Understanding resample (and antialiasing) by Gary Andrew Clarke's “Art Remixed” Series in HTML & CSS.
This principle—also called antialiasing—is the same that is used when photos are resampled to a lower resolution. Our eyes and brain interpret the information contained within the gray pixels and translate it back into sharp contours, so what we perceive is fairly close to the original shape. A similar effect is at work when a relatively coarse newspaper image that can appear nicely shaded if we hold it far enough away (or similarly, in the art of Chuck Close).
