2007.10.05 14:39 "[Tiff] Color issues in Tiff2pdf", by Richard Nolde

2007.10.05 16:46 "Re: [Tiff] Color issues in Tiff2pdf", by Frank Warmerdam

Regarding color issues with tiff2pdf, the following may or may not be related but it is a bug that could be patched. The line numbers are appropriate for the tiff-3.8.2 version of tiff2pdf.c. In personal correspondence with the author of the software, Ross Finlayson, he agreed that the assignment for the alpha channel info is incorrect.

extract from note to Ross:

"I think there is a typo at line 1486 in the current distribution where it appears that the alpha channel overwrites the blue channel in RGBA images.

Should the final line have (i * 4) + 3 instead of (i * 4 ) + 2?

           t2p->pdf_palette[(i*4)] = (unsigned char) (r[i]>>8);
           t2p->pdf_palette[(i*4)+1]= (unsigned char) (g[i]>>8);
           t2p->pdf_palette[(i*4)+2]= (unsigned char) (b[i]>>8);
           t2p->pdf_palette[(i*4)+2]= (unsigned char) (a[i]>>8);


I have committed this fix in "CVS head" and the 3.9 branch.

It is best to report bugs via the Bugzilla so that they don't get lost. Reporting them via the list risks having them fall through the cracks, or using several developers time pursuing them since we don't know the others are working on it. (well - more likely just that no one acts on it!)

Best regards,

I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam@pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam

and watch the world go round - Rush    | President OSGeo, http://osgeo.org