Greyscale
The continuous range of grey tones, from black to white, used to represent varying degrees of X-ray attenuation in a digital dental radiographic image.
Full Definition
In digital dental radiography, greyscale (also spelled 'grayscale' in American English) refers to the spectrum of grey values assigned to each pixel based on the quantity of radiation reaching the receptor at that point. A typical digital dental image uses an 8-bit greyscale, yielding 256 distinct grey levels, while some systems employ 12-bit or 16-bit depth for greater tonal discrimination. The greyscale appearance of anatomical structures determines their perceived radiolucency or radiopacity on screen. Editors should ensure consistent spelling within a document ('greyscale' in British English publications, 'grayscale' in American English) and should not conflate greyscale depth with image contrast or brightness, which are post-processing adjustments.
Usage
Usage note: Use 'greyscale' in British English publications and 'grayscale' in American English publications. Do not hyphenate. Distinguish from 'bit depth', which describes the number of grey levels available, and from 'contrast', which is a post-processing parameter.
In Context
- "The digitised image displayed a full greyscale range, with dense cortical bone appearing near-white and the pulp space appearing near-black." — Digital radiography training manual
- "Windowing the greyscale improved visualisation of the periodontal ligament space in the CBCT slices." — CBCT radiographic report