About:

apache_image_resizer (compiled as image_resize.cgi) is a CGI program to be used with the Apache HTTP server to resize images very fast. Faster than PHP as it's written in C...

JPEG, PNG and GIF formats are supported.

It will keep the proportions of the image and will pad it with a given color.

When using this, it is also recommended to use some sort of caching in front to reduce the number of resize requests. Although apache_image_resizer resizes very quickly, using it with caching will give you the best results.

Pre-requisites:

To compile, you'll need thw following libraries installed:

- cgic: http://www.boutell.com/cgic/#obtain
- libgd: http://www.libgd.org/releases/

To install cgic, download the zip, unzip it and run:

$ sudo make install

To install libgd, download the latest stable zip and run"

$ ./configure && sudo make install

Building:

Just type "make". There's no "make install", install it where you please. It will compile as "image_resizer.cgi".

If you want to mess about with the code, feel free to. Please read the "Testing" section below first though please!

Live Demo:

See a live demo of the resize and padding (in black). Feel free to adjust the width and height parameters:

http://test.whatdoiask.com/image_resizer.cgi/test.jpg?width=600&height=600

Apache Config:

The resizer requires 4 settings, which should be set in the site's config file using "SetEnv":

- IMAGE_ROOT - The path from which images will be served. It is this
  path, along with the path after the script name in the httpd request
  that make up the full path.
- PADDING_COLOR - As the resizer preserves the image ratio, it needs
  to apply padding. This is the 6 character hex code for the padding
  color.
- MAX_HEIGHT - The maximum height that can be requested by the client
  (in pixels).
- MAX_WIDTH - The maximum width that can be requested by the client (in
  pixels).

Here is an example config...

<VirtualHost *:80>

DocumentRoot /xxx/test_whatdoiask

SetEnv IMAGE_ROOT /xxx/test_whatdoiask/images
SetEnv PADDING_COLOR 000000
SetEnv MAX_WIDTH 1024
SetEnv MAX_HEIGHT 1024

<Directory /xxx/test_whatdoiask>
    Options +ExecCGI
    AddHandler cgi-script .cgi
</Directory>

Testing:

I've used Ruby's rspec for testing so you'll want to install Ruby and bundler:

$ gem install bundler

Then you'll need to install the Ruby gems...

$ bundle install

If you have the Image Magick libraries installed you should just be able to run "make test" and voila.