How much a DctEncoder reduces the resolution of chrominance relative to luminance.
public enum DctChromaSubsampling
ITU-T T.81 §A.1.1 (sampling factors H and V) and §A.2 (MCUs). Applies only where the encoder converts colour: RGB to YCbCr and CMYK to YCCK, whose two chrominance components are sampled at 1 x 1 while luminance (and K) take the factors below. Gray, and RGB or CMYK stored without a colour transform, are never subsampled.
kind:method, kind:property, kind:ctor. Press Esc to clear.Horizontal4:2:2: chrominance at half the horizontal resolution (luminance sampling factors 2 x 1).HorizontalAndVertical4:2:0: chrominance at half the resolution in both directions (luminance sampling factors 2 x 2), libjpeg's default.None4:4:4: chrominance at full resolution (luminance sampling factors 1 x 1).