L_SpatialFilterBitmap
#include "l_bitmap.h"
L_LTIMGEFX_API L_INT L_SpatialFilterBitmap(pBitmap, pFilter)
pBITMAPHANDLE pBitmap; |
/* pointer to the bitmap handle */ |
pSPATIALFLT pFilter; |
/* pointer to the spatial filter to use */ |
Imposes a spatial filter on a bitmap. You can supply your own filter or use one of the predefined filters.
Parameter |
Description |
pBitmap |
Pointer to the bitmap handle that references the bitmap to be affected. |
pFilter |
Pointer to the spatial filter to use. For predefined filters, refer to List of Spatial Filters. To define your own filter, refer to SPATIALFLT. |
Returns
SUCCESS |
The function was successful. |
< 1 |
An error occurred. Refer to Return Codes. |
Comments
A spatial filter recomputes the brightness of each pixel in a bitmap by using a weighted averaging technique that considers the surrounding pixels. Spatial filters are used for operations such as sharpening an image or detecting edges within the image.
The L_SpatialFilterBitmap function works best with 24-bit, 16-bit, or grayscale bitmaps. If a bitmap uses a color palette, this function matches the new brightness value of each pixel to the nearest color in the existing palette.
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.
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
Windows 2000 / XP/Vista.
See Also
Example
For complete sample code, refer to the CHILD.C module of the DEMO example. This example loads a bitmap and applies a Prewitt edge detection filter.
L_INT SpatialFilterBitmapExample(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 (TEXT("C:\\Program Files\\LEAD Technologies\\LEADTOOLS 15\\Images\\IMAGE1.CMP"), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); if(nRet !=SUCCESS) return nRet; /* Apply a Prewitt edge detection filter */ nRet = L_SpatialFilterBitmap(&LeadBitmap, FLT_PREWITT_HORZ ); if(nRet !=SUCCESS) return nRet; nRet = L_SaveBitmap(TEXT("C:\\Program Files\\LEAD Technologies\\LEADTOOLS 15\\Images\\Result.BMP"), &LeadBitmap, FILE_BMP, 24, 0, NULL); if(nRet !=SUCCESS) return nRet; //free bitmap if(LeadBitmap.Flags.Allocated) L_FreeBitmap(&LeadBitmap); return SUCCESS; }