Display Control Reference 15.0
Properties

Variables

long AOOCount
 Returns the number of overlay objects that have been installed (AvailableOverlayObjects, AOO). More...
 
long AOOIndex
 It is used to number the availabe overlay objects. More...
 
BSTR AOOName
 Returns the name of the available overlay object with the index(AOOIndex). More...
 
long AOONumVertices
 Returns the number of externally visible vertices of the available overlay object with the index(AOOIndex). More...
 
long AOONumVerticesUsed
 Returns the number of internally used vertices of the available overlay object with the index(AOOIndex). More...
 
long AOOType
 Returns the type of the available overlay object with the index(AOOIndex). More...
 
Appearance Appearance
 Determines the frame shape of a display object. More...
 
boolean BevelInner
 Determines the appearance of the inner frame of a display object. More...
 
boolean BevelOuter
 Determines the appearance of the outer frame of a display object. More...
 
long BluePage
 Determines the image plane to be displayed in the blue channel. More...
 
CoordStyle CoordStyle
 Determines the display style of the coordinate system. More...
 
boolean DirectDrawEnabled
 Enables or disables the support of DirectDraw. More...
 
double DisplayGain
 Determines the image gain for the display. More...
 
long DisplayOffset
 Determines the image offset for the display. More...
 
long DisplayRectPercentage
 Adjust the size of the border of the image that is displayed in the control. More...
 
boolean DrawErase
 Determines the "painting color" used for the overlay bit of an overlay-capable image. More...
 
long GreenPage
 Determines the image plane to be displayed in the green channel. More...
 
HighBitScaleMode HighBitScaleMode
 Set the high bit scaling mode the display should use. More...
 
__int3264 Image
 Determines the image object that is assigned to the Common Vision Display Control. More...
 
LeftButtonMode LeftButtonMode
 Specifies what the response will be to a LeftButton event of the mouse. More...
 
boolean ManualDisplayRefresh
 Indicates whether the display is refreshed manually or not. More...
 
MouseWheelMode MouseWheelMode
 Specifies what the response will be to a MouseWheel event of the mouse. More...
 
boolean OverlayDragAndDelete
 Indicates the behavior of the control when deleting or dragging an overlay. More...
 
long RedPage
 Determines the image plane to be displayed in the red channel. More...
 
boolean RestrictZoomPositions
 Set the current state of the zoom restriction mode. More...
 
RightButtonMode RightButtonMode
 Sets or gets the functionality of the right mouse button. More...
 
boolean RulerEnabled
 Controls whether a crosshair (ruler) will be displayed in the image for easier positioning or not. More...
 
boolean ScrollBars
 Controls the display of scroll bars if the image content does not fit as a whole into the window. More...
 
boolean ShowCoords
 Controls the display of the coordinate system. More...
 
boolean StatusCurrentPos
 Controls the display of the current mouse cursor position in the status window of the display object. More...
 
boolean StatusEmpty
 Controls whether an empty status field is shown in the display object. More...
 
boolean StatusGrayValue
 Controls the display of the gray scale value at the current location of the mouse position in the status window. More...
 
boolean StatusImageSize
 Controls the display of the current image size in the status window of the diplay object. More...
 
boolean StatusScale
 Controls the display of the image scaling information (zoom factor) in the status window of the display object. More...
 
BSTR StatusUserText
 Controls displaying of a text string in the status window of the display object. More...
 
boolean SyncRefreshToMonitor
 Synced the final blit form the offsecreen memory of the VGA to the visible (primary) display surface to the beginning of the the vertical blank of the monitor. DirectDraw (version 8.1) have to be installed on the system. More...
 

Detailed Description

Variable Documentation

◆ AOOCount

long AOOCount
readonly

Returns the number of overlay objects that have been installed (AvailableOverlayObjects, AOO).

A list of all available plug-ins can be generated with the aid of this property.

Parameters
[out]AOOCountAvailabe overlay objects.
Returns
Number of available overlay objects.
Visual Basic Test Code:
The following example shows how a list box is filled with the names of the installed plug-ins.
Dim I As Integer
For I = 0 To Disp.AOOCount - 1
Disp.AOOIndex = I
listAvailable.AddItem Disp.AOOName
Next I
Related Topics:
AOOIndex, AOOName, AOONumVertices, AOONumVerticesUsed, AOOType

◆ AOOIndex

long AOOIndex

It is used to number the availabe overlay objects.

