Bug 689252 - Regression: differences in 478-01.ps
Summary: Regression: differences in 478-01.ps
Status: RESOLVED FIXED
Alias: None
Product: Ghostscript
Classification: Unclassified
Component: Regression (show other bugs)
Version: master
Hardware: PC Linux
: P1 normal
Assignee: Ray Johnston
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2007-05-28 09:11 UTC by Marcos H. Woehrmann
Modified: 2013-06-26 19:40 UTC (History)
1 user (show)

See Also:
Customer:
Word Size: ---


Attachments
screenshot.png (58.57 KB, image/png)
2007-05-28 09:11 UTC, Marcos H. Woehrmann
Details
478-01_from_CPSI_600_dpi.pdf (1.46 MB, application/pdf)
2007-05-28 15:13 UTC, Ray Johnston
Details
478-01_gs8015_600dpi.png (553.06 KB, image/png)
2007-05-28 15:39 UTC, Ray Johnston
Details
screen.png (194.11 KB, image/png)
2007-05-29 18:59 UTC, Marcos H. Woehrmann
Details

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Description Marcos H. Woehrmann 2007-05-28 09:11:08 UTC
The file 478-01.ps has shows a difference in the first test between baseline and
head (shown with r8013, but the difference started with r8003).

The shading varies with resolution, the attached screen shot is a reduced 300
dpi example.

The command line used:

  bin/gs -sDEVICE=ppmraw -sOutputFile=test.ppm -r300 ./478-01.ps
Comment 1 Marcos H. Woehrmann 2007-05-28 09:11:32 UTC
Created attachment 2982 [details]
screenshot.png
Comment 2 Ray Johnston 2007-05-28 15:13:13 UTC
Created attachment 2983 [details]
478-01_from_CPSI_600_dpi.pdf
Comment 3 Ray Johnston 2007-05-28 15:39:57 UTC
Created attachment 2984 [details]
478-01_gs8015_600dpi.png
Comment 4 Ray Johnston 2007-05-28 15:59:44 UTC
Our customer that gets frequent snapshots of our code also runs the FTS
and CET which includes this file.

Bumping priority to correspond to important customer level.

I do not see a minor color variation here compared to older (8.57) GS,
but the "blue" is entirely missing from the center of the rightmost shaded
rectangle in the 478-01 panel ("setsmoothness").
Comment 5 leonardo 2007-05-28 16:27:09 UTC
Please read the log message of the revision 8003. The rendering difference is 
expected. "1 setsmoothness" means that the document allows a 100% error in 
shading colors. What you observe is a 100% error. Therefore the bug invalid. If 
a customer needs a special compatibility to another PS interpreter, they should 
pay for a an instandard feature. Returning the bug to Support.
Comment 6 Marcos H. Woehrmann 2007-05-29 18:59:15 UTC
Created attachment 2987 [details]
screen.png

If I modify the 478-01.ps file and change the "1 setsmoothness" to "0.5
setsmoothness" strange things happen (see attached screen.png).

The command line I used:

  bin/gs -sDEVICE=ppmraw -sOutputFile=test.ppm -r300 ./478-01.ps
Comment 7 leonardo 2007-06-20 12:43:39 UTC
The particular reason for a bad view with "0.5 setsmoothness" is 
gx_cspace_is_linear_in_line, which checks the lineariry at 2 points only : 0.3 
and 0.7 . One can implement checking more points, with the proportional slow 
down of the rendering, especially with complex color spaces. However I don't 
think that we want the slowdown. 

Anyway I'm not clear why should I spend time for this nonsense. I guess the 
customer didn't request "0.5 setsmoothness". I think it comes from 
an "academicity" of our Support. Any values less than 1/8 have no practical 
demand. Well I can code "if (smoothness > 0.125) { check linearity at 0.5} in 
gx_cspace_is_linear_in_line. Or even if (smoothness < 0.125) smoothness = 0.125;

I will change the assignment to Ray for a further resolution. 
Comment 8 leonardo 2007-06-20 12:47:27 UTC
Another possible resolution for this - it's a dup of Bug 687414.
Comment 9 Ray Johnston 2008-01-23 11:56:54 UTC
Regression, but customer can run with limiting setsmoothness to small values.
Comment 10 Ray Johnston 2012-09-09 17:40:02 UTC
Change to ASSIGNED. I will re-test.
Comment 11 Ray Johnston 2013-06-26 19:40:20 UTC
Tested with HEAD and this looks OK (matching Adobe).