LBitmapBase::GrayScale

#include "ltwrappr.h"

virtual L_INT LBitmapBase::GrayScale(nBitsPerPixel=8)

L_INT nBitsPerPixel;

/* number of bits per pixel */

Converts a 1-, 4-, 8-, 16-, 24-, or 32-bit bitmap to an 8-bit, 12-bit, or 16-bit grayscale bitmap. Support for 12 and 16-bit grayscale images is available only in the Document/Medical toolkits.

Parameter

Description

nBitsPerPixel

Value indicating the number of bits in the destination bitmap. Valid values are 8, 12, or 16.

Returns

SUCCESS

The function was successful.

< 1

An error occurred. Refer to Return Codes.

Comments

The resulting bitmap can be an 8-bit, 12-bit, or 16-bit grayscale bitmap.

When converting to 12-bit or 16-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 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

LTDIS
LTFIL

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

Element:

LBitmapBase::IsGrayScale, Class Members

Topics:

Raster Image Functions: Doing Color Expansion or Reduction

 

Color Halftones and Halftone Images

 

Raster Image Functions: Working with Color Halftones, Halftones, and Grayscale Images

Example

LBitmapBase MyBitmap;

MyBitmap.SetFileName(TEXT("image1.cmp"));
MyBitmap.Load(24);
if(MyBitmap.IsGrayScale()==GRAY_NO)
   MyBitmap.GrayScale(8);