L_EdgeDetectEffectBitmap

#include "l_bitmap.h"

L_LTIMGEFX_API L_INT L_EdgeDetectEffectBitmap(pBitmap, uLevel, nThreshold, uFlags)

pBITMAPHANDLE pBitmap;

/* pointer to the bitmap handle */

L_UINT uLevel;

/* edge weight */

L_INT nThreshold;

/* threshold value */

L_UINT uFlags;

/* edges type */

Performs edge detection on the image.

Parameter

Description

pBitmap

Pointer to the bitmap handle that references the bitmap on which to apply the effect.

uLevel

Level value used to determine the brightness of the edges. Standard value is 50. Range between 1 and 100. Big values will produce bright edges.

nThreshold

Threshold value used to determine which pixels are going to be filtered. If the difference determined for a pixel is less than this value, the pixel is set to 0. If the difference is greater, the filter will be applied to the pixel. The valid range is from 0 - 65535 for 64-bit, 48-bit and 16-bit grayscale images and from 0 - 4095 for 12-bit grayscale images. Otherwise, it is from 0 to 255.

uFlags

Flag that indicates the type of edge to generate. Possible values are:

 

Value

Meaning

 

EDGE_SOFT

[0] Generate softer (smoother) edges.

 

EDGE_SOLID

[1] Generate rougher edges.

Returns

SUCCESS

The function was successful.

< 1

An error occurred. Refer to Return Codes.

Comments

This function does not support signed data images. It returns the error code ERROR_SIGNED_DATA_NOT_SUPPORTED if a signed data image is passed to this function.

This function detects the edges in a bitmap and then replaces the values of edges by new values calculated according to the uFlags.

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 only in the Document/Medical toolkits.

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

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.

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

Windows 2000 / XP/Vista.

See Also

Functions:

L_EdgeDetectorBitmap, L_SpatialFilterBitmap, L_EdgeDetectStatisticalBitmap, L_DirectionEdgeStatisticalBitmap, L_BricksTextureBitmap, L_DeskewBitmap, L_DeskewBitmapExt, L_DiffuseGlowBitmap, L_GlowFilterBitmap, L_HalfTonePatternBitmap, L_PerspectiveBitmap, L_PlasmaFilterBitmap, L_PointillistBitmap, L_DiffuseGlowBitmap, L_HighPassFilterBitmap, L_MaskConvolutionBitmap, L_DeskewCheckBitmap

Topics:

Raster Image Functions: Modifying Intensity Values

 

Detecting and Enhancing Edges and Lines

 

Raster Image Functions: Detecting and Enhancing Edges and Lines

Example

 L_INT EdgeDetectEffectBitmapExample(L_VOID)
{
   L_INT nRet;
   BITMAPHANDLE LeadBitmap;   /* Bitmap handle for the image */
   /* Load a bitmap at its own bits per pixel  */
   nRet = L_LoadBitmap (TEXT("C:\\Program Files\\LEAD Technologies\\LEADTOOLS 15\\Images\\IMAGE3.CMP"), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
   if(nRet !=SUCCESS)
      return nRet;
   /* Apply find edges effect on the image*/
   nRet = L_EdgeDetectEffectBitmap(&LeadBitmap, 50, 0, EDGE_SOFT);
   if(nRet !=SUCCESS)
      return nRet;
   nRet = L_SaveBitmap(TEXT("C:\\Program Files\\LEAD Technologies\\LEADTOOLS 15\\Images\\Result.BMP"), &LeadBitmap, FILE_BMP, 24, 0, NULL);
   if(nRet !=SUCCESS)
      return nRet;
   //free bitmap 
   if(LeadBitmap.Flags.Allocated)  
      L_FreeBitmap(&LeadBitmap);  
   return SUCCESS;
}