ABSTRACT
Each pixel of an 8-bit image is described in one of a possible 256 tones or colours. Each pixel of a 24-bit image is described in one of a possible 16.7 million tones or colours. The higher the ‘bit depth’ of the image the greater the colour or tonal quality. An 8-bit image (8 bits of data per pixel) is usually sufficient to produce a good quality black and white image, reproducing most of its tonal variations, whilst a 24-bit image (8 bits x 3 channels) is usually required to produce a good quality colour print from a three channel RGB digital file. Images with a higher bit depth require more data or memory to be stored in the image file. Grayscale images are a third of the size of RGB images (same pixel dimensions and print size, but a third of the information or data).
