Real or Fake Image?

[acerimusdux]

1. Digital cameras ARE computers; so even with sharpening and compression artifacts, it's normally impossible to tell what was done in camera. There could easily be no post-processing at all there (for all we know it could have been shot in a low quality jpeg, or in JPEG + RAW).

2. There is no chromatic aberration whatsoever visable in that image, along those high contrast edges. "Chromatic aberration" is when you get colors that don't belong there at all, typically purple or magenta, typically along a high contrast edge.

3. According to that FotoForensics site, on ELA interpretation, "Similar edges should have similar brightness in the ELA result. All high-contrast edges should look similar to each other, and all low-contrast edges should look similar." It also says "Scaling a picture smaller can boost high-contrast edges, making them brighter under ELA."

So to me it seems that the ELA is showing exactly what we should expect. The high contrast edges are brighter, but they are pretty uniform throughout the photo; the water line looks similar to the power line, and to the flagpole. Nothing in there stands out as looking unnatural. So this is evidence that the photo was not altered, is it not?

[Lihu]

2 hours ago, acerimusdux said:

1. Digital cameras ARE computers; so even with sharpening and compression artifacts, it's normally impossible to tell what was done in camera. There could easily be no post-processing at all there (for all we know it could have been shot in a low quality jpeg, or in JPEG + RAW).

2. There is no chromatic aberration whatsoever visable in that image, along those high contrast edges. "Chromatic aberration" is when you get colors that don't belong there at all, typically purple or magenta, typically along a high contrast edge.

3. According to that FotoForensics site, on ELA interpretation, "Similar edges should have similar brightness in the ELA result. All high-contrast edges should look similar to each other, and all low-contrast edges should look similar." It also says "Scaling a picture smaller can boost high-contrast edges, making them brighter under ELA."

So to me it seems that the ELA is showing exactly what we should expect. The high contrast edges are brighter, but they are pretty uniform throughout the photo; the water line looks similar to the power line, and to the flagpole. Nothing in there stands out as looking unnatural. So this is evidence that the photo was not altered, is it not?

This is what I thought as well. . .

What's funny is that my work involves a lot of image processing and recognition algorithms, but figured my opinion is no better than anyone else in this case. It's not. However, I do think what you are kind of implying by stating that digital cameras are computers is correct. In fact, in the digital world, more sophisticated algorithms and editing will make it "virtually impossible" to tell if something is fake or not.

[Zeph]

Is "real" what you can see with your eyes without any gadget or instrument? And "fake" anything that creates a photograph that changes what you'd see if standing next to the camera? All cameras adjust for lighting. Does that make a photo fake? If not, at what point does a camera start making something fake? The lines are hard to define.