Bitmap Class (System.Drawing)

Welcome Sign in

Developer Centers

MSDN Home

Microsoft Developer Network

.NET Framework Class Library

Bitmap Class

Updated: November 2007

Encapsulates a GDI+ bitmap, which consists of the pixel data for a graphics image and its attributes. A Bitmap is an object used to work with images defined by pixel data.

Namespace: System.Drawing
Assembly: System.Drawing (in System.Drawing.dll)

Syntax

Visual Basic (Declaration)

<SerializableAttribute> _
<ComVisibleAttribute(True)> _
Public NotInheritable Class Bitmap _
    Inherits Image

Visual Basic (Usage)

Dim instance As Bitmap

[SerializableAttribute]
[ComVisibleAttribute(true)]
public sealed class Bitmap : Image

Visual C++

[SerializableAttribute]
[ComVisibleAttribute(true)]
public ref class Bitmap sealed : public Image

/** @attribute SerializableAttribute */ 
/** @attribute ComVisibleAttribute(true) */
public final class Bitmap extends Image

JScript

public final class Bitmap extends Image

Remarks

A bitmap consists of the pixel data for a graphics image and its attributes. There are many standard formats for saving a bitmap to a file. GDI+ supports the following file formats: BMP, GIF, EXIG, JPG, PNG and TIFF. For more information about supported formats, see Types of Bitmaps.

You can create images from files, streams, and other sources by using one of the Bitmap constructors and save them to a stream or to the file system with the Save method. Images are drawn to the screen or to memory by using the DrawImage method of the Graphics object. For a list of topics about working with image files, see Working with Images, Bitmaps, Icons, and Metafiles.

Note:
The Bitmap class is not accessible across application domains. For example, if you create a dynamic AppDomain and create several brushes, pens, and bitmaps in that domain, then pass these objects back to the main application domain, you can successfully use the pens and brushes. However, if you call the DrawImage method to draw the marshaled Bitmap, you receive the following exception. Remoting cannot find field "native image" on type "System.Drawing.Image".

Note:

The Bitmap class is not accessible across application domains. For example, if you create a dynamic AppDomain and create several brushes, pens, and bitmaps in that domain, then pass these objects back to the main application domain, you can successfully use the pens and brushes. However, if you call the DrawImage method to draw the marshaled Bitmap, you receive the following exception.

Remoting cannot find field "native image" on type "System.Drawing.Image".

Examples

The following code example demonstrates how to construct a new Bitmap from a file, using the GetPixel and SetPixel methods to recolor the image. It also uses the PixelFormat, Width, and Height properties.

This example is designed to be used with a Windows Forms that contains a Label, PictureBox, and Button named Label1, PictureBox1, and Button1, respectively. Paste the code into the form and associate the Button1_Click method with the button's Click event.

Visual Basic

Dim image1 As Bitmap

Private Sub Button1_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles Button1.Click

    Try
        ' Retrieve the image.
        image1 = New Bitmap( _
            "C:\Documents and Settings\All Users\Documents\My Music\music.bmp", _
            True)

        Dim x, y As Integer

        ' Loop through the images pixels to reset color.
        For x = 0 To image1.Width - 1
            For y = 0 To image1.Height - 1
                Dim pixelColor As Color = image1.GetPixel(x, y)
                Dim newColor As Color = _
                    Color.FromArgb(pixelColor.R, 0, 0)
                image1.SetPixel(x, y, newColor)
            Next
        Next

        ' Set the PictureBox to display the image.
        PictureBox1.Image = image1

        ' Display the pixel format in Label1.
        Label1.Text = "Pixel format: " + image1.PixelFormat.ToString()

    Catch ex As ArgumentException
        MessageBox.Show("There was an error." _
            & "Check the path to the image file.")
    End Try
End Sub

Bitmap image1;

private void Button1_Click(System.Object sender, System.EventArgs e)
{

    try
    {
        // Retrieve the image.
        image1 = new Bitmap(@"C:\Documents and Settings\All Users\" 
            + @"Documents\My Music\music.bmp", true);

        int x, y;

        // Loop through the images pixels to reset color.
        for(x=0; x<image1.Width; x++)
        {
            for(y=0; y<image1.Height; y++)
            {
                Color pixelColor = image1.GetPixel(x, y);
                Color newColor = Color.FromArgb(pixelColor.R, 0, 0);
                image1.SetPixel(x, y, newColor);
            }
        }

        // Set the PictureBox to display the image.
        PictureBox1.Image = image1;

        // Display the pixel format in Label1.
        Label1.Text = "Pixel format: "+image1.PixelFormat.ToString();

    }
    catch(ArgumentException)
    {
        MessageBox.Show("There was an error." +
            "Check the path to the image file.");
    }
}

Visual C++

private:
   Bitmap^ image1;
   void Button1_Click( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      try
      {

         // Retrieve the image.
         image1 = gcnew Bitmap( "C:\\Documents and Settings\\All Users\\"
         "Documents\\My Music\\music.bmp",true );
         int x;
         int y;

         // Loop through the images pixels to reset color.
         for ( x = 0; x < image1->Width; x++ )
         {
            for ( y = 0; y < image1->Height; y++ )
            {
               Color pixelColor = image1->GetPixel( x, y );
               Color newColor = Color::FromArgb( pixelColor.R, 0, 0 );
               image1->SetPixel( x, y, newColor );

            }

         }

         // Set the PictureBox to display the image.
         PictureBox1->Image = image1;

         // Display the pixel format in Label1.
         Label1->Text = String::Format( "Pixel format: {0}", image1->PixelFormat );
      }
      catch ( ArgumentException^ ) 
      {
         MessageBox::Show( "There was an error."
         "Check the path to the image file." );
      }

   }

private Bitmap image1;

private void button1_Click(Object sender, System.EventArgs e)
{
    try {
        // Retrieve the image.
        image1 = new Bitmap("C:\\Documents and Settings\\All Users\\"  
            + "Documents\\My Music\\music.bmp", true);

        int x, y;

        // Loop through the images pixels to reset color.
        for (x = 0; x < image1.get_Width(); x++) {
            for (y = 0; y < image1.get_Height(); y++) {
                Color pixelColor = image1.GetPixel(x, y);
                Color newColor = Color.FromArgb(pixelColor.get_R(), 0, 0);

                image1.SetPixel(x, y, newColor);
            }
        }

        // Set the PictureBox to display the image.
        pictureBox1.set_Image(image1);

        // Display the pixel format in label1.
        label1.set_Text("Pixel format: " 
            + image1.get_PixelFormat().ToString());
    }
    catch (ArgumentException exp) {
        MessageBox.Show(("There was an error."  
            + "Check the path to the image file."));
    }
} //button1_Click

Inheritance Hierarchy

System..::.Object
  System..::.MarshalByRefObject
    System.Drawing..::.Image
      System.Drawing..::.Bitmap

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Platforms

Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC

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.

Version Information