Image Control Reference 14.0
Methods

Functions

void AboutBox ()
 Displays the About box of the Common Vision Image Control.
 
boolean Clear (long Plane, double Value)
 Sets the specified image plane to the required initial gray scale value. More...
 
boolean CopyImageToClipboard ()
 Copies any image that is present to the Windows clipboard. More...
 
boolean CreateEmptyImage (long Dimension, long Width, long Height, boolean ForceOverlay)
 Creates a new, empty image. More...
 
long DataType (long Plane)
 Returns the data type of a specified plane of the image. More...
 
boolean GetGrab2Status (Grab2InfoType Grab2InfoType, double *Grab2Info)
 Returns status information of the IGrab2 inteface of the underlying driver image. More...
 
boolean LoadImage (BSTR Filename)
 Loads an image from a file using the given name. More...
 
boolean LoadImageByDialog ()
 Loads an image from a file using the given file name. More...
 
boolean LoadImageByUserDialog (BSTR DefaultPath, BSTR Titel, BSTR Filter)
 Loads an image from a file using the Windows common dialog box to open files. More...
 
boolean PasteImageFromClipboard ()
 If the Windows clipboard contains an image it will be pasted. More...
 
boolean SaveImage (BSTR Filename)
 Saves an image to a file using the given file name. This method has the same effect as a change to the Filename property. The CVCError event is triggered if an error occurs. More...
 
boolean SaveImageByDialog ()
 Saves an image to a file using the options of a dialog box. More...
 
boolean SaveImageByUserDialog (BSTR DefaultPath, BSTR Titel, BSTR Filter)
 Saves an image to a file using the options of a dialog box. More...
 
boolean SaveLossyImage (BSTR Filename, double Quality)
 Saves an image to a file using the given file name, applying a lossy compression codec. More...
 
boolean ScanImage (long Density, boolean UseCS)
 Scans the image in a defined area. More...
 
boolean ScanPlane (long Plane, long Density, boolean UseCS)
 Scans the image in a defined area in a specified plane. More...
 
boolean Snap ()
 Acquires an individual image from the camera. More...
 

Detailed Description

Function Documentation

◆ Clear()

boolean Clear ( long  Plane,
double  Value 
)

Sets the specified image plane to the required initial gray scale value.

The gray scale value is passed as Double to ensure that different data types of the image can be supported.

Attention
8-bit and 16-bit images are supported at present.
Parameters
[in]PlaneIndex of the plane to be initialized. Index ranges between zero and image dimension.
[in]ValueGray scale value for image data (e.g. 0..255 for an 8-bit image).
Returns
TRUE if successful, FALSE otherwise.
Examples:
Visual Basic - VB Fileformats Example

◆ CopyImageToClipboard()

boolean CopyImageToClipboard ( )

Copies any image that is present to the Windows clipboard.

Returns
TRUE if copying was successful, FALSE otherwise.

◆ CreateEmptyImage()

boolean CreateEmptyImage ( long  Dimension,
long  Width,
long  Height,
boolean  ForceOverlay 
)

Creates a new, empty image.

Parameters
[in]DimensionDimension of the image to be created.
[in]WidthWidht of the image to be created.
[in]HeightHeight of the image to be created.
[in]ForceOverlayTRUE specifies that a overlay-capable image is created, FALSE otherwise.
Returns
TRUE if creation was successful, otherwise FALSE.

◆ DataType()

long DataType ( long  Plane)

Returns the data type of a specified plane of the image.

The data type has following individual bits:

31...10987 6543210
ReservedOFSBits/pixel


Where S = Signed, F = Float (only for 32 or 64 bits/pixel) and O = Overlay bit

Examples for data types:
  • An 8-bit unsigned image has a data type of 8.
  • A signed 32-bit image has 32 + 256.
  • A double image has 64 + 512.
  • The data type for a 24-bit RGB image is 8 and NOT 24, because the number of bits/pixel relates only to a plane of the image.
Parameters
[in]PlaneIndex of the plane of the source image. Index ranges between zero and image dimension.
Returns
Datatyp of plane, -1 otherwise.

◆ GetGrab2Status()

boolean GetGrab2Status ( Grab2InfoType  Grab2InfoType,
double *  Grab2Info 
)

Returns status information of the IGrab2 inteface of the underlying driver image.

