ImageAttributes.SetColorMatrix Method (ColorMatrix, ColorMatrixFlag, ColorAdjustType)


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Sets the color-adjustment matrix for a specified category.

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

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


Type: System.Drawing.Imaging.ColorMatrix

The color-adjustment matrix.

Type: System.Drawing.Imaging.ColorMatrixFlag

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

Type: System.Drawing.Imaging.ColorAdjustType

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

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.

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 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, _

    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, _
End Sub

.NET Framework
Available since 1.1
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