Using 100% Black to spot fake digital art

[salaam]

It occurred to me that digital reproductions of photos etc. will never include as much detail as the original. In fact a photo, (also being a reproduction by default) also suffers a tremendous loss of detail.

Such pondering came about after looking at recent pieces of near photographic quality art. At one point, one forum member seemed to suggest that an image was not a product of skilfulness in Xara but just a photograph. Hence, I decided to investigate.

I don't know if this topic has been posted before (as I couldn't find anything) but in the end I found that a good way to spot the difference between photo and digital art is to make the image grey scale (by dropping a white fill onto the image, from the colour line at the bottom of the XX screen) or even better, by turning the image into a 'negative' by dropping a 100% black fill onto it.

The photo usually has 'too much' detail which is invisible (or too subtle) in colour. The grey scale or negative, increases the contrasts and so brings out more hidden detail.

Even such detailed works submitted by Gray etc. do not produce any hidden detail through this process, unless the area is too dark.
Digital art tends to produce a high contrast grey scale image and is a very much 'what you see is what you get', unlike the mysterious photograph or the even more enigmatic real thing.
Digital art is therefore cleaner and much less blurred or muddy. The better the art the less contrast it has. Putting art through this process also also highlights deficiencies in ones work.

[steve.ledger]

That sounds interesting - can your demonstrate this with examples please.

[MarkMyWords]

Well, filtering or even 'painting over' photos is not 'wrong' in itself. The finished image is what really matters of course, but claiming that you did it all from scratch is a bit sad.

As far as pros are concerned it must only A; do the job, B; not infringe copyright and if possible C; be original (though this is much more optional than many assume).

I used to wonder why people spent such a great deal of time and effort creating 'photo-realistic' images in vector programs, but it was pointed out to me that it is both a good way to learn useful skills and there is a very large market for retouching photos. A really good 'photo-realistic' vector drawing is often much better than an actual photo.

Where we may be impressed by the skill of creating a photo-realistic image, that is somewhat offset when there is reason to suspect it is a filtered photo.

My own particular pet-hate is when someone traces another persons image - photo, drawing or painting and claims it as their own...ARRGH!

[salaam]

A good example is the contribution by Thor entitled; 'Cup of coffee?'
In the Xara Gallery (next door), Thor recently posted 2 pictures of a coffee machine. One is a photo while the other is his reproduction.
Image location:
http://www.talkgraphics.com/attachme...1&d=1194523190
If you convert this double image into a negative, you will see a much bigger difference between the 2 versions than the original colour versions.

'Cup of coffee?' Thread location:
http://www.talkgraphics.com/showthread.php?t=30042

If you study Gray's 'Yellow Trainer' along side a negative copy of the image, you will not see any extra detail in the negative copy. Even though this raster plane image contains more detail than the coffee machine photo.
'Yellow Trainer' thread location:
http://www.talkgraphics.com/showthread.php?t=30012

I even tried tracing a photo and then converted this vector into a bitmap again. The trace was not as good as the original but the negative still had the hallmarks of a photograph. I also reduced the colours of a photo bitmap. Neither process seemed to hide the fact that the image was initially a photo.

Looking at different images in this way has not led me to believe that there are any fakes in Talkgraphics.

[steve.ledger]

... or even better, by turning the image into a 'negative' by dropping a 100% black fill onto it.

When I try this the image goes 100% solid black..

[Doug]

When I try this the image goes 100% solid black..

Agreed. I got the gray scale by dropping white instead of black on the image.

[-=Drifter=-]

It works great for me. Thanks, Salaam, very interesting.

[steve.ledger]

Very interesting. Dropping white certainly gives me greyscale, but dropping black on any raster image/photo whatsoever gives me solid black, no negative effect.

XXP Ver 3.2.3

EDIT: Aha! You need to make the 'LINE COLOUR' white when dropping a black FILL COLOUR.
Now I have the negative effect

[salaam]

You need to make the 'LINE COLOUR' white when dropping a black FILL COLOUR.
Now I have the negative effect

I see; the line colour dictates the colour of the black and darker pixels in grey scale, while it changes the white and lighter pixels in negative. So you can even tint your negatives at a click.

I had just tried looking at photograph touch ups.
http://www.talkgraphics.com/showthread.php?t=25200
It works well here as well but due to the clever Photoshop smudge tool, identifying it requires a little more skill.

[steve.ledger]

Interesting example, I wonder why the member was banned....?

Personally I'm often suspicious of those (fantastic result) before and after photo restoration shots (which could easily be done in reverse.)

But then I have the same suspicion with before and after photo's of people who succeeded with *The $500 You Beauty* diet plan..