6.5. Grayscale mode

You can use the Grayscale command to convert your image to grayscale. The resulting grayscale image will have a single channel composed of various shades of gray ranging from black to white.

The number of available tonal steps between black and white depends on the image precision:

At integer precision:

• An 8-bit integer grayscale image provides 255 available tonal steps from 0 (black) to 255 (white).

• A 16-bit integer grayscale image provides 65535 available tonal steps from 0 (black) to 65535 (white).

• A 32-bit integer grayscale image theoretically will provide 4294967295 tonal steps from 0 (black) to 4294967295 (white). But as high bit depth GIMP 2.10 does all internal processing at 32-bit floating point precision, the actual number of steps will be no more than the number of tonal steps available in a 32-bit floating point image.

At floating point precision: the available number of tonal steps in a grayscale image depends on the specified bit depth (8-bit, 16-bit, or 32-bit) and the type of floating point that is requested by the program (see Floating-point arithmetic for details).

6.5.1. Activating the Command

You can access this command from the image menubar through Image → Mode → Grayscale.