ImagingProcessingPreprocess Method (Bitmap, Boolean, Boolean, Boolean, Boolean, Double, Double, Point)

public static Bitmap Preprocess(
	Bitmap image,
	bool grayscale,
	ref bool edges,
	bool useSobel,
	bool threshold,
	double scaleWidth,
	double scaleHeight,
	out Point offset
)

Public Shared Function Preprocess ( 
	image As Bitmap,
	grayscale As Boolean,
	ByRef edges As Boolean,
	useSobel As Boolean,
	threshold As Boolean,
	scaleWidth As Double,
	scaleHeight As Double,
	<OutAttribute> ByRef offset As Point
) As Bitmap

Parameters

image

Type: System.DrawingBitmap
An image.

grayscale

Type: SystemBoolean
If true and image is not already a grayscale image, converts the image to a grayscale image (see ConvertRgbToGrayscaleImage(Bitmap)).

edges

Type: SystemBoolean
If true, tries to detect object edges in the image (see DetectEdges(Bitmap)). If the image width or height is smaller than 3 pixels, no edge detection will be performed and this parameter will be false when the method returns.

useSobel

Type: SystemBoolean
Decides which edge detection algorithm to use if edges is true. If true, the Sobel edge detection algorithm is used (see DetectEdgesSobel(Bitmap)), otherwise Laplace is used (see DetectEdgesLaplace(Bitmap)).

threshold

Type: SystemBoolean
If true, a threshold (128) is applied to the image (see Threshold(Bitmap, Byte)).

scaleWidth

Type: SystemDouble
If not equal to 1.0, the width of the image will be scaled using the specified factor (see Resize(Bitmap, Double, Double)).

scaleHeight

Type: SystemDouble
If not equal to 1.0, the height of the image will be scaled using the specified factor (see Resize(Bitmap, Double, Double)).

offset

Type: System.DrawingPoint
When this method returns, contains a point that specifies the number of pixels the image has been cropped. Cropping takes place to remove a margin that comes from applying an edge detection filter on the image.

Return Value

Reference