This Standard defines image system contrast, expressed as a ratio, and its measurement. It
applies to permanently installed and temporary display systems and all displayed images
regardless of AV technology (e.g., direct view display, rear projection, front projection). The AV
image system includes the display, source equipment, signal path and distribution, and the room
environment. System contrast ratio measurements are taken in the system’s typical use case (e.g.,
classroom with ambient light and a video distribution system throughout the school). Four contrast
ratios are defined and are based on content viewing requirements. Practical metrics to measure
and validate the required contrast ratios are provided