyk.org/, to obtain a CMYK tif of the RGB screenshot posted here, and that one also shows the same bug: it is inverted in `display`, and shown correctly in Eye of Gnome.
Just for reference, here is a bit of info about `testseps.tif`:
Code: Select all
$ tiffinfo testseps.tif
TIFF Directory at offset 0x8 (8)
Subfile Type: multi-page document (2 = 0x2)
Image Width: 612 Image Length: 792
Resolution: 72, 72 pixels/inch
Bits/Sample: 8
Compression Scheme: LZW
Photometric Interpretation: separated
FillOrder: msb-to-lsb
Orientation: row 0 top, col 0 lhs
Samples/Pixel: 4
Rows/Strip: 428
Planar Configuration: single image plane
Page Number: 0-0
Software: GPL Ghostscript 9.10
DateTime: 2017:04:10 12:53:45
ICC Profile: <present>, 56412 bytes
$ identify -verbose testseps.tif
Image: testseps.tif
Format: TIFF (Tagged Image File Format)
Class: DirectClass
Geometry: 612x792+0+0
Resolution: 72x72
Print size: 8.5x11
Units: PixelsPerInch
Type: ColorSeparation
Endianess: MSB
Colorspace: CMYK
Depth: 8-bit
Channel depth:
cyan: 8-bit
magenta: 8-bit
yellow: 8-bit
black: 8-bit
Channel statistics:
Cyan:
min: 0 (0)
max: 235 (0.921569)
mean: 5.93515 (0.0232751)
standard deviation: 33.3466 (0.130771)
kurtosis: 28.8423
skewness: 5.53334
Magenta:
min: 0 (0)
max: 245 (0.960784)
mean: 2.7823 (0.010911)
standard deviation: 18.73 (0.0734511)
kurtosis: 68.8725
skewness: 8.12072
Yellow:
min: 0 (0)
max: 255 (1)
mean: 5.04176 (0.0197716)
standard deviation: 30.8529 (0.120992)
kurtosis: 34.9211
skewness: 6.05297
Black:
min: 0 (0)
max: 226 (0.886275)
mean: 1.06569 (0.00417917)
standard deviation: 13.7509 (0.0539252)
kurtosis: 227.454
skewness: 15.0002
Image statistics:
Overall:
min: 0 (0)
max: 255 (1)
mean: 3.70622 (0.0145342)
standard deviation: 25.5137 (0.100054)
kurtosis: 51.8946
skewness: 7.28691
Total ink density: 298%
Rendering intent: Undefined
Gamma: 1
Interlace: None
Background color: cmyk(255,255,255,0)
Border color: cmyk(223,223,223,0)
Matte color: cmyk(189,189,189,0)
Transparent color: cmyk(0,0,0,0)
Compose: Over
Page geometry: 612x792+0+0
Dispose: Undefined
Iterations: 0
Compression: LZW
Orientation: TopLeft
Properties:
date:create: 2017-04-10T12:53:45+02:00
date:modify: 2017-04-10T12:53:45+02:00
signature: 1ad1532f697fa72492fe994d79f1b67d617a34cd927f31b41e6a12214b9bc49e
tiff:endian: lsb
tiff:photometric: separated
tiff:rows-per-strip: 428
tiff:software: GPL Ghostscript 9.10
tiff:timestamp: 2017:04:10 12:53:45
Profiles:
Profile-icc: 187484 bytes
Description: Artifex CMYK SWOP Profile
Manufacturer: Artifex CMYK SWOP Profile
Model: Artifex CMYK SWOP Profile
Copyright: Copyright Artifex Software 2011
Artifacts:
filename: testseps.tif
verbose: true
Tainted: True
Filesize: 220KB
Number pixels: 485K
Pixels per second: 24.24MB
User time: 0.020u
Elapsed time: 0:01.019
Version: ImageMagick 6.7.7-10 2017-03-14 Q16 http://www.imagemagick.org