Comment by OptionOfT
3 months ago
> Cameras should have just rotated the actual image pixels when saving, instead of cheating. If that's too slow, implement it in hardware, or schedule a deferred process and don't let the images be exported until that's done.
What if I want to rotate an image by 90 degrees because my camera didn't correctly detect up & down?
To my understanding rotation is lossless, where as moving the data will incur quality loss (except for certain exceptions).
JPEG rotation can be lossless for certain image dimensions (multiples of 8 or 16 pixels respectively, depending on chroma subsampling).
I suppose it's no coincidence that the native output format of many sensors (or ISPs, to be precise) is divisible by 16 in both width and height.