G'MIC (GREYC's Magic Image Converter) is a GIMP plugin based on GREYCStoration. It is a complete image processing toolbox that contains all the GREYCstoration features (of course), but also much many more filters for image denoising, enhancement, applying artistic effects, and more.
GREYCstoration is an image regularization algorithm that processes an image by locally removing small variations of pixel intensities while preserving significant global image features, such as sharp edges and corners. The most direct application is denoising. By extension, it can also be used to inpaint or resize images. It is based on methods using nonlinear multi-valued diffusion PDEs (Partial Differential Equations) for image regularization. This kind of method generally outperforms basic image filtering techniques (such as convolution, median filtering, etc.) classically encountered in painting programs. Other image denoising plugins are available, but are not free, and the corresponding algorithms are kept secret.
MP3Gain analyzes and adjusts mp3 files so that they have the same volume. It does not just do peak normalization, as many normalizers do. Instead, it does some statistical analysis to determine how loud the file actually sounds to the human ear. Also, the changes MP3Gain makes are completely lossless. There is no quality lost in the change because the program adjusts the mp3 file directly, without decoding and re-encoding.
mp3splt is a command-line utility that splits MP3, Ogg vorbis, and native FLAC files at specified times without decoding and re-encoding. It works with Mp3Wrap and AlbumWrap files and has a silence detection split mode, a cue mode and a "cddb source" mode. Libmp3splt is a library created from mp3splt. Mp3splt-gtk is a GTK3 GUI that uses libmp3splt.
PowerTop is tool that detects which Linux programs and kernel tunables are resulting in the largest power consumption and use of battery time. By fixing (or closing) these applications or processes, you can immediately see the power savings in the tool. You'll also see the estimated time left for battery power if you are running a laptop.