ImageAttributes.SetColorMatrix Method

Definition

Namespace:

System.Drawing.Imaging

Assembly:

System.Drawing.Common.dll

Sets the color-adjustment matrix.

Overloads

SetColorMatrix(ColorMatrix)	Sets the color-adjustment matrix for the default category.
SetColorMatrix(ColorMatrix, ColorMatrixFlag)	Sets the color-adjustment matrix for the default category.
SetColorMatrix(ColorMatrix, ColorMatrixFlag, ColorAdjustType)	Sets the color-adjustment matrix for a specified category.

SetColorMatrix(ColorMatrix)

Sets the color-adjustment matrix for the default category.

public:
 void SetColorMatrix(System::Drawing::Imaging::ColorMatrix ^ newColorMatrix);

public void SetColorMatrix (System.Drawing.Imaging.ColorMatrix newColorMatrix);

member this.SetColorMatrix : System.Drawing.Imaging.ColorMatrix -> unit

Public Sub SetColorMatrix (newColorMatrix As ColorMatrix)

Parameters

newColorMatrix

ColorMatrix

The color-adjustment matrix.

Examples

The following code example is designed for use with Windows Forms, and it requires PaintEventArgs e, which is a parameter of the Paint event handler. The code performs the following actions:

1. Creates a rectangle image that has all the color values set to 128, producing a rectangle that is filled with a solid medium-gray color. The code then draws this rectangle image to the screen.

2. Creates a ColorMatrix and sets its Matrix location to 1.75, which emphasizes the red component of the image.

3. Creates an ImageAttributes object and calls the SetColorMatrix method.

4. Draws the image (a second rectangle) to the screen using the ColorMatrix just set in the ImageAttributes object.

Note that the second rectangle has the color red emphasized.

private:
   void SetColorMatrixExample( PaintEventArgs^ e )
   {
      // Create a rectangle image with all colors set to 128 (medium
      // gray).
      Bitmap^ myBitmap = gcnew Bitmap( 50,50,PixelFormat::Format32bppArgb );
      Graphics^ g = Graphics::FromImage( myBitmap );
      g->FillRectangle( gcnew SolidBrush( Color::FromArgb( 255, 128, 128, 128 ) ), Rectangle(0,0,50,50) );
      myBitmap->Save( "Rectangle1.jpg" );

      // Open an Image file and draw it to the screen.
      Image^ myImage = Image::FromFile( "Rectangle1.jpg" );
      e->Graphics->DrawImage( myImage, 20, 20 );

      // Initialize the color matrix.
      ColorMatrix^ myColorMatrix = gcnew ColorMatrix;

      // Red
      myColorMatrix->Matrix00 = 1.75f;

      // Green
      myColorMatrix->Matrix11 = 1.00f;

      // Blue
      myColorMatrix->Matrix22 = 1.00f;

      // alpha
      myColorMatrix->Matrix33 = 1.00f;

      // w
      myColorMatrix->Matrix44 = 1.00f;

      // Create an ImageAttributes object and set the color matrix.
      ImageAttributes^ imageAttr = gcnew ImageAttributes;
      imageAttr->SetColorMatrix( myColorMatrix );

      // Draw the image using the color matrix.
      Rectangle rect = Rectangle(100,20,200,200);
      e->Graphics->DrawImage( myImage, rect, 0, 0, 200, 200, GraphicsUnit::Pixel, imageAttr );
   }

private void SetColorMatrixExample(PaintEventArgs e)
{
             
    // Create a rectangle image with all colors set to 128 (medium
             
    // gray).
    Bitmap myBitmap = new Bitmap(50, 50, PixelFormat.Format32bppArgb);
    Graphics g = Graphics.FromImage(myBitmap);
    g.FillRectangle(new SolidBrush(Color.FromArgb(255, 128, 128, 128)),
        new Rectangle(0, 0, 50, 50));
    myBitmap.Save("Rectangle1.jpg");
             
    // Open an Image file and draw it to the screen.
    Image myImage = Image.FromFile("Rectangle1.jpg");
    e.Graphics.DrawImage(myImage, 20, 20);
             
    // Initialize the color matrix.
    ColorMatrix myColorMatrix = new ColorMatrix();
    
    // Red
    myColorMatrix.Matrix00 = 1.75f; 
    
    // Green
    myColorMatrix.Matrix11 = 1.00f; 
    
    // Blue
    myColorMatrix.Matrix22 = 1.00f; 
    
    // alpha
    myColorMatrix.Matrix33 = 1.00f; 
   
    // w
    myColorMatrix.Matrix44 = 1.00f; 

    // Create an ImageAttributes object and set the color matrix.
    ImageAttributes imageAttr = new ImageAttributes();
    imageAttr.SetColorMatrix(myColorMatrix);
             
