Definition of Raster scanning

Photonics Dictionary

Raster scanning: Raster scanning is a technique used in imaging and scanning systems to systematically capture and process information from a two-dimensional area or surface. It involves moving a sensor or scanning element across the area of interest in a grid-like pattern, collecting data point by point.

In raster scanning:

Mechanical movement: The sensor or scanning element is moved systematically across the surface being scanned. This movement can be achieved using mechanical components such as motors or actuators.

Grid pattern: The scanning process follows a grid pattern, with the sensor moving horizontally and vertically in a sequential manner.

Data collection: At each position along the grid, the sensor collects data or samples the signal corresponding to the property being measured, such as light intensity in optical scanning or electrical voltage in electronic scanning.

Sequential processing: The collected data is processed sequentially, with each point corresponding to a specific location in the scanned area.

Image reconstruction: After all the data points have been collected, they are processed and reconstructed to form a complete image or representation of the scanned area. This may involve interpolation or filtering techniques to enhance the quality of the final image.

Raster scanning is commonly used in various applications, including:

Image scanning: In flatbed scanners and document scanners, raster scanning is used to capture digital images of documents or photographs.

Remote sensing: Satellite and aerial imaging systems use raster scanning to capture high-resolution images of the Earth's surface for mapping, environmental monitoring, and resource management.

Display devices: Cathode ray tube (CRT) monitors and older television systems use raster scanning to display images on a screen by systematically illuminating individual pixels in a grid pattern.

3D printing: Some 3D printing techniques use raster scanning to deposit material layer by layer, building up a three-dimensional object from a series of two-dimensional slices.