Direct3D Rendering Cookbook

Detecting edges with the Sobel edge-detection filter

In this recipe we will implement a single pass 3x3 Sobel convolution filter. This is the first convolution filter we will look at that does not implement a simple "sum of products" calculation as well as not being separable.

To keep things simple, this implementation has not undergone the same level of optimization as the separable convolution filter compute shaders; however, it would be a fairly simple task to modify it to work with the group-shared memory approach.

Getting ready

This recipe makes use of the constant buffer and the lerpKeepAlpha function that we implemented in the Adjusting the contrast and brightness recipe.

You will also use the LUMINANCE #define macro we created in the Running ...