L_MedianFilterBitmap
#include "l_bitmap.h"
L_INT EXT_FUNCTION L_MedianFilterBitmap(pBitmap, uDim)
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pBITMAPHANDLE pBitmap; |
/* pointer to the bitmap handle */ |
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L_UINT uDim; |
/* dimensions of the neighborhood (uDim x uDim), in pixels */ |
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.
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Parameter |
Description |
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pBitmap |
Pointer to the bitmap handle referencing the bitmap to be converted. |
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uDim |
Dimensions of the neighborhood used for filtering (uDim x uDim), in pixels. |
Returns
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SUCCESS |
The function was successful. |
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< 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 only in the Document/Medical 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 signed data images. It returns the error code ERROR_SIGNED_DATA_NOT_SUPPORTED if a signed data image is passed to this function.
Required DLLs and Libraries
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LTIMG 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 95 / 98 / Me, Windows 2000 / XP.
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. */
BITMAPHANDLE LeadBitmap; /* Bitmap handle to hold the loaded image. */
/* Load the bitmap, keeping the bits per pixel of the file */
L_LoadBitmap (TEXT("IMAGE1.CMP"), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL);
/* Apply a median filter with a neighborhood of 3x3 pixels */
L_MedianFilterBitmap(&LeadBitmap, 3 );