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Anyone got a jpeg un-glitcher? I'm thinking of a tool to fix these sorts of minor corruptions in the jpeg bitstream. The tool would load up the corrupt image,
by Amadou 13y ago
Anyone got a jpeg un-glitcher? I'm thinking of a tool to fix these sorts of minor corruptions in the jpeg bitstream. The tool would load up the corrupt image, let the user visually select where the glitch starts by clicking the first "weird" looking pixel and then iterate through different values until the user says the picture looks better. Rinse and repeat.
- afhof 13y agoIts doubtful that the image can be recovered. The information really is gone. I suspect it would be easier to make it simple to have redundant copies of the data, rather than trying to fix the images after they're gone.
- nitrogen 13y agoIf it's only a single bit that's toggled, you can just iterate through all the bits until you find one that fixes the image after you flip it.
- JosephRedfern 13y agoFor a 1MB JPEG, that'd be over 8 million different images.
- nitrogen 13y agoIf you could point to a region of the image where the corruption begins, you would reduce the number of possible images significantly.
- porges 13y agoThat sounds plausible. Another idea: choose a section of "bad image" and a section of "good image" which should have similar colours and then generate mutations of the corrupted DCT square until you have a close match between the two areas.
- aninhumer 13y agoGiven that we're assuming some kind of correctness metric for the final image, could we not also use this metric to locate the start of the corruption?
- WatchDog 13y agoFor a single byte error that is visibly obvious, you could just iterate through 255 combinations until the user thinks the image looks right.
- tehwebguy 13y agoYeah maybe you could have the user iterate through a search tree the way an optometrist performs an eye exam, "Which is better, one flip or two?" But I don't know if there is a way to create a tree of the possibilities.
- logicallee 13y agowe should make your unglitcher part of the standard, that way every jpeg across the whole Internet could be reduced in size by just throwing away certain parts of it. Then your unglitcher could get those parts back. oh, wait....
- likeclockwork 13y agoA paint program!
- K2h 13y agomost pictures don't have hard transitions between block areas, so once the fault area has been identified an algorithm could be made to look for the change that results in the image having the softest transition between neighboring blocks.