L_ApplyLinearVOILUT

#include "l_bitmap.h"

L_INT EXT_FUNCTION L_ApplyLinearVOILUT (pBitmap, fCenter, fWidth, uFlags)

pBITMAPHANDLE pBitmap;	/* pointer to the main bitmap handle */
L_DOUBLE fCenter;	/* window center */
L_DOUBLE fWidth;	/* window width */
L_UINT uFlags;	/* flags */

Sets up the paint or paint and image processing functions' window leveling options for a specific bitmap through a linear transformation described by window center and width. This function is available in the Document/Medical Toolkit only.

Parameter	Description
pBitmap	Pointer to the bitmap handle referencing the bitmap to be leveled.
fCenter	Window Center for display.
fWidth	Window Width for display.
uFlags	Flags which determine the behavior of this function. Possible values are one or an OR-ed combination of the following:
	Value	Meaning
	VOI_LUT_UPDATE_MIN_MAX	[0x0001] If set, the function will recalculate pBitmap->MinVal based on the minimum intensity inside the bitmap and recalculate pBitmap->MaxVal based on the maximum intensity inside the bitmap.
	VOI_LUT_REVERSE_ORDER	[0x0002] If set, the function will fill the bitmap display LUT in reverse order (light to dark instead of dark to light).

Returns

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

Comments

This function sets up the paint or paint & image processing functions' window leveling options for a specific bitmap through a linear transformation described by window center and width. In the DICOM world, this is referred to as "applying a linear VOI LUT".

This function will remap the LUT used to display and process a bitmap by applying the linear transformation described by window center and window width. In the DICOM world this is referred to as applying a "linear VOI LUT". The DICOM standard states:

"Window Center and Window Width specify a linear conversion from stored pixel values (after any Modality LUT or Rescale Slope and Intercept specified in the IOD have been applied) to values to be displayed. Window Center contains the input value that is the center of the window. Window Width contains the width of the window." Please see "VOI LUT Module Attributes" in the DICOM standard for more details.

This function does not change the image data; it only updates the entries inside the bitmap LUT.

It’s recommended to always set the VOI_LUT_UPDATE_MIN_MAX flag.

In the DICOM world you will need to set VOI_LUT_REVERSE_ORDER flag if the photometric interpretation of the image is "MONOCHROME1", where the minimum grayscale value is intended to be displayed as white after any VOI gray scale transformations have been performed.

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.

This function supports signed data images.

Required DLLs and Libraries

LTIMG

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.

Functions:	L_ApplyVOILUT, L_RemapBitmapIntensity, L_ApplyModalityLUT, L_ApplyLinearModalityLUT, L_DicomGetWindow, L_AdjustBitmapTint, L_GammaCorrectBitmapExt
Topics:	Raster Image Functions: Modifying Intensity Values
	Changing Brightness and Contrast
	Raster Image Functions: Changing Brightness and Contrast