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Available in LEADTOOLS Imaging Pro, Vector, Document, and Medical Imaging toolkits. |
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Available in LEADTOOLS Imaging Pro, Vector, Document, and Medical Imaging toolkits. |
L_WindowLevelExt
#include "l_bitmap.h"
L_LTDIS_API L_INT L_WindowLevelExt (pBitmap, nLowBit, nHighBit, pLUT, ulLUTLength, uFlags)
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pBITMAPHANDLE pBitmap; |
/* pointer to the bitmap handle */ |
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L_INT nLowBit; |
/* low bit to use */ |
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L_INT nHighBit; |
/* high bit to use */ |
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L_RGBQUAD16* pLUT; |
/* 16-bit lookup table */ |
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L_UINT ulLUTLength; |
/* number of entries */ |
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L_UINT uFlags; |
/* flags */ |
Sets up the paint or paint and image processing functions' window-leveling options for a specific bitmap.
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Parameter |
Description |
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pBitmap |
Pointer to the bitmap handle referencing the bitmap to be leveled. |
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nLowBit |
Value indicating the low bit used for leveling. 0 <= nLowBit <= nHighBit <= (11 for 12-bit grayscale or 15 for 16-bit grayscale). |
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nHighBit |
Value indicating the high bit used for leveling. 0 <= nLowBit <= nHighBit <= (11 for 12-bit grayscale or 15 for 16-bit grayscale). |
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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 a L_RGBQUAD16 entry. 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 16-bit grayscale or 48-bit bitmap (depending on whether the LUT contains only grayscale entries or whether it has color entries as well). |
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ulLUTLength |
Value indicating the number of entries pointed to by pLUT. If pLUT is NULL, then set this to 0 too. |
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uFlags |
Value indicating whether pLUT is used by the paint and image processing functions or only by the paint functions. Possible values are: |
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Value |
Meaning |
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WINDOWLEVEL_PAINT |
[0x00] pLUT is used only by the paint functions. |
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WINDOWLEVEL_PAINT_AND_PROCESSING |
[0x01] pLUT is used for both paint and image processing routines. |
Returns
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SUCCESS |
The function was successful. |
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< 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_WindowLevelBitmapExt.
This function is similar to L_WindowLevel, except that it uses 16-bit per component LUT instead of 8-bit per component LUT. The 16-bit LUT offers more precision than the 8-bit LUT, so it is better to use L_WindowLevelExt instead of L_WindowLevel.
The 16-bit and 8-bit LUTs are synchronized, which means the LUT applied by L_WindowLevelExt will change the LUT applied with L_WindowLevel and vice versa.
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
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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
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Functions: |
L_WindowLevel, L_WindowLevelBitmap, L_PaintDC, L_PaintDCCallback, L_ShiftBitmapData, L_WindowLevelBitmapExt, L_WindowLevelFillLUT, L_WindowLevelFillLUTExt |
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Topics: |
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Example
This example sets the window-levell values for painting and processing the bitmap with a custom palette.
L_INT WindowLevelExample(pBITMAPHANDLE pBitmap)
{
L_INT nRet;
L_UINT32 x;
L_RGBQUAD16* ptmp;
L_RGBQUAD16* 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 = (L_RGBQUAD16 *)GlobalAllocPtr(GHND, nSize * sizeof(L_RGBQUAD16));
ptmp = pLUT;
/* fill the first half of the LUT with RED */
for(x=0;x<nSize/2;x++)
{
ptmp->rgbRed = 0xFFFF;
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_UINT16) ((L_UINT32) (x - nLow) * 0xFFFF / (nHigh - nLow)));
ptmp->rgbGreen = ptmp->rgbRed;
ptmp->rgbBlue = ptmp->rgbGreen;
ptmp->rgbReserved = 0;
ptmp++;
}
nRet = L_WindowLevelExt( pBitmap, nLowBit, nHighBit,
pLUT, nSize, WINDOWLEVEL_PAINT_AND_PROCESSING );
if(nRet != SUCCESS)
return nRet;
GlobalFreePtr(pLUT);
return SUCCESS;
}