Attention
This function works correct if the driver image supports the IGrab2 interface and if this interface is used for acquisition.
Parameters
[in]Grab2InfoTypeInformation you want querry. For information you might request see Grab2InfoType.
[out]Grab2InfoRequested information as return value.
Returns
TRUE if successful, otherwise FALSE.
Examples:
Delphi - Delphi RingBuffer Example
Visual Basic - VB RingBuffer Examples
Visual C++ - VC RingBuffer Example

◆ LoadImage()

boolean LoadImage ( BSTR  Filename)

Loads an image from a file using the given name.

It is possible to load CVB VIN-drivers for the supported image acquisition devices like framegrabbers, cameras or other devices. This method has the same effect as a change to the Filename property. The CVCError event is triggered if an error occurs.

Attention
Check first the supported image formats.
Since CVB version 9.0 it is possible to include enviroment variables in the path. Use the environment variables enclosed in % signs as they are used in the command prompt (e.g. cvb%\Tutorial\Clara.bmp).
Parameters
[in]FilenameEntire path of the file.
Returns
TRUE if loading was successful, otherwise FALSE.
Examples:
Visual Basic - VB Fileformats Example

◆ LoadImageByDialog()

boolean LoadImageByDialog ( )

Loads an image from a file using the given file name.

This includes also loading CVB vin-drivers for the supported image acquistion devices like frame grabbers, cameras or other devices.

Returns
TRUE if loading was successful, FALSE otherwise.
Examples:
Delphi - Delphi Display Example
Visual Basic - VB Fileformats Example
Visual C++ - VC Sizeable Display Example

◆ LoadImageByUserDialog()

boolean LoadImageByUserDialog ( BSTR  DefaultPath,
BSTR  Titel,
BSTR  Filter 
)

Loads an image from a file using the Windows common dialog box to open files.

The user can change the appearance of the dialog box.
It is possible to load CVB VIN-drivers for the supported image acquisition devices like framegrabbers, cameras or other devices.
This method has the same effect as a change to the Filename property. The CVCError event is triggered if an error occurs.

Attention
Check first the supported image formats.
Parameters
[in]DefaultPathThe default path of the dialog box. In case of NULL the current path will be taken.
[in]TitelTitle of the dialog box.
[in]FilterA valid filter string (refer to Windows documentation on FileDialog), e.g. "CVC Drivers (*.vin)|*.vin".
Returns
TRUE if image was loaded successfully, otherwise FALSE (e.g. if the dialog box was closed with cancel).
Visual Basic Test Code:
The following example shows a user-defined File Open dialog.
Private Sub bOpen_Click()
Dim Dummy As Integer
' load image via dialog
Dummy = Img.LoadImageByUserDialog("", "Load CVC Driver", "CVC Drivers (*.vin)|*.vin")
End Sub
boolean LoadImageByUserDialog(BSTR DefaultPath, BSTR Titel, BSTR Filter)
Loads an image from a file using the Windows common dialog box to open files.
Examples:
Visual Basic - VB Fileformats Example

◆ PasteImageFromClipboard()

boolean PasteImageFromClipboard ( )

If the Windows clipboard contains an image it will be pasted.

Returns
TRUE if pasting was successful, FALSE otherwise.

◆ SaveImage()

boolean SaveImage ( BSTR  Filename)

Saves an image to a file using the given file name. This method has the same effect as a change to the Filename property. The CVCError event is triggered if an error occurs.

Parameters
[in]FilenameEntire path of the file.
Returns
TRUE if saving was successful, FALSE otherwise.

◆ SaveImageByDialog()

boolean SaveImageByDialog ( )

Saves an image to a file using the options of a dialog box.

This method has the same effect as a change to the Filename property. The CVCError event is triggered if an error occurs.

Attention
It is not necessary to explicity enter the file name in this function like in SaveImage. Check first the supported image formats.
Returns
TRUE if saving was successful, FALSE otherwise.

◆ SaveImageByUserDialog()

boolean SaveImageByUserDialog ( BSTR  DefaultPath,
BSTR  Titel,
BSTR  Filter 
)

Saves an image to a file using the options of a dialog box.

It is possible to change the appearance of teh dialog box.

Parameters
[in]DefaultPathThe default path of the dialog box. In case of NULL the current path will be taken.
[in]TitelTitle of the dialog box.
[in]FilterA valid filter string (refer to Windows documentation on FileDialog), e.g. "CVC Drivers (*.vin)|*.vin".
Returns
TRUE if saving was successful, otherwise FALSE.
Visual Basic Test Code:
The following example shows a user-defined File Save dialog.
Private Sub bSave_Click()
Dim Dummy As Integer ' save image via dialog
Dummy = Img.SaveImageByUserDialog("", "Save Image ", "CVC Image Format (*.mio)|*.mio")
End Sub
boolean SaveImageByUserDialog(BSTR DefaultPath, BSTR Titel, BSTR Filter)
Saves an image to a file using the options of a dialog box.
__int3264 Image
Determines the image object that is assigned to the Common Vision Image Control.
Definition: CVimage.odl:99

◆ SaveLossyImage()

boolean SaveLossyImage ( BSTR  Filename,
double  Quality 
)

Saves an image to a file using the given file name, applying a lossy compression codec.

