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L_GlowFilterBitmap

Summary

Makes the colored edges shine with a neon glow.

Syntax

#include "l_bitmap.h"

L_LTIMGSFX_API L_INT L_GlowFilterBitmap(pBitmap, uDim, uBright, uThreshold, uFlags)

Parameters

pBITMAPHANDLE pBitmap

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

L_UINT uDim

Size of the neighborhood used to determine the width of the glow.

L_UINT uBright

Brightness factor used to create the "glow". This can be any number that is 0 or greater. If it is 0 the image will be black.

L_UINT uThreshold

Threshold value used to determine which pixels are edge pixels. If the difference determined for a pixel is greater than this value, the pixel is an edge pixel. Valid values range from 0 through 65535 for 64-bit, 48-bit and 16-bit grayscale images and from 0 through 4095 for 12-bit grayscale images. Otherwise, it is from 0 to 255. Use this parameter to control the number of edge pixels found.

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

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 edge pixels by comparing the values of the pixel with surrounding pixels and if the edge value (the difference between the surrounding pixels and the pixel being evaluated) is greater than the Threshold value, the pixel is an edge pixel. The function then multiplies the values for the edge pixels by the uBright Brightness factor.

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.

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

For an example, click here

To obtain this effect, the following settings were used with the function:

uDim = 15; 
uBright = 5; 
uThreshold = 0;

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.

Glow Function - Before

Glow Function - After

View additional platform support for this Glow function.

Required DLLs and Libraries

LTIMGSFX
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 GlowFilterBitmapExample(L_VOID) 
{ 
   L_INT nRet; 
   BITMAPHANDLE LeadBitmap;   /* Bitmap handle for the image */ 
 
   /* Load a bitmap at its own bits per pixel  */ 
   nRet = L_LoadBitmap(MAKE_IMAGE_PATH(TEXT("sample5.cmp")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
   if (nRet != SUCCESS) 
      return nRet; 
 
   /* Apply glow effect on the image*/ 
   nRet = L_GlowFilterBitmap(&LeadBitmap, 5, 3, 0, 0); 
   if (nRet != SUCCESS) 
      return nRet; 
 
   nRet = L_SaveBitmap(MAKE_IMAGE_PATH(TEXT("Result.BMP")), &LeadBitmap, FILE_BMP, 24, 0, NULL); 
   if (nRet != SUCCESS) 
      return nRet; 
 
   //free bitmap 
   if (LeadBitmap.Flags.Allocated) 
      L_FreeBitmap(&LeadBitmap); 
 
   return SUCCESS; 
}