Bug 689494

Summary: Differences in tiffsep and tiff32nc
Product: Ghostscript Reporter: Marcos H. Woehrmann <marcos.woehrmann>
Component: Graphics LibraryAssignee: Ray Johnston <ray.johnston>
Status: NOTIFIED FIXED    
Severity: normal    
Priority: P4    
Version: 8.60   
Hardware: Macintosh   
OS: MacOS X   
Customer: 190 Word Size: ---
Attachments: screenshot.png
Simple_Rect_Trans.pdf
Cyan.tif
Yellow.tif

Description Marcos H. Woehrmann 2007-10-03 10:43:51 UTC 
The customer reports and I've verified that there are significant differences in the output of Ghostscript 
8.60 using the tiffsep and tiff32nc devices (see screenshot.png, attached); gshead (r8268) behaves the 
same way.  Note that 32nc.tiff and sep.tiff are both CMYK files, so there shouldn't be any question of 
CMYK -> RGB conversion causing the difference.

The command lines I used for testing:

  bin/gs -sDEVICE=tiff32nc -sOutputFile=32nc.tiff ./Simple_Rect_Trans.pdf
  bin/gs -sDEVICE=tiffsep -sOutputFile=sep.tiff ./Simple_Rect_Trans.pdf
Comment 1 Marcos H. Woehrmann 2007-10-03 10:48:20 UTC 
Created attachment 3434 [details]
screenshot.png
Comment 2 Marcos H. Woehrmann 2007-10-03 10:49:03 UTC 
Created attachment 3435 [details]
Simple_Rect_Trans.pdf
Comment 3 Ray Johnston 2007-10-03 13:28:57 UTC 
The Cyan and Yellow separations show the problem. It looks like the opacity
of 0.5 is being ignored and the original C=0.7 Y=0.2 is being used.

This is lower-right rectangle is written by:
%Resolving: [11 0]
<<
/OPM 1 /BM /Normal /CA 0.5 /OP false
/SMask /None /ca 0.5 /AIS false
/op false
/Type /ExtGState /SA true
>>
endobj
/Fm0 Do
%Resolving: [10 0]
%Resolving: [8 0]
<<
/I false
/K false
/S /Transparency /Type /Group >>
endobj
0.7 0 0.2 0 k
0 i
/RelativeColorimetric ri
/GS0 gs
%Resolving: [9 0]
462.197 256.749 -294.366 319.718 re
f
Comment 4 Ray Johnston 2007-10-03 13:30:12 UTC 
Created attachment 3436 [details]
Cyan.tif

Cyan separation
Comment 5 Ray Johnston 2007-10-03 13:31:02 UTC 
Created attachment 3437 [details]
Yellow.tif

Yellow Separation
Comment 6 Ray Johnston 2007-10-11 09:37:58 UTC 
This was caused by inverted blending logic in pdf14_cmykspot_put_image.

Fixed by rev 8287 (but the fixes for 689493 are needed as well for testing).
Those fixes will be committed next.