gråskalenbild

A gråskalenbild, often translated as grayscale image or black and white image, is a digital image where the value of each pixel is a single sample, representing an intensity value. Grayscale images are composed of shades of gray, ranging from black to white. Unlike color images which use multiple color channels (typically red, green, and blue) to represent a wide spectrum of colors, grayscale images only utilize one channel.

The intensity of a pixel in a grayscale image is typically represented by a single number. In digital imaging, this number is often an integer value within a specific range, such as 0 to 255 for an 8-bit image, where 0 represents black and 255 represents white, with intermediate values representing various shades of gray. Other bit depths are also possible, leading to more or fewer shades of gray.

Grayscale images are fundamental in various imaging applications. They are often used in scientific imaging, medical imaging (like X-rays), and surveillance systems where color information may not be necessary or beneficial. They are also frequently used as a precursor to other image processing techniques, such as edge detection or feature extraction, as simplifying the image to luminance information can reduce computational complexity. Furthermore, many digital cameras and scanners have a "grayscale" mode that captures images without color information, resulting in smaller file sizes. The process of converting a color image to grayscale involves discarding the color information and retaining only the luminance or perceived brightness.