Image-Togglebutton Animation
<Button Height="53" HorizontalAlignment="Left" IsEnabled="True" IsHitTestVisible="True" Margin="23,294,0,0" Name="ok_button" VerticalAlignment="Top" Width="128">
        <Button.Template>
            <ControlTemplate TargetType="{x:Type Button}">
                <ControlTemplate.Resources>
                    <Storyboard x:Key="MouseDownTimeLine">
                        <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="Pressed" Storyboard.TargetProperty="Opacity">
                            <SplineDoubleKeyFrame KeyTime="00:00:00.05" Value="1" />
                        </DoubleAnimationUsingKeyFrames>
                    </Storyboard>
                    <Storyboard x:Key="MouseUpTimeLine">
                        <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="Pressed" Storyboard.TargetProperty="Opacity">
                            <SplineDoubleKeyFrame KeyTime="00:00:00.25" Value="0" />
                        </DoubleAnimationUsingKeyFrames>
                    </Storyboard>
                    <Storyboard x:Key="MouseEnterTimeLine">
                        <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="Hover" Storyboard.TargetProperty="Opacity">
                            <SplineDoubleKeyFrame KeyTime="00:00:00.25" Value="1" />
                        </DoubleAnimationUsingKeyFrames>
                    </Storyboard>
                    <Storyboard x:Key="MouseExitTimeLine">
                        <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="Hover" Storyboard.TargetProperty="Opacity">
                            <SplineDoubleKeyFrame KeyTime="00:00:00.25" Value="0" />
                        </DoubleAnimationUsingKeyFrames>
                    </Storyboard>
                </ControlTemplate.Resources>
                <Grid>
                    <Image Name="Normal" Source="/Specter;component/Images/ok_btn_n.png" />
                    <Image Name="Hover" Opacity="0" Source="/Specter;component/Images/ok_btn_h.png" />
                    <Image Name="Pressed" Opacity="0" Source="/Specter;component/Images/ok_btn_p.png" />
                </Grid>
                <ControlTemplate.Triggers>
                    <Trigger Property="ButtonBase.IsPressed" Value="True">
                        <Trigger.EnterActions>
                            <BeginStoryboard Storyboard="{StaticResource MouseDownTimeLine}" />
                        </Trigger.EnterActions>
                        <Trigger.ExitActions>
                            <BeginStoryboard Storyboard="{StaticResource MouseUpTimeLine}" />
                        </Trigger.ExitActions>
                    </Trigger>
                    <Trigger Property="UIElement.IsMouseOver" Value="True">
                        <Trigger.EnterActions>
                            <BeginStoryboard Storyboard="{StaticResource MouseEnterTimeLine}" />
                        </Trigger.EnterActions>
                        <Trigger.ExitActions>
                            <BeginStoryboard Storyboard="{StaticResource MouseExitTimeLine}" />
                        </Trigger.ExitActions>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Button.Template>
    </Button>