This filter will emboss an image. It's an implementation of an algorithm described in Graphics Gems. It looks at each pixel in the image, calculates the gradient of brightness and from that, a normal to the surface. It then shades the pixel according to the direction of the normal compared with a light source. You can vary the azimuth and elevation of the light source and you can also make the filter texture your image by multiplying in some of the source image. In the picture, the word "Embossing" is embossed in three different ways. On the left is the original image, next is simple embossing, next the text was blurred before embossing and finally the texturing option is used.