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
Created attachment 6075 [details] screenshot.png
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.
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.
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.