An Open Source Alternative

Following Meg's suggestion, I have explored open source alternative approaches to converting a photograph into an underdrawing.

In addition to the Gimp, I used an open source HDR prgram, Qtpfsgui.

These are simply the results. I will publish detailed procedures later.

Open Source:

Photoshop:

After being imported into Painter and further adjusted, here's how they compare

Open Source:

Photoshop:

Remember, the particular differences between the two photos here probably suggest nothing about the inherent properties of the two approaches. Do not conclude that the Open Source would always be more robust or the Photoshop more refined. Both programs could be adjusted to produce differing results; and this is the first time I have ever attempted to transform via the Open Source approach. Rather, focus on the similarities between the and the feasibility of the Open Source option. Here's another, lighter Open Source version obtained by adjusting a few controls: