[filmscanners] Re: another Sharpening question

["Arthur Entlich" <artistic@telus.net>]

austin@darkroom.com wrote:


>
> Has anyone tried sharpening the channels individually for a color image?
> Since I don't do much color, I never thought of that before...but it seems
> like it might be advantageous, as you wouldn't lose as much detail in the
> sharper channels...  Any thoughts on this?
>
> Regards,
>
> Austin
>


A common trick of the trade is to convert the image to LAB, and then
only sharpen the monochromic image, leaving the color alone.  Since the
human eye responds much more to brightness levels than color (we have a
lot more rods than cones) that can sometimes be effective is reducing
color artifacting that USM can create.  It's the same basic principal
that was used with "s-video" and super 8mm video.  hey increased the
frequency on the luma signal, pretty much leaving the color signal alone
since it is much more prone to noise when "pushed".

Art

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