An Identicon is a visual representation of a hash value, usually of the IP address, serving to identify a user of a computer system. The original Identicon is a 9-block graphic, which has been extended to other graphic forms by third parties some of whom have used MD5 instead of the IP address as the identifier. In summary, an Identicon is a privacy protecting derivative of each user's IP address built into a 9-block image and displayed next the user's name. A visual representation is thought to be easier to compare than one which uses only numbers and more importantly, it maintains the person's privacy. The Identicon graphic is unique since it's based on the users IP, but it is not possible to recover the IP by looking at the Identicon.
I would like to use identicons for my own CMS that I am working on as a hobby, but also as a way to create aesthetically pleasing markers for Augmented Reality applications.
So I wrapped the PHP-Identicons library into a class to be able to use the same code for different applications without having to touch it again.
The original code was taken from here:
http://sourceforge.net/projects/identicons/
PHP-Identicons is a lightweight PHP implementation of Don Park's original identicon code for visual representation of MD5 hash values. The program uses the PHP GD library for image processing.
The code can be used to generate unique identicons, avatars, and system-assigned images based on a user's e-mail address, user ID, etc.
- Create images of any size by passing it in the constructor
- Randomly rotate elements so that the output image is no longer rotation-independent. (This is completely optional since it defeats the point of an identicon: The same string will no longer produce the exact same image twice. But it is a critical feeature for usage as an AR-Marker image)
- Caching of image data
Include the class.identicon.php file in your project
The basic usage of this class is like this:
$identicon = new Identicon('my string',256);
echo $identicon->image();
which will output an image tag like this:
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAQAAAAEACAIAAADTE (...) vn/wEcisrTmERAjwAAAABJRU5ErkJggg==">
The string will be md5()'d by the class itself
Have a look at the index.html for an example implementation
- Implement a good way to be able to save the images on the server. Right now you can only output the base64-encoded image data
- Pass html attributes to the image() method
- Figure out why random rotation causes artifacts
- Customizable background color
- Transparency