User`s guide

Getting Started Doing Image Acquisition Programmatically
1-15
• Describes the types of image acquisition objects used by the toolbox
• Describes how to view all the properties supported by these objects, with their current
values
• Describes how to set the values of object properties
Types of Image Acquisition Objects
The toolbox uses two types of objects to represent the connection with an image
acquisition device:
• Video input objects
• Video source objects
A video input object represents the connection between MATLAB and a video acquisition
device at a high level. The properties supported by the video input object are the same for
every type of device. You created a video input object using the videoinput function in
step 3.
When you create a video input object, the toolbox automatically creates one or more
video source objects associated with the video input object. Each video source object
represents a collection of one or more physical data sources that are treated as a single
entity. The number of video source objects the toolbox creates depends on the device
and the video format you specify. At any one time, only one of the video source objects,
called the selected source, can be active. This is the source used for acquisition. For more
information about these image acquisition objects, see “Creating Image Acquisition
Objects” on page 5-8.
Viewing Object Properties
To view a complete list of all the properties supported by a video input object or a video
source object, use the get function. To list the properties of the video input object created
in step 3, enter this code at the MATLAB prompt.
get(vid)
The get function lists all the properties of the object with their current values.
General Settings:
DeviceID = 1
DiskLogger = []
DiskLoggerFrameCount = 0
EventLog = [1x0 struct]
FrameGrabInterval = 1