grab_imageT_grab_imageGrabImageGrabImagegrab_image (Operator)

Name

grab_imageT_grab_imageGrabImageGrabImagegrab_image — Synchronous grab of an image from the specified image acquisition device.

Signature

grab_image( : Image : AcqHandle : )

Description

The operator grab_imagegrab_imageGrabImageGrabImageGrabImagegrab_image grabs an image via the image acquisition device specified by AcqHandleAcqHandleAcqHandleAcqHandleacqHandleacq_handle. 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_framegrabberopen_framegrabberOpenFramegrabberOpenFramegrabberOpenFramegrabberopen_framegrabber and set_framegrabber_paramset_framegrabber_paramSetFramegrabberParamSetFramegrabberParamSetFramegrabberParamset_framegrabber_param.

To abort the grab, the operator set_framegrabber_paramset_framegrabber_paramSetFramegrabberParamSetFramegrabberParamSetFramegrabberParamset_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.

Attention

For a multithreaded application all image acquisition operators (as listed in open_framegrabberopen_framegrabberOpenFramegrabberOpenFramegrabberOpenFramegrabberopen_framegrabber) are an own group in which info_framegrabberinfo_framegrabberInfoFramegrabberInfoFramegrabberInfoFramegrabberinfo_framegrabber, open_framegrabberopen_framegrabberOpenFramegrabberOpenFramegrabberOpenFramegrabberopen_framegrabber, close_framegrabberclose_framegrabberCloseFramegrabberCloseFramegrabberCloseFramegrabberclose_framegrabber and close_all_framegrabbersclose_all_framegrabbersCloseAllFramegrabbersCloseAllFramegrabbersCloseAllFramegrabbersclose_all_framegrabbers are executed exclusively.

grab_imagegrab_imageGrabImageGrabImageGrabImagegrab_image runs in parallel with all non-exclusive operators inside and outside of this group.

Execution Information

Multithreading type: reentrant (runs in parallel with non-exclusive operators).
Multithreading scope: global (may be called from any thread).
Processed without parallelization.

Parameters

ImageImageImageImageimageimage (output_object) image → object (byte / uint2)

Grabbed image.

AcqHandleAcqHandleAcqHandleAcqHandleacqHandleacq_handle (input_control) framegrabber → (handle)

Handle of the acquisition device to be used.

Example (HDevelop)

* 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)

Result

If the image could be acquired successfully, the operator grab_imagegrab_imageGrabImageGrabImageGrabImagegrab_image returns the value 2 (H_MSG_TRUE). Otherwise an exception is raised.

Possible Predecessors

open_framegrabberopen_framegrabberOpenFramegrabberOpenFramegrabberOpenFramegrabberopen_framegrabber, set_framegrabber_paramset_framegrabber_paramSetFramegrabberParamSetFramegrabberParamSetFramegrabberParamset_framegrabber_param

Possible Successors

grab_image_startgrab_image_startGrabImageStartGrabImageStartGrabImageStartgrab_image_start, grab_image_asyncgrab_image_asyncGrabImageAsyncGrabImageAsyncGrabImageAsyncgrab_image_async, close_framegrabberclose_framegrabberCloseFramegrabberCloseFramegrabberCloseFramegrabberclose_framegrabber

Module

Foundation

Operators