PBase

Hi there
If I have a photo is there any way to tell or any program that will show/tell me if something has been edited out of it?

Thanks
Ross

skier wrote:Hi there
If I have a photo is there any way to tell or any program that will show/tell me if something has been edited out of it?

Thanks
Ross

I think there are specialised software apps that are used for security purposes to embed data into an image file so that you can tell later if it has been edited. The ease of editing digital images is one reason why law enforcement agencies have been wary of adopting digital photography on a wide basis. Have you tried a search on Google or Yahoo!?

There is a way - but it can be very technical.

You know when you change just one pixel in any way in Photoshop and then try and close the image it asks if you want to save it? Well Photoshop is keeping count of the binary code (usually hexadecimal code) that describes every aspect of your image. If you could extract this code for your "original" image and derive a unique number (it could be a very long alphamumeric string) and then compare your number with the one you extract from another "version" of your image that looks identical (but might not be), you will be able to tell whether your original has been changed - even by a slight alteration to a single pixel.

Backup software does this very same thing when it asks you if you want to overwrite the new or the old version of the file because one of them has changed.

Complicating this of course is image compression and what various methods do to byte counts etc. You may need to adopt a rigorous "system" for saving and/or compressing (or not) your original RAW files, TIFF files and EXIF-JPEGs so that you can detect whether your images are ever altered.

Sorry I can't be much more help....

Phil
Dallas, TX

embed a watermark on your image there is a plug in for photoshop for it. I simply use it to encode all my images with my name on it and a copyright. quite handy

shorthand wrote:embed a watermark on your image there is a plug in for photoshop for it. I simply use it to encode all my images with my name on it and a copyright. quite handy

What is the current charge that Digimarc is charging to embed the water mark on an image? I was interrested in that plugin in Pshop once until I learned there was a charge-per-file for using it.

wwebbjr wrote:

shorthand wrote:embed a watermark on your image there is a plug in for photoshop for it. I simply use it to encode all my images with my name on it and a copyright. quite handy

What is the current charge that Digimarc is charging to embed the water mark on an image? I was interrested in that plugin in Pshop once until I learned there was a charge-per-file for using it.

Just visit their webite and look for details of their charges, it's not that difficult.