Events

Functions
void	CVCError (ErrorCode ErrorCode, BSTR ErrorString, boolean *Continue)
	This event is fired if an error occurs in the Image Control. More...
void	EndOfLine (long LinesToDo, boolean *Cancel)
	This event is triggered when ScanImage or ScanPlane is called at the end of every scanned line. More...
void	ImageSnaped ()
	This event is only triggered if the image object is an image acquisition device and if the Grab property is set to TRUE. More...
void	ImageUpdated ()
	This event is only triggered when the image object has changed. This is the case when a new image has been loaded from the hard disk or an image acquisition device driver.
void	NextPixel (long Plane, long x, long y, long *Value, boolean *Cancel)
	This event is triggered for all scanned pixels. More...
void	StartOfLine (long LinesToDo, boolean *Cancel)
	This event is triggered when ScanImage or ScanPlane is called at the beginning of every scanned line. More...

Detailed Description

Function Documentation

CVCError()

void CVCError	(	ErrorCode	ErrorCode,
		BSTR	ErrorString,
		boolean *	Continue
	)

This event is fired if an error occurs in the Image Control.

Attention

Please include the appropriate header file for your compiler (cvcerror.*).

Parameters

[in]	ErrorCode	A unique number describing the error. The following error codes have been defined: 1 CVC_E_ERROR   This error cannot be described more precisely. 2 CVC_E_PARAMETER   Incorrect parameter in a function call. 3 CVC_E_FILEIO   File I/O error, for example while saving or loading an image. 4 CVC_E_TIMEOUT   Timeout during acquisition of an image in ping-pong mode if, for example, there is no trigger although the image acquisition device is waiting for such a signal. 5 CVC_E_MEMORY   Memory could not be allocated. 6 CVC_E_INVALIDPLANE   An invalid image plane has been specified. 7 CVC_E_UNSUPPORTEDDATATYPE   Data type that is not supported. 16 CVC_E_NOIMAGE   No image at all. 17 CVC_E_NOINTERFACE   No interface available.
[in]	ErrorString	Specifies the error text of the output.
[in]	Continue	This specifies whether execution should continue despite the error. The user can overwrite the value in order to change the default action. The default value depends on the function that caused the error. TRUE specifies that a messate box will appear to inform the user of the error. FALSE means that it is possible to perform custom error handling, e.g. use a self-defined message-box.

Visual Basic Test Code:

This example shows the trapping of a timeout during image acquisition.

  Private Sub cvImg_CVCError(Index As Integer, ByVal ErrorCode As CVIMAGELib.ErrorCode, ByVal ErrorString As String, Continue As Boolean)
 Dim res As Integer
   ' ACQ timeout ? this is only available if pingpong is active
   If ErrorCode = CVC_E_TIMEOUT Then
     res = MsgBox(ErrorString & " Do you want to continue?", vbYesNo + vbSystemModal)
     If res = vbYes Then
       ' continue acq and display automatically Image control error msg
       Continue = True
     Else
       ' cancel acq
       Continue = False
     End If
   Else
     MsgBox ErrorString
   End If
End Sub

Examples:

Visual Basic - VB Fileformats Example

EndOfLine()

void EndOfLine	(	long	LinesToDo,
		boolean *	Cancel
	)

This event is triggered when ScanImage or ScanPlane is called at the end of every scanned line.

Parameters

[in]	LinesToDo	Number of lines still to come.
[in]	Cancel	TRUE specifies that the scanning is terminated, otherwise FALSE.

ImageSnaped()

void ImageSnaped

(

)

This event is only triggered if the image object is an image acquisition device and if the Grab property is set to TRUE.

Related Topics:

Grab

Examples:

Delphi - nearly every Delphi example
Visual Basic - Basic nearly every VB example
Visual C++ - nearly every VC example, VC Sizeable Display

NextPixel()

void NextPixel	(	long	Plane,
		long	x,
		long	y,
		long *	Value,
		boolean *	Cancel
	)

This event is triggered for all scanned pixels.

Scanning is started by ScanImage or ScanPlane and can be terminated by setting Cancel to TRUE. The gray scale value of the pixel is passed by way of reference so that the pixel can be overwritten.

Parameters

[in]	Plane	Index of the current plane.
[in]	x	X position of the pixel.
[in]	y	Y position of the pixel.
[in,out]	Value	Gray scale value of the pixel on position x and y.
[in]	Cancel	TRUE specifies that the scanning is terminated, otherwise FALSE.

StartOfLine()

void StartOfLine	(	long	LinesToDo,
		boolean *	Cancel
	)

This event is triggered when ScanImage or ScanPlane is called at the beginning of every scanned line.

Parameters

[in]	LinesToDo	Number of lines still to come.
[in]	Cancel	TRUE specifies that the scanning is terminated, otherwise FALSE.