Managing Buffers; Camera Attributes - National Instruments Image Acquisition Software User Manual

Chapter 3 Programming with NI-IMAQ

Managing Buffers

Camera Attributes

Note Currently, camera attributes are supported only by the IMAQ PCI-1424.
NI-IMAQ User Manual
This example opens an interface to
acquire images. When the program is finished with the interface and
session, it then closes both handles using the
For a complete list of the available session functions, refer to the NI-IMAQ
Function Reference Manual.
Buffer management can be performed either by you or automatically by
NI-IMAQ. If the high-level acquisition routines (
imgSequenceSetup
pointers for buffer addresses, NI-IMAQ will automatically allocate a buffer
and return the value of the buffer pointer to you. After you have a buffer
pointer, you can use this pointer in successive calls.
For greater control of the acquisition buffers, such as creating buffers larger
than the image size for adding borders, you can create them by calling a
memory allocation routine (for example,
function
imgCreateBuffer
dispose of the buffers using
to free PC memory for maximum performance.
The camera attributes allow you to control camera functions, such as
integration time and pixel binning, directly from NI-IMAQ. These camera
attributes are camera-specific and can also be set in the IMAQ
Configuration Utility on the Advanced tab. Information about specific
attributes for your camera is contained in
be found in the
ni-imaq/camera info
about camera attributes and their uses, please consult your camera
documentation.
The camera attribute file lists all attributes for the camera. Each attribute
description contains four fields—Attribute Name, Description,
Data Type, and Possible Values. The Attribute Name field contains the
name of the attribute in quotes. The Data Type field contains the data type
of the attribute—String, Integer, or Float. String indicates that there are
several valid values for this attribute that are expressed as strings. The list
of valid values is indicated in Possible Values. Integer indicates that the
and then creates a session to
img0
, and
imgRingSetup
malloc
. When creating buffers using either approach,
or
free imgDisposeBuffer
<my camera>.txt
directory. For more information
3-4
function.
imgClose
,
imgSnap imgGrab
) are initiated with NULL
) or using the low-level
when applicable
, which can
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