UnsharpMask Class

Syntax

Public NotInheritable Class UnsharpMask _
	Inherits MaskedBitmapTransform

public sealed class UnsharpMask : MaskedBitmapTransform

Remarks

Unsharp mask is a wide-spread technique used by photographers to increase image sharpness even in precomputer times. The idea is to combine the image with the unfocused (blurred) version. This class provides BlurType and Radius to specify blur settings. During combining the algorithm calculates the difference between corresponding pixels of original and blurred image. If this difference is greater than value specified with Threshold property, algorithm adds this N percents of this difference to original pixel (N is set by Amount property). Otherwise no changes to original pixel is done. As blurred image differs from original ones mainly on the object edges, sharpening effect is achieved.

Using this technique is quite difficult to untrained user as it requires to supply three non-intuitive parameters (amount, radius, and threshold). That's why if you want to provide user easy way to manipulate image sharpness, you can use Sharpen transform which is less flexible, but much more easy-to-use.

Examples

'Sharpen image via unsharp mask
Dim unsharpMask As New Aurigma.GraphicsMill.Transforms.UnsharpMask
unsharpMask.Amount = 1.5
unsharpMask.Radius = 2.1
unsharpMask.Threshold = 0.04
unsharpMask.ApplyTransform(bitmap)

//Sharpen image via unsharp mask
Aurigma.GraphicsMill.Transforms.UnsharpMask unsharpMask =
    new Aurigma.GraphicsMill.Transforms.UnsharpMask();
unsharpMask.Amount = 1.5f;
unsharpMask.Radius = 2.1f;
unsharpMask.Threshold = 0.04f;
unsharpMask.ApplyTransform(bitmap);

Inheritance Hierarchy

Thread Safety

Supported Pixel Formats

See Also

Reference

• UnsharpMask Members
• Aurigma.GraphicsMill.Transforms Namespace