[Digikam-users] Unsharp Mask in Digikam

[Mikolaj Machowski]

Dnia Thursday 03 of April 2008, TransFXB napisał:
> Hello,
>
> I am continuing my review of Digikam for my next article on [fr]
> http://www.questionsphoto.com
> Deeper I go, more I realize that Digikam is the most advanced picture
> manager in Linux world, by far.
>
> Beside my early comment on thumbnail display process (a bit long to
> built...), I have a question regading Unsharp Mark function:
>
> Lower limit of radius range setting is 1 pixel, which is a bit unusual.
> 1 pixel radius is convenient for pictures within 7 to 10Mpix and more
> but is to high for lower resolution pictures, resulting in some
> oversharpening even is "gain" is set to a low value.
> One should be able to go down to 0.1 pixel radius instead of 1 as the
> lower limit.

Joke with subpixel radius in USM is that is only a tricky way to
calculate standard deviation of the Gaussian as far as I understand GIMP
code. So there are two ways to fulfill this comment: add subpixel radius
(like GIMP) or add explicit control of standard deviation (like
ImageMagick, which has both ways BTW).

m.