WindowLevel Method

Summary

Sets up the paint or paint and image processing methods' window leveling options for this RasterImage

Syntax

Objective-C

C++/CLI

Java

Python

public void WindowLevel( 
   int lowBit, 
   int highBit, 
   RasterColor[] palette, 
   RasterWindowLevelMode mode 
)

- (BOOL)windowLevel:(NSInteger)lowBitValue  
            highBit:(NSInteger)highBitValue  
            palette:(nullable NSArray<LTRasterColor *> *)palette  
               mode:(LTRasterWindowLevelMode)mode  
              error:(NSError **)error

public void windowLevel( 
   int lowBit, 
   int highBit, 
   RasterColor[] palette, 
   RasterWindowLevelMode mode 
);

public: 
void WindowLevel(  
   int lowBit, 
   int highBit, 
   array<RasterColor>^ palette, 
   RasterWindowLevelMode mode 
)

def WindowLevel(self,mode):

Parameters

lowBit
Value indicating the low bit used for leveling. 0 <= LowBit <= HighBit <= (11 for 12-bit grayscale or 15 for 16-bit grayscale).

highBit
Value indicating the high bit used for leveling. 0 <= LowBit <= HighBit <= (11 for 12-bit grayscale or 15 for 16-bit grayscale).

palette
Optional 8-bit lookup table that can be used to implement a user defined conversion. For every intensity value between 0 and 2 raised to the power of (HighBit - LowBit + 1)-1 there should be a corresponding entry in the lookup table that contains a color. If palette is null, the conversion is a normal shift (right or left) and the painted image is 8-bit grayscale. If palette is not null, the painted image is a 24-bit image.

mode
Value indicating whether palette is used by the paint and image processing methods or only by the paint methods.

Remarks

This method is available in the (Document/Medical only) Toolkits.

Provides "on demand" window leveling for the paint methods and does not alter the image data. To convert the image data to a window leveled image, use WindowLevelCommand.

If RasterWindowLevelMode.PaintAndProcessing is specified, then all image processing methods will take the palette into account.

Only TIFF and DICOM file formats are capable of saving images that have been window-leveled. Images can be window-leveled by calling WindowLevel and specifying RasterWindowLevelMode.PaintAndProcessing for the mode parameter, by using the WindowLevelCommand or by loading an image from a file format that supports Window Leveling. If a window-leveled image is saved as any other file format, the image data will be converted before being saved. For more information, refer to

For a version of this function that uses an 8-bit palette, see WindowLevelExt.

Saving Window-Leveled Images. LEADTOOLS supports two types of LUTs for 10-16-bit grayscale images (8-bit LUT and 16-bit LUT). Typical grayscale image display and processing is done using an 8-bit LUT. But, you can also use a 16-bit LUT, which offers more precision. Some special video cards and monitors also support display of grayscale images using a 16-bit LUT.

For more information, refer to Introduction to Image Processing With LEADTOOLS.

For more information, refer to Grayscale Images.

Example

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Core; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Dicom; 
using Leadtools.Drawing; 
using Leadtools.Controls; 
using Leadtools.Svg; 
 
 
public void WindowLevelExample() 
{ 
   RasterCodecs codecs = new RasterCodecs(); 
   // Load an image that has BottomLeft ViewPerspective 
   RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "IMAGE1.CMP")); 
 
   // Change the image to 16-bit grayscale  
   GrayscaleCommand grayscaleCmd = new GrayscaleCommand(16); 
   grayscaleCmd.Run(image); 
 
   MinMaxBitsCommand minMaxBitsCmd = new MinMaxBitsCommand(); 
   minMaxBitsCmd.Run(image); 
 
   MinMaxValuesCommand minMaxValuesCmd = new MinMaxValuesCommand(); 
   minMaxValuesCmd.Run(image); 
 
   int lowBit = minMaxBitsCmd.MinimumBit; 
   int highBit = minMaxBitsCmd.MaximumBit; 
 
   int size = (1 << (image.HighBit - image.LowBit + 1)); 
   RasterColor[] palette = new RasterColor[size]; 
 
   // fill the first half of the LUT with RED 
   for (int x = 0; x < size / 2; x++) 
   { 
      palette[x].R = 255; 
      palette[x].G = 0; 
      palette[x].B = 0; 
      palette[x].Reserved = 0; 
   } 
 
   int minVal = minMaxValuesCmd.MinimumValue; 
   int maxVal = minMaxValuesCmd.MaximumValue; 
 
   // Fill the rest with gray values  
   for (int x = (size / 2); x < size; x++) 
   { 
      palette[x].R = Convert.ToByte(Math.Min(255, ((x - minVal) * 255 / (maxVal - minVal)))); 
      palette[x].G = palette[x].R; 
      palette[x].B = palette[x].R; 
      palette[x].Reserved = 0; 
   } 
   image.WindowLevel(lowBit, highBit, palette, RasterWindowLevelMode.PaintAndProcessing); 
 
   codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "IMAGE1_WindowLevel.BMP"), RasterImageFormat.Bmp, 0); 
 
   image.Dispose(); 
   codecs.Dispose(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
}