Bitmap Constructors

Definition

Namespace:

System.Drawing

Assembly:

System.Drawing.Common.dll

Initializes a new instance of the Bitmap class.

Overloads

Bitmap(Image)	Initializes a new instance of the Bitmap class from the specified existing image.
Bitmap(Stream)	Initializes a new instance of the Bitmap class from the specified data stream.
Bitmap(String)	Initializes a new instance of the Bitmap class from the specified file.
Bitmap(Image, Size)	Initializes a new instance of the Bitmap class from the specified existing image, scaled to the specified size.
Bitmap(Int32, Int32)	Initializes a new instance of the Bitmap class with the specified size.
Bitmap(Stream, Boolean)	Initializes a new instance of the Bitmap class from the specified data stream.
Bitmap(String, Boolean)	Initializes a new instance of the Bitmap class from the specified file.
Bitmap(Type, String)	Initializes a new instance of the Bitmap class from a specified resource.
Bitmap(Image, Int32, Int32)	Initializes a new instance of the Bitmap class from the specified existing image, scaled to the specified size.
Bitmap(Int32, Int32, Graphics)	Initializes a new instance of the Bitmap class with the specified size and with the resolution of the specified Graphics object.
Bitmap(Int32, Int32, PixelFormat)	Initializes a new instance of the Bitmap class with the specified size and format.
Bitmap(Int32, Int32, Int32, PixelFormat, IntPtr)	Initializes a new instance of the Bitmap class with the specified size, pixel format, and pixel data.

Bitmap(Image)

Initializes a new instance of the Bitmap class from the specified existing image.

public:
 Bitmap(System::Drawing::Image ^ original);

public Bitmap (System.Drawing.Image original);

new System.Drawing.Bitmap : System.Drawing.Image -> System.Drawing.Bitmap

Public Sub New (original As Image)

Parameters

original

Image

The Image from which to create the new Bitmap.

Bitmap(Stream)

Initializes a new instance of the Bitmap class from the specified data stream.

public:
 Bitmap(System::IO::Stream ^ stream);

public Bitmap (System.IO.Stream stream);

new System.Drawing.Bitmap : System.IO.Stream -> System.Drawing.Bitmap

Public Sub New (stream As Stream)

Parameters

stream

Stream

The data stream used to load the image.

Exceptions

ArgumentException

stream does not contain image data or is null.

-or-

stream contains a PNG image file with a single dimension greater than 65,535 pixels.

Examples

The following code example demonstrates how to load a bitmap from a stream.

This example is designed to be used with Windows Forms. Create a form that contains a PictureBox named PictureBox1. Paste the code into the form and call the InitializeStreamBitmap method from the form's constructor or Load event-handling method.

void InitializeStreamBitmap()
{
   try
   {
      System::Net::WebRequest^ request = System::Net::WebRequest::Create( "http://www.microsoft.com//h/en-us/r/ms_masthead_ltr.gif" );
      System::Net::WebResponse^ response = request->GetResponse();
      System::IO::Stream^ responseStream = response->GetResponseStream();
      Bitmap^ bitmap2 = gcnew Bitmap( responseStream );
      PictureBox1->Image = bitmap2;
   }
   catch ( System::Net::WebException^ ) 
   {
      MessageBox::Show( "There was an error opening the image file."
      "Check the URL" );
   }

}

private void InitializeStreamBitmap()
{
    try
    {
        System.Net.WebRequest request = 
            System.Net.WebRequest.Create(
            "http://www.microsoft.com//h/en-us/r/ms_masthead_ltr.gif");
        System.Net.WebResponse response = request.GetResponse();
        System.IO.Stream responseStream = 
            response.GetResponseStream();
        Bitmap bitmap2 = new Bitmap(responseStream);
        PictureBox1.Image = bitmap2;
    }
    catch(System.Net.WebException)
    {
        MessageBox.Show("There was an error opening the image file."
           + "Check the URL");
    }
}

Private Sub InitializeStreamBitmap()
    Try
        Dim request As System.Net.WebRequest = _
            System.Net.WebRequest.Create( _
            "http://www.microsoft.com//h/en-us/r/ms_masthead_ltr.gif")
        Dim response As System.Net.WebResponse = request.GetResponse()
        Dim responseStream As System.IO.Stream = response.GetResponseStream()
        Dim bitmap2 As New Bitmap(responseStream)
        PictureBox1.Image = bitmap2

    Catch ex As System.Net.WebException
        MessageBox.Show("There was an error opening the image file. Check the URL")
    End Try
End Sub

Remarks

You must keep the stream open for the lifetime of the Bitmap.

