National Instruments IEEE 1394 Manual De Usuario
Chapter 2
Basic Acquisition with NI-IMAQ for IEEE 1394 Cameras
2-10
ni.com
Grab
A grab initiates a continuous high-speed acquisition of images to one or
more internal buffers. Figure 2-3 illustrates the typical programming order
of a high-level grab acquisition.
more internal buffers. Figure 2-3 illustrates the typical programming order
of a high-level grab acquisition.
Figure 2-3. High-Level Grab Flowchart
Use a grab for high-speed applications during which you need to process
only one image at a time. You can copy the last acquired buffer to a separate
user buffer for processing or analysis. To use these functions, you must
have a valid session. If you do not have a valid session, the NI-IMAQ for
IEEE 1394 Cameras Grab Setup function creates a session using
only one image at a time. You can copy the last acquired buffer to a separate
user buffer for processing or analysis. To use these functions, you must
have a valid session. If you do not have a valid session, the NI-IMAQ for
IEEE 1394 Cameras Grab Setup function creates a session using
cam0
.
Calling the Grab Setup function initializes a session for a grab acquisition.
During acquisition, each successive grab copies the last acquired internal
buffer into a user buffer where you can process the image.
During acquisition, each successive grab copies the last acquired internal
buffer into a user buffer where you can process the image.
Opens and Configures Camera
Copies Contents of Internal Buffer
to User Buffer; Can Call Grab Function
Multiple Times for High-Speed Acquisition
to User Buffer; Can Call Grab Function
Multiple Times for High-Speed Acquisition
Executes User-Specific Image Processing
Closes the Camera Session
Configures Camera for
Continuous Acquisition
Continuous Acquisition
(Loop)
Initialize
Grab Setup
Grab
User-Specific Functions
Close