rgb2ycbcr¶
Synopsis¶
rgb2ycbcr [ options ] src1.tif src2.tif … dst.tif
Description¶
rgb2ycbcr converts RGB color, greyscale, or bi-level TIFF images to YCbCr images by transforming and sampling pixel data. If multiple files are specified on the command line each source file is converted to a separate directory in the destination file.
By default, chrominance samples are created by sampling
2 by 2 blocks of luminance values; this can be changed with the
-h and -v options.
Output data are compressed with the PackBits
compression scheme, by default; an alternate scheme can be selected with the
-c option.
By default, output data are compressed in strips with
the number of rows in each strip selected so that the
size of a strip is never more than 8 kilobytes;
the -r
option can be used to explicitly set the number of
rows per strip.
Options¶
- -c compress¶
Specify a compression scheme to use when writing image data: -c none for no compression, -c packbits for the PackBits compression algorithm (the default), -c jpeg for the JPEG compression algorithm, -c zip for the deflate compression algorithm, and -c lzw for Lempel-Ziv & Welch.
- -h size¶
Set the horizontal sampling dimension to one of: 1, 2 (default), or 4.
- -r striprows¶
Write data with a specified number of rows per strip; by default the number of rows/strip is selected so that each strip is approximately 8 kilobytes.
- -v size¶
Set the vertical sampling dimension to one of: 1, 2 (default), or 4.