Pixelation

Early graphical applications such as video games ran at very low resolutions with a small number of colors, resulting in easily visible pixels.

The resulting sharp edges gave curved objects and diagonal lines an unnatural appearance.

However, when the number of available colors increased to 256, it was possible to gainfully employ anti-aliasing to smooth the appearance of low-resolution objects, not eliminating pixelation but making it less jarring to the eye.

Alternatives such as vector graphics or purely geometric polygon models can scale to any level of detail.

This is one reason vector graphics are popular for printing – most modern computer monitors have a resolution of about 100 dots per inch, and at 300 dots per inch printed documents have about nine times as many pixels per unit of area as a screen.

An example of pixelation. The image looks smooth when zoomed out, but when a small section is viewed more closely, the eye can distinguish individual pixels.

A diamond without (left) and with (right) anti-aliasing

The zoomed portion of the cat image above, resized using nearest neighbor *(left)* and with Adobe Photoshop 's bicubic resampling , which uses pixel interpolation *(right)* . The interpolated image has no sharp edges, but is considerably blurrier.