ColorResolutionCommand Class

Summary

Converts an image from any bits-per-pixel to any bits-per-pixel.

Syntax

Objective-C

C++

Java

public class ColorResolutionCommand : RasterCommand

Public Class ColorResolutionCommand  
   Inherits RasterCommand

@interface LTColorResolutionCommand : LTRasterCommand

public class ColorResolutionCommand extends RasterCommand

public ref class ColorResolutionCommand : public RasterCommand

Remarks

This class provides flexibility in specifying the output destination and in specifying the palette to use.

For general information about dithering, refer to Color Resolution and Dithering and Dithering Methods.

You can convert the image in place or create a new converted image.

In specifying a palette, you can use simple palette options, or you can specify a palette that is tailored to your needs. The tailored palette can be any size that you specify. It can include specific colors, reserved blank entries, and open entries that this method fills with optimized colors.

If you use the same tailored palette more than once, you can improve performance by creating a table, using RasterUserMatchTable.

NOTE: Using this class to change the color order of a 24-bit or 32-bit image (i.e. RGB to BGR) will have no effect on the image when painting or saving (to a file). If you want to change the visual appearance, you can simply swap the color order using the RasterImage.Order property.

When converting to 32 and 64-bit images, you can control whether to initialize the alpha channel values to all 0's or 1's through the InitAlpha property.

This class does not support signed data images. An exception will be thrown if a signed data image is passed to this class.

This class supports stripping the alpha channel from the image.

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

For more information, refer to Introduction - Palette Handling.

Example

This example will run the ColorResolutionCommand on an image to convert it to 8 and 4 bits/pixel.

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
 
 
public void ColorResolutionCommandExample() 
{ 
	RasterCodecs codecs = new RasterCodecs(); 
 
	string srcFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"); 
	string destFileName1 = Path.Combine(LEAD_VARS.ImagesDir, "Image1_colorres8.bmp"); 
	string destFileName2 = Path.Combine(LEAD_VARS.ImagesDir, "Image1_colorres4.bmp"); 
 
	// Load the source image from disk 
	RasterImage image = codecs.Load(srcFileName); 
 
	// First color-res it to 8 bits per pixel  using the Netscape palette into a seperate image 
	ColorResolutionCommand cmd = new ColorResolutionCommand(); 
	cmd.Mode = ColorResolutionCommandMode.CreateDestinationImage; 
	cmd.BitsPerPixel = 8; 
	cmd.Order = RasterByteOrder.Rgb; 
	cmd.DitheringMethod = RasterDitheringMethod.None; 
	cmd.PaletteFlags = ColorResolutionCommandPaletteFlags.UsePalette; 
	cmd.SetPalette(RasterPalette.Netscape()); 
	cmd.Run(image); 
 
	RasterImage destImage = cmd.DestinationImage; 
	Assert.IsTrue(destImage.BitsPerPixel == 8); 
 
	// Save it to disk 
	codecs.Save(destImage, destFileName1, RasterImageFormat.Bmp, 8); 
	destImage.Dispose(); 
 
	// Now color-res the image in-place to 4-bits per pixel using the Optimized palette 
	cmd.Mode = ColorResolutionCommandMode.InPlace; 
	cmd.BitsPerPixel = 4; 
	cmd.Order = RasterByteOrder.Rgb; 
	cmd.DitheringMethod = RasterDitheringMethod.None; 
	cmd.PaletteFlags = ColorResolutionCommandPaletteFlags.Optimized; 
	cmd.Run(image); 
	Assert.IsTrue(image.BitsPerPixel == 4); 
 
	// Save it to disk 
	codecs.Save(image, destFileName2, RasterImageFormat.Bmp, 4); 
 
	// Clean Up 
	destImage.Dispose(); 
	image.Dispose(); 
	codecs.Dispose(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS21\Resources\Images"; 
}

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing 
 
Public Sub ColorResolutionCommandExample() 
   Dim codecs As RasterCodecs = New RasterCodecs() 
 
   Dim srcFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp") 
   Dim destFileName1 As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1_colorres8.bmp") 
   Dim destFileName2 As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1_colorres4.bmp") 
 
   ' Load the source image from disk 
   Dim image As RasterImage = codecs.Load(srcFileName) 
 
   ' First color-res it to 8 bits per pixel  using the Netscape palette into a seperate image 
   Dim cmd As ColorResolutionCommand = New ColorResolutionCommand() 
   cmd.Mode = ColorResolutionCommandMode.CreateDestinationImage 
   cmd.BitsPerPixel = 8 
   cmd.Order = RasterByteOrder.Rgb 
   cmd.DitheringMethod = RasterDitheringMethod.None 
   cmd.PaletteFlags = ColorResolutionCommandPaletteFlags.UsePalette 
   cmd.SetPalette(RasterPalette.Netscape()) 
   cmd.Run(image) 
 
   Dim destImage As RasterImage = cmd.DestinationImage 
   Debug.Assert(destImage.BitsPerPixel = 8) 
 
   ' Save it to disk 
   codecs.Save(destImage, destFileName1, RasterImageFormat.Bmp, 8) 
   destImage.Dispose() 
 
   ' Now color-res the image in-place to 4-bits per pixel using the Optimized palette 
   cmd.Mode = ColorResolutionCommandMode.InPlace 
   cmd.BitsPerPixel = 4 
   cmd.Order = RasterByteOrder.Rgb 
   cmd.DitheringMethod = RasterDitheringMethod.None 
   cmd.PaletteFlags = ColorResolutionCommandPaletteFlags.Optimized 
   cmd.Run(image) 
   Debug.Assert(image.BitsPerPixel = 4) 
 
   ' Save it to disk 
   codecs.Save(image, destFileName2, RasterImageFormat.Bmp, 4) 
   destImage.Dispose() 
 
   ' Clean Up 
   image.Dispose() 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\LEADTOOLS21\Resources\Images" 
End Class