Bug 689264

Summary:	Regression: differences in Testform.v1.0.2.pdf
Product:	Ghostscript	Reporter:	Marcos H. Woehrmann <marcos.woehrmann>
Component:	Regression	Assignee:	leonardo <leonardo>
Status:	NOTIFIED WONTFIX
Severity:	normal	Keywords:	bountiable
Priority:	P2
Version:	master
Hardware:	PC
OS:	Linux
Customer:		Word Size:	---
Bug Depends on:	690036
Bug Blocks:
Attachments:	r8016.png r8017.png Simplified.pdf Simplified.pdf Simplified.pdf

Description Marcos H. Woehrmann 2007-06-05 11:01:43 UTC

There is a slight but significant difference in Testform.v1.0.2.pdf at 72 dpi
with Ghostscript r8017 vs r8016.  Some of the yellow/black gradient boxes change
size such that they are now wider than the black boxes immediately below them.  

See the attached screenshots for a zoomed in demonstration of this.

The command line I used to generate the test files:

  bin/gs -sDEVICE=ppmraw -sOutputFile=test.ppm -r72 ./Testform.v1.0.2.pdf

Comment 1 Marcos H. Woehrmann 2007-06-05 11:02:05 UTC

Created attachment 3001 [details]
r8016.png

Comment 2 Marcos H. Woehrmann 2007-06-05 11:02:20 UTC

Created attachment 3002 [details]
r8017.png

Comment 3 leonardo 2007-12-02 11:20:55 UTC

Downgrade priority because (1) we think it's an unimportant raster difference, 
and (2) insufficient engineering resources for important bugs.

Comment 4 leonardo 2008-08-13 07:12:58 UTC

Setting P2 for regression bug.

Comment 5 leonardo 2008-08-21 06:40:40 UTC

The problem is not related to r8017. That revision occasionally madse it 
visible due to omitting a conversion of a clipping path to a path and then 
back to clipping path. While r8017, the new rendering appears worse than the 
old one.

The reason for the worse rendering is that we apply different filling rules 
when filling and clipping at small resolutions. I opened bug "Bug 690036  
clipping differ from Adobe" about that.

Comment 6 leonardo 2008-08-21 06:42:58 UTC

I will close this bug with wontfix because it's not a real regression of the 
algorithm due to Commant #5. The new general bug 690036 will store the 
continuation.

Comment 7 leonardo 2008-08-21 06:50:47 UTC

Created attachment 4305 [details]
Simplified.pdf

A simplified PDF that was used for analyzis. It is made from
Testform.v1.0.2.pdf with removin g unrelated objects with Acrobat, the with
unpacking streams and manual editing of one of them (a form stream).

Comment 8 leonardo 2008-08-21 06:50:50 UTC

Created attachment 4306 [details]
Simplified.pdf

A simplified PDF that was used for analyzis. It is made from
Testform.v1.0.2.pdf with removin g unrelated objects with Acrobat, the with
unpacking streams and manual editing of one of them (a form stream).

Comment 9 leonardo 2008-08-21 06:50:57 UTC

Created attachment 4307 [details]
Simplified.pdf

A simplified PDF that was used for analyzis. It is made from
Testform.v1.0.2.pdf with removing unrelated objects with Acrobat, the with
unpacking streams and manual editing of one of them (a form stream).