Parameters
[in,out]AOOIndexSet current index for the list of available overlay objects. The AOOIndex lies in the range between 0 and AOOCount - 1.
Returns
Current index.
Examples:
See AOOCount

◆ AOOName

BSTR AOOName
readonly

Returns the name of the available overlay object with the index(AOOIndex).

Parameters
[out]AOONameName of the available overlay object.
Returns
Name of the available overlay object.
Examples:
See AOOCount

◆ AOONumVertices

long AOONumVertices
readonly

Returns the number of externally visible vertices of the available overlay object with the index(AOOIndex).

Parameters
[out]AOONumVerticesNumber of externally visible vertices.
Returns
Number of externally visible vertices of the available overlay object.
Examples:
See AOOCount

◆ AOONumVerticesUsed

long AOONumVerticesUsed
readonly

Returns the number of internally used vertices of the available overlay object with the index(AOOIndex).

Parameters
[out]AOONumVerticesUsedNumber of internally used vertices.
Returns
Number of internally used vertices of the available overlay object.
Examples:
See AOOCount

◆ AOOType

long AOOType
readonly

Returns the type of the available overlay object with the index(AOOIndex).

Attention
The type information is not evaluated any further at present.
Parameters
[out]AOOTypeType of the available overlay object.
Returns
Type of the available overlay object.
Examples:
See AOOCount

◆ Appearance

Determines the frame shape of a display object.

Parameters
[in,out]AppearanceSets the style of the ccordinate system. For possible frame shapes refer to Appearance.
Returns
Current frame shape/appearance.

◆ BevelInner

boolean BevelInner

Determines the appearance of the inner frame of a display object.

Parameters
[in,out]BevelInnerTRUE specifies that the inner frame is shaded, FALSE otherwise.
Returns
TRUE if inner frame is shaded, FALSE otherwise.

◆ BevelOuter

boolean BevelOuter

Determines the appearance of the outer frame of a display object.

Parameters
[in,out]BevelOuterTRUE specifies that the outer frame is shaded, FALSE otherwise.
Returns
TRUE if outer frame is shaded, FALSE otherwise.

◆ BluePage

long BluePage

Determines the image plane to be displayed in the blue channel.

This function might be used if only one channel of a color image is to be displayed as a gray scale image.

Parameters
[in,out]BluePageImage plane to be set as blue channel.
Returns
Number of image plane to be displayed in the blue channel.

◆ CoordStyle

Determines the display style of the coordinate system.

The coordinate system can be shown in the conventional way (x-axis to the right, y-axis to the bottom) or as a crosshair.

Parameters
[in,out]CoordStyleSets the style of the coordinate system. For possible styles refer to CoordStyle.
Returns
Current coordinate style.

◆ DirectDrawEnabled

boolean DirectDrawEnabled

Enables or disables the support of DirectDraw.

Refer to the introduction for information on DirectDraw.

Attention
This value is only TRUE when the GLobel Direct Draw is ENABled (via SetGlobalDirectDrawEnabled function). If this value is FALSE, synchronisation of the ImageSnaped event with the message loop of the program will occur. Please see the Multithreading information in the Image Manager - Common Vision Blox Technology section of the documentation.

If DirectDraw could not be enabled (e.g because the graphic adapter has no DirectDraw support) the value will be switched to FALSE.
Parameters
[in,out]DirectDrawEnabledsTRUE enables DirectDraw, FALSE disables DirectDraw.
Returns
TRUE if DirectDraw is enabled, FALSE otherwise.
Examples:
Visual C++ - VC Sizeable Display Example

◆ DisplayGain

double DisplayGain

Determines the image gain for the display.

P'(x,y) = gain * P(x,y) - offset

Attention
Pixels containing a value smaller than the offset value are displayed as black. The image data itself is not modified.
Parameters
[in,out]DisplayGainSets the given value for the gain. Default value is 1.0.
Returns
Current gain.
Related Topics:
DisplayOffset
For modifying image data please refer to
  • Image Manager: Image Library with Image data access functions e.g. GetImageVPA
  • Arithmetic Tool
  • Foundation Package LUT functions
Examples:
Delphi - Delphi Display Example
Visual Basic - VB Display Example
Visual C++ - VC Display Example

◆ DisplayOffset

long DisplayOffset

Determines the image offset for the display.

