LBitmap::AntiAlias

#include "ltwrappr.h"

virtual L_INT LBitmap::AntiAlias (uThreshold, uDim, uFilter)

L_UINT uThreshold;

/* threshold value */

L_UINT uDim;

/* mask size */

L_UINT uFilter;

/* anti-aliasing filter */

Applies an anti-aliasing filter to the class object's bitmap.

Parameter

Description

uThreshold

Threshold value that indicates which pixels to smooth. The application of the anti-aliasing filter on the image associates a value with each pixel. Only pixels with values above this threshold are smoothed.

uDim

Value that indicates the size of the anti-aliasing mask. For example, a value of three indicates an anti-aliasing mask of 3 X 3.

uFilter

Flag that indicates the type of anti-aliasing filter to use. Possible values are:

 

Value

Meaning

 

ANTIALIAS_1

[0x0000] Anti-alias the bitmap vertically and horizontally.

 

ANTIALIAS_2

[0x0001] Anti-alias the bitmap in all directions.

 

ANTIALIAS_3

[0x0002] Anti-alias the bitmap in all directions. The filter used for this option is different from the filter used for the ANTIALIAS_2 option.

 

ANTIALIAS_DIAG

[0x0003] Anti-alias the bitmap diagonally.

 

ANTIALIAS_HORZ

[0x0004] Anti-alias the bitmap horizontally.

 

ANTIALIAS_VERT

[0x0005] Anti-alias the bitmap vertically.

Returns

SUCCESS

The function was successful.

< 1

An error occurred. Refer to Return Codes.

Comments

The best results for anti-aliasing text can be obtained with the filter ANTIALIAS_2.

The value of the uDim parameter determines the extent of the anti-aliasing.

This function can process the whole image or a region of the image.

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.

The threshold range for 16, 48 and 64-bit bitmaps is from 0 to 65535 and for 12-bit bitmaps the threshold range is from 0 to 4095. Otherwise, it is from 0 to 255. The threshold is applied on channels separately.

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

LTDIS
LTFIL
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.

See Also

Functions:

LBitmap::AdjustTint. LBitmap::ColorHalfTone, LBitmap::AntiAlias2, Class Members

Topics:

Correcting Colors

 

Raster Image Function: Filtering Images

 

Raster Image Functions: Correcting Colors

Example

L_INT LBitmap__AntiAliasExample(LBitmap & Bitmap, L_TCHAR * szFile)
{
   L_INT nRet;
   nRet =Bitmap.Load(szFile);
   if(nRet !=SUCCESS)
      return nRet;
   nRet =Bitmap.AntiAlias(128, 3, ANTIALIAS_1);
   if(nRet !=SUCCESS)
      return nRet;
   return SUCCESS;
}