    // Draw the image using the color matrix.
    Rectangle rect = new Rectangle(100, 20, 200, 200);
    e.Graphics.DrawImage(myImage, rect, 0, 0, 200, 200, 
        GraphicsUnit.Pixel, imageAttr);      
}

Public Sub SetColorMatrixExample(ByVal e As PaintEventArgs)

    ' Create a rectangle image with all colors set to 128 (medium

    ' gray).
    Dim myBitmap As New Bitmap(50, 50, PixelFormat.Format32bppArgb)
    Dim g As Graphics = Graphics.FromImage(myBitmap)
    g.FillRectangle(New SolidBrush(Color.FromArgb(255, 128, 128, _
    128)), New Rectangle(0, 0, 50, 50))
    myBitmap.Save("Rectangle1.jpg")

    ' Open an Image file and draw it to the screen.
    Dim myImage As Image = Image.FromFile("Rectangle1.jpg")
    e.Graphics.DrawImage(myImage, 20, 20)

    ' Initialize the color matrix.
    Dim myColorMatrix As New ColorMatrix
    myColorMatrix.Matrix00 = 1.75F
    ' Red
    myColorMatrix.Matrix11 = 1.0F
    ' Green
    myColorMatrix.Matrix22 = 1.0F
    ' Blue
    myColorMatrix.Matrix33 = 1.0F
    ' alpha
    myColorMatrix.Matrix44 = 1.0F
    ' w

    ' Create an ImageAttributes object and set the color matrix.
    Dim imageAttr As New ImageAttributes
    imageAttr.SetColorMatrix(myColorMatrix)

    ' Draw the image using the color matrix.
    Dim rect As New Rectangle(100, 20, 200, 200)
    e.Graphics.DrawImage(myImage, rect, 0, 0, 200, 200, _
    GraphicsUnit.Pixel, imageAttr)
    ' Image
End Sub
'SetColorMatrixExample

Remarks

An ImageAttributes object maintains color and grayscale settings for five adjustment categories: default, bitmap, brush, pen, and text. For example, you can specify a color-adjustment matrix for the default category, a different color-adjustment matrix for the bitmap category, and still a different color-adjustment matrix for the pen category.

The default color-adjustment and grayscale-adjustment settings apply to all categories that do not have adjustment settings of their own. For example, if you never specify any adjustment settings for the pen category, the default settings apply to the pen category.

Calling the ImageAttributes.SetColorMatrix(ColorMatrix) method is equivalent to calling the ImageAttributes.SetColorMatrix(ColorMatrix, ColorMatrixFlag) method and passing ColorMatrixFlag.Default for the flags parameter. ColorMatrixFlag.Default specifies that all colors (including grays) are adjusted by the color-adjustment matrix

See also

• Recoloring Images

SetColorMatrix(ColorMatrix, ColorMatrixFlag)

Sets the color-adjustment matrix for the default category.

public:
 void SetColorMatrix(System::Drawing::Imaging::ColorMatrix ^ newColorMatrix, System::Drawing::Imaging::ColorMatrixFlag flags);

public void SetColorMatrix (System.Drawing.Imaging.ColorMatrix newColorMatrix, System.Drawing.Imaging.ColorMatrixFlag flags);

member this.SetColorMatrix : System.Drawing.Imaging.ColorMatrix * System.Drawing.Imaging.ColorMatrixFlag -> unit

Public Sub SetColorMatrix (newColorMatrix As ColorMatrix, flags As ColorMatrixFlag)

Parameters

newColorMatrix

ColorMatrix

The color-adjustment matrix.

flags

ColorMatrixFlag

An element of ColorMatrixFlag that specifies the type of image and color that will be affected by the color-adjustment matrix.

Examples

For a code example, see the SetColorMatrix(ColorMatrix) method.

Remarks

An ImageAttributes object maintains color and grayscale settings for five adjustment categories: default, bitmap, brush, pen, and text. For example, you can specify a color-adjustment matrix for the default category, a different color-adjustment matrix for the bitmap category, and still a different color-adjustment matrix for the pen category.

The default color-adjustment and grayscale-adjustment settings apply to all categories that do not have adjustment settings of their own. For example, if you never specify any adjustment settings for the pen category, the default settings apply to the pen category.

