Pixelation is a state in which the individual pixels making up an image can be identified by the naked eye. Typically, raster images displayed on computers are designed with pixels that are so small that they cannot be seen when viewing the image at its normal size. When the image is magnified to a certain level, individual pixels become visible. The blocky effect thus achieved is called pixelation. Sometimes, for artistic, cultural, or technological reasons, an image is pixelated in its normal state and not as a product of magnification.
In most cases, pixelation is the result of viewing an image at a size larger than intended. It was once common to come across pixelation when using computers or video games, but this was due to the limited resolution possible. With more developed technology, it is rare to see a pixelated image except in error or when the image was intentionally made that way.
While most people think of pixelation as a quality of images, it is also possible to have pixelated video. When a video is pixelated, it is usually due to each individual frame being pixelated. In some cases, a larger error may cause pixelation or even distortion of entire blocks of pixels.
Some people use pixelation as a censoring device. This use is called pixelization. Often, if a section of an image is pixelated but the rest of the image is at a normal resolution, the image has been pixelized intentionally.
When a person intentionally creates pixelated images even though more refined options are available, this is sometimes called pixel art. These images are created because a person enjoys the look of the pictures, possibly for nostalgia or as a deliberate reaction to more detailed art. Some artists recreate the look of pixels in real life settings using blocks, sticky notes, or other regular square items. It is even possible to use other images that have one dominant color as pixels to create a larger image.
One problem occasionally encountered by computer users is viewing an image at the wrong size, causing the image to appear pixelated. In these cases, the problem can be fixed by reducing the size of the image. Raster images always have a maximum size at which they can be viewed before this effect becomes apparent, and it depends largely on the resolution of the image.
Occasionally, one sees a pixelated image because one is using an older piece of technology. Vintage video game systems often display pixelated images. Alternatively, one might find the need to magnify an image to the pixel level in order to modify individual pixels. Pixelation can sometimes be a problem, but understanding what causes a pixelated image allows for useful manipulation of the effect.