Available in LEADTOOLS Imaging Pro, Vector, Document, and Medical Imaging toolkits. |
L_HighPassFilterBitmap
#include "l_bitmap.h"
L_LTIMGEFX_API L_INT L_HighPassFilterBitmap(pBitmap, uRadius, uOpacity, uFlags)
pBITMAPHANDLE pBitmap; |
/* pointer to the bitmap handle */ |
L_UINT uRadius; |
/* radius of the neighborhood */ |
L_UINT uOpacity; |
/* opacity */ |
L_UINT32 uFlags; |
/* flags */ |
Removes low frequency details in a bitmap, resulting in a sharpened image.
Parameter |
Description |
pBitmap |
Pointer to the bitmap handle that references the bitmap to which to apply the filter. |
uRadius |
Value greater than 0 that indicates the radius of the neighborhood on which the filter is applied, in pixels. |
uOpacity |
Value that represents the intensity of the effect. The valid range is from 0 to 100. At 100, only the object outlines remain. |
uFlags |
Reserved for future use. Must be 0. |
Returns
SUCCESS |
The function was successful. |
< 1 |
An error occurred. Refer to Return Codes. |
Comments
This filter removes low-frequency detail in the bitmap. The effect is opposite to that of the Gaussian Blur filter (L_GaussianFilterBitmap).
To increase the thickness of the edges, increase the value of uRadius. Usually a low value for uRadius is better.
Unlike the L_UnsharpMaskBitmap function, when using this function image noise is not increased.
If the bitmap has a region, the effect will be applied on the region only.
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.
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
Win32, x64.
See Also
Example
#if defined (LEADTOOLS_V16_OR_LATER) L_INT HighPassFilterBitmapExample(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("ImageProcessingDemo\\Image3.cmp")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); if(nRet !=SUCCESS) return nRet; /*Sharpen image by applying the high pass filter*/ nRet = L_HighPassFilterBitmap(&LeadBitmap, 10, 100, 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 HighPassFilterBitmapExample(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("ImageProcessingDemo\\Image3.cmp")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); if(nRet !=SUCCESS) return nRet; /*Sharpen image by applying the high pass filter*/ nRet = L_HighPassFilterBitmap(&LeadBitmap, 10, 100); 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