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LBitmap::DirectionEdgeStatistical

Summary

Detects the variation of colors in the specified direction using statistical indices. It is similar to LBitmap::EdgeDetectStatistical, but this function allows you to specify the direction angle.

Syntax

#include "ltwrappr.h"

virtual L_INT LBitmap::DirectionEdgeStatistical (uDim, uThreshold, nAngle, crEdgeColor, crBkColor, uFlags = 0)

Parameters

L_UINT uDim

The dimension or the number of pixels used to calculate the edge in the specified direction.

L_UINT uThreshold

Threshold value used to determine which pixels are edge pixels. If the difference in the intensity value between the pixel being tested and the average intensity of the pixels in the uDim around it is greater than this value, the pixel is an edge pixel. Valid values ranges are:

0 to 65535 for the 16, 48, and 64-bit bitmaps.
0 to 4095 for 12-bit bitmaps.
0 to 255 otherwise.

The threshold is applied on channels separately.

L_INT nAngle

Angular amount that specifies edge detector direction, in hundredths of degrees. Valid values range from -18000 through 18000. Positive valued angles are produced by counterclockwise rotation above the horizon and negative valued angles are produced by clockwise rotation below the horizon. This value is divided internally by 100.

COLORREF crEdgeColor

The COLORREF value that specifies the edge color. You can specify a COLORREF value, such as the return value of the Windows RGB macro, or you can use the PALETTEINDEX macro to specify a palette color.

COLORREF crBkColor

The COLORREF value that specifies the non edge color. You can specify a COLORREF value, such as the return value of the Windows RGB macro, or you can use the PALETTEINDEX macro to specify a palette color.

L_UINT32 uFlags

Reserved for future use. Must be 0.

Returns

Value	Meaning
SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

The edges are detected by applying a statistical filter that analyzes the variations of colors in a specified direction around each pixel.

To update a status bar or detect a user interrupt during execution of this function, refer to LBase::EnableStatusCallback.

Support for 12 and 16-bit grayscale and 48 and 64-bit color images is available only in the Document/Medical toolkits.

This function does not support 32-bit grayscale images. It returns the error code ERROR_GRAY32_UNSUPPORTED if a 32-bit grayscale image is passed to this function.

Direction Edge Statistical Function - Before

Direction Edge Statistical Function - After

View additional platform support for this Direction Edge Statistical function.

Required DLLs and Libraries

LTIMGEFX
For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Platforms

Win32, x64.

Example

L_INT LBitmap__DirectionEdgeStatisticalExample(LBitmap *pLeadBitmap)  
{ 
    
   /* Find the edges in the bitmap*/ 
   return pLeadBitmap->DirectionEdgeStatistical (15, 128, 4500, RGB(255, 255, 255), RGB(0, 0, 0));  
}

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