ImageAttributes.SetOutputChannel Method

Definition

Namespace:

System.Drawing.Imaging

Assembly:

System.Drawing.Common.dll

Sets the CMYK (cyan-magenta-yellow-black) output channel.

Overloads

SetOutputChannel(ColorChannelFlag)	Sets the CMYK (cyan-magenta-yellow-black) output channel for the default category.
SetOutputChannel(ColorChannelFlag, ColorAdjustType)	Sets the CMYK (cyan-magenta-yellow-black) output channel for a specified category.

SetOutputChannel(ColorChannelFlag)

Sets the CMYK (cyan-magenta-yellow-black) output channel for the default category.

public:
 void SetOutputChannel(System::Drawing::Imaging::ColorChannelFlag flags);

public void SetOutputChannel (System.Drawing.Imaging.ColorChannelFlag flags);

member this.SetOutputChannel : System.Drawing.Imaging.ColorChannelFlag -> unit

Public Sub SetOutputChannel (flags As ColorChannelFlag)

Parameters

flags

ColorChannelFlag

An element of ColorChannelFlag that specifies the output channel.

Examples

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

private void ShowOutputChannels(PaintEventArgs e)
{
    //Create a bitmap from a file.
    Bitmap bmp1 = new Bitmap("c:\\fakePhoto.jpg");

    // Create a new bitmap from the original, resizing it for this example.
    Bitmap bmp2 = new Bitmap(bmp1, new Size(80, 80));

    bmp1.Dispose();

    // Create an ImageAttributes object.
    ImageAttributes imgAttributes = new ImageAttributes();

    // Draw the image unaltered.
    e.Graphics.DrawImage(bmp2, 10, 10);

    // Draw the image, showing the intensity of the cyan channel.
    imgAttributes.SetOutputChannel(ColorChannelFlag.ColorChannelC,
        System.Drawing.Imaging.ColorAdjustType.Bitmap);

    e.Graphics.DrawImage(bmp2, new Rectangle(100, 10, bmp2.Width, bmp2.Height),
        0, 0, bmp2.Width, bmp2.Height, GraphicsUnit.Pixel, imgAttributes);

    // Draw the image, showing the intensity of the magenta channel.
    imgAttributes.SetOutputChannel(ColorChannelFlag.ColorChannelM,
        ColorAdjustType.Bitmap);

    e.Graphics.DrawImage(bmp2, new Rectangle(10, 100, bmp2.Width, bmp2.Height),
        0, 0, bmp2.Width, bmp2.Height, GraphicsUnit.Pixel, imgAttributes);

    // Draw the image, showing the intensity of the yellow channel.
    imgAttributes.SetOutputChannel(ColorChannelFlag.ColorChannelY,
        ColorAdjustType.Bitmap);

    e.Graphics.DrawImage(bmp2, new Rectangle(100, 100, bmp2.Width, bmp2.Height), 0, 0,
        bmp2.Width, bmp2.Height, GraphicsUnit.Pixel, imgAttributes);

    // Draw the image, showing the intensity of the black channel.
    imgAttributes.SetOutputChannel(ColorChannelFlag.ColorChannelK,

        System.Drawing.Imaging.ColorAdjustType.Bitmap);
    e.Graphics.DrawImage(bmp2, new Rectangle(10, 190, bmp2.Width, bmp2.Height),
        0, 0, bmp2.Width, bmp2.Height, GraphicsUnit.Pixel, imgAttributes);

    //Dispose of the bitmap.
    bmp2.Dispose();
}

Private Sub ShowOutputChannels(ByVal e As PaintEventArgs)

    'Create a bitmap from a file.
    Dim bmp1 As New Bitmap("c:\fakePhoto.jpg")

    ' Create a new bitmap from the original, resizing it for this example.
    Dim bmp2 As New Bitmap(bmp1, New Size(80, 80))

    bmp1.Dispose()

    ' Create an ImageAttributes object.
    Dim imgAttributes As New System.Drawing.Imaging.ImageAttributes()

    ' Draw the image unaltered.
    e.Graphics.DrawImage(bmp2, 10, 10)

    ' Draw the image, showing the intensity of the cyan channel.
    imgAttributes.SetOutputChannel(ColorChannelFlag.ColorChannelC, ColorAdjustType.Bitmap)

    e.Graphics.DrawImage(bmp2, New Rectangle(100, 10, bmp2.Width, bmp2.Height), _
        0, 0, bmp2.Width, bmp2.Height, GraphicsUnit.Pixel, imgAttributes)

