digital image

Definition: Image which has been produced by transforming a picture into a digital record followed by reconstruction of the picture on computer screen or other visible medium such as print. * Process comprises: (a) Image capture: optical image is scanned or captured by regular array (raster) of picture elements (pixels) (b) Translation or transduction: brightness and colour values (if recording in colour) are evaluated and recorded together with location or address of each pixel. (c) Storage: record is kept in electronic form. (d) Output: when digital image is required, electronic record is read for its information in order to reconstruct image using output device such as monitor screen, printer: each pixel in raster is printed or displayed according to brightness values appropriate for it. (e) Reconstruction: when digital image is seen, human eye blends brightness or colour values into an integrated picture, with more or less detail according to quality of image.

Previous Term: digital filter  Next Term: D-line