Available in LEADTOOLS Imaging Pro, Vector, Document, and Medical Imaging toolkits. |
L_GrayScaleBitmap
#include "l_bitmap.h"
L_LTKRN_API L_INT L_GrayScaleBitmap(pBitmap, nBitsPerPixel)
pBITMAPHANDLE pBitmap; |
/* pointer to the bitmap handle */ |
L_INT nBitsPerPixel; |
/* number of bits */ |
Converts a 1-, 4-, 8-, 16-, 24-, or 32-bit bitmap to an 8-bit, 12-bit, 16-bit, or 32-bit grayscale bitmap. Support for 12, 16 and 32-bit grayscale images is available in the Document and Medical Imaging toolkits.
Parameter |
Description |
pBitmap |
Pointer to the bitmap handle referencing the bitmap to be converted. |
nBitsPerPixel |
Value indicating the number of bits in the destination bitmap. Valid values are 8, 12, 16, or 32. |
Returns
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.
The resulting bitmap can be an 8-bit, 12-bit, 16-bit or 32-bit grayscale bitmap. Once the function is complete, the Order member of the bitmap handle is set to ORDER_GRAY.
When converting to 12-bit, 16-bit or 32-bit grayscale, a Lookup table is not used. When converting to 8-bit grayscale, a Lookup table is used to get the RGB for each input pixel. The grayscale value corresponding to that RGB triple is used in the destination bitmap.
To update a status bar or detect a user interrupt during execution of this function, refer to L_SetStatusCallback.
Required DLLs and Libraries
LTKRN 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, Mobile.
See Also
Functions: |
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Topics: |
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Example
For complete sample code, refer to the FEATURE2 example. This example loads a bitmap and changes it to 8-bit grayscale.
L_INT GrayScaleBitmapExample(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; /* Change the bitmap to grayscale */ nRet = L_GrayScaleBitmap(&LeadBitmap, 8 ); 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; L_FreeBitmap(&LeadBitmap); return SUCCESS; }