Subject:VideoToolbox 11:23 AM
3/30/1995
I will be publishing a new edition of the VideoToolbox software for vision
research (described below) in a week or so. No major changes, just bringing
everything up to date: supporting Apple's new Display Manager, new video
drivers, Codewarrior 5.5, a new routine to make gaussian noise quickly, and
new technical info and advice. Anyone who wants a copy sent to them by email
should send me their email address, which will be added to the subscription
list to receive new versions as they are published. As always, the
VideoToolbox will also be available at many public ftp sites. (There are now
75 subscribers, so this may be the last CVNet announcement.)
regards
denis
Denis Pelli
denis@xp.psych.nyu.edu
WHAT IS THE VIDEO TOOLBOX?
The VideoToolbox is a collection of two hundred C subroutines and several
demo and utility programs that I and others have written to do visual
psychophysics with Macintosh computers. It is fully compatible with 680x0 and
PowerPC Macs and with Metrowerks CodeWarrior 5 and Symantec THINK 7 C
compilers. It's free and may not be sold without permission. It should be
useful to anyone who wants to present accurately specified visual stimuli or
use the Mac for psychometric experiments. The text file "Video synch"
discusses all the ways of synchronizing programs to video displays and the
many pitfalls to avoid. The TimeVideo application checks out the timing of
all video devices in anticipation of their use in critical real-time
applications, e.g. movies or lookup table animation. Low-level routines
control video timing and lookup tables, display real-time movies, and
implement the luminance-control algorithms suggested by Pelli and Zhang
(1991). In particular, GetPixelsQuickly and SetPixelsQuickly peek and poke
pixels in bitmaps and pixmaps, CopyBitsQuickly and CopyWindows faithfully
copy between bit/pixmaps and the screen, WindowToEPS saves an image to disk,
for later printing or incorporation into a document, and SetEntriesQuickly
and GDSetEntries load the screen's color lookup table, all without any of
QuickDraw's color translations. High-level routines help analyze
psychophysical experiments (e.g. graphing or maximum-likelihood fitting of
psychometric data). Assign.c is a runtime C interpreter for C assignment
statements, which is useful for controlling experiments and sharing
calibration data. This collection has been continually updated since 1991.
Many colleagues have indicated that they are using the software in their
labs. Documentation is in the source files themselves. Many of the routines
are Mac-specific, but some very useful routines, e.g. the luminance-control,
statistics, maximum-likelihood fitting algorithms, and the runtime
interpreter are written in Standard C and will work on any computer. Those
wishing to acknowledge use of the VideoToolbox software might cite:
Pelli, D. G. and Zhang, L. (1991) Accurate control of contrast on
microcomputer displays. Vision Research, 31, 1337-1350. Reprints are
available.
AVAILABILITY:
The VideoToolbox software is updated several times a year. You can download
the latest version from any of the archives below. To get future versions
automatically, just send me your email address. Each time I post a new
version of the VideoToolbox to the Info-Mac Archive, I email a copy to
everyone on the subscription list; there are currently 75 subscribers.
ftp://sumex-aim.stanford.edu/info-mac/dev/src/video-toolbox-95-01-14-c.hqx
ftp://mirrors.aol.com/pub/info-mac/dev/src/video-toolbox-95-01-14-c.hqx
ftp://grind.isca.uiowa.edu/mac/infomac/dev/src/video-toolbox-95-01-14-c.hqx
ftp://ftp.uu.net/archive/systems/mac/info-mac/dev/src/video-toolbox-95-01-14-c.hqx
ftp://amug.org/pub/ftp1/info-mac/dev/src/video-toolbox-95-01-14-c.hqx
ftp://wuarchive.wustl.edu/systems/mac/info-mac/dev/src/video-toolbox-95-01-14-c.hqx
ftp://src.doc.ic.ac.uk/packages/mac/info-mac/dev/src/video-toolbox-95-01-14-c.hqx
ftp://ftp.stolaf.edu/pub/macpsych/VideoToolbox.95.1.14.sea.hqx
(The filename changes slightly to reflect each version's release date.
Members of CompuServe can download VIDEOT.SEA from Library 4 "C and Pascal"
in the MacDev forum. Anyone can request a file from the Info-Mac Archive by
email; for instructions send a query to
Info-Mac-Request@sumex-aim.stanford.edu.)