Due to a limitation of the GDI+ decoder, an System.ArgumentException is thrown if you construct a bitmap from a .png image file with a single dimension greater than 65,535 pixels.

See also

• Types of Bitmaps

Bitmap(String)

Initializes a new instance of the Bitmap class from the specified file.

public:
 Bitmap(System::String ^ filename);

public Bitmap (string filename);

new System.Drawing.Bitmap : string -> System.Drawing.Bitmap

Public Sub New (filename As String)

Parameters

filename

String

The bitmap file name and path.

Exceptions

FileNotFoundException

The specified file is not found.

Remarks

The file name and path can be relative to the application or an absolute path. Use this constructor to open images with the following file formats: BMP, GIF, EXIF, JPG, PNG and TIFF. For more information about supported formats, see Types of Bitmaps. The file remains locked until the Bitmap is disposed.

See also

• Types of Bitmaps

Bitmap(Image, Size)

Initializes a new instance of the Bitmap class from the specified existing image, scaled to the specified size.

public:
 Bitmap(System::Drawing::Image ^ original, System::Drawing::Size newSize);

public Bitmap (System.Drawing.Image original, System.Drawing.Size newSize);

new System.Drawing.Bitmap : System.Drawing.Image * System.Drawing.Size -> System.Drawing.Bitmap

Public Sub New (original As Image, newSize As Size)

Parameters

original

Image

The Image from which to create the new Bitmap.

newSize

Size

The Size structure that represent the size of the new Bitmap.

Exceptions

Exception

The operation failed.

Bitmap(Int32, Int32)

Initializes a new instance of the Bitmap class with the specified size.

public:
 Bitmap(int width, int height);

public Bitmap (int width, int height);

new System.Drawing.Bitmap : int * int -> System.Drawing.Bitmap

Public Sub New (width As Integer, height As Integer)

Parameters

width

Int32

The width, in pixels, of the new Bitmap.

height

Int32

The height, in pixels, of the new Bitmap.

Exceptions

Exception

The operation failed.

Remarks

This constructor creates a Bitmap with a PixelFormat enumeration value of Format32bppArgb.

Bitmap(Stream, Boolean)

Initializes a new instance of the Bitmap class from the specified data stream.

public:
 Bitmap(System::IO::Stream ^ stream, bool useIcm);

public Bitmap (System.IO.Stream stream, bool useIcm);

new System.Drawing.Bitmap : System.IO.Stream * bool -> System.Drawing.Bitmap

Public Sub New (stream As Stream, useIcm As Boolean)

Parameters

stream

Stream

The data stream used to load the image.

useIcm

Boolean

true to use color correction for this Bitmap; otherwise, false.

Exceptions

ArgumentException

stream does not contain image data or is null.

-or-

stream contains a PNG image file with a single dimension greater than 65,535 pixels.

Remarks

You must keep the stream open for the lifetime of the Bitmap.

Due to a limitation of the GDI+ decoder, an System.ArgumentException is thrown if you construct a bitmap from a .png image file with a single dimension greater than 65,535 pixels.

See also

• Types of Bitmaps

Bitmap(String, Boolean)

Initializes a new instance of the Bitmap class from the specified file.

public:
 Bitmap(System::String ^ filename, bool useIcm);

public Bitmap (string filename, bool useIcm);

new System.Drawing.Bitmap : string * bool -> System.Drawing.Bitmap

Public Sub New (filename As String, useIcm As Boolean)

Parameters

filename

String

The name of the bitmap file.

useIcm

Boolean

true to use color correction for this Bitmap; otherwise, false.

Examples

The following code example demonstrates how to construct a new bitmap from a file. The example uses the GetPixel and SetPixel methods to recolor the image. It also uses the PixelFormat property.

This example is designed to be used with a Windows Form 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.

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." );
      }

   }

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.");
    }
}

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

Remarks

Use this constructor to open images with the following file formats: BMP, GIF, EXIF, JPG, PNG and TIFF. For more information about supported formats, see Types of Bitmaps. The file remains locked until the Bitmap is disposed.

See also

• Types of Bitmaps

Bitmap(Type, String)

Initializes a new instance of the Bitmap class from a specified resource.

public:
 Bitmap(Type ^ type, System::String ^ resource);

public Bitmap (Type type, string resource);

new System.Drawing.Bitmap : Type * string -> System.Drawing.Bitmap

Public Sub New (type As Type, resource As String)

Parameters

type

Type

The class used to extract the resource.

resource

String

The name of the resource.

