Gammakõver

Gammakõver is a term originating from Estonian, often translated as "gamma curve" or "gamma correction." In the context of digital imaging and display technology, it refers to the relationship between the numerical value of a pixel and its actual brightness. This relationship is not linear. Displays typically have a non-linear response, meaning that a change in pixel value does not result in a proportional change in perceived brightness. Gamma correction is a process used to compensate for this non-linearity.

The gamma value, represented by the Greek letter gamma (γ), is a number that describes this relationship. A gamma value of 1.0 would imply a linear relationship, but this is rarely the case in practice. Standard displays often have a gamma value around 2.2. This means that darker tones are compressed, and brighter tones are expanded, in terms of the pixel values needed to represent them accurately.

Gamma correction involves applying a power-law function to the image data. Multiplying the input pixel values by a factor related to the display's gamma curve ensures that the image appears with the intended brightness and contrast when viewed on that display. Without proper gamma correction, images might appear too dark, too bright, or have washed-out shadows and blown-out highlights, depending on the display's characteristics and the source image's intended look. The process is crucial for consistent image reproduction across different devices and for achieving visually pleasing results in photography, video, and graphic design.