    ' Draw the image, showing the intensity of the magenta channel.
    imgAttributes.SetOutputChannel(ColorChannelFlag.ColorChannelM, ColorAdjustType.Bitmap)

    e.Graphics.DrawImage(bmp2, New Rectangle(10, 100, bmp2.Width, bmp2.Height), _
        0, 0, bmp2.Width, bmp2.Height, GraphicsUnit.Pixel, imgAttributes)

    ' Draw the image, showing the intensity of the yellow channel.
    imgAttributes.SetOutputChannel(ColorChannelFlag.ColorChannelY, _
        ColorAdjustType.Bitmap)

    e.Graphics.DrawImage(bmp2, New Rectangle(100, 100, bmp2.Width, bmp2.Height), _
        0, 0, bmp2.Width, bmp2.Height, GraphicsUnit.Pixel, imgAttributes)

    ' Draw the image, showing the intensity of the black channel.
    imgAttributes.SetOutputChannel(ColorChannelFlag.ColorChannelK, _
        ColorAdjustType.Bitmap)

    e.Graphics.DrawImage(bmp2, New Rectangle(10, 190, bmp2.Width, bmp2.Height), _
        0, 0, bmp2.Width, bmp2.Height, GraphicsUnit.Pixel, imgAttributes)

    'Dispose of the bitmap.
    bmp2.Dispose()

End Sub

Remarks

You can use the SetOutputChannel method to convert an image to a CMYK color space and examine the intensities of one of the CMYK color channels. For example, suppose you create an ImageAttributes object and set its bitmap output channel to ColorChannelC. If you pass the path of that ImageAttributes object to the DrawImage method, the cyan component of each pixel is calculated, and each pixel in the rendered image is a shade of gray that indicates the intensity of its cyan channel. Similarly, you can render images that indicate the intensities of the magenta, yellow, and black channels.

An ImageAttributes object maintains color and grayscale settings for five adjustment categories: default, bitmap, brush, pen, and text. For example, you can specify an output channel for the default category and a different output channel for the bitmap 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 bitmap category, the default settings apply to the bitmap category.

SetOutputChannel(ColorChannelFlag, ColorAdjustType)

Sets the CMYK (cyan-magenta-yellow-black) output channel for a specified category.

public:
 void SetOutputChannel(System::Drawing::Imaging::ColorChannelFlag flags, System::Drawing::Imaging::ColorAdjustType type);

public void SetOutputChannel (System.Drawing.Imaging.ColorChannelFlag flags, System.Drawing.Imaging.ColorAdjustType type);

member this.SetOutputChannel : System.Drawing.Imaging.ColorChannelFlag * System.Drawing.Imaging.ColorAdjustType -> unit

Public Sub SetOutputChannel (flags As ColorChannelFlag, type As ColorAdjustType)

Parameters

flags

ColorChannelFlag

An element of ColorChannelFlag that specifies the output channel.

type

ColorAdjustType

An element of ColorAdjustType that specifies the category for which the output channel is set.

Examples

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

private void ShowOutputChannels(PaintEventArgs e)
{
    //Create a bitmap from a file.
    Bitmap bmp1 = new Bitmap("c:\\fakePhoto.jpg");

    // Create a new bitmap from the original, resizing it for this example.
    Bitmap bmp2 = new Bitmap(bmp1, new Size(80, 80));

    bmp1.Dispose();

    // Create an ImageAttributes object.
    ImageAttributes imgAttributes = new ImageAttributes();

    // Draw the image unaltered.
    e.Graphics.DrawImage(bmp2, 10, 10);

    // Draw the image, showing the intensity of the cyan channel.
    imgAttributes.SetOutputChannel(ColorChannelFlag.ColorChannelC,
        System.Drawing.Imaging.ColorAdjustType.Bitmap);

    e.Graphics.DrawImage(bmp2, new Rectangle(100, 10, bmp2.Width, bmp2.Height),
        0, 0, bmp2.Width, bmp2.Height, GraphicsUnit.Pixel, imgAttributes);

    // Draw the image, showing the intensity of the magenta channel.
    imgAttributes.SetOutputChannel(ColorChannelFlag.ColorChannelM,
        ColorAdjustType.Bitmap);

    e.Graphics.DrawImage(bmp2, new Rectangle(10, 100, bmp2.Width, bmp2.Height),
        0, 0, bmp2.Width, bmp2.Height, GraphicsUnit.Pixel, imgAttributes);

