From the reviews: "Middleton and Sivaswamy have attempted to provide a comprehensive survey of the existing literature and a sound theoretical basis for using hexagonal sampling in image processing. ... By covering all of the areas of image processing that a basic image processing text would cover, the authors have succeeded in providing a good reference and a framework for students interested in processing images using hexagonal sampling. The authors provide several examples of advantages of processing using the hexagonal sampling grid over a square sampling grid." (Gopinath Kuduvalli, Computing Reviews, December, 2006)