L_EdgeDetectStatisticalBitmap

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#include "l_bitmap.h"

L_LTIMGEFX_API L_INT L_EdgeDetectStatisticalBitmap(pBitmap, uDim, nThreshold, crEdgeColor, crBkColor, uFlags)

pBITMAPHANDLE pBitmap;	/* pointer to the bitmap handle */
L_UINT uDim;	/* dimensions of the edge detector neighborhood */
L_INT nThreshold;	/* threshold value */
COLORREF crEdgeColor;	/* color value */
COLORREF crBkColor;	/* color value */
L_UINT32 uFlags;	/* flags */

Detects edges by examining the variation of colors in all directions using statistical indices.

Parameter	Description
pBitmap	Pointer to the bitmap handle that references the bitmap in which the edge detector is applied.
uDim	Dimensions of the neighborhood used to detect edges (uDim x uDim), in pixels.
nThreshold	Threshold value used to determine which pixels are edge pixels. If the difference determined by the edge detector algorithm for a pixel is greater than this value, the pixel is an edge pixel.
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.
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.
uFlags	Reserved for future use. Must be 0.

Returns

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 all directions around each pixel.

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

This function supports 12 and 16-bit grayscale and 48 and 64-bit color images. Support for 12 and 16-bit grayscale and 48 and 64-bit color images is available in the Document and Medical Imaging 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.

The threshold range for 16, 48 and 64-bit images is from 0 to 65535 for unsigned images, and from –32768 to +32767 for signed images. For 12-bit images, the threshold range is from 0 to 4095 for unsigned images, and from –2048 to +2047 for signed images. Otherwise, it is from 0 to 255. The threshold is applied to channels separately.

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, Linux.

See Also

Functions:	L_CombineBitmap, L_IntensityDetectBitmap, L_SharpenBitmap, L_SpatialFilterBitmap, L_EdgeDetectorBitmap, L_AutoColorLevelBitmap, L_ColorLevelBitmap, L_CorrelationBitmap, L_GrayScaleToDuotone, L_GrayScaleToMultitone, L_HolesRemovalBitmapRgn, L_SelectiveColorBitmap, L_SkeletonBitmap, L_BricksTextureBitmap, L_DeskewBitmap, L_DiffuseGlowBitmap, L_GlowFilterBitmap, L_HalfTonePatternBitmap, L_HighPassFilterBitmap, L_MaskConvolutionBitmap, L_PerspectiveBitmap, L_PlasmaFilterBitmap, L_PointillistBitmap
Topics:	Detecting and Enhancing Edges and Lines
	Raster Image Functions: Filtering Images
	Using Color Values in LEADTOOLS
	Raster Image Functions: Detecting and Enhancing Edges and Lines

Example

The following example loads a bitmap and applies an edge detector statistical function

#define MAKE_IMAGE_PATH(pFileName) TEXT("C:\\Users\\Public\\Documents\\LEADTOOLS Images\\")pFileName


#if defined (LEADTOOLS_V16_OR_LATER)
 L_INT EdgeDetectStatisticalBitmapExample(L_VOID)
{
   L_INT nRet;
   BITMAPHANDLE LeadBitmap;   /* Bitmap handle to hold the loaded image. */

   /* Load the bitmap, keeping the bits per pixel of the file */
   nRet = L_LoadBitmap(MAKE_IMAGE_PATH(TEXT("IMAGE1.CMP")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL);
   if(nRet !=SUCCESS)
      return nRet;

   /* Apply an edge detector statistical function */
   nRet = L_EdgeDetectStatisticalBitmap(&LeadBitmap, 15, 128, RGB(255, 255, 255), RGB(0, 0, 0), 0); 
   if(nRet !=SUCCESS)
      return nRet;
   //free Bitmap
   if(LeadBitmap.Flags.Allocated)
      L_FreeBitmap(&LeadBitmap);
   return SUCCESS;
}
#else
 L_INT EdgeDetectStatisticalBitmapExample(L_VOID)
{
   L_INT nRet;
   BITMAPHANDLE LeadBitmap;   /* Bitmap handle to hold the loaded image. */

   /* Load the bitmap, keeping the bits per pixel of the file */
   nRet = L_LoadBitmap(MAKE_IMAGE_PATH(TEXT("IMAGE1.CMP")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL);
   if(nRet !=SUCCESS)
      return nRet;

   /* Apply an edge detector statistical function */
   nRet = L_EdgeDetectStatisticalBitmap(&LeadBitmap, 15, 128, RGB(255, 255, 255), RGB(0, 0, 0)); 
   if(nRet !=SUCCESS)
      return nRet;
   //free Bitmap
   if(LeadBitmap.Flags.Allocated)
      L_FreeBitmap(&LeadBitmap);
   return SUCCESS;
}
#endif // LEADTOOLS_V16_OR_LATER