GIMP Plugin Registry

This plugin is not more maintained but still works very well On Gimp 2.6 and even 2.7
Was developed by Peter Heckert , Windows binary were provided by Michael Schumacher. but the original side is offline from years and all old links dead

i am mirroring both source code and binaries to avoid it can get lost and i repost here also in the hope that may found more users and a maintainer (as i said still works very well ,from gimp 2.0 till 2.7 a maintainer may help for the future )

About the most obvious question, what is the difference with standard unsharp mask that is simple,
what gimp USM offer is a only a subset of what this plugin may do.

gimp USM works ,basically by adding a blurred duplicate ,that as result create a white halo around contour's edges.

As example if you have a black arrow on dark grey BG, a more or less wide white halo around the arrow will made it much more visible and the image more sharp
But that easily lead to effect similar to overdone HDR and work better on the darker part of the image to reveal less dark details

Well USM2 may do that but also the contrary, sharpen by adding a dark halo
To use a similar example may sharpen a gray arrow on a white BG by creating a dark halo around arrow's contour

"Dark halo" sharpening on photos look often more natural then white at the most usual settings,
while pushing for dramatic setting is usually a more pleasant and artistic effect,
( we are used to accept black outlines as in draw,comics, illustration, so are more acceptable for our eyes then white outlines ..
Note that a thin but very intense white halo around contours edges is identical to white outlines, as a thin and very dark halo is identical to black outlines ..this is relevant for "artistic" or "creative" uses )

Interface may look too complex at first but just draw a ideal line under the 4th slider will solve

All what up is "BASIC" : on 4 sliders there 3 correspond exactly to that of the Gimp USM
"+" is to regulate the "white halo sharpening" ,"-" to regulate the "dark halo sharpening"
(NOTE: If both"+" and "-" are set to 0 then plugin do not sharpen but create a gaussian blur )

All what after that ideal line is "ADVANCED" ...default is fine in most cases anyway from there you may correct the gamma, or dose the intensity of the effect differently on shadows, middletones and highlights.

More accurate information are included in the zip.
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If someone may provide a better description is welcome , i am a user and not a developer and my English is quite approximate.

DOWNLOAD
http://photocomix-resources.deviantart.com/art/Lost-Found-Gimp-UnsharpMa...