1 | initial version |
What you basically are telling us is that you probably have a school assignment to implement this stuff on your computer and you want us to provide you with a solution. Because I think that people learn more by actually trying, I will set you on the right way.
The orientation map is created by looking at the rough surface of the finger. You want to create a representation of the most specific edges in the image.
So have a look into edge detection algorithms:
After you have segmented out edges, create a binary image from that. You could use the binary image to match linear Hough Transforms to detects lines, straight parts and see if that gets you anywhere.
http://docs.opencv.org/doc/tutorials/imgproc/imgtrans/hough_lines/hough_lines.html#hough-lines
Try some stuff out and report back with questions.