P'(x,y) = gain * P(x,y) - offset

Attention
Pixels containing a value smaller than the offset value are displayed as black. The image data itself is not modified.
Parameters
[in,out]DisplayOffsetSets the given value for the offset. Default value is 0.
Returns
Current offset.
Related Topics:
DisplayGain
For modifying image data please refer to
  • Image Manager: Image Library with Image data access functions e.g. GetImageVPA
  • Arithmetic Tool
  • Foundation Package LUT functions
Examples:
Delphi - Delphi Display Example
Visual Basic - VB Display Example
Visual C++ - VC Display Example

◆ DisplayRectPercentage

long DisplayRectPercentage

Adjust the size of the border of the image that is displayed in the control.

The painted image that is displayed in the display control has a border that is filled with the backcolor. The aspect ration of the painted image is allways the same as the aspect ratio of the input image specified by the Image property. The size of the border can be adjusted using this property. When setting the size to 100 the image will be painted using the complet width or height of the display control window. Wehn setting the size to 50 only 50% of the width or height are used.

Parameters
[in,out]DisplayRectPercentagePercent of the width or the height of the display window that re used to paint the image.
The value ranges from 10 to 100;
Returns
Percent of the width or height.
Examples:
Visual Basic - VB Display Rectangle Example

◆ DrawErase

boolean DrawErase

Determines the "painting color" used for the overlay bit of an overlay-capable image.

All functions which draw in the overlay use the »painting color« that is currently set.
Only overlay pixels having the value 1 will be visible. Invisible overlay pixels having the value 0. This means that a visible overlay image is drawn by the function if the current »painting color« was set to 1. On the other hand overlay images can be repaint by setting the »painting color« was set to 0.

Attention
This function only operates if the image was transformed beforehand into an overlay-capable image MakeOverlayImage method.
Parameters
[in,out]DrawEraseTRUE sets the »painting color« to 0, FALSE set the »painting color« to 1.
Returns
TRUE if "painting color" is 0, otherwise FALSE when »painting color« is 1.

◆ GreenPage

long GreenPage

Determines the image plane to be displayed in the green channel.

This function might be used if only one channel of a color image is to be displayed as a gray scale image.

Parameters
[in,out]GreenPageImage plane to be set as green channel.
Returns
Number of image plane to be displayed in the green channel.

◆ HighBitScaleMode

Set the high bit scaling mode the display should use.

Please refer to the description of the HighBitScaleMode enum for the available values and their meaning.
Note that...

  • High bit scaling is currently not available in DirectDraw mode. If you want to make use of this feature, you will need to set the property DirectDrawEnabled to false.
  • Regardless of your scaling mode, images with floating point accuracy will always be displayed as if the ViewPort mode is set.
  • When using the ViewPort mode, the values for DisplayGain and DisplayOffset will be ignored.
Parameters
[in,out]HighBitScaleModeSpecify the mode to be used.
Returns
current state

◆ Image

__int3264 Image

Determines the image object that is assigned to the Common Vision Display Control.

The image object manages the image information, e.g. the images from hard disk or a image acquisition device driver.

Parameters
[in,out]ImageHandle of the image object.
Returns
Image object handle.

◆ LeftButtonMode

Specifies what the response will be to a LeftButton event of the mouse.

Parameters
[in,out]LeftButtonModeSets the left button mode. For possible modes refer to LeftButtonModeEnumeration.
Returns
Left button mode.
Related Topics:
MakeOverlayImage
Examples:
Delphi - nearly every CVB Tutorial
Visual Basic - nearly every CVB Tutorial
Visual C++ - nearly every CVB Tutorial

◆ ManualDisplayRefresh

boolean ManualDisplayRefresh

Indicates whether the display is refreshed manually or not.

To increase the performance you can set the ManualDisplayRefresh property to TRUE. In this case the control will not repaint the window automatically when adding/removing overlays from the display. Instead you have to call explicitly the Refresh method after you have added all overlays in order to repaint the display window.
Otherwise FALSE indicates that the display window is automatically repainted if you add or remove an overlay. If you need to add a hugeg number of overlays (no matter which kind of overlay) the control will repaint for every single overlay and therefore it will be relatively slow.

