Image scanner

An image scanner is an input device that captures a physical image and converts it into digital data. It samples reflected or transmitted light to create a digital representation.

Charge-coupled device: A semiconductor sensor that converts incident light into electrical charge for image capture. CCD arrays detect light from the image as the scanner moves across it.
Pixel: The smallest addressable element of a raster image. A scanner’s sampled image is represented as a grid of pixels.
Document scanning: The capture of paper documents as digital images, often for storage or processing. It applies scanner hardware to paperwork and administrative records.
Digital camera: An electronic device that records images using a sensor and an optical lens. A camera captures images without requiring the original to pass beneath scanning optics.
Contact image sensor: A compact image sensor that places a row of detectors close to the surface being imaged. CIS scanners replace the lens-and-mirror optics used in many CCD models.
Raster graphics: Digital images represented as grids of colored or grayscale pixels. Most scanner output is a raster image rather than vector geometry.
Optical character recognition: Software that converts text in images into machine-readable characters. OCR can turn a scanned page into searchable, editable text.
Camera scanning: The digitization of documents or objects by photographing them with a camera. It can capture bound or three-dimensional materials that resist flatbed scanning.
Optical resolution: The finest spatial detail an optical imaging system can distinguish. It sets the detail the scanner can capture before software interpolation.
Image resolution: A measure of the spatial detail represented in an image, often expressed in pixels or pixels per unit length. Resolution describes the detail in a scan’s pixel grid.

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Input deviceBroader topic: It turns marks on paper into data a computer can process.