P3D Re: JPG and destruction

[roberts@xxxxxxxxxxxxxxxxx (John W Roberts)]

>Date: Sun, 19 Apr 1998 18:09:07 -0600
>From: Ole Hansen <oha@xxxxxxxxxx>
>Subject: P3D JPG and destruction

>I am not pleased with the destruktion of the stereograms by JPG
>due to ghosting, false pixels etc, etc. as compared with PNG, but
>what can I do ? All comments are appreciated.

Does JPS address this issue? (For instance, using rules to process both
images together in a coordinated manner to facilitate 3D?)

>That is right, but GIF is useless with color photograps

I disagree - you might say "limited", but I do not agree with "useless".

>> JPEG retains the spatial resolution of the original image....
>It certainly does not !

I agree. Whatever the process is called, some spatial information is lost
in the process of lossy JPG compression.

>> ....but homogenizes the colors of adjacent pixels to achieve
>> high data compression ratios....

Note to Jon Gross: homogenizing the colors of adjacent pixels does affect
spatial resolution - consider an extreme case where you homogenize *all the
pixels in the image* to the same color - effectively you've reduced the
resolution of the image to 1x1! :-)

John R


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