A simple plug-in to convert RGB images to YUV in GIMP. This means that after having applied the filter, you will get luminance (Y) in the red channel (R), and chrominances in green and blue channel. By using the decompose plugin, or the channel dialog, you will be able to work in YUV space, and be back in RGB space by the reverse plugin.
A simple plug-in to do fourier transform on you image. The major advantage of this plugin is to be able to work with the transformed image inside GIMP. You can so draw or apply filters in fourier space, and get the modified image with an inverse FFT.
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.
This script will make a single eyeball, and has been updated for v2.6. The colors of the iris, and size of the pupil, lighter iris, and darker iris, are all adjustable. Ideally, the inner eye color should be about half the brightness of the outer eye color to provide a nice transition from the pupil, but any two colors can be used. The image itself can be anywhere from 300x300 to 3000x3000 in size. The eye will have a transparent background. Enjoy! The attached picture is what the final product will look like (your colors may vary, obviously!)
"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.
None of the sample images are sharpened. The original picture was 3000×2000.
This script crops the image so that the current selection winds up at the center of the image. It is especially useful when postprocessing digital images: When the subject of a photograph appears off-center, simply select the subject, click on Script-Fu/Selection/Center Selection..., optionally customize the script's parameters (described below), et voilà—the subject is now perfectly centered.