Amanda writes:

>> Can anyone recommend a good method for sharpening images where there is a
lot of noise present?.   <<

Reduce the noise first and or sharpen the least noisy channels...(more
below).

Dupe your RGB file. Convert the dupe to CMYK (often the legacy custom CMYK
engine UCR or Light Black GCR is a good choice). Select the cyan and the
black channels (for a skintone for example). Sharpen away. Often do this in
a duped layer set to luminosity blend mode with some additions as noted
here:

http://members.ozemail.com.au/~binaryfx/ST_USM1.html

Then flatten and drag this as a layer back to your RGB file and blend in
luminosity mode, so that the wider RGB gamut is not lost from the file which
has had it's gamut reduced in CMYK for the advantage of the four plates
which are often better than the three of RGB. You may need to adjust the
endpoints if the CMYK trip has lost a bit of contrast.

Links to more on grain/noise reduction can be found here:

http://members.ozemail.com.au/~binaryfx/PSTV_links.html#G (grain/noise links
section)

Links to more on sharpening can be found here:

http://members.ozemail.com.au/~binaryfx/PSTV_links.html#S (scroll to the USM
links section)


Hope this helps,

Stephen Marsh.

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