Unsharp Mask Node

The Unsharp Mask Node is an effect that can be used to sharpen an image. It is a common tool in photography and photo editing. By creating a blurred copy of the image as a mask, the Unsharp Mask Node increases the contrast between the surrounding pixels resulting in a sharper image.

About the Unsharp Mask Node

The Unsharp Mask Effect Node is an effect that can be added to sharpen an image. It does so by creating a blurred copy of the image that is subsequently applied as a mask affecting the contrast in the original image. This technique is best used to sharpen Bitmap images or to reduce the look and feel of the anti-aliasing of a vector image.

When the Unsharp Mask Node is applied, it takes into account the tonal contrast between pixels. The higher the contrast between the pixels, the sharper the edge is going to appear. The effect can also be used to smooth out areas with little contrast to smooth an area of an image. If the threshold is low, then subtle variations in tone will be averaged out smoothing the image.

Applying the Unsharp Mask Node

In order to set up the Unsharp Mask Node in the Node view, the Unsharp Mask Node requires an image input and image output. The image input can be any node providing an image as its output. This will provide the image to which the effect is applied. The output image is the result of the effect applied to the image source.

  1. In the Node library search for the Unsharp Mask.

  2. Drag the Unsharp Mask into the Node view.

  3. Link the Unsharp Mask between an image input and image output

    In the example above, the Drawing node is acting as the image input for the Unsharp Mask node and the Composite is acting as its image output.

    The Unsharp Mask node will instantly apply the sharpening effect once inserted into the network in the Node view.

    You can also use a matte to apply the effect to certain areas. See Using a Matte.

    NOTE You will only be able to see the effect in the Render view.

Unsharp Mask Node Layer Properties

The Unsharp Mask Node will instantly apply the effect once it is inserted into the network in the Node view. The strength and overall effect can be adjusted in the Unsharp Mask Node Layer Properties. To access the Layer Properties, you need to click the yellow square on the Unsharp Mask Node.

There are three options that can be adjusted in the Unsharp Mask Node. The three options are the following:

  • Amount: The overall strength of the effect on the final image.

  • Radius: The level of blur on the underlying mask.

  • Threshold: The level of tonal contrast between surrounding pixels.

These three parameters will dictate the strength, range and appearance of the effect in a scene.

You also have the ability to adjust the quality of the preview render, the truck factor and any mattes that may be applied.

The Quality option allows you to choose between low and high quality for the test render. For the final render you always want a high quality but not necessarily while you are working. To keep heavier scenes from lagging when the effect is applied, it can be beneficial to see your render previews with the low quality option selected.

The truck factor is a useful option when there is a camera move in your scene. When the option is activated, enlarging your shot would enlarge the properties of the effect too. It would give the illusion that the camera is moving through the scene as opposed to appearing like a flat zoom.

The inverse matte option will only apply if a matte is linked to the Unsharp Mask Node. When this option is enabled, the effect is applied to the transparent areas of the matte instead of the area where the stroke is made in the matte drawing.

For more information on the Unsharp Mask Node Layer Properties, see Properties.

Using the Unsharp Mask Node

The Unsharp Mask Node is an ideal tool when you want to apply a sharpening effect in a scene. Its effect can be used to increase the sharpness of a bitmap image, apply rack focus or give emphasis to an object in your scene.

In the example below, the fire pit is emphasized in the scene, the Unsharp Mask Node is applied to that asset to make it sharper than the rest of the objects in the image.

To use the Unsharp Mask Node, it just needs to be installed into the network chain in the Node view. To see the effect applied, you need to render the scene in the Render view.

NOTE The changes applied will not be visible in the Camera view in OpenGL.

Using a Matte

On the leftmost side of the Unsharp Mask Node is an optional Matte input. By adding an image to this input, you can create a matte. This matte can be used to isolate an area for the effect to be applied. The advantage of using a matte is that you can sharpen specific details in an image to give it emphasis.

The matte-image input can be any node providing an image with a valid alpha channel. The matte is applied based on the transparency of the incoming pixels.

In the example below, the tent has been isolated in the Matte drawing.

As a result, the tent is sharpened while the rest of the scene remains untouched.

Like all mattes, the Unsharp Mask Node has the option to invert the matte drawing. This can be activated by checking Invert Matte in the Unsharp Mask Layer Properties or clicking the mask icon. Once active, the area surrounding the stroke will be affected, excluding the area with the stroke.

In the example below, the Invert Matte has been activated.

As a result, the entire scene has been sharpened excluding the tent which is drawn in the matte.