T3D Re: Digital resolution

[John Ohrt <johrt@xxxxxxx>]

Not really.  I'm saying that if you can't resolve the intensity into
sufficient discernable levels for the task at hand, then spatial
resolution is irrelevant.  ie you can't measure what you can't see.


Some comments.

Just because phenomena are measured according to some standard condition
doesn't mean that the standard condition is significant.  Usually it is
just convenient.  For eample a negative can contain subtle levels
differences which are discernable to the eye but not discernable after
coversion to 8 bit linear levels.

The faithfulness of representation is a very significant issue in some
applications.  For example, if I take a picture of a flower, I want
controllable colour rendition and controllable resolution.  In some
cases, I may wish to have the best attainable.  As I have discussed
elsewhere, just to faithfully reproduce what I see within the limits of
a monitor requires 12 bit linear resolution to approximate the shades
that my eye can distinguish when looking at the flower.

Now a radiologist looking for cancer has somewhat higher levels than you
or I because he/she is a trained observer capable of even further
discrimination.

Now someone can say that 8 bit linear levels are "good enough".

Surprise, I agree that it is good enough for many applications, and
certainly much more affordable!

> 
> What one would seem to be able to infer from all this is that printers are
> better able to represent fine detail of moderate or greater contrast, and
> monitors are better able to represent larger areas of subtle shading (in
> either luminance or chrominance).

You could argue that.  However, the are a lot of different perceptions. 
For example, I prefer printed text output and schematics because that is
how I learned to deal with the world.  But for photos, nothing beats a
good calibrated monitor!!!

Regards,
--
John Ohrt,
Toronto * Ontario * Canada



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