Optical Character Recognition (OCR)
Optical character recognition systems use scanners to capture printed text and convert it into computer-readable characters for editing. See OCR and document scanner.
Scanners and Cameras
Scanners are similar to digital cameras, except cameras can focus into infinity. Desktop scanners have physical dimensions that determine the size and bulk of the material that can be scanned. Automatic feeders are used to scan stacks of paper, typically for OCR jobs.
Scanners are rated in dots per inch (dpi), whereas cameras are rated in total pixels. Both scanners and cameras have an optical resolution (the real lens resolution) and an interpolated resolution computed by software. The higher the optical, the better.
Scanners are also rated by the maximum color depth of each pixel (how many colors can be stored). At minimum, scanners support 24-bit color, and many go up to 48 bits. See optical resolution, interpolated resolution, 4K resolution, document scanner, flatbed scanner, sheet-fed scanner, handheld scanner, drum scanner, slide scanner, photo scanner and digital camera.