The document discusses image processing and provides an overview of the topic in three paragraphs or less: Image processing involves processing or altering existing images in a desired manner. It has two main aspects - improving visual appearance for human viewers and preparing images for feature measurement and structure analysis. Image processing is needed to prepare digital images for viewing on output devices, optimize images for applications by enhancing structures, and allow computer-assisted analysis to detect important structures. It acquires images from scientific instruments and space missions to communicate results.