// Create the CIImage from a file
CIImage flower = CIImage.FromCGImage (UIImage.FromFile ("flower.png").CGImage);

// Scale the image to make it more interesting
flower = new CILanczosScaleTransform {
	Image = flower,
	Scale = .2f
}.OutputImage;

// Create a CIAffineClamp filter with the input image
var affine_clamp = new CIAffineClamp () {
	Image = flower
};

// Get the clamped image from the filter
var output = new CICrop () { 
	Image = affine_clamp.OutputImage,
	Rectangle = new CIVector (0, 0, 300, 200) 
}.OutputImage;

// To render the results, we need to create a context, and then
// use one of the context rendering APIs, in this case, we render the
// result into a CoreGraphics image, which is merely a useful representation
//
var context = CIContext.FromOptions (null);

var cgimage = context.CreateCGImage (output, output.Extent);

// The above cgimage can be added to a screen view, for example, this
// would add it to a UIImageView on the screen:
myImageView.Image = UIImage.FromImage (cgimage);