I never thought that I could draw a sketch some day, but today, I make my dream come true.
1. Open a photo in photoshop cs2 (or other version), duplicate layer as "layer 1";
3. Activate Layer 2
(1) Image --> Adjustments -->Invert;
(3) modify blending options --> general blending --> blend mode: color dodge;
(5) Choose brush tool，use Normal mode and set the color of foreground as black, its opacity is 2% and flow is 100%, highlight the characteristic part, then raise opacity to 5%, highlight eye, eyebrow and slash; then change the color of foreground to white, clean the background of photo with brush.
5. Adjust brightness/contrast and curves to have a bright color and sharp curve.
7. Make a signature.