Bas Relief

The Bas Relief effect makes an image appear as if it has been carved in low relief and lit to show the surface modulations.

By default, this effect produces a monochrome (gray-scale) image.

Name	Specifies the operator's name.
Opacity	Sets the opacity of the effect over the input image. A value of 0 makes the effect completely transparent, while a value of 100 makes it completely opaque.
Use Alpha As Mask	Uses the input image's alpha channel as a mask for applying the effect. The effect is fully applied to areas of the image where the alpha channel is white, and not at all to areas where it is black.
Run Effect On	Enable the RGB and/or Alpha options to specify whether the effect is applied to the RGB channels, the Alpha channel, or both.
Detail	Set higher values to have the resulting image surface contain more detail, or set lower values for less detail.
Light Position	Select the direction from which to illuminate the image. Changing the light position will highlight different carved areas.
Smoothness	Set higher values for an overall smoother surface, or set lower values to retain more detail.
Background Color	Sets the color for background regions of the effect. Set a color using the sliders.
Foreground Color	Sets the color for foreground regions of the effect. Set a color using the sliders.