Graphics modes of home computers in the 1970s and 1980s
"Artifacting" redirects here. For other uses of the term, see Artifact.
Orange artifact color, generated from white and black pixels, on the TRS-80 Color ComputerExample of artwork created with the intent of having individual pixel values horizontally averaged over composite video
Composite artifact colors is a designation commonly used to address several graphic modes of some 1970s and 1980s home computers. With some machines, when connected to an NTSC TV or monitor over composite video outputs, the video signal encoding allowed for extra colors to be displayed, by manipulating the pixel position on screen, not being limited by each machine's hardware color palette.[1][2][3]
This mode was used mainly for games, since it limits the display's effective horizontal resolution. It was most common on the IBM PC (with CGA graphics),[4] TRS-80 Color Computer,[5] Apple II[6] and Atari 8-bit[1] computers, and used famously by the Ultima role-playing video games.[6] Software titles (such as King's Quest for the IBM PC) usually provided an option to select between "RGB mode" and "Color Composite mode".[7]
On PAL displays the effect is also present, but generates more limited colors.[8][9] Depending on the exact PAL system used results will vary (if PAL-M or PAL-N are used, color artifacts similar to NTSC might be possible).
Although related, artifact colors are not the same as horizontal blurring. Blurring is a general effect of using a composite connection, that simply creates new colors due to a mix of adjacent horizontal pixel values. The exact mix will depend on the saturation and specific colors of the original pixels. Nevertheless, this effect can be exploited by using dither patterns, generating new intermediate palette colors[10] on machines with a sufficiently high resolution display, like the ZX Spectrum,[11] Mega Drive/Genesis,[12][13] NES/Famicom[14] or Amiga.
^ abCrawford, Chris (1982). "De Re Atari - APPENDIX D - TELEVISION ARTIFACTS".
^"Composite Video: Why it was good then, and why you might even use it today!". nicole.express.
^"Exodus Project / Wiki / CGA Composite". Sourceforge.net. Retrieved 7 August 2016.
^"256 color mode (composite mode artifacting) - The TRS-80/Tandy Color Computer COCO SuperSite!". Coco3.com. Retrieved 7 August 2016.
^ ab"Nerdly Pleasures: The Overlooked Artifact Color Capabilities of non-Apple II Computers". Nerdlypleasures.blogspot.pt. 24 September 2013. Retrieved 7 August 2016.
environments (other colors are possible but less common), as for example in Sky Captain and the World of Tomorrow. More commonly, composited backgrounds are...
generate color (see Compositeartifactcolors). Dot crawl has long been recognized as a problem by professionals since the creation of composite video. When the...
combining of component signals to form the composite signal does the same, causing a checkerboard video artifact known as dot crawl. Dot crawl is a defect...
pixels on the computer screen, with the possibility of exploiting compositeartifactcolors. The Apple II display provides two pixels per subcarrier cycle...
deals with digital television broadcast standards Broadcast-safe Compositeartifactcolors Glossary of video terms List of common resolutions § Television...
compression artifacts in different parts of the data may therefore indicate that the data has been edited. In the case of JPEG, even a composite with parts...
interpreted as color by a composite video display. High resolution provides two pixels per Colorburst cycle, allowing for two possible colors if one pixel is on...
the luminance loss by design. Another artifact that can occur with chroma subsampling is that out-of-gamut colors can occur upon chroma reconstruction...
and other sections. The colors are thus displayed sequentially at a sufficiently high rate that the observer sees a composite "full color" image. In early...
device, the overall spatial resolution is degraded by simple line doubling—artifacts, such as flickering or "comb" effects in moving parts of the image that...
manufacturer. Many early models output composite video colors. When seen on TV devices, the perception of the colors may not correspond with the value levels...
stag and the tail of a fish. Today, however, it is often described as a composite of many birds including the head of a golden pheasant, the body of a mandarin...
pixel, according to NASA). The light bands across the photograph are an artifact, the result of sunlight reflecting off parts of the camera and its sunshade...
dispersion (the degree to which white light is split into its spectral colors as it passes through the stone) of 0.044, as measured by the sodium B and...
supports palette-based images (with palettes of 24-bit RGB or 32-bit RGBA colors), grayscale images (with or without an alpha channel for transparency),...
Time in Korea when jade ornament production began Philippine jade artifacts – Artifacts made from white and green nephrite, dating as far back as 2000–1500...
of colors available, so a 2 bpp image can have 4 colors, and a 3 bpp image can have 8 colors: 1 bpp, 21 = 2 colors (monochrome) 2 bpp, 22 = 4 colors 3...
panorama image needs to be taken into account to create a visually pleasing composite. For panoramic stitching, the ideal set of images will have a reasonable...
32 arbitrary colors plus 32 more colors set at half the value of the first 32), and Hold-And-Modify (HAM) which allows all 4096 colors to be used on...
(Application layer) may realise a ‘business object’ (Business layer); or an ‘artifact’ (Technology layer) may realise either a ‘data object’ or an ‘application...
well as more advanced facilities such as edge detection, masking, alpha compositing, and color and channel-based extraction. The border of a selected area...
offsets applied to it, as specified by the applicable video standard. In composite video signals, the U and V signals modulate a color subcarrier signal...
Global Information
