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When building a camera, you decide once and then most parameters stay fixed. It would be trivial to just append 1000 bytes for a mostly fixed DNG header to each
by schobi 1y ago
When building a camera, you decide once and then most parameters stay fixed. It would be trivial to just append 1000 bytes for a mostly fixed DNG header to each image.
But how do you test this?
While the DNG specification is open source, the implementation was/is(?) not. Do I really need a copy of Photoshop to test if my files are good? How would I find good headers to put into my files? what values are even used in processing?
Maybe the situation has changed, but in the old days when I was building cameras there was only a closed-source Adobe library for working with DNGs. That scared me off.
- Cadwhisker 1y agoFor testing, there's the Adobe DNG SDK: https://helpx.adobe.com/camera-raw/digital-negative.html https://helpx.adobe.com/camera-raw/digital-negative.html You'll find the whole spec there, too. I think the source is also available somewhere.
- goeiedaggoeie 1y agoThings like camera intrinsics and extrinsics are not fixed. 1000 bytes seems small to me given the amount of processing in modern cameras to create a raw image. I could easily imagine storing more information like focus point, other potential focus points with weights as part of the image for easier user on device editing.
- seba_dos1 1y agoThe camera app on my GNU/Linux phone stores DNGs with no troubles using FLOSS only.