színmap

A színmap, often translated as "color map" or "colormaps," is a data structure used in computer graphics and image processing to represent colors. Instead of storing the full color information for each pixel directly, a színmap stores a limited palette of colors. Each pixel in the image then stores an index into this color map, referencing the specific color to be displayed. This approach can significantly reduce the amount of memory required to store an image, particularly for images with a limited number of distinct colors.

The concept is fundamental to early digital imaging, where memory was a scarce resource. For example, the GIF image format commonly uses színmaps to store images. The size of the színmap can vary, ranging from 2 colors (for monochrome images) to 256 colors (for 8-bit color images). The colors within a színmap are typically arranged in a specific order or follow a particular gradient, which can influence the visual appearance of the image.

Applications of színmaps extend beyond simple image storage. In scientific visualization, színmaps are used to represent data values, such as temperature or elevation, with corresponding colors. The choice of színmap can greatly affect how data is perceived and interpreted. Sequential színmaps are used for data that progresses from low to high, diverging színmaps are used for data that diverges from a central value, and qualitative színmaps are used for categorical data.