https://bugs.documentfoundation.org/show_bug.cgi?id=150777
--- Comment #6 from Tomaz Vajngerl <[email protected]> --- This issue is "by design" - at least partially. I'm not sure it can be addressed in the short term at least. The new libpng based PNG reader doesn't read to a 1-bit and other palette based Bitmap formats anymore. This is generally to minimize the number of esoteric Bitmap formats we need to support and to improve the performance as the back-ends don't support palette surfaces in general anymore. So what happens in this case is that we read in the 1-bit PNG into Bitmap, but as we don't want 1-bit Bitmap, we just enable the switched in libpng to convert from 1 to 8bit and from palette to RGB. The result of that is that we read-in an 8-bit RGB Bitmap. Then at PDF export we can't just reuse and store the PNG, which is still associated (I think), because PDF uses it's own lossless format, so we instead look and write the content of the Bitmap - which will be RGB 8-bit. What we can do here is to check the original PNG file or store some "origin" information into the Bitmap class, and then convert the Bitmap to a palette based 1-bit Bitmap (which shouldn't cause any loss of information). -- You are receiving this mail because: You are the assignee for the bug.
