Re: Digicam vs. Scanner resolutions

["Igor Klinchin" <karmen38@xxxxxxxxxxxx>]

----- Original Message -----
From: "Kennedy McEwen" <rkm@kennedym.demon.co.uk>
> That is why MTF is so useful - all the components just multiply together
> to give the end result.  The one exception is when you scan the image
> you also introduce a "brick wall" limit and any residual resolution
> above that is "reflected" to appear as the MTF of the aliased component.
> Thus, appropriately tuning the MTF of the scanner can eliminate grain
> entirely from the scanned image without loss of performance.

Does it mean reducing scanner optics MTF? Or how can scanner do it
otherwise? In other words scanner reduces resolution of the image to match
the resolution of its sensors. I hope that I am using concepts of MTF and
resolution in the same sence.

The first question about this issue is whether a drum scanner uses the same
technique or is it inherently the "problem" of CCDs? Theoretically this
antialiasing technique should be applied to any device converting continuous
tone image to matrix of pixels. On the other hand drum scanner can
potentially sample in points forming an irregular pattern.

The other question is a question of how large should this antialiasing
degradation of MTF be comparing to let's say traditional darkroom prints. In
the traditional darkroom there is no artificial "brick wall" limit of the
pixel matrix that could produce a feeling of ability to improve the image
quality continuously.

Thank you,
Igor


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