How to: Apply an Effect to Part of an Image

This example demonstrates how to apply a BitmapEffect to a portion of an Image using the BitmapEffectInput property.

Example

The following example shows two ways to apply an effect to a portion of the visual content.

<Page xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml">
  <Page.Resources>
    <BitmapImage x:Key="sourceImage" UriSource="/images/WaterLilies.jpg"/>
  </Page.Resources>

  <StackPanel>
    <DockPanel>
      <StackPanel DockPanel.Dock="Left">
        <TextBlock>AreaToApplyEffect=".25,.25,.50,.50"</TextBlock>
        <TextBlock>AreaToApplyEffectUnits="RelativeToBoundingBox"</TextBlock>
      </StackPanel>
      <Image Width="360" Source="{StaticResource sourceImage}" Margin="10" DockPanel.Dock="Left">
        <Image.BitmapEffect>

          <!-- <BitmapEffectGroup> would go here if you wanted to apply more 
             then one effect to the TextBox. However, in this example only  
             one effect is being applied so BitmapEffectGroup does not need  
             to be included. -->

          <!-- Effect to Apply to the Image -->
          <EmbossBitmapEffect Relief="0.8" LightAngle="320" />
        </Image.BitmapEffect>
        <Image.BitmapEffectInput>

          <!-- BitmapEffectInput is used to apply the bitmap effect to a specified
                 region of the visual. When this property is not used, the effect
                 is applied to the entire visual.

               AreaToApplyEffect is a rectangular area in which to apply the effect.
               - When AreaToApplyEffectUnits is "Absolute", the rectangle is read as
                 pixel coordinates within the visual.
               - When AreaToApplyEffectUnits is "RelativeToBoundingBox",
                 the rectangle values are relative to the entire bounding box.
                 Values range between 0 and 1, where (0,0) is the top-left corner
                 and (1,1) is the bottom-right corner. -->

          <BitmapEffectInput AreaToApplyEffect=".25,.25,.50,.50" AreaToApplyEffectUnits="RelativeToBoundingBox"/>
        </Image.BitmapEffectInput>
      </Image>
    </DockPanel>
    <DockPanel>
      <StackPanel DockPanel.Dock="Left">
        <TextBlock>AreaToApplyEffect="90,66,180,135"</TextBlock>
        <TextBlock>AreaToApplyEffectUnits="Absolute"</TextBlock>
      </StackPanel>
      <Image Width="360" Source="{StaticResource sourceImage}" Margin="10" DockPanel.Dock="Left">
        <Image.BitmapEffect>

          <!-- <BitmapEffectGroup> would go here if you wanted to apply more 
             then one effect to the TextBox. However, in this example only  
             one effect is being applied so BitmapEffectGroup does not need  
             to be included. -->

          <!-- Effect to Apply to the Image -->
          <EmbossBitmapEffect Relief="0.8" LightAngle="320" />
        </Image.BitmapEffect>
        <Image.BitmapEffectInput>

          <!-- BitmapEffectInput is used to apply the bitmap effect to a specified
                 region of the visual. When this property is not used, the effect
                 is applied to the entire visual.

             AreaToApplyEffect is a rectangular area in which to apply the effect.
               - When AreaToApplyEffectUnits is "Absolute", the rectangle is read as
                 pixel coordinates within the visual.
               - When AreaToApplyEffectUnits is "RelativeToBoundingBox",
                 the rectangle values are relative to the entire bounding box.
                 Values range between 0 and 1, where (0,0) is the top-left corner
                 and (1,1) is the bottom-left corner. -->

          <BitmapEffectInput AreaToApplyEffect="90,66,180,135" AreaToApplyEffectUnits="Absolute"/>
        </Image.BitmapEffectInput>
      </Image>
    </DockPanel>
  </StackPanel>

</Page>

The following illustration shows an emboss effect applied to only the middle of an image.

See Also

Reference

EmbossBitmapEffect