Examples

The following code example demonstrates how to construct a bitmap from a type, and how to use the Save method. To run this example, paste the code into a Windows Form. Handle the form's Paint event and call the ConstructFromResourceSaveAsGif method, passing e as PaintEventArgs

private:
    void ConstructFromResourceSaveAsGif(PaintEventArgs^ e)
    {
        // Construct a bitmap from the button image resource.
        Bitmap^ bmp1 = gcnew Bitmap(Button::typeid, "Button.bmp");
        String^ savePath =  
            Environment::GetEnvironmentVariable("TEMP") + "\\Button.bmp";

        try
        {
            // Save the image as a GIF.
            bmp1->Save(savePath, System::Drawing::Imaging::ImageFormat::Gif);
        }
        catch (IOException^)
        {
            // Carry on regardless
        }

        // Construct a new image from the GIF file.
        Bitmap^ bmp2 = nullptr;
        if (File::Exists(savePath))
        {
            bmp2 = gcnew Bitmap(savePath);
        }

        // Draw the two images.
        e->Graphics->DrawImage(bmp1, Point(10, 10));

        // If bmp1 did not save to disk, bmp2 may be null
        if (bmp2 != nullptr)
        {
            e->Graphics->DrawImage(bmp2, Point(10, 40));
        }

        // Dispose of the image files.
        delete bmp1;
        if (bmp2 != nullptr)
        {
            delete bmp2;
        }
    }

private void ConstructFromResourceSaveAsGif(PaintEventArgs e)
{

    // Construct a bitmap from the button image resource.
    Bitmap bmp1 = new Bitmap(typeof(Button), "Button.bmp");

    // Save the image as a GIF.
    bmp1.Save("c:\\button.gif", System.Drawing.Imaging.ImageFormat.Gif);

    // Construct a new image from the GIF file.
    Bitmap bmp2 = new Bitmap("c:\\button.gif");

    // Draw the two images.
    e.Graphics.DrawImage(bmp1, new Point(10, 10));
    e.Graphics.DrawImage(bmp2, new Point(10, 40));

    // Dispose of the image files.
    bmp1.Dispose();
    bmp2.Dispose();
}

Private Sub ConstructFromResourceSaveAsGif(ByVal e As PaintEventArgs)

    ' Construct a bitmap from the button image resource.
    Dim bmp1 As New Bitmap(GetType(Button), "Button.bmp")

    ' Save the image as a GIF.
    bmp1.Save("c:\button.gif", System.Drawing.Imaging.ImageFormat.Gif)

    ' Construct a new image from the GIF file.
    Dim bmp2 As New Bitmap("c:\button.gif")

    ' Draw the two images.
    e.Graphics.DrawImage(bmp1, New Point(10, 10))
    e.Graphics.DrawImage(bmp2, New Point(10, 40))

    ' Dispose of the image files.
    bmp1.Dispose()
    bmp2.Dispose()
End Sub

Remarks

This constructor combines the namespace of the given type with the string name of the resource and looks for a match in the assembly manifest. For example you can pass in the Button type and Button.bmp to this constructor and it will look for a resource named System.Windows.Forms.Button.bmp.

See also

• Types of Bitmaps

Bitmap(Image, Int32, Int32)

Initializes a new instance of the Bitmap class from the specified existing image, scaled to the specified size.

public:
 Bitmap(System::Drawing::Image ^ original, int width, int height);

public Bitmap (System.Drawing.Image original, int width, int height);

new System.Drawing.Bitmap : System.Drawing.Image * int * int -> System.Drawing.Bitmap

Public Sub New (original As Image, width As Integer, height As Integer)

Parameters

original

Image

The Image from which to create the new Bitmap.

width

Int32

The width, in pixels, of the new Bitmap.

height

Int32

The height, in pixels, of the new Bitmap.

Exceptions

Exception

The operation failed.

Bitmap(Int32, Int32, Graphics)

Initializes a new instance of the Bitmap class with the specified size and with the resolution of the specified Graphics object.

public:
 Bitmap(int width, int height, System::Drawing::Graphics ^ g);

public Bitmap (int width, int height, System.Drawing.Graphics g);

new System.Drawing.Bitmap : int * int * System.Drawing.Graphics -> System.Drawing.Bitmap

Public Sub New (width As Integer, height As Integer, g As Graphics)

Parameters

width

Int32

The width, in pixels, of the new Bitmap.

height

Int32

The height, in pixels, of the new Bitmap.

g

Graphics

The Graphics object that specifies the resolution for the new Bitmap.

