User`s guide

6 Working with Acquired Image Data

triggerconfig(vid,'manual')

In addition, configure a large enough acquisition to allow several ca

lls to

peekdata before it finishes.

set(vid,'FramesPerTrigger',300);

3 Start the image acquisition object —Callthestart function to start

the image acquisition object.

start(vid)

The video object is now running but not logging.

isrunning(vid)

ans =

islogging(vid)

ans =

4 Use peekdata to view frames before a trigger —Ifyoucallpeekdata

before you trigger the acquisition, peekdata can only return a single frame

of data because data logging has not been initiated and the memory buffer

is empty. If more than one frame is requested,

peekdata issues a warning

that it is returning fewer than the requested number of frames.

pdata = peekdata(vid, 50);

Warning: PEEKDATA coul d no t return all the frames reques ted.

Verify that peekdata returned a single frame. A single frame of data

should have the same width and height as specified by the

ROIPosition

property and the same number of bands, as specified by the NumberOf Bands

property. In this example, the video format o f the data is RGB so the value

of the

NumberOfBands property is 3.

whos

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