1JPEGOPTIM(1) General Commands Manual JPEGOPTIM(1)
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6 jpegoptim - utility to optimize/compress JPEG/JFIF files.
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11 jpegoptim [ options ] [ filenames ]
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15 jpegoptim is used to optimize/compress jpeg files. Program supports
16 lossless optimization, which is based on optimizing the Huffman tables.
17 And so called "lossy" optimization where in addition to optimizing
18 Huffman tables user can specify upperlimit for image quality.
19 NOTE! By default jpegoptim modifies the input files (if they are opti‐
21 mized), to preserve original files use option -d to specify alternate
22 directory for saving the optimized files to.
23 Only normal files are optimized (symbolic links and special files are
25 skipped). Also, any other hard links to the file being optimized (as
26 created using link(2)) are unaffected.
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31 Options may be either the traditional POSIX one letter options, or the
32 GNU style long options. POSIX style options start with a single ``-'',
33 while GNU long options start with ``--''.
34 Options offered by jpegoptim are the following:
36 -d<path>, --dest=<path>
38 Sets alternative destination directory where to save optimized
39 files (default is to overwrite the originals). Please note that
40 unchanged files won't be added to the destination directory. This
41 means if the source file can't be compressed, no file will be
42 created in the destination path.
43 -f, --force
45 Force optimization, even if the result would be larger than the
46 original file.
47 -h, --help
49 Displays short usage information and exits.
50 -m<quality>, --max=<quality>
52 Sets the maximum image quality factor (disables lossless opti‐
53 mization mode, which is by default enabled). This option will
54 reduce quality of those source files that were saved using higher
55 quality setting. While files that already have lower quality
56 setting will be compressed using the lossless optimization
57 method.
58 Valid values for quality parameter are: 0 - 100
60 -n, --noaction
62 Don't really optimize files, just print results.
63 -S<size>, --size=<size>
65 Try to optimize file to given size (disables lossless optimiza‐
66 tion mode). Target size is specified either in kilobytes (1 - n)
67 or as percentage (1% - 99%) of the original file size.
68 -T<threshold>, --threshold=<threshold>
70 Keep the file unchanged if the compression gain is lower than the
71 threshold (%).
72 Valid values for threshold are: 0 - 100
74 -b, --csv
76 Print progress info in CSV format.
77 -o, --overwrite
79 Overwrite target file even if it exists (when using -d option).
80 -p, --preserve
82 Preserve file modification times.
83 -P, --preserve-perms
85 Preserve file permissions (owner/group) by overwriting the origi‐
86 nal file. This is slightly less safe than the default mode of
87 operation (where new file is first saved as temporary file and
88 then renamed over the original file). In this mode a backup of
89 the original file is made with .jpegoptim.bak extension, and this
90 file is removed after the original file has been successfully
91 replaced. NOTE! if running jpegoptim as root there is generally
92 no need to use this option, as jpegoptim is able to preserve file
93 permissions when run by root in default mode.
94 -q, --quiet
96 Quiet mode.
97 -t, --totals
99 Print totals after processing all files.
100 -v, --verbose
102 Enables verbose mode (positively chatty).
103 --all-normal
106 Force all output files to be non-progressive. Can be used to con‐
107 vert all input files to progressive JPEGs when used with --force
108 option.
109 --all-progressive
111 Force all output files to be progressive. Can be used to convert
112 all normal (non-progressive) JPEGs input files to progressive
113 when used with --force option.
114 -s, --strip-all
117 Strip all markers from output file. (NOTE! by default only Com‐
118 ment & Exif/IPTC/PhotoShop/ICC/XMP markers are kept, everything
119 else is discarded). Output JPEG still likely will contains one
120 or two markers (JFIF and Adobe APP14) depending on colorspace
121 used in the image, as these markers are generated by the libjpeg
122 encoder automatically.
123 --strip-none
125 Preserve "all" markers in the image. This will leave all markers
126 untouched in the image, except JFIF (APP0) and Adobe (APP14)
127 markers as those get regenerated by the libjpeg library.
128 --strip-com
130 Strip Comment (COM) markers from output file.
131 --strip-exif
133 Strip EXIF markers from output file.
134 --strip-iptc
136 Strip IPTC / Adobe Photoshop (APP13) markers from output file.
137 --strip-icc
139 Strip ICC profiles from output file.
140 --strip-xmp
142 Strip XMP profiles from output file.
143 --stdout
147 Send output image to standard output. Note, if optimization
148 didn't create smaller file than the input file, then no output
149 (image) is sent to standard output. (Option -f can be used to
150 force output of image always, even if optimized image was not
151 smaller than input).
152 --stdin
155 Read input image from standard input. When this option is used
156 then only one image is read from standard output. Any (other)
157 input files specified on command line are ignored. Note, if
158 input file '-' is seen on command line then standard input is
159 also assumed.
160 Currently this option will explicitly enable -f option, thus out‐
162 put image is always sent to standard output (even if no optimiza‐
163 tion was possible).
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169 When using --size option, resulting file is not always exactly the
170 requested size. Workaround is to re-run jpegoptim on the same file
171 again which often will result file closer to target size.
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175 jpeginfo(1)
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179 Timo Kokkonen <tjko@iki.fi>
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183 Copyright (C) 1996-2018 Timo Kokkonen
184 This program is free software; you can redistribute it and/or modify it
186 under the terms of the GNU General Public License as published by the
187 Free Software Foundation; either version 2 of the License, or (at your
188 option) any later version.
189 This program is distributed in the hope that it will be useful, but
190 WITHOUT ANY WARRANTY; without even the implied warranty of MER‐
191 CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
192 Public License for more details.
193 You should have received a copy of the GNU General Public License
194 along with this program; if not, write to the Free Software Foundation,
195 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
1964th Berkeley Distribution 17 Apr 2018 JPEGOPTIM(1)