Fan

This transformation lets you distort an image into the shape of a fan, i.e. with upper and lower boundaries in the shape of circular arcs and with straight sides. You can adjust the curvature of the resulting image and the background color. This transformation usually works best with images that are somewhat wider than they are tall. The upper half of the image is expanded and the lower half is compressed -- the scale of the horizontal mid-line of the image is preserved.

To get a full circle, the input image must be at least π times as wide as it is tall. If the image is wider than this, you will not be able to reduce the inner radius all the way to zero as this would compress the image mid-line, so if you want a full circle with a zero inner radius you need to crop the input image to the proportions of π to 1.0 beforehand.

Background Color

This color control lets you specify the color of the border around the edges of the fan. If you want more background, you can widen the borders using the Crop/Add Border transformation.

Inner Radius

The inner radius slider lets you adjust how sharply the input image is bent. Larger values leave the image more or less rectangular while larger values distort the image to make it more circular.

As you decrease the inner radius, the output image becomes larger.