View Issue Details

IDProjectCategoryView StatusLast Update
0011483ScribusColor Managementpublic2013-10-30 21:39
Reportertroy_s Assigned Tojghali  
PrioritynormalSeveritymajorReproducibilityalways
Status closedResolutionfixed 
PlatformLinux amd64OSUbuntuOS Version12.10
Fixed in Version1.5.0svn 
Summary0011483: Achromatic images convert non-uniformly with colored images in PDF CMYK export
DescriptionScribus version: 1.5.0svn

In laying out multiple spreads of images, any image with achromatic (uniform greyscale) values will be converted differently than the same images that have color (non uniform values), despite being RGB and flagged as sRGB.

This is different behaviour than 1.4.x lineage.
Steps To Reproduce1) Insert an achromatic sRGB image.
2) Insert an sRGB image with non-uniform channels, such as the sample image with a spot of red or other color in it.
3) Export to PDF.

Resultant images appear to us different conversion approaches, with the achromatic image using only K channel.
Additional InformationTested against the PPA version of Scribus at https://launchpad.net/~scribus/+archive/ppa.

CMYK printer export profile was US Web Coated (SWOP v2).

Tested on identical images, with the second image having a stroke of red applied.
TagsNo tags attached.
Patch

Activities

troy_s

2013-04-05 17:44

reporter   ~0030035

It happens every time on an SVG import with files that I sadly cannot share currently.

File format of original image is TIFF. Trying to generate a sample using non-restricted images.

troy_s

2013-04-05 18:02

reporter  

sample-chromatic.pdf (372,097 bytes)

troy_s

2013-04-05 18:02

reporter  

sample-chromatic.sla (696,900 bytes)

troy_s

2013-04-05 18:03

reporter   ~0030036

See samples attached. Managed to coax the behaviour using non-restricted image portions.

jghali

2013-04-05 20:18

administrator   ~0030040

The issue is limited to images imported through Qt. It does not happen with jpeg, tiff and psd files. This issue is now fixed...

Why are you embedding images in svg files? There is no interest in doing so. Just import the TIFF directly. If the purpose is embedding image into sla, well that's usually not recommended as embedding image into sla is not scalable.

gez

2013-04-05 22:55

reporter   ~0030041

Since scribus doesn't support SVG filters and has troubles importing clipped and masked objects as well, inkscape's "bitmap copy" command comes handy to rasterize those unsupported features.
It creates a raster copy of the selected objects using a custom resolution, and the result is embedded in the SVG file.
Doing that to "prepare" inkscape documents for scribus is very useful, and extracting the bitmap to an external file and link would be yet another extra step to get the file open in Scribus. There are many things to take care of when doing so (setting viewbox manually or scaling down to solve the 90 vs. 72 dpi problem, convert type to curves to avoid kerning changes, taking care of filtered/masked images, etc), so adding an extra step is not a desirable situation.

BTW, What do you mean with embedded images are not scalable?

jghali

2013-04-05 23:19

administrator   ~0030042

>> What do you mean with embedded images are not scalable?

If you use lots of images, you have a higher risk of running out of memory with embedded images than when using image links. If you reach that point your document will become unusable. When using image links, there is always a fallback strategy.

Also performance will be worse than when using image links as Scribus has to write embedded image to temporary files, which is unnecessary when using image links.

troy_s

2013-04-07 04:43

reporter   ~0030047

"If you use lots of images, you have a higher risk of running out of memory with embedded images than when using image links. If you reach that point your document will become unusable."

Except that Scribus will randomly delete images from your drive.

Excellent feature. So that said, I'd suggest that having Scribus randomly delete an image from your drive is likely more unusable.

jghali

2013-04-07 08:10

administrator   ~0030048

Last edited: 2013-04-07 08:36

>> Except that Scribus will randomly delete images from your drive.

This issue specific to 1.5.0svn was fixed a few days ago. These are the risks of using development versions...

christoph_s

2013-07-06 06:18

administrator   ~0030411

troy_s: Could you test and confirm that this has been fixed, please?

Issue History

Date Modified Username Field Change
2013-04-05 16:59 troy_s New Issue
2013-04-05 17:44 troy_s Note Added: 0030035
2013-04-05 18:02 troy_s File Added: sample-chromatic.pdf
2013-04-05 18:02 troy_s File Added: sample-chromatic.sla
2013-04-05 18:03 troy_s Note Added: 0030036
2013-04-05 19:03 jghali Summary COLOR MANAGEMENT: Achromatic images convert non-uniformly with colored images in PDF CMYK export => Achromatic images convert non-uniformly with colored images in PDF CMYK export
2013-04-05 20:18 jghali Note Added: 0030040
2013-04-05 20:18 jghali Status new => resolved
2013-04-05 20:18 jghali Fixed in Version => 1.5.0svn
2013-04-05 20:18 jghali Resolution open => fixed
2013-04-05 20:18 jghali Assigned To => jghali
2013-04-05 22:55 gez Note Added: 0030041
2013-04-05 23:19 jghali Note Added: 0030042
2013-04-07 04:43 troy_s Note Added: 0030047
2013-04-07 08:10 jghali Note Added: 0030048
2013-04-07 08:36 jghali Note Edited: 0030048
2013-07-06 06:18 christoph_s Note Added: 0030411
2013-10-30 21:39 cbradney Status resolved => closed