[Gimp-user] PS scaling looks noticeably better then Gimp's

[Sven Neumann]

Hi,

On Sun, 2008-11-30 at 08:43 +1030, David Gowers wrote:
> Hi,
> 
> On Sun, Nov 30, 2008 at 6:21 AM, Ruud Amesz <hesamz at hotmail.com> wrote:
> > After scaling down an image you have to use the filter USM (unsharp mask) to
> > sharpen your image. You did not mention if you did so.
> 
> Are you saying that Photoshop automatically does that when you scale down?

They are probably not really applying unsharp mask, but there are
interpolation methods that do something similar. The Lanczos method in
GIMP has this quality. The Sinc kernel used for interpolation works
somewhat similar to what Unsharp Mask does. Still it is sometimes
necessary to do additional sharpening after scaling.


Sven