värisykkyys

Värisykkyys, often translated as color constancy, is a perceptual phenomenon where the perceived color of an object remains relatively stable despite changes in the illumination of its surroundings. This means that we tend to see a red apple as red, whether it is viewed under bright sunlight, dim indoor lighting, or even under a colored light source. Our visual system achieves this by taking into account the overall spectral distribution of the light that reflects off the object and its environment.

The brain compensates for the color of the light source, effectively "subtracting" its influence to infer the object's intrinsic color. This ability is crucial for object recognition and navigation in our environment, allowing us to identify objects consistently across different lighting conditions. Without värisykkyys, our visual world would appear to dramatically shift in hue throughout the day or when moving between different locations. Several theories attempt to explain the mechanisms behind color constancy, including von Kries' coefficient rule and more complex computational models that consider context and surface properties. The effectiveness of color constancy can vary, and under certain extreme lighting conditions or with unusual objects, it can be overcome, leading to color illusions.