In the past days, I got a lot of feedback after sharing and I wanted to sit down and clarify the issue :) Photoshop was made, a new image was added, fake photos were used, how do we analyze them?
We see that there are fake, unrealistic photos that travel around social media, especially during war periods and epidemics. Some accounts on Twitter expose them very nicely. So how are they made? Celebrities, phenomena are playing on their own photos, changing their background (this issue appeared in some famous phenomena:)) and how are they understood? I will try to explain how it is done by addressing these issues in general. Let’s reveal photos that are not exact but changed.
Let’s see how it’s done;
When you search for photo forensics on Google, you can see many applications. My favorite is Error Level Analysis (ELA). ELA briefly errors caused by saving the file at a certain image quality level, It is an algorithm that is used to compare the state before it was saved. If you save any JPEG file over and over again, you can easily see that the quality of the picture decreases, and after saving 20 times, the quality of the picture has reached the lowest quality level. This has been tried and this has been reached after the trials. JPEG is an image, file format that loses some of the image quality in every recording (save), thus enabling ELA.
Some Sample Sites:
https://www.imageforensic.org/
https://29a.ch/photo-forensics/#forensic-magnifier
There are tools for online and offline where we can analyze ELA. I’m not going to go through offline, that is, through the program. Since the modified places in the photograph have higher error levels after recording, it is possible to identify the places that are visually manipulated thanks to ELA.
As an example, let’s briefly analyze the original version of the photo I took and its manipulation with the photo editing software with the ELA technique.
Below is the normal version of my photo, and just below it, the pocket sections of my shorts are painted in red.
When I analyzed these two photos, the analysis of my first photo came out;
Analysis result of the photograph with pockets painted
As you can see, he highlighted my pockets with light color and emphasized that there was a change in these areas.
Apart from these changes, as you know, location information and time information of the place where the photo was taken is also kept in smart devices such as apple and samsung. In addition, there are some subjects of hiding data in the picture that I published as an article in the past. In other words, it is possible to hide text, password etc. in the picture.
With these programs, these issues can be identified. But only in the original photos :)
Now everyone seems to see that they are logged into Instagram and this site :) Good analysis to everyone :)