Image properties

[domac80]

I had to remove all posts containing obviously modern content. Most of the pics have been taken from various modern threads and can be found there. Please guys, keep it vintage!

I was wondering, and I am not trying to be a wiseguy - just asking a serious (kind of technical) question;

If we ignore the obvious indicators (e.g. familiarity with the model/the span of her career, vintage of any clothing/furniture/automobiles used as back drops, etc.) how can one truly determine the age of any posted image with any degree of certainty?

I have heard - on good authority - that any image taken with a digital camera contains certain, unalterable, data within the properties section of the file.

This data can easily be accessed - for those who know how. It includes the actual date that the photo was taken (the real-time date, not the one one you & I see).

If the image is saved to a hard disk, the serial number of the computer's system board - the machine that was used to transfer the file - is indelibly imprinted within the properties data.

Further, if the image is ever posted on the internet, the ISP address of the registered user is etched into the properties data.

If you purchase a digital camera (or a cell phone with image capturing capabilities), and you register it with the manufacturer, that device is forever and unalterably assigned to you.

It follows that; no matter who actually has possession of the device in the future, the properties of any photo (well... one that is ever saved to disk, e-mailed, posted, etc.) will bear your stamp.

After review, it appears that this may be more appropriate for the "Help" section.


I'm not a conspiracy nut or anything - just wondering if anyone else has any thoughts on this topic?

[lagerlout]

There is a proggy to strip all this data out, you could do a whole folder at once, It was back in My Xp days and I can't remember the name of it unfortunately. I'm sure someone here will know it

[NIN]

I think it's called metadata
http://www.photometadata.org/meta-resources-field-guide-to-metadata

http://www.makeuseof.com/tag/3-ways-to-remove-exif-metadata-from-photos-and-why-you-might-want-to/

http://download.cnet.com/BatchPurifier-Lite/3000-2144_4-10908843.html

http://download.cnet.com/Remove-Metadata-From-JPG-and-PNG-Software/3000-12511_4-75756349.html

but there is also Steganography, but that's something altogether weirder

[electile disfunction]

There is also metadata placed on many other files when you use a computer, too.

You may want to check out Metability and similar programs to alter or remove this data:
http://www.metabilitysoftware.com/

e.d.

[deepsepia]

Originally Posted by domac80

I have heard - on good authority - that any image taken with a digital camera contains certain, unalterable, data within the properties section of the file.

Anything that's in the properties section of the file can be changed.

The real danger, that is much harder to change, is if the information is embedded in the pixels. This was done with inkjet printers, described here

http://w2.eff.org/Privacy/printers/docucolor/

You can digitally "watermark" an image file by changing a few pixels in ways which don't alter the visible image -- there's no way to tell that its been done. While this technique could be used to identify particular cameras or other imaging applications in use, there's no evidence that that's actually happening.

[electile disfunction]

Originally Posted by deepsepia

Anything that's in the properties section of the file can be changed.

The real danger, that is much harder to change, is if the information is embedded in the pixels. This was done with inkjet printers, described here

http://w2.eff.org/Privacy/printers/docucolor/

You can digitally "watermark" an image file by changing a few pixels in ways which don't alter the visible image -- there's no way to tell that its been done. While this technique could be used to identify particular cameras or other imaging applications in use, there's no evidence that that's actually happening.

(Remeber, this works only on images that are printed onto another medium. Images that remain in digital forms can have the watermark removed by many methods--like a simple screen capture, for example. )

e.d.

[deepsepia]

Originally Posted by electile disfunction

(Remeber, this works only on images that are printed onto another medium. Images that remain in digital forms can have the watermark removed by many methods--like a simple screen capture, for example. )

e.d.

Digital watermarks are resistant to removal, but not impervious. Some destructive transforms will obliterate them, some won't. It would be very hard to be sure that you'd processed an image file with a digital watermark, and to be sure that you'd destroyed it, without substantially degrading the image.

Screen capture and resizing won't reliably destroy robust watermarks, here's a reference from Digimarc:

http://blog.digimarc.com/images/2009...ve-result.html

[electile disfunction]

Originally Posted by deepsepia

Digital watermarks are resistant to removal, but not impervious. Some destructive transforms will obliterate them, some won't. It would be very hard to be sure that you'd processed an image file with a digital watermark, and to be sure that you'd destroyed it, without substantially degrading the image.

Screen capture and resizing won't reliably destroy robust watermarks, here's a reference from Digimarc:

http://blog.digimarc.com/images/2009...ve-result.html

Digital watermarks have certainly come a long way in the last few years! Thank you for the link, deepsepia.

e.d.