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.


#include "ltwrappr.h"

virtual L_INT LBitmap::ApplyLinearVOILUT(fCenter, fWidth, uFlags)


L_DOUBLE fCenter

Window Center for display.


Window Width for display.

L_UINT uFlags

Flags which determine the behavior of this function. Use one value or use a bitwise OR ( | ) to combine values. Possible values are:

Value Meaning
VOI_LUT_UPDATE_MIN_MAX [0x0001] 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] Fill the bitmap display LUT in reverse order (light to dark instead of dark to light).
VOI_LUT_PAINT_ONLY [0x0004] Set the LUT for paint only, not image processing. For more information, refer to BITMAPHANDLE.Flags.UseLUT.
VOI_LUT_IGNORE_EXISTING_PALETTE [0x0008] If set, the function will exclude any existing LookupTable or palette from the calculations.


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


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.

Its 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.

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


Win32, x64.

See Also




For an example, refer to LBitmap::ApplyVOILUT.

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