ImageAttributes.SetRemapTable Method

Definition

Namespace:

System.Drawing.Imaging

Assembly:

System.Drawing.Common.dll

Sets the color-remap table.

Overloads

SetRemapTable(ColorMap[])	Sets the color-remap table for the default category.
SetRemapTable(ColorMap[], ColorAdjustType)	Sets the color-remap table for a specified category.

SetRemapTable(ColorMap[])

Sets the color-remap table for the default category.

public:
 void SetRemapTable(cli::array <System::Drawing::Imaging::ColorMap ^> ^ map);

public void SetRemapTable (System.Drawing.Imaging.ColorMap[] map);

member this.SetRemapTable : System.Drawing.Imaging.ColorMap[] -> unit

Public Sub SetRemapTable (map As ColorMap())

Parameters

map

ColorMap[]

An array of color pairs of type ColorMap. Each color pair contains an existing color (the first value) and the color that it will be mapped to (the second value).

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 an image (a red circle), saves it as Circle2.jpg, opens that image, and draws it to the screen.

2. Creates a color map that maps the color red to the color green.

3. Draws the image created earlier to the screen again, but this time using the color map.

private:
   void SetRemapTableExample( PaintEventArgs^ e )
   {
      // Create a filled, red image, and save it to Circle2.jpg.
      Bitmap^ myBitmap = gcnew Bitmap( 50,50 );
      Graphics^ g = Graphics::FromImage( myBitmap );
      g->Clear( Color::White );
      g->FillEllipse( gcnew SolidBrush( Color::Red ), Rectangle(0,0,50,50) );
      myBitmap->Save( "Circle2.jpg" );

      // Create an Image object from the Circle2.jpg file, and draw it to
      // the screen.
      Image^ myImage = Image::FromFile( "Circle2.jpg" );
      e->Graphics->DrawImage( myImage, 20, 20 );

      // Create a color map.
      array<ColorMap^>^myColorMap = gcnew array<ColorMap^>(1);
      myColorMap[ 0 ] = gcnew ColorMap;
      myColorMap[ 0 ]->OldColor = Color::Red;
      myColorMap[ 0 ]->NewColor = Color::Green;

      // Create an ImageAttributes object, and then pass the
      // myColorMap object to the SetRemapTable method.
      ImageAttributes^ imageAttr = gcnew ImageAttributes;
      imageAttr->SetRemapTable( myColorMap );

      // Draw the image with the remap table set.
      Rectangle rect = Rectangle(150,20,50,50);
      e->Graphics->DrawImage( myImage, rect, 0, 0, 50, 50, GraphicsUnit::Pixel, imageAttr );
   }

private void SetRemapTableExample(PaintEventArgs e)
{
             
    // Create a filled, red image, and save it to Circle2.jpg.
    Bitmap myBitmap = new Bitmap(50, 50);
    Graphics g = Graphics.FromImage(myBitmap);
    g.Clear(Color.White);
    g.FillEllipse(new SolidBrush(Color.Red),
        new Rectangle(0, 0, 50, 50));
    myBitmap.Save("Circle2.jpg");
             
    // Create an Image object from the Circle2.jpg file, and draw it to
             
    // the screen.
    Image myImage = Image.FromFile("Circle2.jpg");
    e.Graphics.DrawImage(myImage, 20, 20);
             
    // Create a color map.
    ColorMap[] myColorMap = new ColorMap[1];
    myColorMap[0] = new ColorMap();
    myColorMap[0].OldColor = Color.Red;
    myColorMap[0].NewColor = Color.Green;
             
    // Create an ImageAttributes object, and then pass the
   // myColorMap object to the SetRemapTable method.
    ImageAttributes imageAttr = new ImageAttributes();
    imageAttr.SetRemapTable(myColorMap);
             
    // Draw the image with the remap table set.
    Rectangle rect = new Rectangle(150, 20, 50, 50);
    e.Graphics.DrawImage(myImage, rect, 0, 0, 50, 50, 
        GraphicsUnit.Pixel, imageAttr);    
}

Public Sub SetRemapTableExample(ByVal e As PaintEventArgs)

    ' Create a filled, red image and save it to Circle2.jpg.
    Dim myBitmap As New Bitmap(50, 50)
    Dim g As Graphics = Graphics.FromImage(myBitmap)
    g.Clear(Color.White)
    g.FillEllipse(New SolidBrush(Color.Red), New Rectangle(0, 0, _
    50, 50))
    myBitmap.Save("Circle2.jpg")

    ' Create an Image object from the Circle2.jpg file, and draw

    ' it to the screen.
    Dim myImage As Image = Image.FromFile("Circle2.jpg")
    e.Graphics.DrawImage(myImage, 20, 20)

    ' Create a color map.
    Dim myColorMap(0) As ColorMap
    myColorMap(0) = New ColorMap
    myColorMap(0).OldColor = Color.Red
    myColorMap(0).NewColor = Color.Green

    ' Create an ImageAttributes object, and then pass the

    ' myColorMap object to the SetRemapTable method.
    Dim imageAttr As New ImageAttributes
    imageAttr.SetRemapTable(myColorMap)

    ' Draw the image with the remap table set.
    Dim rect As New Rectangle(150, 20, 50, 50)
    e.Graphics.DrawImage(myImage, rect, 0, 0, 50, 50, _
    GraphicsUnit.Pixel, imageAttr)
    ' Image
End Sub

Remarks

A color-remap table is an array of ColorMap structures. Each ColorMap structure has two Color objects: one that specifies an old color and one that specifies a corresponding new color. During rendering, any color that matches one of the old colors in the remap table is changed to the corresponding new color.

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 remap for the default category, a color-remap table for the bitmap category, and still a different color-remap table 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.

SetRemapTable(ColorMap[], ColorAdjustType)

Sets the color-remap table for a specified category.

public:
 void SetRemapTable(cli::array <System::Drawing::Imaging::ColorMap ^> ^ map, System::Drawing::Imaging::ColorAdjustType type);

public void SetRemapTable (System.Drawing.Imaging.ColorMap[] map, System.Drawing.Imaging.ColorAdjustType type);

member this.SetRemapTable : System.Drawing.Imaging.ColorMap[] * System.Drawing.Imaging.ColorAdjustType -> unit

Public Sub SetRemapTable (map As ColorMap(), type As ColorAdjustType)

Parameters

map

ColorMap[]

An array of color pairs of type ColorMap. Each color pair contains an existing color (the first value) and the color that it will be mapped to (the second value).

type

ColorAdjustType

An element of ColorAdjustType that specifies the category for which the color-remap table is set.

Examples

For a code example, see the SetRemapTable(ColorMap[]) method.

Remarks

A color-remap table is an array of ColorMap structures. Each ColorMap structure has two Color objects: one that specifies an old color and one that specifies a corresponding new color. During rendering, any color that matches one of the old colors in the remap table is changed to the corresponding new color.

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 remap for the default category, a color-remap table for the bitmap category, and still a different color-remap table 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-remap table for the pen category by passing Pen to the SetRemapTable method, none of the default adjustment settings will apply to pens.