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L_CannyEdgeDetectorBitmap

Summary

Performs Canny edge detection for the master channel of the image, or for one or more of the three colored channels (Red, Green, Blue) if the image is colored.

Syntax

#include "l_bitmap.h"

L_LTIMGCOR_API L_INT L_CannyEdgeDetectorBitmap(pBitmap, pOptions)

Parameters

pBITMAPHANDLE pBitmap

Pointer to the bitmap handle referencing the bitmap to be changed.

CANNYOPTIONS *pOptions

Pointer to the structure containing Canny edge detection options. This value cannot be null.

Returns

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

Comments

This function supports 12 and 16-bit grayscale and 48-bit color images.

This function supports setting rectangle region.

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_GRAY32_UNSUPPORTED error code if a 32-bit grayscale image is passed to this function.

Required DLLs and Libraries

LTIMGCOR
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.

Example

Performs Canny edge detection on the image.

L_INT CannyEdgeDetectorBitmapExample(L_VOID) 
{ 
   L_INT nRet; 
   BITMAPHANDLE LeadBitmap;   /* Bitmap handle for the image */ 
   CANNYOPTIONS Options; 
   Options.uHighThreshold = 5; 
   Options.uLowThreshold = 2; 
   Options.uRadius = 1; 
 
   /* Load a bitmap at its own bits per pixel  */ 
   nRet = L_LoadBitmap(MAKE_IMAGE_PATH(TEXT("cannon.jpg")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGRORGRAY, NULL, NULL); 
   if (nRet != SUCCESS) 
      return nRet; 
 
   /* Apply find edges effect on the image*/ 
   nRet = L_CannyEdgeDetectorBitmap(&LeadBitmap, &Options); 
   if (nRet != SUCCESS) 
      return nRet; 
 
   nRet = L_SaveBitmap(MAKE_IMAGE_PATH(TEXT("cannon_Result.jpg")), &LeadBitmap, FILE_BMP, 24, 0, NULL); 
   if (nRet != SUCCESS) 
      return nRet; 
 
   //free bitmap 
   if (LeadBitmap.Flags.Allocated) 
      L_FreeBitmap(&LeadBitmap); 
 
   return SUCCESS; 
}