National Instruments IEEE 1394 用户手册

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IMAQ Dispose, shown in Figure 4-2, frees the memory allocated for the 
image buffer. Call this VI only after the image is no longer required for 
processing.

Figure 4-2.  IMAQ Dispose

The following sections describe snap, grab, and sequence acquisitions in 
LabVIEW and give examples.

Use the IMAQ1394 Snap VI for snap applications. Figure 4-3 shows a 
simplified block diagram for using IMAQ1394 Snap.

Figure 4-3.  Acquiring an Image Using Snap

Use two VIs—IMAQ1394 Grab Setup and IMAQ1394 Grab Acquire—for 
a grab acquisition in LabVIEW. Call IMAQ1394 Grab Setup once to 
initialize the acquisition and start capturing the image to an internal 
software buffer. You can call IMAQ1394 Grab Acquire multiple times to 
copy the image currently stored in the internal buffer to a LabVIEW image 
buffer. After the program finishes copying images, call IMAQ1394 Close 
once to shut down the acquisition.

Figure 4-4 shows a simplified block diagram for using IMAQ1394 Grab 
Setup and IMAQ1394 Grab Acquire.