Return the Vertical subsampling factor for requested Component. Returns true if the image information in the ParamBlock is currently valid. Returns true if the tables in the ParamBlock are currently valid. YCbCr-Alpha with Y, Cb, and Cr inverted. The X and Y units simply indicate the aspect ratio of the pixels.
Pixel density is in pixels per inch.
The height of the image data in pixels. Return the Horizontal subsampling factor for requested Component. The Subsample factor is the number of input pixels that contribute to each output pixel. This is distinct from the way the JPEG to each output pixel. The subsample factor.