What you mention sound like tipical corruption of JPG files with foreign data in the middle. If you have access to the disk image, commercial software like Adro

What you mention sound like tipical corruption of JPG files with foreign data in the middle. If you have access to the disk image, commercial software like Adroit Photo Recovery could (in theory) help you. They've developed a technique for recovery of photo files that is very robust and can handle fragmentation. On the more open source front... There's little. Adroits algorithms have been published, be the implementation is proprietary. Poisel, Tjoa and Tavolato implemented the algorithm in Python+C, but its quite difficult to get their carver up and running, mostly due to "library rot" -- last I tried, there was no repo from where to download the particular version of PyQT they used and I didn't have the time to fix and translate all the old calls to new ones. You could also try PhotoRec, but for fragmented data it isn't the best solution. Finally, you could try custom code to try and find the JPG blocks in the images and then all the combinations until you find something that makes sense. Welcome to the beautiful and monstrous world of file/data carving!