Accessing squid cache content for processing

[Lukasz Koszanski <lkoszanski@xxxxxxxxxxxxxxx>]

Hi, I would like to convert all png images in my cache to jpegs. I know 
how to do the conversion, all I need to know is how to access the cache 
content, for example to run a script on all the png or jpeg files. I 
know that squid parses content by content-type, since I can see this in 
storage.log. Please tell me if it is possible to process the cache content.
Luke