Converts one image to another with an optional vertical flip.
The function cvConvertImage converts one image to another and flips the result vertically if desired. The function is used by ShowImage .
Creates a trackbar and attaches it to the specified window
The function cvCreateTrackbar creates a trackbar (a.k.a. slider or range control) with the specified name and range, assigns a variable to be syncronized with trackbar position and specifies a callback function to be called on trackbar position change. The created trackbar is displayed on the top of the given window. [Qt Backend Only] qt-specific details:
- windowName Name of the window which will be used as a parent for created trackbar. Can be NULL if the trackbar should be attached to the control panel.
The created trackbar is displayed at the bottom of the given window if windowName is correctly provided, or displayed on the control panel if windowName is NULL.
By clicking on the label of each trackbar, it is possible to edit the trackbar’s value manually for a more accurate control of it.
CV_EXTERN_C_FUNCPTR( void (*CvTrackbarCallback)(int pos) );
The function cvDestroyAllWindows destroys all of the opened HighGUI windows.
Destroys a window.
|Parameter:||name – Name of the window to be destroyed.|
The function cvDestroyWindow destroys the window with the given name.
Returns the trackbar position.
The function cvGetTrackbarPos returns the current position of the specified trackbar. [Qt Backend Only] qt-specific details:
- windowName Name of the window which is the parent of the trackbar. Can be NULL if the trackbar is attached to the control panel.
Gets the window’s handle by its name.
|Parameter:||name – Name of the window|
The function cvGetWindowHandle returns the native window handle (HWND in case of Win32 and GtkWidget in case of GTK+). [Qt Backend Only] qt-specific details: The function cvGetWindowHandle returns the native window handle inheriting from the Qt class QWidget.
Gets the window’s name by its handle.
|Parameter:||windowHandle – Handle of the window.|
The function cvGetWindowName returns the name of the window given its native handle (HWND in case of Win32 and GtkWidget in case of GTK+). [Qt Backend Only] qt-specific details: The function cvGetWindowName returns the name of the window given its native handle (QWidget).
The function cvInitSystem initializes HighGUI. If it wasn’t called explicitly by the user before the first window was created, it is called implicitly then with argc=0 , argv=NULL . Under Win32 there is no need to call it explicitly. Under X Window the arguments may be used to customize a look of HighGUI windows and controls. [Qt Backend Only] qt-specific details: The function cvInitSystem is automatically called at the first cvNameWindow call.
Sets the position of the window.
The function cvMoveWindow changes the position of the window.
Creates a window.
The function cvNamedWindow creates a window which can be used as a placeholder for images and trackbars. Created windows are referred to by their names.
If a window with the same name already exists, the function does nothing. [Qt Backend Only] qt-specific details:
flags Flags of the window. Currently the supported flags are:
- CV_WINDOW_NORMAL or CV_WINDOW_AUTOSIZE: CV_WINDOW_NORMAL let the user resize the window, whereas CV_WINDOW_AUTOSIZE adjusts automatically the window’s size to fit the displayed image (see ShowImage ), and the user can not change the window size manually.
- CV_WINDOW_FREERATIO or CV_WINDOW_KEEPRATIO: CV_WINDOW_FREERATIO adjust the image without respect the its ration, whereas CV_WINDOW_KEEPRATIO keep the image’s ratio.
- CV_GUI_NORMAL or CV_GUI_EXPANDED: CV_GUI_NORMAL is the old way to draw the window without statusbar and toolbar, whereas CV_GUI_EXPANDED is the new enhance GUI.
This parameter is optional. The default flags set for a new window are CV_WINDOW_AUTOSIZE , CV_WINDOW_KEEPRATIO , and CV_GUI_EXPANDED .
However, if you want to modify the flags, you can combine them using OR operator, ie:cvNamedWindow( ``myWindow'', ``CV_WINDOW_NORMAL`` textbar ``CV_GUI_NORMAL`` );
Sets the window size.
The function cvResizeWindow changes the size of the window.
Assigns callback for mouse events.
The function cvSetMouseCallback sets the callback function for mouse events occuring within the specified window.
The event parameter is one of:
- CV_EVENT_MOUSEMOVE Mouse movement
- CV_EVENT_LBUTTONDOWN Left button down
- CV_EVENT_RBUTTONDOWN Right button down
- CV_EVENT_MBUTTONDOWN Middle button down
- CV_EVENT_LBUTTONUP Left button up
- CV_EVENT_RBUTTONUP Right button up
- CV_EVENT_MBUTTONUP Middle button up
- CV_EVENT_LBUTTONDBLCLK Left button double click
- CV_EVENT_RBUTTONDBLCLK Right button double click
- CV_EVENT_MBUTTONDBLCLK Middle button double click
The flags parameter is a combination of :
- CV_EVENT_FLAG_LBUTTON Left button pressed
- CV_EVENT_FLAG_RBUTTON Right button pressed
- CV_EVENT_FLAG_MBUTTON Middle button pressed
- CV_EVENT_FLAG_CTRLKEY Control key pressed
- CV_EVENT_FLAG_SHIFTKEY Shift key pressed
- CV_EVENT_FLAG_ALTKEY Alt key pressed
Sets the trackbar position.
The function cvSetTrackbarPos sets the position of the specified trackbar. [Qt Backend Only] qt-specific details:
- windowName Name of the window which is the parent of trackbar. Can be NULL if the trackbar is attached to the control panel.
Displays the image in the specified window
The function cvShowImage displays the image in the specified window. If the window was created with the CV_WINDOW_AUTOSIZE flag then the image is shown with its original size, otherwise the image is scaled to fit in the window. The function may scale the image, depending on its depth:
Waits for a pressed key.
|Parameter:||delay – Delay in milliseconds.|
The function cvWaitKey waits for key event infinitely ( ) or for delay milliseconds. Returns the code of the pressed key or -1 if no key was pressed before the specified time had elapsed.
Note: This function is the only method in HighGUI that can fetch and handle events, so it needs to be called periodically for normal event processing, unless HighGUI is used within some environment that takes care of event processing. [Qt Backend Only] qt-specific details: With this current Qt implementation, this is the only way to process event such as repaint for the windows, and so on ldots