color, greyscale, or bi-level
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
Output data are compressed with the
compression scheme, by default; an alternate scheme can be selected with the
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;
option can be used to explicitly set the number of
rows per strip.
Specify a compression scheme to use when writing image data:
for no compression,
for the PackBits compression algorithm (the default),
for the JPEG compression algorithm,
for the deflate compression algorithm,
for Lempel-Ziv & Welch.
Set the horizontal sampling dimension to one of: 1, 2 (default), or 4.
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.
Set the vertical sampling dimension to one of: 1, 2 (default), or 4.