Re: [xine-devel] Re: Microblock

[Billy B. <ve...@du...>]

Patrick Chase (pc...@pa...):

> Believe it or not, the JPEG standard doesn't specify the positioning
> of subsampled components. That's why JPEG-based file formats such as
> EXIF have tended to add metadata for that. FWIW, EXIF supports either
> co-location (chroma samples aligned to top-left luminance pixel in the
> example you show) or centering (what MPEG does).

  Thanks, I didn't know that.

  MPEG's chroma is weirdly centered too, since it's to the left of the
actual center.  Makes resampling a little stranger.

-- 
Billy Biggs
ve...@du...