Ljusgradient

Ljusgradient is a term used to describe the spatial variation of light intensity, and sometimes spectral content, across a scene or image. In formal terms, it refers to the gradient of a light quantity such as luminance or irradiance, often denoted as ∇L, where L can represent luminance (cd/m^2) or irradiance (lux). The magnitude of the gradient indicates how quickly brightness changes over distance, while the direction points toward increasing brightness.

Ljusgradient arises from the combined effects of light sources, geometry, materials, and occlusion. Direct illumination, shadows, interreflections, and surface reflectance all contribute to how brightness changes from point to point. Variations in color or spectral content can also form a gradient, for example when different wavelengths are absorbed or scattered unevenly across a scene.

Measurement and use: The gradient can be measured in units of luminance or irradiance per unit distance (for instance, cd/m^2 per meter or lux per meter). In practice, photographers, designers, and computer graphics specialists analyze ljusgradient to understand shading, depth cues, and visual contrast, or to manipulate images and render scenes more realistically.

Applications: In photography and cinematography, managing gradients helps control dynamic range and perceived form. In computer graphics, gradient-domain rendering and processing exploit ljusgradient to produce smooth lighting transitions and reduce artifacts. In image processing, gradient information supports edge detection, tone mapping, and scene analysis.

See also: luminance, irradiance, BRDF, shading, gradient-domain processing, HDR imaging.