Difference of Gaussians

Difference Of Gaussians filter performs edge detection by rendering a Gaussian blur to an image at a specified theta (also known as sigma or standard deviation). The resulting image is a blurred version of the source image. Then the module performs another blur with a sharper theta that blurs the image less than previously. The final image is then calculated by replacing each pixel with the difference between the two blurred images and detecting when the values cross zero, i.e. negative becomes positive and vice versa. The resulting zero crossings will be focused on the edges or areas of pixels that have some variation in their surrounding neighborhood.

To use the Difference of Gaussians filter:

Choose Filters > Edges > Difference of Gaussians