Sampling and quantization

The first step in digitizing an image is sampling. The density of the image is apportioned at fixed increments. The size of the increments should be determined by the ultimate purpose of the final image (fine images can be made coarse, but coarse images cannot be made fine).

For instance, images for a Web page can be quite rough, but graphics for commercial printing should be sampled at a level that yields fine detail.

The finer the image, the larger the data file and this will put a greater burden on the computer. The conversion of the sampled image into numeric values is called quantization. For instance, white is converted to "1" and black to "0".