opt-jpg(1) opt-jpg(1)
NAME
opt-jpg - losslessly optimize JPEG image files
SYNOPSIS
opt-jpg [ -a(rithmetic) ] [ -g(ray) ] [ -h(elp) ]
[ -m markers_to_copy ] [ -q(uiet) ] file...
DESCRIPTION
opt-jpg losslessly optimizes JPEG images. This is accomplished using a
combination of the filesize, jpegtran, and tempname utilities.
OPTIONS
-a Allow arithmetic coding to be used on re-written image files
instead of the more prevalent Huffman coding. This can yield
image files that are 5-7% smaller, but older software (viewers,
web browsers, image editors) might not read them successfully.
USE WITH CAUTION.
-g Force the output to grayscale.
-h Print help and quit.
-m none
Copy no markers from source file. Identical to "-copy none"
option from jpegtran. This is the default.
-m comments
Copy only comment markers. Identical to "-copy comments" option
from jpegtran.
-m all Copy all extra markers. Identical to "-copy all" option from
jpegtran.
-q Quiet output. No output commentary will be printed.
EXAMPLES
Optimize a couple of image files:
opt-jpg image001.jpg image002.jpg
Optimize all JPEG images in an entire directory tree:
find . -name "*.jpg" -exec opt-jpg {} \;
Or alternatively, optimize all JPEG images this way:
find . -name "*.jpg" -print0 | xargs -0 opt-jpg
Fully utilize a quad-core system while optimizing all JPEG images:
find . -name "*.jpg" -print0 | xargs -0 -n 1 -P 4 opt-jpg
find . -name "*.jpg" | parallel -j+0 opt-jpg
NOTES
This program may create progressive JPEG files from images that were
previously non-progressive. Curiously, they are sometimes smaller.
SEE ALSO
filesize(1), jpegtran(1), tempname(1)
COPYRIGHT
Copyright (C) 2004-2011 by Brian Lindholm. This program is free soft-
ware; you can use it, redistribute it, and/or modify it under the terms
of the GNU General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MER-
CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
Public License for more details.
littleutils 2011 Jan 07 opt-jpg(1)
littleutils 1.0.24 - Generated Fri Mar 11 11:37:10 CST 2011