PhotoVCarve
PhotoVCarve is a specialist program designed to convert photographs and images into toolpaths that can be run on a CNC Router or Engraver. It has a simple wizard based interface that guides you through the process from loading an image to creating the toolpath.
There are two main ways to use the program either to create a line-etched image carving or a back-lit permanent picture known as a "lithophane". The software has an additional use to process specially created grey-scale height maps into simple 3D toolpaths.
You can download a Free Trial version of either version of the software from this page on the Vectric website: http://www.vectric.com/downloads/trial-software.html