Constant turbojpeg_sys::TJSAMP_TJSAMP_411

pub const TJSAMP_TJSAMP_411: TJSAMP = 5;

4:1:1 chrominance subsampling. The JPEG or YUV image will contain one chrominance component for every 4x1 block of pixels in the source image. JPEG images compressed with 4:1:1 subsampling will be almost exactly the same size as those compressed with 4:2:0 subsampling, and in the aggregate, both subsampling methods produce approximately the same perceptual quality. However, 4:1:1 is better able to reproduce sharp horizontal features.

@note 4:1:1 subsampling is not fully accelerated in libjpeg-turbo.