This volume emphasizes the primary role played by images in computer science. In the last two decades images have replaced written texts; the enormous possibilities of the image language have overcome written language in an ever-more-restricted ambit. An image is better than one thousand words; so it was straightforward to apply visual language in the field of computer science. Nowadays everything that appears on a computer screen is an image, regardless of whether it is a word or a picture. Is it possible to realize an e-learning program without working in terms of images? The answer is undoubtedly no, even if several problems arise in this context: the qualitative and quantitative content of the image we need to use for a specific task; the psychological effect on the user, including the level of attention and the correct perception of the image significance. Most of these problems form the basis of image-understanding techniques. Widespread use of images requires organization of the information in the databank or database, whose dimensions are sometimes so wide as to be too complex to manage; therefore information retrieval techniques arise from this need. The new instruments used in image and/or remote diagnosis, image transmission, the respect of the law in force and the ever-more-relevant image storage capacity required for this task imply the use of techniques of visual language and information retrieval.