LBitmap::HalfTone
#include "ltwrappr.h"
virtual L_INT LBitmap::HalfTone(uType, nAngle, uDim, hList)
virtual L_INT LBitmap::HalfTone(uType, nAngle, uDim, pLList)
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L_UINT uType; |
/* the type of halftoning */ |
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L_INT32 nAngle; |
/* angle of rotation */ |
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L_UINT uDim; |
/* size of the grain */ |
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HBITMAPLIST hList; |
/* handle to the list of bitmaps */ |
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LBitmapList * pLList; |
/* pointer to LBitmapList object that will be used in halftoning if the HT_USERDEF option is selected */ |
Converts a 1-, 4-, 8-, 16-, 24-, or 32-bit bitmap to a halftoned bitmap, with a specified pattern rotation. A halftoned bitmap is a 1-bit bitmap that has been dithered for black and white printing or display.
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Parameter |
Description |
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uType |
Value that indicates the type of halftoning to perform. Possible values are: |
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Value |
Meaning |
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HT_PRINT |
[0x0000] Halftone for printing |
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HT_VIEW |
[0x0001] Halftone for display |
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HT_RECT |
[0x0002] Rectangular halftone |
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HT_CIRC |
[0x0003] Circular halftone |
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HT_ELLIPS |
[0x0004] Elliptical halftone |
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HT_RAND |
[0x0005] Random halftone |
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HT_LINEAR |
[0x0006] Linear halftone |
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HT_USERDEF |
[0x0007] User-defined halftone |
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nAngle |
The angle of rotation, expressed in hundredths of degrees. A value of 0 produces a horizontal halftone pattern. This parameter specifies the number of degrees to change the pattern. Positive values rotate the pattern clockwise; negative values rotate the pattern counterclockwise. This value is ignored if the selected halftone pattern is HT_RECT, HT_CIRC or HT_RAND or HT_USERDEF. |
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uDim |
Value that indicates the size of the grain. This value is ignored if the selected halftone pattern is HT_VIEW or HT_PRINT. If the pattern is not HT_VIEW or HT_PRINT, uDim should be >= 1. If this parameter is < 1 this function will return ERROR_INV_PARAMETER (-13). |
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hList |
Handle to the list of bitmaps that will be used in halftoning if the HT_USERDEF option is selected. |
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pLList |
Pointer to LBitmapList object that will be used in halftoning if the HT_USERDEF option is selected. |
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Returns
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SUCCESS |
The function was successful. |
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< 1 |
An error occurred. Refer to Return Codes. |
Comments
For the HT_USERDEF option, the number of bitmaps in the list must be at least equal to (uDim * uDim + 1). Bitmaps with higher indexes correspond to higher intensity values.
This function can process the whole image or a region of the image.
This function does not support 12 and 16-bit grayscale and 48 and 64-bit color images.
To update a status bar or detect a user interrupt during execution of this function, refer to LBase::EnableStatusCallback.
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.
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. |
See Also
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Functions: |
LDialogColor::DoModalHalfTone, Class Members |
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Topics: |
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Raster Image Functions: Working with Color Halftones, Halftones, and Grayscale Images |
Example
L_VOID TestFunction(LBitmap & Bitmap, L_TCHAR * pszFile)
{
Bitmap.Load(pszFile);
Bitmap.HalfTone(HT_ELLIPS, 4500, 5, (LBitmapList*)NULL);
}