colorindexed
Colorindexed refers to a method of image compression, particularly used in older graphics formats like GIF. In a colorindexed image, the full range of colors is not stored directly for each pixel. Instead, a limited palette of a maximum of 256 distinct colors is defined for the entire image. Each pixel in the image then stores an index number, which corresponds to a specific color within this predefined palette. This index number is typically 8 bits, allowing for up to 256 different colors. When the image is displayed, the graphics hardware or software looks up the color associated with the index number in the palette and uses that color for the pixel. This technique significantly reduces file size compared to storing full RGB color information for every pixel, especially for images with large areas of solid color or a limited color spectrum. However, it also means that the image cannot display colors outside of its defined palette, which can lead to color banding or dithering effects if the original image contained a wider range of colors.