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ImageAttributes.SetOutputChannel Method (ColorChannelFlag)

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

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

public void SetOutputChannel(
	ColorChannelFlag flags
)

Parameters

flags
Type: System.Drawing.Imaging.ColorChannelFlag

An element of ColorChannelFlag that specifies the output channel.

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.

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 asPaintEventArgs.

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();

}

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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