HALCON 6.1 Frame Grabber Interface for Video for Windows

This page provides the documentation about the HALCON frame grabber interface HFGVideoForWindows.dll for the Microsoft Video for Windows system interface. Registered customers can download the latest revision of this interface from the MVTec WWW server.

Revision: 2.0

• Intel compatible PC with Windows NT 4.0 (Service Pack 4) including multimedia support. Note: Windows 2000 is not yet supported !
• A Video for Windows compatible capture device and
• a successfully installed Video for Windows capture driver for that device.
• HALCON frame grabber interface HFGVideoForWindows.dll or parHFGVideoForWindows.dll, respectively.
  If you have properly installed the interface, both DLLs should reside in bin\i586-nt4 within the HALCON base directory %HALCONROOT% you have chosen during the installation of HALCON.

• Multiple capture devices.
• Synchronous and asynchronous grabbing.
• Realtime grabbing (30 frames per second for NTSC).

• Image scaling and cropping only supported via device specific dialogs. Appearance, functionality, behaviour and the mere existance of such dialogs lie fully in the responsibility of the capture devices vendor.
• Video input selection only supported via device specific dialogs. Appearance, functionality, behaviour and the mere existance of such dialogs lie fully in the responsibility of the capture devices vendor.
• grab_region() and grab_region_async() not supported.
• No LUTs.

Parameters for open_framegrabber():

	Name	'VideoForWindows'	The name of the HALCON frame grabber interface.
	HorizontalResolution	---	Ignored.
	VerticalResolution	---	Ignored.
	ImageWidth	---	Ignored.
	ImageHeight	---	Ignored.
	StartRow	---	Ignored.
	StartColumn	---	Ignored.
	Field	---	Ignored.
	BitsPerChannel	5, 8	Number of bits per image channel which will be delivered. Specifying 5 bits per channel is only allowed in combination with ColorSpace='rgb' and enables the 5-5-5 bit encoded RGB raw data transfer. You will get an 8-8-8 three channel RGB HALCON image in this case, too. Default: 8.
	ColorSpace	'gray', 'rgb', 'xrgb'	Specify the desired color space and thus the number of image channels of the resulting HALCON image. Default: 'rgb'.
	Gain	---	Ignored.
	ExternalTrigger	---	Ignored.
	CameraType	---	Ignored.
	Device	'0', '1', '2', ..., '9', 'name'	The number of the capture driver (passed as a string!). Alternatively, you can pass the name of the capture driver as it is returned by info_framegrabber(). Default: '0'.
	Port	---	Ignored.
	LineIn	---	Ignored.

Parameters for set_framegrabber_param():

	'frame_rate'	0.0 - 60.0	Desired frame rate in frames per second. Default: 15.0.
	'video_format_dialog'	---	Opens a dialog to select the actual video format to capture. The dialog is provided by the capture driver. Note that not necessarily every capture driver has to provide a video format dialog. Use get_framegrabber_param() to query if a specific capture driver provides a video format dialog. Any values passed with 'video_format_dialog' are ignored.
	'video_source_dialog'	---	Opens a dialog to select the actual video input to capture from. The dialog is provided by the capture driver. Note that not necessarily every capture driver has to provide a video source dialog. Use get_framegrabber_param() to query if a specific capture driver provides a video source dialog. Any values passed with 'video_source_dialog' are ignored.

Parameters for get_framegrabber_param():

Additional parameters supported by get_framegrabber_param() only. Note that all parameters supported by set_framegrabber_param() can also be accessed by get_framegrabber_param().

	'avicap_version'	version	The version number of the capture library avicap32.dll.
	'revision'	revision	The revision number of the HALCON frame grabber interface HFGVideoForWindows.dll.
	'video_format_dialog'	'true', 'false'	When 'true', the capture driver provides a video format dialog to select the actual video format from, otherwise not.
	'video_source_dialog'	'true', 'false'	When 'true', the capture driver provides a video source dialog to select the actual video input from, otherwise not.

• Revision 2.0 (Aug 13, 2001):
  
  • First official release.