Vision Resources

Bootstrap thresholds 

Given a set of binomial responses at different stimulus levels, this program fits a psychometric function and derives a threshold and slope. It then estimates the standard deviation and confidence intervals of the threshold and slope by a bootstrap procedure. Another program compares thresholds and slopes from two sets of data and estimates confidence intervals to test the significance of their differences.  For an introduction to the software, see Foster & Bischof (1997) Spat. Vis., 11, 135-139.

The programs are available in a variety of downloading formats at http://personalpages.manchester.ac.uk/staff/david.foster/Research/bootstrap.html, mirrored on the AVA anonymous ftp site at: ftp://ftp.psy.dmu.ac.uk/pub/ava/foster/.

Hyperspectral images of natural scenes.

Images of size approx. 1344 x 1024 x 31 used in Foster et al. (2004) Vis. Neurosci., 21, 331-336 are available from http://personalpages.manchester.ac.uk/staff/david.foster/Hyperspectral_images_of_natural_scenes_04.html.

Images of size approx. 725 x 685 x 31 used in Nascimento et al. (2002). J. Opt. Soc. Am. A, 19, 1484-1490, are available from http://personalpages.manchester.ac.uk/staff/david.foster/Hyperspectral_images_of_natural_scenes_02.html.