Analog image: an image that is continuous/indivisible in space and has no hierarchical structure of signal values. Digital image: an image divided into discrete pixels in space, and the signal values are divided into finite levels, which are represented by the numbers 0 and 1.

Image digitization must be based on image electronization, which converts analog images into electronic signals and then into digital image signals. The main method of image information acquisition technology is scanning technology, which is very mature. Another method is to directly use digital photography technology.

meaning

Image processing is a process from image to image, which transforms the input image to improve the visual effect of the image or enhance some specific information. This processing technology includes drying, enhancement, sharpening, color processing, restoration and so on.

Image analysis, through the detection and calculation of image-related targets and contents, obtains some objective information, thus establishing the description of the image and identifying the image content. Image analysis is a process from image to non-image (data or characters), including image segmentation, image description and analysis.