rgb2ycbcr.1

tiff文件开发库

.\"	$Header: /cvsroot/osrs/libtiff/man/rgb2ycbcr.1,v 1.2 2002/06/27 07:41:33 dron Exp $
.\"
.\" Copyright (c) 1991-1997 Sam Leffler
.\" Copyright (c) 1991-1997 Silicon Graphics, Inc.
.\"
.\" Permission to use, copy, modify, distribute, and sell this software and 
.\" its documentation for any purpose is hereby granted without fee, provided
.\" that (i) the above copyright notices and this permission notice appear in
.\" all copies of the software and related documentation, and (ii) the names of
.\" Sam Leffler and Silicon Graphics may not be used in any advertising or
.\" publicity relating to the software without the specific, prior written
.\" permission of Sam Leffler and Silicon Graphics.
.\" 
.\" THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 
.\" EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 
.\" WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
.\" 
.\" IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
.\" ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
.\" OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
.\" WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 
.\" LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 
.\" OF THIS SOFTWARE.
.\"
.if n .po 0
.TH RGB2YCBCR 1 "October 15, 1995"
.SH NAME
rgb2ycbcr \- convert non-YCbCr
.SM TIFF
images to a YCbCr
.SM TIFF
image
.SH SYNOPSIS
.B rgb2ycbcr
[
.I options
]
.I "src1.tif src2.tif ... dst.tif"
.SH DESCRIPTION
.I rgb2ycbcr
converts
.SM RGB
color, greyscale, or bi-level
.SM 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.
.PP
By default, chrominance samples are created by sampling
2 by 2 blocks of luminance values; this can be changed with
the
.B \-h
and
.B \-v
options.
Output data are compressed with the
.SM PackBits
compression scheme, by default; an alternate scheme can be
selected with the
.B \-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
.B \-r
option can be used to explicitly set the number of
rows per strip.
.SH OPTIONS
.TP
.B \-c
Specify a compression scheme to use when writing image data:
.B "\-c none"
for no compression,
.B "-c packbits"
for the PackBits compression algorithm (the default),
.B "-c jpeg"
for the JPEG compression algorithm,
.B "-c zip"
for the deflate compression algorithm,
and
.B "\-c lzw"
for Lempel-Ziv & Welch.
.TP
.B \-h
Set the horizontal sampling dimension to one of: 1, 2 (default), or 4.
.TP
.B \-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.
.TP
.B \-v
Set the vertical sampling dimension to one of: 1, 2 (default), or 4.
.SH "SEE ALSO"
.IR tiffinfo (1),
.IR tiffcp (1),
.IR libtiff (3)