Linear Blur

This transformation blurs an image in one direction.

Clicking on the input image display centers the 1:1 preview on the location you clicked on, or you can click and drag to scroll the preview window.

Amount

The amount control lets you control how much of the blur transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Radius

The larger the radius, the more blurred the result.

Angle

This compass control lets you specify the direction of the blur. There is an angle readout (in degrees) just to the right of the compass control.

Preview

A 1:1 preview of the blur effect is displayed in the right-hand side of the dialog box. Clicking on the input image display centers the preview on the location you clicked on, or you can click and drag to scroll the preview window.

If you enlarge the dialog box, you can make the sliders wider and the preview area narrower or vice versa by dragging the vertical separator line between them.

 Preview Button

Clicking the Preview button causes the full output image to be recalculated, not just the preview area. This can be useful if you want to view the entire image at once and not just a small section, but it can take longer to compute.