Image links with width and height

Source i开发者_开发百科mage:http://cdn2.supergoodmovies.com/FilesTwo/efb04e43d3e3471c86e406df449f75b8.jpg/151/99

i need to know how to make this type of links i.e, the width and height of the image can be changed by changing 151/99 in the link.please let me know what is the concept behind it.i am a beginner in this things so please give answer in detail. Waiting for the answer.

Thanks in advance..

You can set the image width and hight trough the url extension. But this is only rescaling for the screen. Better is to interpret the url and resize the image on the server with image magick or other programs for image manipulation. But the important part here is the they have a rewrite url and interpret the url extension as get parameters. Those can be read by a php, asp, jsp whatever server application and trigger a process to either set the image attributes or resize an image with an additional programm on the server. The created image can then be sent as an image stream to the user.