The FormatConvertedBitmap is used to apply formatting on images in WPF. The FormatConvertedBitmap.Source property is a BitmapImage that will be used in the formatting process.

This code creates a BitmapImage.

BitmapImage bitmap = new BitmapImage();

bitmap.BeginInit();

bitmap.UriSource = new Uri(@"C:\Books\Book WPF\How do I\ImageSample\ImageSample\Flower.JPG");

bitmap.EndInit();

This code snippet creates a FormatConvertedBitmap from the BitmapImage created above.

FormatConvertedBitmap grayBitmapSource = new FormatConvertedBitmap();

grayBitmapSource.BeginInit();

grayBitmapSource.Source = bitmap;

The DestinationFormat property of FormatConvertedBitmap is used to apply formatting on images. The follow code snippet sets the formatting of an image to gray. 

grayBitmapSource.DestinationFormat = PixelFormats.Gray32Float;   
grayBitmapSource.EndInit();

The complete source code looks like this.

private void GrayScaleButton_Click(object sender, RoutedEventArgs e)

{

// Create a BitmapSource

BitmapImage bitmap = new BitmapImage();

bitmap.BeginInit();

bitmap.UriSource = new Uri(@"C:\Books\Book WPF\How do I\ImageSample\ImageSample\Flower.JPG");

bitmap.EndInit();

// Create a FormatConvertedBitmap

FormatConvertedBitmap grayBitmapSource = new FormatConvertedBitmap();

// BitmapSource objects like FormatConvertedBitmap can only have their properties

// changed within a BeginInit/EndInit block.

grayBitmapSource.BeginInit();

grayBitmapSource.Source = bitmap;

// Key of changing the bitmap format is DesitnationFormat property of BitmapSource.

// It is a type of PixelFormat. FixelFormat has dozens of options to set

// bitmap formatting.

grayBitmapSource.DestinationFormat = PixelFormats.Gray32Float;

grayBitmapSource.EndInit();

// Create a new Image

Image grayImage = new Image();

grayImage.Width = 300;

// Set Image source to new FormatConvertedBitmap

grayImage.Source = grayBitmapSource;

// Add Image to Window

LayoutRoot.Children.Add(grayImage);

}