So called "copyright" pictures

:-)

I would be intrigued to hear an explanation of how any system can distinguish professional photographs from amateur photographs? I cannot, for the life of me, think how that could be done from the image alone???

Mike Harding

"Mike Harding" schreef in bericht news: snipped-for-privacy@4ax.com...

Very minor jumps in color, sort of an overlay, invisible for us mortals. Information is encoded in this overlay. Plus lots of redundancy to make it reliable.

Well, my eyes can tell the difference when I see good, pro quality pictures. Maybe some bad-ass DSP guys came up with an algorithm to do what the eye does for free?

To CBFalconer, I suppose one solution would be to scan them in yourself with a nice 4800DPI scanner and copy the pic onto one of the flash cards that cameras use now. Then you can use one of the camera shop's digital print stations and perhaps, since the pic is coming from a CF or SD or whatever card, they might not run the "pro scanning" algorithm on it...

--Keith

That would make sense.

You might be surprised... did she sign anything at all ? That industry sees the customer as a revenue stream, and not as a client who hired time and equipment. Thus the 'downstream' cash flow is important for them to protect, and from what you say, it seems Kodak considers them enough of a revenue stream ( or a lawsuit risk ? :) to add protection.

Years ago, there was talk of a similar 'watermark' scheme for EPROMS that I presume was threshold-margin related - ie chip worked fine at

-jg

Approximately 11/23/03 15:36, Mike Harding uttered for posterity:

Trivial. Steganography would be one way. In a non-lossy format is as simple as encoding the data into the least significant bits of the image. Works best with higher bit depths or images where there is little correlation between the higher bits and the least-sig ones. In a lossy format such as jpeg, the data is added in the non-lossy compression stage done after the lossy encoding. Defeatable with any image editing app just by suitable edits of the image.

Several digital watermark systems are also available as software, some a bit cleverer and harder to eliminage than steganography.

I think I remember reading about the Digimark digital watermark which could survive being printed and then scanned. I have tried checking on their website but despaired at the sight of so much content-free prose.

Phil

I'm confused. Is the OP trying to copy some sort of digitally derived image or a "normal" photograph taken with 35mm or plate film?

I can certainly see how a digital image could be "watermarked" but I'm still unsure how this could be done during a normal developing/printing process with the required degree of reliability required to enable detection X years later and not hit lots of false positives?

Mike Harding

'Taint the way the law works. Unless the photographer specifically agreed to do a "work for hire" (which professional portrait-type photographers are typically loathe to do), the default is that he/she owns the copyright to the photos. Of course they can't use them without your permission, but they can extract a fee for you to copy them.

Anyway, and speaking only technically, this kind of digital watermark or steganography can be easily defeated in an image editing program by adding some Gaussian noise and then filtering the image. There might be some slight loss in quality. Newer versions of image-editing programs may refuse to do it, or may renew the watermark- I have not kept up with that kind of digital rights management issues.

You might be able to get an acceptable result with optical filtering by overlaying the photo and a sheet of pebble or frosted plastic, but that's just speculation. Presumably there's a preview screen so you wouldn't waste any money giving it a shot. Of course actually making a copy you would phone up the copyright owner and offer to pay whatever they feel it is worth, right?

Best regards, Spehro Pefhany

Are you sure it is nothing mundane such as the size of the picture, the aspect ratio, some sort of special matte or ???

-- why are you talking about Siberia in this newsgroup????? too many bad memorys

It depends what software you're using to do the scanning; if you've noticed, when you import from a TWAIN device in, say, Photoshop, before it will finish importing the picture it goes through a "watermark detection" phase.

By the way, many of those standalone devices also have currency detection.

Sorry, but legally, the photographer owns the copyright unless it was explicitly assigned to you in a contract of sale. Wedding photographers love to stick it to you vigorously by charging for albums. When we were choosing wedding photographers, one of our criteria was to make sure we would own the copyright and negatives.

He was talking about prints being scanned. That's about as far from "non-lossy" as you can get.

And they work on prints?!

I wouldn't be surprised- they are pretty robust on digital photos, you have to add a visible amount of noise (which can then be smoothed and sharpened), and cropping doesn't affect it, but we don't really have any solid evidence that this is what's actually happening.

It might be something really low tech like the IR response of the print paper, which I have a vague recollection was used-- to prevent photocopying of sensitive documents (?)..

Best regards, Spehro Pefhany

And since up till a few years ago, there were no digital cameras, nor even a hint that they would exist, and film was taken out of the camera, processed with chemicals, and transferred to paper, there was no point where such a digital signature could be embedded, nor reason for doing so.

I'm still puzzling over why this question is posted to comp.arch.embedded and alt.folklore.computers Neither has anything remotely connected with this.

Michael

Relax. It's on topic if the detection algorithm is embodied in an embedded computer.

nor reason for doing so.

Relax. Give it a day or so, and then we'll know what they are up to.

And give it a week or so, and we'll have an MSP430 crack for it :-)

--Keith

This may be a strech, but have you tried looking at the photo under a blacklight, or perhaps through a video camera? Many camcorders can see infrared and ultraviolet wavelengths of light outside of the human eye range, just like the kodak scanner can. I'd be interested to see how this was pulled off...

-Jim

It's off-topic and all, but CB has been around and contributed to this group forever. He/she is among friends and has something to talk about. Nothing wrong with asking the question. The fact that there's been a slew of interesting replies tells me that most readers found it of interest and non-inappropriate.