sharpen

LAB Sharpen

adamkemp — Wed, 19 Aug 2009 05:11:52 +0200

This script does LAB sharpening using the unsharp mask in the luminance (L) layer. It decomposes the image into LAB layers, sharpens the luminance layer (using the supplied settings), and then recomposes the image. The interface is the same as the unsharp mask (radius, amount, threshold), but the filter is only applied to the luminance layer.

Sharpening

Redphoenix — Tue, 07 Jul 2009 19:20:35 +0200

This script sharpens an image using some simpel layer manipulations. It offers a Radius and a strength operator to increase strength vs quality. I also added a simpel brightness correction in order to remove highlights created by a too high sharpening value. IT's therefore recommended to increase the correction value when increasing the strength value a lot.

UnsharpMask2.0.12 (Windows binary -source code)

PhotoComiX — Mon, 16 Mar 2009 06:00:38 +0100

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...

G'MIC plug-in

dtschump — Tue, 13 Jan 2009 14:16:31 +0100

The G'MIC plug-in for GIMP defines a set of various filters, including artistic filters, image denoising and enhancement, 3D renderers, etc.. It is a quite large plug-in, integrating a lot of different effects to apply.

This plug-in is able to update his list of filter definitions from the Internet (so it improves itself over time), as well as allows any user to add its own custom filters in it.
It has been written by the author of the GREYCstoration algorithm (used for image denoising). It is actually intended to replace it in a near future.

Download G'MIC for Windows 32 bits

Here is one screenshot of the plug-in in action, as well as a result of filter application :

Wavelet Sharpen-0.1.1 Windows 32 binary

Francois_C — Mon, 12 Jan 2009 14:26:09 +0100

A new Windows compilation of the last version of this fine plugin written by Marcor.
No console window. Compiled with LDFLAGS=-mwindos as usual.

Manny Librodo Script

cprogrammer — Sat, 22 Nov 2008 20:29:42 +0100

This implements a sharpening technique as described at
http://digitalphotographer.com.ph/forum/showthread.php?t=1085
This is Manny Librodo's Sharpening moves. You can give it a try and you will be surpised with the quality. One caveat, there really is no one set formula for sharpening so you may want to experiment with different amounts for different images.

Wavelet sharpen

marcor — Mon, 29 Sep 2008 11:02:08 +0200

The wavelet sharpen plugin enhances apparent sharpness of an image by increasing contrast in high frequency space. The amount of unsharpness of the original image can be taken into account by adjusting the sharpening radius. As an option you can choose to sharpen the luminance (YCbCr) channel of the image only.

Features

Graphical user interface
Preview image
Option to sharpen luminance channel only
Selectable sharpen radius
Lossless image conversions

Description

The wavelet decomposition of an image results in multiple images with different frequency content. When amplifying the high frequency parts the recomposed image appears to be sharper than the original one. That way the frequency which should be amplified most can also be selected and a given unsharpness in the original image can be taken into account.

This GIMP plugin allows to perform this wavelet decomposition and allows the user to adjust the amount of sharpening and the radius of unsharpness in the original image. As an option you can sharpen the luminance channel of the YCbCr converted image only which reduces colour artifacts to appear (especially in noisy images). The sharpness of the colour contrast is not critical to the human eye.

Example

This picture was taken with the Nikon D80 and the Nikkor AF 50mm 1:1.8 lens fully open. Because the image is slightly out of focus and due to the wide apperture and aliasing the image is not quite sharp.

License

The plugin is distributed under the General Public License (GPL) version 2 and newer.

Scale in steps

Loxley — Thu, 25 Sep 2008 07:50:39 +0200

About

"Scale in steps" resizes an image to the given dimensions in several steps to get a way sharper result compared to resizing in one step. The step size is given in percent and should range between seven and ten percent.

Samples

None of the sample images are sharpened. The original picture was 3000×2000.

baerm_s5.jpg: Stepsize: 5%
baerm_s.jpg: Stepsize: 10%
baerm_f.jpg: Traditional scaling

National Geographic Script

elsamuko — Mon, 22 Sep 2008 23:27:57 +0200

This script simulates a high quality (portrait) photo like these from the National Geographic.
Copy it into the scripts folder from GIMP, you will find it then under Filters -> Generic -> National Geographic.
Thanks to Martin Egger for the shadow revovery and the sharpen script, which I included in the script.
Examples here and here:

Update1: Added local contrast option.
Update2: Optional inverted layer mask for brighter skin types.
Update3: Added a batch version of this script, run it with
gimp -i -b '(elsamuko-national-geographic-batch "picture.jpg" 60 1 60 25 0.4 1)' -b '(gimp-quit 0)'
or for more than one picture
gimp -i -b '(elsamuko-national-geographic-batch "*.jpg" 60 1 60 25 0.4 1)' -b '(gimp-quit 0)'
Be careful, the batch script overwrites the original image. More info here.
Update4: Fix for the batch script, it merges now all layers before saving.

Smart Sharpen (Redux)

eg — Mon, 07 Jan 2008 14:05:46 +0100

Implements the redux version of smart sharpening

Tutorial: http://www.gimpguru.org/Tutorials/SmartSharpening2/

The Refocus plugin from http://hphsite.de/refocus/ must be installed seperately if you want to use this option in the script.