GIMP is an acronym for GNU Image Manipulation Program. It is a freely distributed program for such tasks as photo retouching, image composition and image authoring.
It has many capabilities. It can be used as a simple paint program, an expert quality photo retouching program, an online batch processing system, a mass production image renderer, an image format converter, etc.
GIMP is expandable and extensible. It is designed to be augmented with plug-ins and extensions to do just about anything. The advanced scripting interface allows everything from the simplest task to the most complex image manipulation procedures to be easily scripted.
BIMP Lite is a small and simple batch processor for image files, that allows you to perform various functions on multiple images. It can be used to create thumbnail images from your pictures, add a prefix/postfix (with meta variables), rename using a sequential number, change the case of filenames, replace/remove spaces & underscores, flip or rotate images and also apply anti-aliasing, inverse, greyscale and bevel effects. The thumbnail resizing allows you to force a specified width or height and keep the proportions, or define fixed image dimensions. Images can have text overlayed on them at any corner or side, as well as the center of the image. This text can include meta variables such as image height, width, number of colours etc. In addition, the program can also convert the file format to GIF, JPG, PNG, BMP, MIFF, TIFF, PCX or TGA. All of the actions can be performed individually, or combined. BIMP now also includes an FTP client, so you can automatically output images to a remote server via the File Transfer Protocol.