Define Brightness
Brightness generally refers to the subjective perception of the intensity of light emitted from or reflected by an object. It is a qualitative attribute related to the visual sensation of how "bright" or "dim" an object appears to an observer.
In various contexts, brightness can be defined more precisely:
-
Physics and Optics: In physics and optics, brightness refers to the total amount of light emitted from or reflected by an object per unit area, often measured in units like lumens per square meter (cd/m²).
-
Perceptual Psychology: In perceptual psychology, brightness is understood as the attribute of visual perception in which an area appears to emit more or less light compared to its surroundings. It is influenced by factors such as the intensity of the light source, surface reflectance, and the adaptation level of the observer's visual system.
-
Display Technology: In display technology, brightness refers to the luminance level of a display screen, typically measured in nits or candelas per square meter (cd/m²). It indicates how bright the screen appears to the viewer.
Brightness is often contrasted with other perceptual qualities like hue (color) and saturation (color purity). It plays a crucial role in visual experiences, influencing how objects are perceived under varying lighting conditions and how displays are optimized for readability and visual comfort.
