If you are generating the page, append a random number to the call for the image. 
<IMG SRC="/cgi-bin/image.pl?rand=4531269823">

[download]
Each time the page draws the string will be different, eliminating the cached image problem because to the browser it is not the same image.

In reply to Re: Preventing an image from caching by bastard
in thread Preventing an image from caching by belize

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