Abstract

Off-the-shelf microcomputers can now display arbitrary 8-bit images, but accurate control of these images requires dealing with several undesirable properties of real digital to analog converters (DACs) and analog video monitors. The limitations of DACs and video monitors are presented in the form of a model for their calibration and use in vision experiments. Low contrasts can be accurately rendered by summing a small accurate a.c. signal and a large less-accurate d.c. signal (Watson et al., 1986; Behavior Research, Method, Instrument and Computers, 18, 587-594). Exploiting that idea, this note presents an easy-to-build passive resistor network, a video attenuator, that combines the outputs of three 8-bit DACs to render low contrasts with 12-bit accuracy at the display. Measurements confirm the 12-bit accuracy.

Keywords

Contrast (vision)MicrocomputerOptometryOpticsComputer scienceArtificial intelligencePhysicsMedicineTelecommunications

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Publication Info

Year
1991
Type
article
Volume
31
Issue
7-8
Pages
1337-1350
Citations
476
Access
Closed

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Cite This

Denis G. Pelli, Lan Zhang (1991). Accurate control of contrast on microcomputer displays. Vision Research , 31 (7-8) , 1337-1350. https://doi.org/10.1016/0042-6989(91)90055-a

Identifiers

DOI
10.1016/0042-6989(91)90055-a