IKOutline

This function produces an outline of a raster image.

[C++Builder] HANDLE IKOutline(PTR_IKSELECT_IMAGE SrcHandle, BYTE SelectMode, LPPOINT lpPoint, int Points, LPRECT Rect, BOOL InOut, BYTE Plane, BYTE Operator, BYTE Level, IKPROCESSPROC UserProc, LPCTSTR Caption, LPCTSTR Message, LPCTSTR Button);

[Delphi] function IKOutline(var SrcHandle: IKSELECT_IMAGE; SelectMode: Byte; var lpPoint: TPoint; Points: Integer; var Rect : TRect; InOut: LongBool; Plane, Operator, Level: Byte; UserProc: LONG_PTR; Caption, Message, Button: PChar): THandle;

Parameters

Name	Explanation
SrcHandle	A structure containing the image handle and the mask image handle member variables hImgBmh must be 8bit grayscale, 16, 24, or 32 bit images
SelectMode	Sets the method for selecting the area on the image that will be processed (0: Mask handle, 1: Total image, 2: Polygon, 3: Ellipse)
lpPoint	A structure defining coordinates for the points of the polygonal area on the image. (This parameter is enabled when SelectMode is 2) In C++Builder, pass the pointer to the first element in the structure array. In Delphi, if Pt is an array of TPoint, then the arguments are returned in the first elements of the array Pt[0]
Points	The number of points defining the polygonal area on the image, i.e. the number of points in the lpPoint array (This parameter is enabled when SelectMode is 2).
Rect	A structure specifying the coordinates for the rectangle bounding the elliptical area on the image (This parameter is enabled when SelectMode is 3)
InOut	Determines whether the area inside the selected area will be processed or the area outside the selected area will be processed. Enabled for polygon and ellipse (SelectMode is 2 or 3). If False (0), the area outside the selected area is processed. If True (nonzero) the area inside the selected area is processed.
Plane	Sets which plane will be used to process the outline. (0:Y, 1:R, 2:G, 3:B)
Operator	Sets the edge filtering function used to process the outline (0:Differential, 1:Roberts, 2:Sobel)
Level	Sets the brightness of the outline (from 0 to 100)
UserProc	The address of the user function (If not using the user function then set to 0)
Caption	Sets the text displayed in the title bar of the progress dialog box
Message	Sets the message displayed in the progress dialog box
Button	Sets the name of the button displayed in the progress dialog box

Return Value

Returns the raster image handle if successful. Returns 0 if unsuccessful.

Explanation

The IKOutline function produces an outline of a raster image by identifying and displaying only the "edges" within the image. In general, the luminance plane is most commonly used. (Plane parameter = 0). In this case, differences in brightness are used to identify edges. However, the red plane, green plane or blue plane can also be used to identify an edge. So for example if the red plane is used (Plane parameter = 1) then differences in the R values would be used to identify the edges within an image.

The Operator parameter determines how an edge is identified. The Level parameter determines the brightness of an outline. When the Differential Operator is used, (Operator= 0), the differences between the pixel values (either brightness, red, green, or blue) are calculated and then depending on the value of the Level parameter, the edges are displayed. The Differential Operator evaluates these difference in a horizontal and/or vertical direction. The Roberts Operator (Operator=1) also uses a differential calculation, but evaluates these differences at a 45 degree orientation. The Sorbel Operator (Operator=2) is very similar to the above two operators except that with Sorbel there is an additional correction for images that have a lot of complexity.

Before executing this function, you must set the area on the image that will be affected. There are 4 ways to do this.

To use a mask image, set SelectMode to 0. Then set the mask image handle in SrcHandle.
To process the total image, set SelectMode to 1.
To process the polygonal area on the image, set SelectMode to 2. Select the polygon by setting the appropriate coordinate values for the points of the polygon in the lpPoint structure. Then set the number of points defining the polygon in Points (must be 3 or more).
To process an elliptical area on the image, set SelectMode to 3. Select the ellipse by setting the appropriate values for the bounding rectangle in the Rect structure.

For the lpPoint and Rect structure members, coordinate points are in pixel units. When SelectMode is set to a value other than 2, set a dummy array in lpPoint and set Points to 0. When SelectMode is set to a value other than 3, then set a dummy array in Rect.

Note: the image handles passed to IKSELECT_IMAGE are NOT automatically freed after executing this function.

If the user function is set or if the Caption, Message, and Button parameters are blank then the Progress dialog box is not displayed. If the Progress dialog box is displayed, it indicates the percentage of the current process completed. For more information about the user function please refer to the Definition of User Function in the Ik10Effect.dll, Ik10EffectA.dll, Ik10Effect64.dll, Ik10Effect64A.dlll section.