Lossy codecs drop image information for the sake of a higher compression ratio. This generally introduces artifacts into the image. The WriteLossyImageFile gives control over the tradeoff between compression ratio and image quality by means of the Quality parameter.

Attention
The codec for saving an image file is selected based on the extension of the filename. When calling this function you should supply a filename with an extension that corresponds to a lossy image codec.
If you specify a lossless codec, the Quality paramter is ignored and the function call will be re-routed to WriteImageFile.
Parameters
[in]FilenameEntire path of the file to save.
[in]QualityControls the balance between the quality and the compression ratio.
The value ranges from a codec-specific minimum and 1.0. Higher values leading to image files that are bigger and contain less artifacts.
Returns
TRUE if saving was successful, otherwise FALSE.

◆ ScanImage()

boolean ScanImage ( long  Density,
boolean  UseCS 
)

Scans the image in a defined area.

The image data can be accessed easily with this function (especially using Visual Basic). An event is gernerated for each pixel. This event returns the reference of the pixel and allows the user to modify the pixel value (refer to StartOfLine, EndOfLine and NextPixel events).

Attention
This method works on 8 Bit images.
Parameters
[in]DensityDefines the scan density. The density is between zero and 1000.
[in]UseCSThe defined coordinate system will be used if UseCs is TRUE. Otherwise the area of interest relates to the left, upper corner of the image.
Returns
TRUE if succeeded, otherwise FALSE.
Visual Basic Test Code:
Private Sub Scan_Click()
bCancel = False CVImage1.ScanImage 1000, True
CVDisplay1.Refresh
End Sub
Sub Private Sub CVImage1_EndOfLine(ByVal LinesToDo As Long, Cancel As Boolean)
LinesLeft = LinesToDo
End Sub Private
Private Sub CVImage1_NextPixel(ByVal Plane As Long, ByVal x As Long, ByVal y As Long, Value As Long, Cancel As Boolean)
Value = Value And 129
DoEvents
Cancel = bCancel
End Sub
boolean ScanImage(long Density, boolean UseCS)
Scans the image in a defined area.

◆ ScanPlane()

boolean ScanPlane ( long  Plane,
long  Density,
boolean  UseCS 
)

Scans the image in a defined area in a specified plane.

The image data can be accessed easily with this function (especially using Visual Basic). An event is gernerated for each pixel. This event returns the reference of the pixel and allows the user to modify the pixel value (refer to StartOfLine, EndOfLine and NextPixel events).

Attention
This method works on 8 Bit images.
Parameters
[in]PlaneDefines the disired plane. The index of the plane have to be between zero and the image dimension.
[in]DensityDefines the scan density. The density is between zero and 1000.
[in]UseCSThe defined coordinate system will be used if UseCs is TRUE. Otherwise the area of interest relates to the left, upper corner of the image.
Returns
TRUE if succeeded, otherwise FALSE.
Visual Basic Test Code:
Private Sub Scan_Click()
bCancel = False CVImage1.ScanPlane 0, 1000, True
CVDisplay1.Refresh
End Sub
Sub Private Sub CVImage1_EndOfLine(ByVal LinesToDo As Long, Cancel As Boolean)
LinesLeft = LinesToDo
End Sub Private
Private Sub CVImage1_NextPixel(ByVal Plane As Long, ByVal x As Long, ByVal y As Long, Value As Long, Cancel As Boolean)
Value = Value And 129
DoEvents
Cancel = bCancel
End Sub
boolean ScanPlane(long Plane, long Density, boolean UseCS)
Scans the image in a defined area in a specified plane.

◆ Snap()

boolean Snap ( )

Acquires an individual image from the camera.

Attention
If the Grab property is TRUE, the value is reset to FALSE. The function returns after acquiring the image. A sequence of Snapcalls cannot generally replace live image acquisition. For live image acquisition please use the Grab property.
Returns
TRUE if acquisition was successful, otherwise FALSE or when an error occured during acquisition.
Related Topics:
Grab
Examples:
Delphi - Delphi Image Access Example
Visual Basic - VB Fileformats Example
Visual C++ - VC Sizeable Display Example