Linux for Designers

GREYCstoration is a Gimp plugin for image denoising and interpolation, using state-of-the-art image processing techniques. It offers really cool, denoised and sharp results of noisy and artifacted images (check out the demo images).
Just download the 2.9 zip archive from the website and copy the "GREYCstoration_gimp_pc_linux" file into "~/.gimp-2.4/plug-ins/". The filter can be found at the Gimp Image Window in "Filter > Enhance > GREYCstoration".