The CImage.php is a PHP class that can resize and crop images on the fly and output them to, for example to a webpage. The class preserves a cache of the generated images and responds with HTTP 304 (not modified) if the image has not changed.

The file img.php uses CImage.php to resize images. It is a usecase on how to use the class. img.php is useful for webpages which want to dynamically resize the images.

The file test.php has testcases that show the results of img.php with different settings.

Start by reviewing the test.php, then have a look at img.php and finally go through CImage.php.

CImage lives at github: https://github.com/mosbth/cimage

You can try out a live example at: http://dbwebb.se/kod-exempel/cimage/

Enjoy!

Mikael Roos (me@mikaelroos.se)

Installation

Clone from github: git://github.com/mosbth/cimage.git
Make the cache directory writable by the webserver.


chmod 777 cache

Point your browser to test.php.
Review the settings in img.php and try it out.
Advanced usage. Put img.php in your /img-directory. Create a .htaccess in your web root folder containing the following line:


RewriteEngine on 
RewriteRule ^image/(.*)$ img/img.php?src=$1 [QSA,NC,L]

Now you can access and resize your images through /image/someimage.jpg?w=80. Very handy.

Revision history

ToDo.

Improved support for pre-defined sizes.
crop-to-fit, add parameter for offset x and y to enable to define which area is the center of the image from which the crop is done.
Show how to integrate with WordPress, shortcodes.
Support for resizing opaque images.
Clean up code in CImage.php.

v0.3 (2012-10-02)

Added crop. Can crop a area (width, height, start_x, start_y) from the original image.
Corrected to make the 304 Not Modified header work.
Pre-defined sizes can be configured for width in img.php.
Corrected to make crop work with width or height in combination with crop-to-fit.

v0.2 (2012-05-09)

Implemented filters as in http://php.net/manual/en/function.imagefilter.php
Changed crop to crop_to_fit, works the same way.
Changed arguments and sends them in array.
Added quality-setting.
Added testcases for above.

v0.1.1 (2012-04-27)

Corrected calculation where both width and height were set.

v0.1 (2012-04-25)

Initial release after rewriting some older code I had lying around.