contrastwaardes

Contrast values, or contrastwaarden in Dutch, are quantitative measures that express the perceptual difference between two visual regions, signals, or colors. They are used across disciplines such as imaging, display technology, photography, and vision science to characterize how distinctly one area stands out from another.

Common types include luminance contrast, color contrast, and contrast ratios. Luminance contrast can be quantified with Michelson contrast (Lmax - Lmin) / (Lmax + Lmin) or Weber contrast (Ltarget - Lbackground) / Lbackground. Color contrast is often assessed with color-difference metrics such as Delta E in a uniform color space (for example CIEDE2000). A widely used display metric is the luminance contrast ratio, defined as (L1 + 0.05) / (L2 + 0.05) where L1 is the higher luminance and L2 the lower, and is central to accessibility guidelines in WCAG.

Applications and interpretation: In user interfaces and typography, contrast values determine readability and visual distinctness. In photography and imaging, they guide contrast enhancement and tone mapping. In research, they help model perceptual thresholds for discrimination of differences under given lighting.

Limitations: Contrast values depend on lighting, viewing conditions, and observer variation; different metrics may not be directly comparable. Therefore, multiple measures are often reported to provide a complete picture of perceptual difference.