U of S | Mailing List Archive | alt-photo-process-l | Re: "evidence tampering"

Re: "evidence tampering"

The idea on working with an image is to scan or enter via RAW conversion and maintain it
as a TIFF or Photoshop file until you are 100% sure that is the way you wish it. You can then save it
as a fine quality JPEG and you'd never notice any loss. If you continue to work on it and save it again,
THEN you'll perhaps notice loss of data.
Jack Fulton

On September2006, at 8:51 PM, Camden Hardy wrote:

My question, which I figure some of the digital mavens around
here would know, is, can you see by examining a jpeg (or digital camera
file) if that's been altered as apparently you can with video?
If done correctly?  Absolutely not. :)

I would assume if it's been saved in a different format, editing would
not be detectable. But if it were saved in the same jpeg format ????
I would suggest staying the hell away from jpeg if you have any intention
of making a print (or any other reproduction...or in general). Jpeg is a
lossy format, which means that every time you save as a jpeg the
compression throws away data. If you were to save the modified jpeg as a
tiff, png, or any other lossless format, you wouldn't lose any information
and could (in theory) get away with it.

Camden Hardy