Pixel art

Pixel art is a form of digital art, created on the computer through the use of raster graphics software, where images are edited on the pixel level. Graphics in most old (or relatively limited) computer and video games, Game Boy games, graphing calculator games, and many mobile phone games are considered pixel art.

History

The term pixel art was first published by Adele Goldbert and Robert Flegal of Xerox Palo Alto Research Center in 1982^[1]. The concept, however goes back about 10 years before that, for example in Richard Shoup's SuperPaint system in 1972, also at Xerox PARC.

Some traditional art forms, such as cross-stitch, mosaic and beadwork, bear some similarity to pixel art by constructing pictures out of small colored units analogous to the pixels of modern digital computing.

Constraints

File:Yus ptoing.png

This pixel art image shows how different coloring techniques with unusual colors and limited palettes can create interesting effects.

Generally, "pure" pixel art must be created by manual pixel-level editing, without the use of any automatic filters. In the pure form, it is generally said that "each pixel was placed carefully". Purists within the pixel art scene say that pixel artists should only use tools that place individual pixels (usually the pencil tool), and no tools that automatically create shapes for you (like circle, square and line tools). Others say that the line tools and the bucket fill are acceptable, as they do nothing more than speed up the work without impacting how the work looks. The use of automatic filters such as anti-aliasing, on the other hand, is generally considered not valid in "true" pixel art, since the filters will add new pixels automatically, eliminating the careful placement.

Also, a common mistake is to think that any drawing or doodle done using the pencil tool is pixel art. This is not true, since pixel art is categorized by the method of drawing (pixel by pixel), not the results (therefore, special renders and automated filters do not apply either). Such drawings are actually called oekakis.

Techniques of drawing

Drawings usually start with what is called the line art, which is the basic line that defines the character, building or anything else the artist is intending to draw. Linearts are usually traced over scanned drawings and are often shared among other pixel artists. Other techniques, some resembling painting, also exist.

The limited palette often requires the use of dithering in order to achieve different shades and colors, but due to the nature of this form of art this is done completely by hand. Hand-made anti-aliasing is also used.

Here are a few parts of the above image in detail, depicting a few of the techniques involved:

1. The basic form of dithering, using two colors in a 2x2 checkerboard pattern. Changing the density of each color will lead to different subtones.

2. Stylized dithering with 2x2 pixel squares randomly scattered can produce interesting textures. Small circles are also frequent.

3. Anti-aliasing can be done, by hand, to smooth curves and transitions. Some artists use this is only internally in order to keep the crisp outlines that can go over any background. The PNG alpha channel can be used to create external anti-aliasing for any background.

Saving and compression

GIF file (318 bytes).

PNG file (275 bytes).

JPEG file (706 bytes).

Pixel art is preferably stored losslessly, that is, in a format that can save each pixel of the image without loss of precision. Because of the often-limited color space, using a color palette can be very efficient. PNG and GIF are two examples of formats that can do this space-efficiently. Run-length encoding is a possible tradeoff when memory or computational power is limited.

Pixel art is not generally saved as JPEG files because the lossy compression of the image is not suited to the details involved in pixel art, even when minimising the compression of the file. The nature of JPEG compression can cause a severe loss of the original look of the pixel art, especially due to its tendency to alter the colours of individual pixels and thus the exact look of the original piece. JPEG files also tend to have larger file sizes than other formats, for images with only a few colors.

Uses

File:Metal Slug 3.png

Metal Slug 3 is considered by many pixel artists as a game with excellent examples of pixel art

Pixel art was very often used in older computer and video console games. With the increasing use of 3D graphics in games, pixel art lost some of its use. Despite that, this is still a very active professional/amateur area, since mobile phones and other portable devices still have low resolution and then require a skillful use of space and memory. Sometimes pixel art is used for advertising too. One such company that uses pixel art to advertise is Bell.

Icons for operating systems with limited graphics abilities are also pixel art. The limited number of colors and resolution presents a challenge when attempting to convey complicated concepts and ideas in an efficient way. On the Microsoft Windows desktop icons are raster images of various sizes, the smaller of which are not necessarily direct scalings of the larger ones and could be considered pixel art. On the GNOME and KDE desktops, icons are represented primarily by SVG images, but with hand-optimised, pixel art PNGs for smaller sizes such as 16x16 and 24x24. Another use of pixel art on modern desktop computers is favicons.

Modern pixel art has been seen as a reaction to the 3D graphics industry by amateur game/graphic hobbyists. Many retro enthusiasts often choose to mimic the style of the past . Some view the pixel art revival as restoring the golden age of second and third generation consoles, where it is argued graphics were more aesthetically pleasing. Pixel art still remains popular among handheld devices such as the Nintendo DS and Cellphones.

Communities

Several pixel art communities exist on the internet where artists share their art and techniques, as well as giving out hints, tips, tricks etc. There is usually a request to keep the comments and critics as constructive as possible in order to help the community and their members to improve.

Pixel fights or pixel battles occur when a number of artists take turns on editing the same picture, usually divided in "slots" (frequently square or hexagonal). The fight consists on making things as tricky as possible to continue for the next artist. These pixel battles are, of course, made just for the fun and challenge.

Community collaborations also exist. These usually involve a basic "make your own" idea over a theme (a city, a building, a totem, etc.), where a template is given for the users to participate creating their own entries. These will then be put together in a single and usually large pixel art piece.

References

^ Adele Goldbert and Robert Flegal, "ACM president's letter: Pixel Art", Communications of the ACM, Vol. 25, Issue 12, Dec. 1982.

External links

[1] Adele Goldbert and Robert Flegal, "ACM president's letter: Pixel Art", Communications of the ACM, Vol. 25, Issue 12, Dec. 1982.

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