Attention
This property replaces the 'Manual Display Refresh Enabled' registry setting of previous versions. The default value is still loaded from the registry key.
Parameters
[in,out]ManualDisplayRefreshTRUE specifies that the display will be refreshed manually using the Refresh method, FALSE otherwise.
Returns
TRUE means that the display have to be repaint explicitly calling the Refresh method. FALSE means that the display will be refreshed automatically when a overlay is added or removed.
Related Topics:
Refresh

◆ MouseWheelMode

Specifies what the response will be to a MouseWheel event of the mouse.

To zoom a display window using the mouse wheel, click first in the display control to put the focus on it. Than place the mouse cursor over the position you want to zoom or unzoom. Use the wheel to zoom in or out at this position. The maximum zoom factor using the mouse wheel is 64. to use finer zoom steps hold down the 'CTRL' key of the keyboard.

Parameters
[in,out]MouseWheelModeSets the mouse wheel mode. For possible modes refer to MouseWheelMode.
Returns
Mouse wheel mode.
Related Topics:
RightButtonMode, SetDisplayZoom, SetDisplayZoomEx
Examples:
Delphi - nearly every CVB Tutorial
Visual Basic - nearly every CVB Tutorial
Visual C++ - nearly every CVB Tutorial

◆ OverlayDragAndDelete

boolean OverlayDragAndDelete

Indicates the behavior of the control when deleting or dragging an overlay.

If this property is set to TRUE the control produces in very rare cases a GPF if you delete an overlay from a seperate thread while you drag another overlay.
If the property is set to FALSE a drag operation is canceled when you delete an overlay to pervent the GPF.

Attention
This property replaces the registry key 'Overlay DragAndDelete Enabled'. This key was implemented in Common Vision Blox version 7.1.2 (refer to the release notes). The default value is still loaded from the registry key.
Parameters
[in,out]OverlayDragAndDeleteTRUE specifies that overlays can be deleted at any time from any thread, even while they are dragged. Caution: a GPF might be the result.
FALSE means that a potential drag operation is canceled when deleting an overlay to prevent a possible GPF. using the Refresh method, FALSE otherwise.
Returns
TRUE means that the overlay can be deleted at any time. FALSE means that deleting an overlay can be canceled if a GPF would occur.

◆ RedPage

long RedPage

Determines the image plane to be displayed in the red channel.

This function might be used if only one channel of a color image is to be displayed as a gray scale image or if RGB images are be displayed in the BGR format.

Parameters
[in,out]RedPageImage plane to be set as red channel.
Returns
Number of image plane to be displayed in the red channel.

◆ RestrictZoomPositions

boolean RestrictZoomPositions

Set the current state of the zoom restriction mode.

When set to true, the display automatically applies a restriction to the possible center locations of the display zoom so that it cannot happen that a zoomed display consists of up to 75% background when zooming into one of the image's corners. This also means that when calling SetDisplayZoom or SetDisplayZoomEx and right after that GetDisplayZoom or GetDisplayZoomEx, the x/y position retrieved may not actually be the position that has just been set!
When calculating the positional restrictions on the zoom center, the current DisplayRectPercentage value is being taken into account and ideally the amount of border visible in the display will exactly match that percentage. It is, however, not always possible to achieve this ideal value because the zoom centers are only pixel accurate in the CVB display, which means that for higher zoom levels, the roundoff that causes a deviation from the ideal value is likely to become visible.

Parameters
[in,out]RestrictZoomPositionsswitch the mode in which the zoom positions are restricted on or off.
Returns
current state

◆ RightButtonMode

Sets or gets the functionality of the right mouse button.

Functionality of the modes:
RB_MENUClicking the right mouse button opens a context menu on which you can copy the image to the clipboard, save it or zoom it.
RB_ZOOMThe image is zoomed with the aid of the right mouse button.
RB_NONE;The right mouse button has been disabled so that it does not have any function. This mode enables you to implement your own context menus.
Parameters
[in,out]RightButtonModeSets the current right botton mode. For possible modes refer to RightButtonMode.
Returns
Current right button mode.
Examples:
Visual C++ - VC Right Mouse Button Example

◆ RulerEnabled

boolean RulerEnabled

Controls whether a crosshair (ruler) will be displayed in the image for easier positioning or not.

The crosshair is first located in the middle of the window and can then be moved interactively.

