How to digitally watermark

[E. ALLEN SMITH]

>Adam Shostack <adam at homeport.org> wrote..
>>Creating watermarks that can't be removed without degrading
>>image quality is not especially difficult.  The two tricky bits are
>>durability and collusion protection.

	The difficulty I can see is with the "without degrading image quality"
part. Given ever-improving image enhancement and processing techniques, someone
probably could - or at least will be able to in the near future - take any
image in which the watermark didn't degrade the image by itself and remove
the watermark without _perceptible_ alterations in image quality. 

>I hope someone, somewhere finds this interesting...

	Yes, actually; I was just at a seminar on computer image interpretation
for the biomedical field.
	-Allen