Algorithm 1
The method of producing the palm mask.
Input: A Group of points sampled uniformly from the circle  Find the nearest boundary point of one sampled point (refer to (1))  Step 1. