A 24 bits TIFF file (3 samples per pixel: R,G,B) which correctly contains 3 values for the SampleFormat TIFF tag (one for each of the 3 samples), after being edited and saved by paint.net 4.3.12 as a 32 bits TIFF file (4 samples per pixel: R,G,B,A) still incorrectly contains the same 3 values of the sampleformat TIFF tag instead of the correct 4 values (one for each of the 4 sample). So it seems paint.net fails to update the sampleformat TIFF tag to 4 values (i.e. adding the 4th value for the 4th sample per pixel).
This lead to the impossibility to open the TIFF file with some image processing software like GIMP, which throws the error: Not a TIFF image or image is corrupt / Incorrect count for SampleFormat; or GIS software like QGIS which thrown the error: TIFFReadDirectory:Incorrect count for "SampleFormat".
To replicate the issue:
- open the "sample.tiff" 24 bit file (contained in the attached "sample.zip" file) with paint.net
- save the image as a 32 bit tiff file
While the original "sample.tiff" 24 bit file can be opened by e.g. GIMP or QGIS without issue, the new 32 bit file saved by paint.net cannot be opened by e.g. GIMP or QGIS.
sample.zip
