This method produces an outline effect on the image.
Parameters
| Name | Explanation |
|---|---|
| Points | An array of x and y coordinate values defining
points of a polygonal area on the image. (in pixels) In C++Builder, the size of the Points array is given by Points_Size - 1 |
| 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 at which an outline is drawn. (from 0 to 100) |
Return Value
Returns True if successful, otherwise returns False.
Explanation
The Outline method 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 at which value an edge will be displayed. 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.
To execute the Outline method, set the image handle of the image in the ImageHandle property or the Layer(LayerNo).ImageHandle property. The Outline method supports 8 bit grayscale, 16, 24, and 32 bit images.
Before executing the Outline method, 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 the SelectMode property to vikEffectMask. Set the mask image handle in the MaskImageHandle property
- To process the total image, set the SelectMode property to vikEffectAll.
- To process the polygonal area on the image, set the SelectMode property to vikEffectPolygon. Select the polygon by setting the appropriate coordinate values for the points of the polygon in the Points array. The number of points defining the polygon must be 3 or more.
- To process an elliptical area on the image, set the SelectMode property to vikEffectEllipse. Select the ellipse by setting the appropriate values for the bounding rectangle in the RectLeft, RectTop, RectRight, and RectBottom properties
When the SelectMode property is set to vikEffectPolygon or vikEffectEllipse, the InOut property should be set. When the SelectMode property is set to values other than vikEffectPolygon, please set the Points parameter to a dummy array or to NULL.
If successful the resulting raster image data is set in the LayerNo property (the ImageHandle property or the Layer(LayerNo).ImageHandle property. If unsuccessful, 0 is returned.
When the Caption, Message, and ButtonName properties are blank, the progress dialog box will not be displayed. When the progress dialog box is displayed, the percentage that the processing has completed will be shown in the dialog box.
Differences from the ImageKit 7/8/9/10 ActiveX
The parameters x, y have been changed to type TPoint
In Delphi, it is not necessary to pass the size of the array of x,
y points.