Re: filmscanners: File format

[Arthur Entlich <artistic@ampsc.com>]

Without wishing to add to you "pain" ;-),  I was surprised to determine 
that this exact situation (the "leveling" of the compression) occurs 
much sooner than I expected.  You will probably have noted that via my 
recent posting to that effect, where I monitored file sizes after 
repeated Jpeg compression.

It seems the algorithm rather rapidly reaches the point of "no further 
benefit" and stabilizes the file size, and likely also the amount of 
change in the pixel structure.

Art


Bill Ross wrote:

>       The only very slight disagreement I'd have is that it might be possible 
>       that if you open and save in JPEG format enough times, you might 
>       actually reach a point where you are "chasing your tail" and that 
>       certain random pixels will change one way one time and then return to 
>       the same position the next.  However, by the time the process reached 
>       this point, it would seem you'd have such an abstraction of the 
>       original, it wouldn't much matter ;-)
> 
> The ever-recurring discussion of whether jpeg is always
> lossy has become just such a cyclic abstraction to me. 
> But that's life :-)
> 
> Bill Ross