L_WindowLevel
#include "l_bitmap.h"
L_LTDIS_API L_INT L_WindowLevel (pBitmap, nLowBit, nHighBit, pLUT, ulLUTLength, uFlags)
pBITMAPHANDLE pBitmap; |
/* pointer to the bitmap handle */ |
L_INT nLowBit; |
/* low bit to use */ |
L_INT nHighBit; |
/* high bit to use */ |
L_RGBQUAD* pLUT; |
/* lookup table */ |
L_UINT ulLUTLength; |
/* number of entries */ |
L_UINT uFlags; |
/* flags */ |
Sets up the paint or paint and image processing functions' window leveling options for a specific bitmap.
Parameter |
Description |
|
pBitmap |
Pointer to the bitmap handle referencing the bitmap to be leveled. |
|
nLowBit |
Value indicating the low bit used for leveling. 0 <= nLowBit <= nHighBit <= (11 for 12-bit grayscale or 15 for 16-bit grayscale). |
|
nHighBit |
Value indicating the high bit used for leveling. 0 <= nLowBit <= nHighBit <= (11 for 12-bit grayscale or 15 for 16-bit grayscale). |
|
pLUT |
Optional lookup table that can be used to implement a user defined conversion. For every intensity value between 0 and 2 raised to the power of (nHighBit - nLowBit + 1)-1 there should be a corresponding entry in the lookup table that contains an RGB quad. If pLUT is NULL, the conversion is a normal shift (right or left) and the painted bitmap is 8-bit grayscale. If pLUT is not NULL, the painted bitmap is a 24-bit bitmap. |
|
ulLUTLength |
Value indicating the number of entries pointed to by pLUT. If pLUT is NULL, then set this to NULL too. |
|
uFlags |
Value indicating whether pLUT is used by the paint and image processing functions or only by the paint functions. Possible values are: |
|
|
Value |
Meaning |
|
WINDOWLEVEL_PAINT |
[0x00] pLUT is used only by the paint functions. |
|
WINDOWLEVEL_PAINT_AND_PROCESSING |
[0x01] pLUT is used for both paint and image processing routines. |
Returns
SUCCESS |
The function was successful. |
< 1 |
An error occurred. Refer to Return Codes. |
Comments
Provides "on demand" window leveling for the paint functions and does not alter the image data. To convert the image data to a window leveled bitmap, use L_WindowLevelBitmap.
If WINDOW_LEVEL_PAINT_PROCESSING is specified, then all image processing functions will take the pLUT into account.
For information on saving bitmaps that have been window leveled, refer to Saving Window-Leveled Bitmaps.
Required DLLs and Libraries
LTDIS 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, Windows CE.
See Also
Example
This example sets the window level values for painting and processing the bitmap with a custom palette.
L_INT WindowLevelExample(pBITMAPHANDLE pBitmap) { L_INT nRet; L_UINT32 x; RGBQUAD* ptmp; RGBQUAD* pLUT; L_INT nLowBit; L_INT nHighBit; L_INT nLow; L_INT nHigh; L_UINT32 nSize; /* Change the bitmap to 16-bit grayscale */ nRet = L_GrayScaleBitmap(pBitmap, 16 ); if(nRet != SUCCESS) return nRet; nRet = L_GetMinMaxBits(pBitmap, &nLowBit, &nHighBit); if(nRet != SUCCESS) return nRet; nRet = L_GetMinMaxVal(pBitmap, &nLow, &nHigh); if(nRet != SUCCESS) return nRet; nSize = (L_UINT32)(1L<<(pBitmap->HighBit - pBitmap->LowBit + 1)); pLUT = (RGBQUAD *)GlobalAllocPtr(GHND, nSize * sizeof(RGBQUAD)); ptmp = pLUT; /* fill the first half of the LUT with RED */ for(x=0;x<nSize/2;x++) { ptmp->rgbRed = 255; ptmp->rgbGreen = 0; ptmp->rgbBlue = 0; ptmp->rgbReserved = 0; ptmp++; } /* fill the rest with gray values */ for(x=nSize/2;x<nSize;x++) { ptmp->rgbRed = ((L_UCHAR) ((L_UINT32) (x - nLow) * 255 / (nHigh - nLow))); ptmp->rgbGreen = ptmp->rgbRed; ptmp->rgbBlue = ptmp->rgbGreen; ptmp->rgbReserved = 0; ptmp++; } nRet = L_WindowLevel ( pBitmap, nLowBit, nHighBit, (RGBQUAD *)pLUT, nSize, WINDOWLEVEL_PAINT_AND_PROCESSING ); if(nRet != SUCCESS) return nRet; GlobalFreePtr(pLUT); return SUCCESS; }