RGB2YCBCR(1)                                       RGB2YCBCR(1)





NAME
       rgb2ycbcr  -  convert  non-YCbCr  TIFF images to a YCbCr
       TIFF image

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 com-
       mand  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     Specify  a compression scheme to use when writing
              image data: -c none for no compression, -c  pack-
              bits  for the PackBits compression algorithm (the
              default), -c jpeg for the JPEG compression  algo-
              rithm,  -c  zip for the deflate compression algo-
              rithm, and -c lzw for Lempel-Ziv & Welch.

       -h     Set the horizontal sampling dimension to one  of:
              1, 2 (default), or 4.

       -r     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     Set the vertical sampling dimension to one of: 1,
              2 (default), or 4.

SEE ALSO
       tiffinfo(1), tiffcp(1), libtiff(3)



                        October 15, 1995           RGB2YCBCR(1)
