GetPalette Method

Summary

Gets the palette for uncompressed data that is 8 bits per pixel or less.

Syntax

Objective-C

C++/CLI

Java

Python

public RasterColor[] GetPalette()

@property (nonatomic, strong, nullable) NSArray<LTRasterColor *> *palette;

public RasterColor[] getPalette()

public: 
array<RasterColor>^ GetPalette();

def GetPalette(self):

Return Value

An array of RasterColor object that represents the palette for uncompressed data that is 8 bits per pixel or less.

Remarks

The first 1 << BitsPerPixel (2 ^ BitsPerPixel) entries in this palette is used.

Example

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Svg; 
 
 
private struct RawData 
{ 
   public int Width;                               // Width of image 
   public int Height;                              // Height of image 
   public int BitsPerPixel;                        // Bits per pixel of image--if palettized, a gray palette is generated 
   public RasterViewPerspective ViewPerspective;   // View perspective of raw data (TopLeft, BottomLeft, etc) 
   public RasterByteOrder Order;                   // Rgb or Bgr 
   public int XResolution;                         // Horizontal resolution in DPI 
   public int YResolution;                         // Vertical resolution in DPI 
   public int Offset;                              // Offset into file where raw data begins 
   public bool Padding;                            // true if each line of data is padded to four bytes 
   public bool ReverseBits;                        // true if the bits of each byte are reversed  
} 
 
private RawData myRawData; 
 
private void codecs_LoadInformation(object sender, CodecsLoadInformationEventArgs e) 
{ 
   // Set the information 
   e.Format = RasterImageFormat.Raw; 
   e.Width = myRawData.Width; 
   e.Height = myRawData.Height; 
   e.BitsPerPixel = myRawData.BitsPerPixel; 
   e.XResolution = myRawData.XResolution; 
   e.YResolution = myRawData.YResolution; 
   e.Offset = myRawData.Offset; 
   e.MotorolaOrder = false; 
   e.PhotoInterpolation = CodecsPhotoInterpolation.WhiteIsZero; 
   e.PlanarConfiguration = CodecsPlanarConfiguration.PlanarFormat; // This value is used only if Format is RasterImageFormat.RawPackBits 
   e.Reverse = true; 
   e.StripSize = 10; 
   e.WhiteOnBlack = false; 
   e.GetPalette(); 
          
   Debug.WriteLine($"Stream: {e.Stream.ToString()}"); 
          
   if (myRawData.Padding) 
      e.Pad4 = true; 
 
   e.Order = myRawData.Order; 
 
   if (myRawData.ReverseBits) 
      e.LeastSignificantBitFirst = true; 
 
   e.ViewPerspective = myRawData.ViewPerspective; 
 
   // If image is palettized create a grayscale palette 
   if (e.BitsPerPixel <= 8) 
   { 
      int colors = 1 << e.BitsPerPixel; 
      RasterColor[] palette = new RasterColor[colors]; 
      for (int i = 0; i < palette.Length; i++) 
      { 
         byte val = (byte)((i * 255) / (colors - 1)); 
         palette[i] = new RasterColor(val, val, val); 
      } 
 
      e.SetColorMask(palette); 
      e.SetPalette(palette); 
   } 
} 
public void LoadInformationExample() 
{ 
   // First, load a JPEG or CMP file 
   string srcFilename = Path.Combine(LEAD_VARS.ImagesDir, "IMAGE2.CMP"); 
   string rawFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1.raw"); 
   RasterCodecs codecs = new RasterCodecs(); 
   RasterImage image = codecs.Load(srcFilename); 
         
   // Save this image as RAW data 
 
   // Set RAW options 
   codecs.Options.Raw.Save.Pad4 = true; 
   codecs.Options.Raw.Save.ReverseBits = true; 
   codecs.Options.Save.OptimizedPalette = true; 
 
   codecs.Save(image, rawFileName, RasterImageFormat.Raw, 0); 
 
   // Save information about this image so we can use it to load the RAW file 
   myRawData = new RawData(); 
   myRawData.Width = image.Width; 
   myRawData.Height = image.Height; 
   myRawData.BitsPerPixel = image.BitsPerPixel; 
   myRawData.ViewPerspective = image.ViewPerspective; 
   myRawData.Order = image.Order; 
   myRawData.XResolution = image.XResolution; 
   myRawData.YResolution = image.YResolution; 
   myRawData.Offset = 0; 
   myRawData.Padding = true; 
   myRawData.ReverseBits = true; 
 
   // We dont need the image anymore 
   image.Dispose(); 
 
   // Now load this RAW image back 
 
   // First subscribe to the LoadInformation event so we can set the image information 
   codecs.LoadInformation += new EventHandler<CodecsLoadInformationEventArgs>(codecs_LoadInformation); 
 
   // Load the image 
   image = codecs.Load(rawFileName); 
 
   // Unsubscribe from the event 
   codecs.LoadInformation -= new EventHandler<CodecsLoadInformationEventArgs>(codecs_LoadInformation); 
 
   // save it as bmp for testing 
   codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "Image1_raw.bmp"), RasterImageFormat.Bmp, 0); 
 
   // Clean up 
   image.Dispose(); 
   codecs.Dispose(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 
}

Requirements

Target Platforms

Reference

CodecsLoadInformationEventArgs Class

CodecsLoadInformationEventArgs Members

Download our FREE evaluation

Help Version 22.0.2023.5.5

Leadtools.Codecs Assembly

Introduction

Getting Started

Namespaces

Leadtools.Codecs Namespace

Assemblies