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throttleimg - Script to automatically split images into multiple sizes


throttleimg [options] file1 ...


throttleimg is a script distributed with Apache::Throttle. It can be used to automatically create a set of different size images from one large image and store them in a format that Apache::Throttle will understand.

The file (or files) you specify will be replaced with a directory of the same name. The original file will be saved in this directory as "Z-<original name>". throttleimg will then create a set of images (the number of images can be set with the --steps option and defaults to 3) that look like the original image but have a lower quality.

Theoretically, this script can be used to automatically convert all of your existing images to be controlled by Apache::Throttle. You might try a command like:

    find /home/httpd -name '*.gif' -o -name '*.jpg' | \
        xargs throttleimg --time=5 --steps=3


--help, -h

Shows usage information.

--quiet, -q

This option tells throttleimg not to output any status messages to STDOUT. Only warnings and errors are printed to STDERR.

--time=<seconds>, -t=<seconds>

This is the time in seconds that the image should take to load. It is used to determine the speed required to download each image. This can be a floating point number.

--steps=<images>, -s=<seconds>

This option tells throttleimg how many different images to make.


This option tells throttleimg not to change the size of the images created. You probably want to use this if you're using these images inline in a HTML page and don't plan to use WIDTH and HEIGHT arguments in the <IMG> tag.


This option tells throttleimg not to change the number of colors in the images created. It is the default value for JPEGs.


This option tells throttleimg not to change the quality of the images created. It is the default value for GIFs.

--undo, -u

This option causes throttleimg to do the opposite of what it normally does. Instead of turning an image into a directory of different images, it removes all of the images created by a previous call to throttleimg and replaces the directory with the original image.


Don Schwarz <>


Apache::Throttle, mod_perl


Copyright (c) 1998 Don Schwarz. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.