See also

• Recoloring Images

SetColorMatrix(ColorMatrix, ColorMatrixFlag, ColorAdjustType)

Sets the color-adjustment matrix for a specified category.

public:
 void SetColorMatrix(System::Drawing::Imaging::ColorMatrix ^ newColorMatrix, System::Drawing::Imaging::ColorMatrixFlag mode, System::Drawing::Imaging::ColorAdjustType type);

public void SetColorMatrix (System.Drawing.Imaging.ColorMatrix newColorMatrix, System.Drawing.Imaging.ColorMatrixFlag mode, System.Drawing.Imaging.ColorAdjustType type);

member this.SetColorMatrix : System.Drawing.Imaging.ColorMatrix * System.Drawing.Imaging.ColorMatrixFlag * System.Drawing.Imaging.ColorAdjustType -> unit

Public Sub SetColorMatrix (newColorMatrix As ColorMatrix, mode As ColorMatrixFlag, type As ColorAdjustType)

Parameters

newColorMatrix

ColorMatrix

The color-adjustment matrix.

mode

ColorMatrixFlag

An element of ColorMatrixFlag that specifies the type of image and color that will be affected by the color-adjustment matrix.

type

ColorAdjustType

An element of ColorAdjustType that specifies the category for which the color-adjustment matrix is set.

Examples

The following code example demonstrates how to use the SetColorMatrix method. To run this example, paste the code into a Windows Form and call RotateColors from the form's Paint event-handling method, passing e as PaintEventArgs.

private void RotateColors(PaintEventArgs e)
{
    Bitmap image = new Bitmap("RotationInput.bmp");
    ImageAttributes imageAttributes = new ImageAttributes();
    int width = image.Width;
    int height = image.Height;
    float degrees = 60f;
    double r = degrees * System.Math.PI / 180; // degrees to radians

    float[][] colorMatrixElements = { 
        new float[] {(float)System.Math.Cos(r),  (float)System.Math.Sin(r),  0,  0, 0},
        new float[] {(float)-System.Math.Sin(r),  (float)-System.Math.Cos(r),  0,  0, 0},
        new float[] {0,  0,  2,  0, 0},
        new float[] {0,  0,  0,  1, 0},
        new float[] {0, 0, 0, 0, 1}};

    ColorMatrix colorMatrix = new ColorMatrix(colorMatrixElements);

    imageAttributes.SetColorMatrix(
       colorMatrix,
       ColorMatrixFlag.Default,
       ColorAdjustType.Bitmap);

    e.Graphics.DrawImage(image, 10, 10, width, height);

    e.Graphics.DrawImage(
       image,
       new Rectangle(150, 10, width, height),  // destination rectangle 
        0, 0,        // upper-left corner of source rectangle 
        width,       // width of source rectangle
        height,      // height of source rectangle
        GraphicsUnit.Pixel,
       imageAttributes);
}

Private Sub RotateColors(ByVal e As PaintEventArgs)
    Dim image As Bitmap = New Bitmap("RotationInput.bmp")
    Dim imageAttributes As New ImageAttributes()
    Dim width As Integer = image.Width
    Dim height As Integer = image.Height
    Dim degrees As Single = 60.0F
    Dim r As Double = degrees * System.Math.PI / 180 ' degrees to radians
    Dim colorMatrixElements As Single()() = { _
       New Single() {CSng(System.Math.Cos(r)), _
                     CSng(System.Math.Sin(r)), 0, 0, 0}, _
       New Single() {CSng(-System.Math.Sin(r)), _
                     CSng(-System.Math.Cos(r)), 0, 0, 0}, _
       New Single() {0, 0, 2, 0, 0}, _
       New Single() {0, 0, 0, 1, 0}, _
       New Single() {0, 0, 0, 0, 1}}

    Dim colorMatrix As New ColorMatrix(colorMatrixElements)

    imageAttributes.SetColorMatrix( _
       colorMatrix, _
       ColorMatrixFlag.Default, _
       ColorAdjustType.Bitmap)

    e.Graphics.DrawImage(image, 10, 10, width, height)

    ' Pass in the destination rectangle (2nd argument), the upper-left corner 
    ' (3rd and 4th arguments), width (5th argument),  and height (6th 
    ' argument) of the source rectangle.
    e.Graphics.DrawImage( _
       image, _
       New Rectangle(150, 10, width, height), _
       0, 0, _
       width, _
       height, _
       GraphicsUnit.Pixel, _
       imageAttributes)
End Sub

Remarks

An ImageAttributes object maintains color and grayscale settings for five adjustment categories: default, bitmap, brush, pen, and text. For example, you can specify a color-adjustment matrix for the default category, a different color-adjustment matrix for the bitmap category, and still a different color-adjustment matrix for the pen category.

The default color-adjustment and grayscale-adjustment settings apply to all categories that do not have adjustment settings of their own. For example, if you never specify any adjustment settings for the pen category, the default settings apply to the pen category.

As soon as you specify a color-adjustment or grayscale-adjustment setting for a certain category, the default adjustment settings no longer apply to that category. For example, suppose you specify a collection of adjustment settings for the default category. If you set the color-adjustment matrix for the pen category by passing Pen to the SetColorMatrix method, none of the default adjustment settings will apply to pens.