I’m trying to process a custom-made DNG file, that was created using pydng (GitHub - schoolpost/PyDNG: Create Adobe DNG RAW files using Python. Works with any Bayer RAW Data including native support for Raspberry Pi cameras.). The file created by this project seems to partially comply with the DNG format, which causes some issues with RawTherapee, yet surprisingly not so with other (simpler) image viewers.
For example, this is via faststone viewer:
and via https://raw.pics.io/app:
On the other hand, RawTherapee shows this DNG very weirdly (using AMaZE demosaic):
This is a comparison of the non-demosaiced image from RT (top), next to a correct conversion (bottom; via faststone)
Here you can see something strange: some of the pixels seem to show correct levels (look at the top-most part of the letter “S”, or the top half of the dot in the lower-left corner), whereas most pixel seem to undergo some kind of underflow, and appear to get saturated.
I’m aware that this not a fully-compliant file, yet several (simpler) applications appear to process it correctly.
What is going on?
attachment: DNG file: color.dng (6.1 MB)