Exceptions

ArgumentNullException

g is null.

Remarks

The new Bitmap that this method creates takes its horizontal and vertical resolution from the DpiX and DpiY properties of g, respectively.

Bitmap(Int32, Int32, PixelFormat)

Initializes a new instance of the Bitmap class with the specified size and format.

public:
 Bitmap(int width, int height, System::Drawing::Imaging::PixelFormat format);

public Bitmap (int width, int height, System.Drawing.Imaging.PixelFormat format);

new System.Drawing.Bitmap : int * int * System.Drawing.Imaging.PixelFormat -> System.Drawing.Bitmap

Public Sub New (width As Integer, height As Integer, format As PixelFormat)

Parameters

width

Int32

The width, in pixels, of the new Bitmap.

height

Int32

The height, in pixels, of the new Bitmap.

format

PixelFormat

The pixel format for the new Bitmap. This must specify a value that begins with Format.

Exceptions

ArgumentException

A PixelFormat value is specified whose name does not start with Format. For example, specifying Gdi will cause an ArgumentException, but Format48bppRgb will not.

Bitmap(Int32, Int32, Int32, PixelFormat, IntPtr)

Initializes a new instance of the Bitmap class with the specified size, pixel format, and pixel data.

public:
 Bitmap(int width, int height, int stride, System::Drawing::Imaging::PixelFormat format, IntPtr scan0);

public Bitmap (int width, int height, int stride, System.Drawing.Imaging.PixelFormat format, IntPtr scan0);

new System.Drawing.Bitmap : int * int * int * System.Drawing.Imaging.PixelFormat * nativeint -> System.Drawing.Bitmap

Public Sub New (width As Integer, height As Integer, stride As Integer, format As PixelFormat, scan0 As IntPtr)

Parameters

width

Int32

The width, in pixels, of the new Bitmap.

height

Int32

The height, in pixels, of the new Bitmap.

stride

Int32

Integer that specifies the byte offset between the beginning of one scan line and the next. This is usually (but not necessarily) the number of bytes in the pixel format (for example, 2 for 16 bits per pixel) multiplied by the width of the bitmap. The value passed to this parameter must be a multiple of four.

format

PixelFormat

The pixel format for the new Bitmap. This must specify a value that begins with Format.

scan0

IntPtr

nativeint

Pointer to an array of bytes that contains the pixel data.

Exceptions

ArgumentException

A PixelFormat value is specified whose name does not start with Format. For example, specifying Gdi will cause an ArgumentException, but Format48bppRgb will not.

Examples

The following code example shows how to use the Bitmap(Int32, Int32, Int32, PixelFormat, IntPtr) constructor. This example is designed to be used with Windows Forms and requires a PaintEventArgs parameter, which is a parameter of the Paint event.

private void BitmapConstructorEx(PaintEventArgs e)
{

    // Create a bitmap.
    Bitmap bmp = new Bitmap("c:\\fakePhoto.jpg");
    
   // Retrieve the bitmap data from the bitmap.
    System.Drawing.Imaging.BitmapData bmpData = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), 
        ImageLockMode.ReadOnly, bmp.PixelFormat);

    //Create a new bitmap.
    Bitmap newBitmap = new Bitmap(200, 200, bmpData.Stride, bmp.PixelFormat, bmpData.Scan0);

    bmp.UnlockBits(bmpData);

    // Draw the new bitmap.
    e.Graphics.DrawImage(newBitmap, 10, 10);
}

Private Sub BitmapConstructorEx(ByVal e As PaintEventArgs)

    ' Create a bitmap.
    Dim bmp As New Bitmap("c:\fakePhoto.jpg")

    ' Retrieve the bitmap data from the bitmap.
    Dim bmpData As System.Drawing.Imaging.BitmapData = bmp.LockBits(New Rectangle(0, 0, bmp.Width, bmp.Height), _
        ImageLockMode.ReadOnly, bmp.PixelFormat)

    'Create a new bitmap.
    Dim newBitmap As New Bitmap(200, 200, bmpData.Stride, bmp.PixelFormat, bmpData.Scan0)

    bmp.UnlockBits(bmpData)

    ' Draw the new bitmap.
    e.Graphics.DrawImage(newBitmap, 10, 10)

End Sub

Remarks

The caller is responsible for allocating and freeing the block of memory specified by the scan0 parameter. However, the memory should not be released until the related Bitmap is released.