Gewusst wie: Konvertieren einer BitmapSource in ein indiziertes Pixelformat

Dieses Beispiel veranschaulicht das Konvertieren einer BitmapSource in ein indiziertes Pixelformat.

Beispiel

Imports System
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Media
Imports System.Windows.Media.Imaging
Imports System.Collections.Generic

Namespace SDKSample

    Class FormatConvertedBitmapExample2
        Inherits Page

        Public Sub New()

            '/// Create a BitmapImage and set it's DecodePixelWidth to 200. Use  /////
            '/// this BitmapImage as a source for other BitmapSource objects.    /////
            Dim myBitmapImage As New BitmapImage()

            ' BitmapSource objects like BitmapImage can only have their properties
            ' changed within a BeginInit/EndInit block.
            myBitmapImage.BeginInit()
            myBitmapImage.UriSource = New Uri("sampleImages/WaterLilies.jpg", UriKind.Relative)

            ' To save significant application memory, set the DecodePixelWidth or  
            ' DecodePixelHeight of the BitmapImage value of the image source to the desired 
            ' height or width of the rendered image. If you don't do this, the application will 
            ' cache the image as though it were rendered as its normal size rather then just 
            ' the size that is displayed.
            ' Note: In order to preserve aspect ratio, set DecodePixelWidth
            ' or DecodePixelHeight but not both.
            myBitmapImage.DecodePixelWidth = 200
            myBitmapImage.EndInit()

            '//////// Convert the BitmapSource to a new format ////////////
            ' Use the BitmapImage created above as the source for a new BitmapSource object
            ' which is set to a two color pixel format using the FormatConvertedBitmap BitmapSource.                                               
            ' Note: New BitmapSource does not cache. It is always pulled when required.
            Dim newFormatedBitmapSource As New FormatConvertedBitmap()

            ' BitmapSource objects like FormatConvertedBitmap can only have their properties
            ' changed within a BeginInit/EndInit block.
            newFormatedBitmapSource.BeginInit()

            ' Use the BitmapSource object defined above as the source for this new 
            ' BitmapSource (chain the BitmapSource objects together).
            newFormatedBitmapSource.Source = myBitmapImage

            ' Because the DestinationFormat for the FormatConvertedBitmap will be an
            ' indexed pixel format (Indexed1),a DestinationPalette also needs to be specified.
            ' Below, create a custom two color palette to be used for the DestinationPalette.
            Dim colors As New List(Of Color)
            colors.Add(System.Windows.Media.Colors.Red)
            colors.Add(System.Windows.Media.Colors.Blue)
            Dim myPalette As New BitmapPalette(colors)

            ' Set the DestinationPalette property to the custom palette created above.
            newFormatedBitmapSource.DestinationPalette = myPalette

            ' Set the DestinationFormat to the palletized pixel format of Indexed1.
            newFormatedBitmapSource.DestinationFormat = PixelFormats.Indexed1
            newFormatedBitmapSource.EndInit()

            ' Create Image Element
            Dim myImage As New Image()
            myImage.Width = 200
            'set image source
            myImage.Source = newFormatedBitmapSource

            ' Add Image to the UI
            Dim myStackPanel As New StackPanel()
            myStackPanel.Children.Add(myImage)
            Me.Content = myStackPanel

        End Sub 'New
    End Class 'FormatConvertedBitmapExample2
End Namespace 'ImagingSnippetGallery

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Collections.Generic;
namespace SDKSample
{
    public partial class FormatConvertedBitmapExample2 : Page
    {
        public FormatConvertedBitmapExample2()
        {

            ///// Create a BitmapImage and set it's DecodePixelWidth to 200. Use  /////
            ///// this BitmapImage as a source for other BitmapSource objects.    /////

            BitmapImage myBitmapImage = new BitmapImage();

            // BitmapSource objects like BitmapImage can only have their properties
            // changed within a BeginInit/EndInit block.
            myBitmapImage.BeginInit();
            myBitmapImage.UriSource = new Uri(@"sampleImages/WaterLilies.jpg",UriKind.Relative);

            // To save significant application memory, set the DecodePixelWidth or  
            // DecodePixelHeight of the BitmapImage value of the image source to the desired 
            // height or width of the rendered image. If you don't do this, the application will 
            // cache the image as though it were rendered as its normal size rather then just 
            // the size that is displayed.
            // Note: In order to preserve aspect ratio, set DecodePixelWidth
            // or DecodePixelHeight but not both.
            myBitmapImage.DecodePixelWidth = 200;
            myBitmapImage.EndInit();

            ////////// Convert the BitmapSource to a new format ////////////
            // Use the BitmapImage created above as the source for a new BitmapSource object
            // which is set to a two color pixel format using the FormatConvertedBitmap BitmapSource.                                               
            // Note: New BitmapSource does not cache. It is always pulled when required.

            FormatConvertedBitmap newFormatedBitmapSource = new FormatConvertedBitmap();

            // BitmapSource objects like FormatConvertedBitmap can only have their properties
            // changed within a BeginInit/EndInit block.
            newFormatedBitmapSource.BeginInit();

            // Use the BitmapSource object defined above as the source for this new 
            // BitmapSource (chain the BitmapSource objects together).
            newFormatedBitmapSource.Source = myBitmapImage;

            // Because the DestinationFormat for the FormatConvertedBitmap will be an
            // indexed pixel format (Indexed1),a DestinationPalette also needs to be specified.
            // Below, create a custom two color palette to be used for the DestinationPalette.
            List<System.Windows.Media.Color> colors = new List<System.Windows.Media.Color>();
            colors.Add(System.Windows.Media.Colors.Red);
            colors.Add(System.Windows.Media.Colors.Blue);
            BitmapPalette myPalette = new BitmapPalette(colors);

            // Set the DestinationPalette property to the custom palette created above.
            newFormatedBitmapSource.DestinationPalette = myPalette;

            // Set the DestinationFormat to the palletized pixel format of Indexed1.
            newFormatedBitmapSource.DestinationFormat = PixelFormats.Indexed1;
            newFormatedBitmapSource.EndInit();

            // Create Image Element
            Image myImage = new Image();
            myImage.Width = 200;
            //set image source
            myImage.Source = newFormatedBitmapSource;

            // Add Image to the UI
            StackPanel myStackPanel = new StackPanel();
            myStackPanel.Children.Add(myImage);
            this.Content = myStackPanel;
        }
    }
}