Export resolutions in 8-bit

I have an undistorted workflow issue.

The undistorted resolution is an arbitrary value intended to contain the resized bowtie.

However in Flame I can export an EXR sequence at the 2446 x 1702 resolution but not a JPG

When I export a JPG sequence it forces the width to 2448 and does some ugly padding through the centre of the frame.

I took a look at some other formats and it seems to be an 8-bit 16-bit problem. When I export a 8-bit TIF it reformats the width. When I export a 16-bit TIF it doesn’t.

Are there only a set number of resolutions that can be used at 8-bit?

I’ve run into this exact same issue before and came to the same conclusion. I don’t recall the math off-hand but yeah, there’s something about 8-bit images and them having to be divisible by a certain number. Interestingly you have nice even numbers so perhaps it’s related to the aspect ratio.

In the end we went EXRs all the way to avoid such unexpected headaches.

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Jpeg uses DCT - based compression math, and because of analyzing data by blocks, JPG pixel size should divide on 8 or 16 (do not remember exactly) - DCT algorythm analyzing data by 16x16 pixels block


UPDATE: So I can export the resolution but if I try and import it at 8-bit it will try and pad the resolution (badly)

If I force the bit depth to be 10-bit I can get the resolution I need. Just a little extra info I have just discovered.

I was trying to find a suitable working resolution. Footage shot on the ArriLF @ 4448 x 3096 and I needed to protect for a vertical resolution of 1920.
Made sense then to do all VFX at the plate resized to 2758 x 1920 except 2758 was getting rounded up to 2760 when ever an 8-but file was used.

Ah! Just one to watch out for. To be honest I have been getting some very funky stuff from 8-bit files recently so I have been promoting them to 10-bit anyways.