Someone else linked the image and its original file name was "gimp-2.png" so it wasn't Photoshop :P Doing it in Gimp is easy. Load the image; Filters->Edge De

Someone else linked the image and its original file name was "gimp-2.png" so it wasn't Photoshop :P Doing it in Gimp is easy. Load the image; Filters->Edge Detect->Sobel