Jan Wassenberg (jan.wassenberg.delete@this.gmail.com) on May 22, 2022 5:53 am wrote:
> Michael S (already5chosen.delete@this.yahoo.com) on May 22, 2022 5:12 am wrote:
>
> > Let's do back-of-envelop math.
> > 4K*60p ~= 500 Mpixel/s. Ignoring color for sake of brevity it means ~500,000 32x32 blocks per second.
> Ignoring color means we're off by a factor of 3.


I am used to formats where color (Chroma) is sampled at 1/4th to 1/16th rate of the intensity (Luma) and also has lower # of bits allocated per sample, which reflects low resolution/sensitivity of human color vision relatively to gray scale vision.
Is JPEG XL different in that regard?

Or, may be, it's not different, but you use luma-like IDCT on chroma instead of interpolation?
If the later then it's probably much slower than interpolation and does not really improve quality of the output.

> And IDCT (I assume your FLOP count is accurate, not sure) is perhaps ~1/4 the total,
> so we're concluding it would be fine without SIMD if your CPU were 12x as fast. OK :)