contraste

Contraste is the degree of difference between two or more elements in a given context. It is used to distinguish shapes, colors, values, ideas, or sounds. In color theory and visual design, contrast helps create emphasis, improve legibility, and establish perceptual separation.

Visual contrast has several dimensions, including luminance contrast (brightness difference), chromatic contrast (color difference), and textural or spatial contrast. Luminance contrast is often quantified as a contrast ratio between two colors or areas. In web and print design, accessibility standards specify minimum contrast for readability: for normal body text, a contrast ratio of at least 4.5 to 1 is recommended; large text can use at least 3 to 1.

In art, photography and film, contrast contributes to atmosphere and depth, with high contrast producing crisp delineation and strong visual impact, while low contrast yields a softer, more muted image. Color contrast mixes hue, saturation, and brightness to separate elements and create harmony or tension.

In language and logic, contrast refers to the opposition between ideas, terms, or states. Rhetorical contrast, including antithesis, highlights differences to strengthen argument or meaning. In psychology, contrast effects describe how the perception of a stimulus is influenced by preceding or surrounding stimuli.

The concept also appears in science and medicine, where contrast enhances differences in tissues or structures in imaging modalities such as MRI or CT scans, and in sensory systems where contrast detection underlies edge perception and vision.