PNG
Install
pkg install pngquant optipng
For example:
pngquant --quality 0-1 highlight2.png -o s.png
JPEG
Install jpegotim with:
pkg install jpegoptim
Help doc:
jpegoptim v1.4.6 Copyright (C) 1996-2018, Timo Kokkonen
Usage: jpegoptim [options] <filenames>
-d<path>, --dest=<path>
specify alternative destination directory for
optimized files (default is to overwrite originals)
-f, --force force optimization
-h, --help display this help and exit
-m<quality>, --max=<quality>
set maximum image quality factor (disables lossless
optimization mode, which is by default on)
Valid quality values: 0 - 100
-n, --noaction don't really optimize files, just print results
-S<size>, --size=<size>
Try to optimize file to given size (disables lossless
optimization mode). Target size is specified either in
kilo bytes (1 - n) or as percentage (1% - 99%)
-T<threshold>, --threshold=<threshold>
keep old file if the gain is below a threshold (%)
-b, --csv print progress info in CSV format
-o, --overwrite overwrite target file even if it exists (meaningful
only when used with -d, --dest option)
-p, --preserve preserve file timestamps
-P, --preserve-perms
preserve original file permissions by overwriting it
-q, --quiet quiet mode
-t, --totals print totals after processing all files
-v, --verbose enable verbose mode (positively chatty)
-V, --version print program version
-s, --strip-all strip all markers from output file
--strip-none do not strip any markers
--strip-com strip Comment markers from output file
--strip-exif strip Exif markers from output file
--strip-iptc strip IPTC/Photoshop (APP13) markers from output file
--strip-icc strip ICC profile markers from output file
--strip-xmp strip XMP markers markers from output file
--all-normal force all output files to be non-progressive
--all-progressive force all output files to be progressive
--stdout send output to standard output (instead of a file)
--stdin read input from standard input (instead of a file)
Note: backup your images first, it is, by default, will overwrite your original file or use --dest=newDir. Simple use:
jpegoptim sample.jpg
This command reduces ALL .jpg files in the current dir:
jpegoptim --size=150k ./*.jpg
Output:
./upcal_html_dawn_rise.jpg 1080x2400 24bit N JFIF [OK] 817145 --> 154112 bytes (81.14%), optimized..
/upcal_html_main.jpg 1080x2400 24bit N JFIF [OK] 553073 --> 109040 bytes (80.28%), optimized.
Google more or read the help: jpegoptim --help
jpegoptim function
function resizeIMG() {
# jpegoptim <percent> <files>
perCent=10
outDir=_jpegoptim
if [[ $1 -gt 0 ]]; then
perCent=$1
else
echo reducing to $perCent%
fi
# shift will consume/remove the first arg
# "$@" : then "$@" will have 2nd arg onwards
echo resizing "${@:2}" to $perCent% quality to $outDir
mkdir -p $outDir
jpegoptim --size=$perCent% --overwrite --dest=$outDir "${@:2}"
}