Is there a program that can undo edits to a photo?

Question

I'm assuming that any changes done to a photo from the time that it exists, is simply a layering process of data.

There was one time where I had a photo that was cropped by someone else and the file was on my computer. In windows...you can see a preview of your picture file in the corner and the strange thing is...the preview showed the full uncropped version of the picture with more objects in the photo that were initially cut out. When I double clicked the photo to see the full sized version...it of course showed the intended cropped/edited version by the original owner of the picture. One thing is for sure, the photo was not cropped on my computer so my computer certainly does not have the "data" of what the pic looked like anywhere for a glitch like this to even happen if it were possible.

What does this mean for sure? That old versions of "undo-able" data MUST still stay on editd digital photos.

My question is this...does anybody know of a program out there that specializes in opening and then undoing every single change done to a given photo? I would love to play around with such a program if it exists, free if possible.

Answer 1

The thumbnail that you see in Windows Explorer is a low-rez copy of the image stored inside the file's exif data. It would appear that this thumbnail wasn't updated when the image was edited.

The exif data includes a whole bunch of information for each shot:

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Date and time information. Digital cameras will record the current date and time and save this in the metadata.

Camera settings. This includes static information such as the camera model and make, and information that varies with each image such as orientation, aperture, shutter speed, focal length, metering mode, and ISO speed information.

A thumbnail for previewing the picture on the camera's LCD screen, in file managers, or in photo manipulation software.

Descriptions and copyright information.

http://en.wikipedia.org/wiki/Exif

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To see the full exif data for a picture, you can download Opanda IExif viewer (free).

For the rest, as everyone else has already said, if it's a jpg image there is no way to undo the changes to the actual image.

Answer 2

It depends on what you saved the photo as.

If you used photoshop to alter the photo and saved it as a PSD file then it is just layers that can be undone but if you saved it as a jpeg, gif, png ect then no because now they layer has merged with the picture and it is read as one file instead of multiple layers.

Answer 3

I don't know of any specific program like that. Yes, most edits, if done correctly, are done in layers. The thing is, if all the layers are flattened, then the edits cannot be undone. If left in the layer state, called PSD in Photoshop, then yes, anything can be easily undone by removing the layers. If you had the program in which the photo was edited, such as Photoshop, you could try opening the photo there and see if it still has the layers intact. Otherwise, I know of no other way to "un-edit" the photo.

steve

Answer 4

It depends on the program used to edit the photo. If photoshop was used, and a flattened tiff or jpeg is saved out as the final product, then there is no way to reverse the edits. If the PSD was the final file, or a layered TIFF, then you can turn on and off layers and layer sets to undo edits made, if you reopen the file in Photoshop.

It's possible that images that are cropped and edited might be done without actually altering the data in the image, and the edits are in a file header or sidecar file, to be interpreted and processed when the file is printed. That would be program specific, and I haven't heard of anything like it, except as stated above with layered photoshop files.