GIMP Plugin Registry

FX-Foundry/Photo/Enhancement/Maximize Local Contrast... Like Stretch Contrast, but instead of using the minimum and maximum pixel values from the entire image, uses the minimum and maximum in the vicinity of a pixel to compute its new value. Takes a while to run, but really brings out textures. Result is a Grain Merge layer that adjusts values of the original image.

This filter operates on the visible image, not on a layer or selection.  read more »

This plugin is an alternative to the existing Engrave plugin supplied with GIMP. Basically, the plug-in transforms a grayscale image into a series of horizontal lines of varying widths. For example, the following (small) image

can be transformed into:

(stand back 10-20 feet).

Full description at: http://pages.infinit.net/leware/engrave.html .

The G'MIC plug-in for GIMP defines a set of various filters, including artistic filters, image denoising and enhancement, 3D renderers, etc..  read more »

This script converts color images to B&W using channel mixer settings,
which simulate the use of color filters in B&W photography. It allows to choose many predefined filters and set their intensity. Previously posted to old registry in July 2006, now updated to work with GIMP 2.4. Avoid setting intensity to 1, besause it totally filters one of RGB channels and increases noise.

This is another script for converting a picture to black & white. The decompose plugin must to be available. The way of converting the picture is rather different than what other plugins do. Two different luminance layers are mixed according to a mask made with a saturation layer. Six different combinations are provided. Functions are available under the menu script-fu/Photography/BW Labs.

Digital Negative Calibration Pattern - creates B&W calibration pattern. Menu Item is placed in Gimp main window Xtn -> Script-fu -> Utils

Implement several different black and white conversions including color filters

More information:

http://epaperpress.com/psphoto/
http://www.thelightsrightstudio.com