[gdal-dev] Possible RGB 16-bit PNG read error?

[Even Rouault]

Ray,

what tool do you use to assess if the colors are wrong ? Doing 
"gdal_translate 48bpp.png 48bpp.tif", and then opening in GIMP 
48bpp.png, 48bpp.tif and 24bpp.tif, the colors are all identical. I see 
that the 3 files have an ICC profile. Perhaps your visualization tool 
doesn't honour it for the 16-bit version ?

Even

Le 24/12/2025 à 04:58, Ray at Daylon via gdal-dev a écrit :
> I came across a 16-bit RGB PNG file that appears to read incorrectly 
> in GDAL 3.11.3. I didn't see any changes in the readme's for later 
> GDAL versions in regards to this.
>
> The file content is okay but the colors are wrong. Looking at the band 
> pixel data returned by GDAL, it might be similar to the endian issue 
> that happened with 16-bit grayscale PNGs earlier, but applying endian 
> corrections and RGB/BGR ordering on my end didn't help. Near as I can 
> tell it looks like the channels are shifted in some other way.
>
> An example file is available at
> daylongraphics.com/download/test/gdal_png_issue/48bpp.png (554K)
>
> For reference, a correctly read 8-bit version is available at
> daylongraphics.com/download/test/gdal_png_issue/24bpp.png
>
> Ray Gardener
> Daylon Graphics Ltd.
>
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