User`s guide

2 Introduction
Setting Up Gener
ic Windows V ideo Acquisition
Devices
IEEE 1394 (FireW
ire) and generic Windows v ideo acquisition devices that use
Windows Driver M
odel (WDM) or Video for Windows (VFW) device drivers
typically requ
ire le ss setup. Plug the device into the US B or IEEE 1394
(FireWire) por
t on your computer and install the device driver provided by the
vendor.
Setting Up DCA
M Devices
If you intend t
o access a DCAM-compliant IEEE 1394 (FireWire) camera, you
must install a
nd configure the Carnegie Mellon University (CMU) DCAM
driver. The to
olbox is n ot compatible wi th any other vendor-supplied driv er,
even if the dr
iver is DCAM compliant. See “Installing the CMU DCAM
Driver” on pa
ge 10-10 for more inform ation.
Resetting Y
our Image Acquisition Hardware
To return MAT
LAB and your image acquisition hardware to a known state,
wherenoima
ge acquisition objects exist and the hardware is not configured,
use the
imaq
reset
function.
If you conne
ct a no ther image acquisition dev ice to your system aft er MATLAB
is started,
you ca n use
imaqreset to make the toolbox aware of the new
hardware.
ANoteAbou
t Frame Rates and Processing Speed
The frame r
ate describes how fast an image a cquisition device provides data,
typically
measure d as frames per second .
Devices th
at support industry-standard video formats must provide frames
at the rat
e specified by the standard. For RS17 0 and N TSC, the sta n dard
dictates
a frame rate of 30 frames per second (30 Hz). The CCIR and
PAL stand
ards define a frame rate of 25 Hz. Nonstandard devices can be
configur
ed to o perate at higher rate s. Generic Windows image acquisition
devices
,suchaswebcams,mightsupportmany different frame rates.
Dependi
ng on the device being used, the frame rate might be configurable
using a d
evice-specific property of the image acquisition object.
2-6