The Persistence of Vision Raytracer (POV-Ray).
This is the legacy Bug Tracking System for the POV-Ray project. Bugs listed here are being migrated to our github issue tracker. Please refer to that for new reports or updates to existing ones on this system.
FS#57 - Compressed TIFF image_map renders all transparent
Opened by Christoph Lipka (clipka) - Wednesday, 09 September 2009, 20:29 GMT
Last edited by Christoph Lipka (clipka) - Friday, 26 March 2010, 16:48 GMT
The attached TIFF file was created with IC using compression. When used in an image_map, POV-Ray 3.7.0.beta.34 on Windows XP x64 renders the image all transparent, while POV-Ray 3.6.2 renders the file fine. The same effect can be seen with LZW-compressed TIFF files created with Adobe Photoshop 6.0.
Uncompressed TIFF files created with either IC or Photoshop render fine in both versions of POV-Ray.
Stepping through the code of POV-Ray 3.7.0 shows that the same code path is taken regardless of compression, but the libtiff library returns different alpha channel values, indicating a problem in that library. POV-Ray 3.7 still uses libtiff 3.6.1, whereas the POV-Ray 3.6 branch has been updated to libtiff 3.8.2, which according to the change history includes a few alpha-related changes.
Friday, 26 March 2010, 16:48 GMT
Reason for closing: Fixed
Additional comments about closing: No feedback from beta testers for months, so probably "no news is good news"