My intention was to get a better undrstanding of the JPEG file structure and find a way to alter the files creatively without destroying them. My first attempts at JPEG glitching consisted in random byte replacement and ended up in lots of unusable / unaestethetical files. After some web searching, I realized that most of the job should be done in the file header by altering specific bytes and carefully avoiding others. This approach allowed me to get visual alterations that go beyond what is usually seen under the "glitch" flag (particle effects, saturation artifacts, file size alterations, to name a few).
The idea here was to build a "swiss knife" for JPEG glitching: a software tool that could alter a JPEG picture in any possible way without destroying it, thus providing glitch artists with a tool that would enable them to create something like a "glitch vocabulary" to express themselves.
You can get an idea of what this tool can do here
This is version 1 of the first of several (I hope) glitching objects. I'd like to push the exploration towards sound and video as well. If there are people out there interested in collaborating, please get in touch, I'll be happy to talk to you.
This is a GOP abstraction: it is meant to be used within a patch and has full control thru inlets, enabling you to trigger it remotely the way you want. There's a mac version and a pc version. They've been tested under pd-extended 0.43.4/OSX Mavericks on a MacBook Pro and pd-extended 0.43.3/Windows 7 on an Acer revo desktop. I do not have any other system to test it on, so please report any bug encountered. There's also a standalone version for mac,for those who do not have Pd installed.
And let me know what you think...