L_ConvertBitmapUnsignedToSigned

#include "l_bitmap.h"

L_INT EXT_FUNCTION L_ConvertBitmapUnsignedToSigned(pBitmap, uFlag)

pBITMAPHANDLE pBitmap;	/* pointer to the bitmap handle */
L_UINT uFlag;	/* flag */

Converts an unsigned bitmap to signed.

Parameter	Description
pBitmap	Pointer to the bitmap handle referencing the bitmap.
uFlag	Flag that indicates how to process bits outside the low bit to high bit range. Possible values are:
	Value	Meaning
	PROCESS_RANGE_ONLY	[0x0001] Shift data by adding half the range to each pixel without changing bits outside the (LowBit-HighBit) range.
	PROCESS_OUTSIDE_RANGE	[0x0002] Shift data by adding half the range to each pixel and set to zero all bits outside the (LowBit-HighBit) range.

Returns

SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

This function updates pBitmap->MaxVal and pBitmap-> MinVal with new values that reflect the bitmap's new signed data. In addition, the pBitmap->Flags.Signed value will be set to one.

This function supports 12 and 16-bit grayscale images. Support for 12 and 16-bit grayscale images is available only in the Document/Medical toolkits.

Required DLLs and Libraries

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.

Platforms

Windows 95 / 98 / Me, Windows 2000 / XP.

See Also

Functions:	L_ClearNegativePixels, L_ConvertBitmapSignedToUnsigned
Topics:	Processing an Image
	Raster Image Functions: Getting and Setting Pixel Values

Example

BITMAPHANDLE LeadBitmap; /* Bitmap handle to hold the loaded image. */
LOADFILEOPTION LoadFileOption;

/* enable negative pixels to be loaded from TIFF files */
L_GetDefaultLoadFileOption(&LoadFileOption, sizeof(LOADFILEOPTION));
LoadFileOption.Flags |= ELO_SIGNED;

/* Load the bitmap, keeping the bits per pixel of the file */
L_LoadBitmap(TEXT("IMAGE1.TIF"), &LeadBitmap,sizeof(BITMAPHANDLE), 0, ORDER_BGRORGRAY, &LoadFileOption, NULL);

/* convert bitmap to signed */
if(!LeadBitmap.Flags.Signed)
L_ConvertBitmapUnsignedToSigned(&LeadBitmap, PROCESS_RANGE_ONLY);