Parameters
[in,out]RulerEnabledTRUE specifies that crosshair is enabled, FALSE otherwise.
Returns
TRUE if crosshair is enabled, FALSE otherwise.
Examples:
Visual C++ - VC Sizeable Display Example

◆ ScrollBars

boolean ScrollBars

Controls the display of scroll bars if the image content does not fit as a whole into the window.

Parameters
[in,out]ScrollBarsTRUE specifies that scroll bars will be displayed, FALSE otherwise.
Returns
TRUE if scroll bars are displayed, FALSE otherwise.

◆ ShowCoords

boolean ShowCoords

Controls the display of the coordinate system.

Parameters
[in,out]ShowCoordsTRUE specifies that the coordinate system displayed, FALSE otherwise.
Returns
TRUE if coordinate system is displayed, FALSE otherwise.

◆ StatusCurrentPos

boolean StatusCurrentPos

Controls the display of the current mouse cursor position in the status window of the display object.

Parameters
[in,out]StatusCurrentPosTRUE specifies that the mouse cursor position will be displayed, FALSE otherwise.
Returns
TRUE if the mouse cursor position is displayed, FALSE otherwise.
Examples:
Visual C++ - VC Right Mouse Button Example

◆ StatusEmpty

boolean StatusEmpty

Controls whether an empty status field is shown in the display object.

Parameters
[in,out]StatusEmptyTRUE specifies that an empty status window will be diplayed, FALSE otherwise.
Returns
TRUE if empty status window is displayed, FALSE otherwise.

◆ StatusGrayValue

boolean StatusGrayValue

Controls the display of the gray scale value at the current location of the mouse position in the status window.

Parameters
[in,out]StatusGrayValueTRUE specifies that the gray scale value will be displayed, FALSE otherwise.
Returns
TRUE if the gray scale value is displayed, FALSE otherwise.
Examples:
Visual C++ - VC Right Mouse Button Example

◆ StatusImageSize

boolean StatusImageSize

Controls the display of the current image size in the status window of the diplay object.

Parameters
[in,out]StatusImageSizeTRUE specifies that the current image size will be diplayed, FALSE otherwise.
Returns
TRUE if image size is displayed, FALSE otherwise.
Examples:
Visual C++ - VC Right Mouse Button Example

◆ StatusScale

boolean StatusScale

Controls the display of the image scaling information (zoom factor) in the status window of the display object.

Parameters
[in,out]StatusScaleTRUE specifies that the scaling information is shown, FALSE otherwise.
Returns
TRUE if scaling information is shown, FALSE otherwise.
Related Topics:
SetDisplayZoom
Examples:
Visual C++ - VC Right Mouse Button Example

◆ StatusUserText

BSTR StatusUserText

Controls displaying of a text string in the status window of the display object.

Parameters
[in,out]StatusUserTextSets the text to be displayed in the status window.
Returns
Current user status text.
Examples:
Visual C++ - VC Sizeable Display Example

◆ SyncRefreshToMonitor

boolean SyncRefreshToMonitor

Synced the final blit form the offsecreen memory of the VGA to the visible (primary) display surface to the beginning of the the vertical blank of the monitor. DirectDraw (version 8.1) have to be installed on the system.

As result the display does not show any artefacts related to the asynchronicity between monitor and camera vertical blank.

Attention
DirectDraw (version 8.1) have to be installed on the system.
Two important issues to consider when using the feature:
  • As the blit is synced to the beginning of the VD of the monitor it might happen, that the blitter does not finish before the end of the VD. In this case you will still notice some artefacts in the top of the display window.
    This effect is related to the speed of the blitter of the VGA as well as to the size of the image to be displayed.
  • For the same reason reduce the maximum framerate to the frequency of the monitor, even if the camera can run at higher frame rates.
    For example: The camera is running at 120 FPS while your monitor is running at 60 Hz; both are running without any phase shift. When the first image was acquired (appr. after 1/120sec) the display will wait again for 1/120sec (a complet VGA frame) for the VD of the monitor.
Parameters
[in,out]SyncRefreshToMonitorTRUE specifies that the display refresh is synced to the VD of the monitor. FALSE means that the refresh is asynchronous to the VD of the monitor.
Returns
TRUE if the refresh is synced to the VD of the monitor, FALSE otherwise.
Related Topics:
Refresh