Identification of band-pass filtered letters and faces by human and ideal observers.

Development of Visual Acuity and Contrast Sensitivity in Children

http://www.mapageweb.umontreal.ca/gosselif/labogo/gold%26bennett%26sekuler.pdf

Characterizing perceptual learning with external noise

The effects of aging on orientation discrimination

PsyScope is a system for building behavioral experiments on the Apple Macintosh computer using a graphic user interface that requires no computer programming. The program supports a wide variety of experimental designs, multimedia formats, and stimulus control. A freeware version is available at the author's web site.

The PsyScope experiment-building system

The precision of human vision requires displays to be accurate to about 0.2% of the luminance range. We present a technique by which this grey-level precision can be achieved with the use of an 8-bit color monitor. The basic idea is to 'steal' adjacent bits from the color variation for use in increasing the precision of the luminance variation. On a monitor with 8 bits per color gun, the technique can provide 1786 or more grey levels at a cost of one bit of color jitter, with standard D/A hardware. The color variations are invisible under almost all conditions.

Bit stealing: how to get 1786 or more gray levels from an 8-bit color monitor

Software for measurement of psychophysical thresholds with 2D moving and coloured images is described. It is menu-driven and has contrast resolution to 0.2% without hardware modifications. A calibrator to provide the full calibration of the Macintosh monitor required by the software is also described.

Brennan McBride

Papers

Bit stealing: how to get 1786 or more gray levels from an 8-bit color monitor

The Morphonome image psychophysics software and a calibrator for Macintosh systems.