Bug 691183

Summary:	Regression: another problem with -dDOINTERPOLATE
Product:	Ghostscript	Reporter:	Marcos H. Woehrmann <marcos.woehrmann>
Component:	Graphics Library	Assignee:	Michael Vrhel <michael.vrhel>
Status:	RESOLVED INVALID
Severity:	normal	CC:	christinedelight.top85
Priority:	P1
Version:	master
Hardware:	PC
OS:	Linux
Customer:		Word Size:	---
Attachments:	screenshot.png

Description Marcos H. Woehrmann 2010-03-17 17:26:49 UTC

Created attachment 6074 [details]
vtm2k.pdf

This problem may be the same as Bug 691182 but the symptoms are different enough that it likely is a different issue.

The attached file renders incorrectly when converted by Ghostscript head (r10928) and -dDOINTERPOLATE is specified on the command line.  This behaviour is a regression, r7646 renders the file correctly, however later revisions are different yet again:

r7646 - correct
r7647 - wrong
r8515 - wrong in a different way
r8664 - wrong in another different way

See the attached screenshot.png for output from these revisions.

The command line I'm using:

  bin/gs -sDEVICE=ppmraw -o test.ppm -dDOINTERPOLATE ./vtm2k.pdf

Comment 1 Marcos H. Woehrmann 2010-03-17 17:27:17 UTC

Created attachment 6075 [details]
screenshot.png

Comment 2 Ray Johnston 2010-03-18 16:54:09 UTC

Also assigning to Michael. Note that rev 7647 is the one that effectively enables -dDOINTERPOLATE for PDF files. Before that it was ignored, so the problem was probably there before.

Comment 3 Michael Vrhel 2011-08-15 03:12:13 UTC

One of the unique things about this file is that the source image is in the CIELAB color space.  Likely there is a decoding issue.

Comment 4 Michael Vrhel 2011-08-17 21:16:40 UTC

I don't believe this is incorrect with head.  The source file is a tiny image (like 3x5) and doing our interpolation method on this is going to give an odd looking result.  My belief is that r7646 was not doing the interpolation.