How easy is it to hide that a file has been photoshopped?

Question

Programming

Good afternoon!

There is such a problem, they send us statistics in screenshots. I know that the metadata of a file (zhpega, for example) indicates when the file was created, when it was changed, in what program, if it is a picture - what camera was taken, shutter speed, aperture - in general, everything (I look at this data in ICDIS.

But I know also that if you set a goal, you can photoshop the file and hide all traces.Question

(s): How difficult is it to do?What skills should the person who does it have?How expensive is it for a programmer / hacker to order such work?

An example of a screenshot at the request of the comments:

Answer 1

If the screenshot is from the web, then you can correct the numbers in the firebug or house inspector before actually “shooting”, and then you don’t even have to photoshop.
In most cases, editing in Photoshop can be hindered by a non-uniform background, it will be very difficult to change numbers on such a background without noticeable artifacts. It is only necessary to choose a background that will be difficult to reproduce in a "pure" form, without numbers, for example, a scan of some rare stamped paper.

Answer 2

In case of changing the data on the page, even Photoshop is not needed.

Answer 3

For your case, fake is elementary, and you can never know if there was a fake or not.

Answer 4

At our institute, a “former” police officer taught computer graphics. He told us that calculating changes in a photo is not difficult, usually just walking through the histogram is enough. In the case of image editing, usually there should be clearly visible errors in the histogram, because. image midtones, pixel brightness, will be violated in this case.

Answer 5

Alternatively, if the screenshot is generated programmatically, then insert a watermark (Digimarc) into it based on the image data. In the future, any interference with the image will invalidate the watermark.

Answer 6

Usually I order this from a freelancer for 100-300 rubles.
In your case, in general, you will find out that the screen is redone.

Answer 7

If we are talking about advertising buying systems like Google AdWords, there it seems that advertisers can open a guest account that gives read access.
As for the screenshots, probably, if there is a large sample, you can do some kind of statistical analysis (similar to the one that analyzed the elections), but here you need a lot of data and good knowledge of mathematics, which is far beyond the capabilities of an ordinary earthling.