Defines a decoder for Joint Photographics Experts Group (JPEG) encoded images.
(in PresentationCore.dll)
Visual Basic (Declaration)
Public NotInheritable Class JpegBitmapDecoder _
Inherits BitmapDecoder
Dim instance As JpegBitmapDecoder
public sealed class JpegBitmapDecoder : BitmapDecoder
public ref class JpegBitmapDecoder sealed : public BitmapDecoder
public final class JpegBitmapDecoder extends BitmapDecoder
You cannot directly create an instance of this class in XAML.
The following table list the PixelFormats that are supported by the JpegBitmapDecoder class.
The following examples show how to decode and encode a JPEG image using the specific JpegBitmapDecoder and JpegBitmapEncoder objects. For the complete sample, see JPEG Encoder and Decoder Sample.
This example demonstrates how to decode a JPEG image using a JpegBitmapDecoder from a FileStream.
' Open a Stream and decode a JPEG image
Dim imageStreamSource As New FileStream("tulipfarm.jpg", FileMode.Open, FileAccess.Read, FileShare.Read)
Dim decoder As New JpegBitmapDecoder(imageStreamSource, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default)
Dim bitmapSource As BitmapSource = decoder.Frames(0)
' Draw the Image
Dim myImage As New Image()
myImage.Source = bitmapSource
myImage.Stretch = Stretch.None
myImage.Margin = New Thickness(20)
// Open a Stream and decode a JPEG image
Stream imageStreamSource = new FileStream("tulipfarm.jpg", FileMode.Open, FileAccess.Read, FileShare.Read);
JpegBitmapDecoder decoder = new JpegBitmapDecoder(imageStreamSource, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default);
BitmapSource bitmapSource = decoder.Frames[0];
// Draw the Image
Image myImage = new Image();
myImage.Source = bitmapSource;
myImage.Stretch = Stretch.None;
myImage.Margin = new Thickness(20);
// Open a Stream and decode a JPEG image
Stream^ imageStreamSource = gcnew FileStream("tulipfarm.jpg", FileMode::Open, FileAccess::Read, FileShare::Read);
JpegBitmapDecoder^ decoder = gcnew JpegBitmapDecoder(imageStreamSource, BitmapCreateOptions::PreservePixelFormat, BitmapCacheOption::Default);
BitmapSource^ bitmapSource = decoder->Frames[0];
// Draw the Image
Image^ myImage = gcnew Image();
myImage->Source = bitmapSource;
myImage->Stretch = Stretch::None;
myImage->Margin = System::Windows::Thickness(20);
This example demonstrates how to encode a BitmapSource into a JPEG image using a JpegBitmapEncoder.
Dim width As Integer = 128
Dim height As Integer = width
Dim stride As Integer = CType(width / 8, Integer)
Dim pixels(height * stride) As Byte
' Define the image palette
Dim myPalette As BitmapPalette = BitmapPalettes.Halftone256
' Creates a new empty image with the pre-defined palette
Dim image As BitmapSource = System.Windows.Media.Imaging.BitmapSource.Create(width, height, 96, 96, PixelFormats.Indexed1, myPalette, pixels, stride)
Dim stream As New FileStream("new.jpg", FileMode.Create)
Dim encoder As New JpegBitmapEncoder()
Dim myTextBlock As New TextBlock()
myTextBlock.Text = "Codec Author is: " + encoder.CodecInfo.Author.ToString()
encoder.FlipHorizontal = True
encoder.FlipVertical = False
encoder.QualityLevel = 30
encoder.Rotation = Rotation.Rotate90
encoder.Frames.Add(BitmapFrame.Create(image))
encoder.Save(stream)
int width = 128;
int height = width;
int stride = width / 8;
byte[] pixels = new byte[height * stride];
// Define the image palette
BitmapPalette myPalette = BitmapPalettes.Halftone256;
// Creates a new empty image with the pre-defined palette
BitmapSource image = BitmapSource.Create(
width,
height,
96,
96,
PixelFormats.Indexed1,
myPalette,
pixels,
stride);
FileStream stream = new FileStream("new.jpg", FileMode.Create);
JpegBitmapEncoder encoder = new JpegBitmapEncoder();
TextBlock myTextBlock = new TextBlock();
myTextBlock.Text = "Codec Author is: " + encoder.CodecInfo.Author.ToString();
encoder.FlipHorizontal = true;
encoder.FlipVertical = false;
encoder.QualityLevel = 30;
encoder.Rotation = Rotation.Rotate90;
encoder.Frames.Add(BitmapFrame.Create(image));
encoder.Save(stream);
int width = 128;
int height = width;
int stride = width / 8;
array<System::Byte>^ pixels = gcnew array<System::Byte>(height * stride);
// Define the image palette
BitmapPalette^ myPalette = BitmapPalettes::Halftone256;
// Creates a new empty image with the pre-defined palette.
BitmapSource^ image = BitmapSource::Create(
width, height,
96, 96,
PixelFormats::Indexed1,
myPalette,
pixels,
stride);
System::IO::FileStream^ stream = gcnew System::IO::FileStream("new.jpg", FileMode::Create);
JpegBitmapEncoder^ encoder = gcnew JpegBitmapEncoder();
TextBlock^ myTextBlock = gcnew System::Windows::Controls::TextBlock();
myTextBlock->Text = "Codec Author is: " + encoder->CodecInfo->Author->ToString();
encoder->FlipHorizontal = true;
encoder->FlipVertical = false;
encoder->QualityLevel = 30;
encoder->Rotation = Rotation::Rotate90;
encoder->Frames->Add(BitmapFrame::Create(image));
encoder->Save(stream);
System..::.Object
System.Windows.Threading..::.DispatcherObject
System.Windows.Media.Imaging..::.BitmapDecoder
System.Windows.Media.Imaging..::.JpegBitmapDecoder
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
.NET Framework
Supported in: 3.5, 3.0
Reference
Other Resources