[gs-bugs] [Bug 698721] - Ghostscript - Smooth Shade CMYK: Text missing, anti-aliasing not working

[b***@artifex.com]

http://bugs.ghostscript.com/show_bug.cgi?id=698721

Bug ID: 698721
Summary: Smooth Shade CMYK: Text missing, anti-aliasing not
working
Product: Ghostscript
Version: 9.22
Hardware: PC
OS: All
Status: UNCONFIRMED
Severity: major
Priority: P4
Component: PDF Interpreter
Assignee: ***@artifex.com
Reporter: ***@uwittberg.net
QA Contact: gs-***@ghostscript.com
Word Size: ---

Created attachment 14433
--> http://bugs.ghostscript.com/attachment.cgi?id=14433&action=edit
examples for smooth shading problems

Dear Gostscript team,

I'm not sure where to file my report, so I've put it here in the general PDF
Interpreter section.

What happens:
Fonts and graphics using a CMYK Smooth Shading Pattern will not render at all
(completely missing) in a CMYK TIFF (DEVICE=tiff32nc) or edges won't get
anti-aliased.
If I simply recolor the font (using PitStop Pro) with a simple CMYK color (100%
Magenta) the problems are gone: everything shows up as expected and has smooth
edges.
Comparisons using callas pdfToolbox and poppler-utils pdftoppm/pdftocairo
render the shaded elements into a TIFF without any problems.

The PDF files and screenshots of the results are attached.

Would be great if you could look inti this.

Thanks and regards,
Ulf

[b***@artifex.com]

http://bugs.ghostscript.com/show_bug.cgi?id=698721

--- Comment #1 from Ulf Wittenberg <***@uwittberg.net> ---
Forgot my command line:
gs -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dUseMediaBox -dAlignToPixels=1
-dGridFitTT=2 -dTextAlphaBits=4 -dGraphicsAlphaBits=4 -dSimulateOverprint=true
-sICCProfilesDir="/usr/local/share/ghostscript/9.22/iccprofiles/"
-dUsePDFX3Profile -dRenderIntent=1 -dBlackPtComp=1
-sNamedProfile="/Volumes/AGB_Export/Ulf/GhostScript_ImageMagick_PDF2JPEG/PANTONEplus_Solid_CU__HKSkn_GS.txt"
-sDEVICE=tiff32nc -r200
-sOutputFile="/Volumes/AGB_Export/Ulf/GhostScript_ImageMagick_PDF2JPEG/GS922_OSX_CMYK_OI_PANTONEplusSolidCUHKSkn_VSFP_Problem_Anmeldekarte_noICC_%03d.tif"
"/Volumes/AGB_Export/Ulf/GhostScript_ImageMagick_PDF2JPEG/VBTDS-17433-Anmeldekarte-NewsletterPrivilegeClub20017-210x105-FR_6_noICC.pdf"

The described problem first occured on a Debian system, I did my testing on a
Mac, macOS 10.11.6.

[b***@artifex.com]

http://bugs.ghostscript.com/show_bug.cgi?id=698721

Ken Sharp <***@artifex.com> changed:

What |Removed |Added
----------------------------------------------------------------------------
QA Contact|gs-***@ghostscript.com |
Severity|major |normal
Component|PDF Interpreter |Transparency
Assignee|***@artifex.com |***@artifex.com

--- Comment #2 from Ken Sharp <***@artifex.com> ---
(In reply to Ulf Wittenberg from comment #0)

Post by b***@artifex.com
Dear Gostscript team,
I'm not sure where to file my report, so I've put it here in the general PDF
Interpreter section.

If you find a bug, here's the place to put it. Don't worry too much about the
component we can always change it. Don't bother to set the Importance either,
because we set that too.

Post by b***@artifex.com
Fonts and graphics using a CMYK Smooth Shading Pattern will not render at
all (completely missing) in a CMYK TIFF (DEVICE=tiff32nc) or edges won't get
anti-aliased.

You haven't supplied an example command line. Without that I cannot reproduce
what you are doing. OK forget htat you did add it later.

For what its worth I do see a problem with one file
"VBTDS-17433-Anmeldekarte-NewsletterPrivilegeClub20017-210x105-FR_6_noICC.pdf"
where some text is missing on page 1. I don't see any other problems.

Post by b***@artifex.com
The PDF files and screenshots of the results are attached.

In general we don't need screenshots or output. We'll ask if we can't see what
you're describing.

Though we much prefer simple files to complex ones.....