User`s guide

14 Using the VideoDevice System Object

14-6

Function Purpose

determined by the value of the VideoDevice System object ROI

property. If not specified, it uses the default resolution for the

device.

closepreview Close live image preview window.

closepreview(obj)

closes the live preview window for VideoDevice System object,

obj.

imaqhwinfo Returns information about the object.

imaqhwinfo(obj)

displays information about the VideoDevice System object, obj.

The basic workflow for using the VideoDevice System object is to create the object,

preview the image, set any properties, acquire a frame, and clear the object, as shown

here.

Construct a VideoDevice System object associated with the Winvideo adaptor with

device ID of 1.

vidobj = imaq.VideoDevice('winvideo', 1);

Set an object-level property, such as ReturnedColorSpace.

vidobj.ReturnedColorSpace = 'grayscale';

Note that the syntax for setting an object-level property is

<object_name>.<property_name> = <property_value>, where the value can

be a string or a numeric.

Set a device-specific property, such as Brightness.

vidobj.DeviceProperties.Brightness = 150;

Note that the syntax for setting a device-specific property is to list the object name,

the DeviceProperties object, and the property name using dot notation, and then

make it equal to the property value.

Preview the image.

preview(vidobj)