    // Draw the image, showing the intensity of the yellow channel.
    imgAttributes.SetOutputChannel(ColorChannelFlag.ColorChannelY,
        ColorAdjustType.Bitmap);

    e.Graphics.DrawImage(bmp2, new Rectangle(100, 100, bmp2.Width, bmp2.Height), 0, 0,
        bmp2.Width, bmp2.Height, GraphicsUnit.Pixel, imgAttributes);

    // Draw the image, showing the intensity of the black channel.
    imgAttributes.SetOutputChannel(ColorChannelFlag.ColorChannelK,

        System.Drawing.Imaging.ColorAdjustType.Bitmap);
    e.Graphics.DrawImage(bmp2, new Rectangle(10, 190, bmp2.Width, bmp2.Height),
        0, 0, bmp2.Width, bmp2.Height, GraphicsUnit.Pixel, imgAttributes);

    //Dispose of the bitmap.
    bmp2.Dispose();
}

Private Sub ShowOutputChannels(ByVal e As PaintEventArgs)

    'Create a bitmap from a file.
    Dim bmp1 As New Bitmap("c:\fakePhoto.jpg")

    ' Create a new bitmap from the original, resizing it for this example.
    Dim bmp2 As New Bitmap(bmp1, New Size(80, 80))

    bmp1.Dispose()

    ' Create an ImageAttributes object.
    Dim imgAttributes As New System.Drawing.Imaging.ImageAttributes()

    ' Draw the image unaltered.
    e.Graphics.DrawImage(bmp2, 10, 10)

    ' Draw the image, showing the intensity of the cyan channel.
    imgAttributes.SetOutputChannel(ColorChannelFlag.ColorChannelC, ColorAdjustType.Bitmap)

    e.Graphics.DrawImage(bmp2, New Rectangle(100, 10, bmp2.Width, bmp2.Height), _
        0, 0, bmp2.Width, bmp2.Height, GraphicsUnit.Pixel, imgAttributes)

    ' Draw the image, showing the intensity of the magenta channel.
    imgAttributes.SetOutputChannel(ColorChannelFlag.ColorChannelM, ColorAdjustType.Bitmap)

    e.Graphics.DrawImage(bmp2, New Rectangle(10, 100, bmp2.Width, bmp2.Height), _
        0, 0, bmp2.Width, bmp2.Height, GraphicsUnit.Pixel, imgAttributes)

    ' Draw the image, showing the intensity of the yellow channel.
    imgAttributes.SetOutputChannel(ColorChannelFlag.ColorChannelY, _
        ColorAdjustType.Bitmap)

    e.Graphics.DrawImage(bmp2, New Rectangle(100, 100, bmp2.Width, bmp2.Height), _
        0, 0, bmp2.Width, bmp2.Height, GraphicsUnit.Pixel, imgAttributes)

    ' Draw the image, showing the intensity of the black channel.
    imgAttributes.SetOutputChannel(ColorChannelFlag.ColorChannelK, _
        ColorAdjustType.Bitmap)

    e.Graphics.DrawImage(bmp2, New Rectangle(10, 190, bmp2.Width, bmp2.Height), _
        0, 0, bmp2.Width, bmp2.Height, GraphicsUnit.Pixel, imgAttributes)

    'Dispose of the bitmap.
    bmp2.Dispose()

End Sub

Remarks

You can use the SetOutputChannel method to convert an image to a CMYK color space and examine the intensities of one of the CMYK color channels. For example, suppose you create an ImageAttributes object and set its bitmap output channel to ColorChannelC. If you pass the path of that ImageAttributes object to the DrawImage method, the cyan component of each pixel is calculated, and each pixel in the rendered image is a shade of gray that indicates the intensity of its cyan channel. Similarly, you can render images that indicate the intensities of the magenta, yellow, and black channels.

An ImageAttributes object maintains color and grayscale settings for five adjustment categories: default, bitmap, brush, pen, and text. For example, you can specify an output channel for the default category and a different output channel for the bitmap 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 bitmap category, the default settings apply to the bitmap 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 output channel for the bitmap category by passing Bitmap to the SetOutputChannel method, none of the default adjustment settings will apply to bitmaps.