Available in LEADTOOLS Imaging Pro, Vector, Document, and Medical Imaging toolkits. |
L_MedianFilterBitmap
#include "l_bitmap.h"
L_LTIMGCOR_API L_INT L_MedianFilterBitmap(pBitmap, uDim, uFlags)
pBITMAPHANDLE pBitmap; |
/* pointer to the bitmap handle */ |
L_UINT uDim; |
/* dimensions of the neighborhood (uDim x uDim), in pixels */ |
L_UINT32 uFlags; |
/* flags */ |
Changes the color of each pixel in a bitmap to the median color of pixels in its neighborhood. This is similar to the L_AverageFilterBitmap function, but it is used for noise reduction, rather than a blur effect.
Parameter |
Description |
pBitmap |
Pointer to the bitmap handle referencing the bitmap to be converted. |
uDim |
Dimensions of the neighborhood used for filtering (uDim x uDim), in pixels. |
uFlags |
Reserved for future use. Must be 0. |
Returns
SUCCESS |
The function was successful. |
< 1 |
An error occurred. Refer to Return Codes. |
Comments
You control the effect by specifying the size of the neighborhood that is used for calculating the median value. For 8x8, pass 8 in the uDim parameter.
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.
If the bitmap has a region, this function works only on the region. If the bitmap does not have a region, this function works on the entire bitmap.
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
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.
See Also
Example
For complete sample code, refer to the CHILD.C module of the DEMO example. This example loads a bitmap and applies an median filter.
#if defined (LEADTOOLS_V16_OR_LATER) L_INT MedianFilterBitmapExample(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 a median filter with a neighborhood of 3x3 pixels */ nRet = L_MedianFilterBitmap(&LeadBitmap, 3 , 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; } #else L_INT MedianFilterBitmapExample(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 a median filter with a neighborhood of 3x3 pixels */ nRet = L_MedianFilterBitmap(&LeadBitmap, 3 ); 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; } #endif // LEADTOOLS_V16_OR_LATER