What does bit depth in a raster define?

Bit depth in a raster defines the number of bits used to represent each pixel in the raster image. This measurement directly controls the range of colors (or shades of gray) that can be represented in the image. For instance, a raster with a bit depth of 1 can represent 2 colors (black and white), while an 8-bit raster can represent 256 different colors. Higher bit depths allow for more precise and varied representations of data, which is especially important in applications like remote sensing or image analysis where detail and color accuracy are critical. Understanding bit depth is essential for effective data visualization and analysis in GIS, as it affects both file size and image quality.