Kuvakäyrää

Kuvakäyrää, also known as a tone curve or gamma correction, is a graphical representation used in image editing and display technology to adjust the brightness and contrast of an image. It maps input pixel values to output pixel values, allowing for precise control over how different tonal ranges are rendered.

The curve typically has an X-axis representing the original brightness levels and a Y-axis representing the adjusted brightness levels. A straight diagonal line from the bottom left to the top right signifies no change; the input brightness is directly mapped to the output brightness. Deviations from this line create the adjustments.

Moving a point on the curve upwards brightens the corresponding tonal range, while moving it downwards darkens it. Steep slopes indicate increased contrast, while flatter slopes reduce contrast. By manipulating specific points on the curve, users can selectively lighten shadows, darken highlights, or adjust midtones.

Kuvakäyrää is a fundamental tool for achieving specific aesthetic looks, correcting exposure issues, and enhancing the overall visual impact of an image. It is widely used in digital photography, graphic design, and video production for its powerful and granular control over image tonality. Different curves can be applied to achieve various effects, from a subtle boost in contrast to a dramatic, stylized look. Understanding and utilizing kuvakäyrää is a key skill for anyone working with digital images.