To scan and scale down, or scan at the target resolution?

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Gregory C
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To scan and scale down, or scan at the target resolution?

Postby Gregory C » Mon Sep 02, 2002 5:07 am

Which will produce better output? Scanning at 4000dpi and scaling back to 30% via the SilverFast Scale dimensions, or scanning at 1333dpi?

When scanning at 1333dpi, is the scanner scanning 3 pixels at a time or 1 in every 3 pixels? I feel that scanning 3 pixels at a time and averaging the result would be better than just scanning 1 in every 3 pixels but I don't know anything about scanning technology.

If I use the slider to select a hardware resolution (even in SilverFast HDR), is interpolation used to produce the final output?


regards
Gregory

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LSI_Flyvbjerg
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Postby LSI_Flyvbjerg » Mon Sep 02, 2002 7:08 am

No matter, if you are using the maximum resolution and scaling or the final resolution, SilverFast will always calculate the final scan resolution before a scan (1333 dpi in your case). SilverFast then uses the next higher hardware supported resolution for the scan (the resolutions that can be selected by the resolution slider) and interpolates down to your desired scan resolution while scanning.

Eric.

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Gregory C
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Resolution: scaled or final?

Postby Gregory C » Mon Sep 02, 2002 2:01 pm

Eric Flyvbjerg wrote:... SilverFast will always calculate the final scan resolution before a scan ...
... then uses the next higher hardware supported resolution ...
... and interpolates down to your desired scan resolution...


Is interpolation always on then, even if I choose a hardware resolution with the slider?
Does this somehow explain why the slider offers 8000dpi when I'm processing 4000dpi files with HDR?
Wouldn't interpolation be inferior to a 'clean' hardware scan?

regards,
Gregory

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LSI_Flyvbjerg
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Postby LSI_Flyvbjerg » Tue Sep 03, 2002 7:36 am

Interpolation is NOT on, when you select a hardware resolution with the resolution slider. However interpolation is ON, when you select a different resolution (a value between the slider values).
All SilverFast modules can interpolate up to the double of the optical (maximum) resolution. That?s why you can select 8000 dpi for 4000 dpi images.
BTW: The highest resolution in the resolution slider (the double of the optical resolution) is not a hardware supported resolution, but it is interpolated by SilverFast.

Eric.


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