grab_image — Synchronous grab of an image from the specified image acquisition device.
The operator grab_image grabs an image via the image acquisition device specified by AcqHandle. The desired operational mode of the image acquisition device as well as a suitable image part and additional interface-specific settings can be specified using the operators open_framegrabber and set_framegrabber_param.
To abort the grab, the operator set_framegrabber_param with the parameter 'do_abort_grab' can be used if the specific image acquisition interface supports it. Note that as an exception from the description of the concurrent usage in multiple threads (see below) 'do_abort_grab' can also be used from another thread.
Basically an image acquisition handle AcqHandle cannot be used in multiple threads. However, possible exceptions are described in the specific reference documentation of the respective image acquisition interface. Different image acquisition handles can be used safely with different threads for each handle.
For a multithreaded application all image acquisition operators (as listed in open_framegrabber) are an own group in which info_framegrabber, open_framegrabber, close_framegrabber and close_all_framegrabbers are executed exclusively.
grab_image runs in parallel with all non-exclusive operators inside and outside of this group.
Handle of the acquisition device to be used.
* Select a suitable image acquisition interface name AcqName info_framegrabber(AcqName,'port',Information,Values) * Open image acquisition device using the default settings, see * documentation of the actually used interface for more details open_framegrabber(AcqName,1,1,0,0,0,0,'default',-1,'default',-1.0, \ 'default','default','default',-1,-1,AcqHandle) grab_image(Image,AcqHandle) close_framegrabber(AcqHandle)
If the image could be acquired successfully, the operator grab_image returns the value 2 (H_MSG_TRUE). Otherwise an exception is raised.
grab_image_start, grab_image_async, close_framegrabber
open_framegrabber, info_framegrabber, set_framegrabber_param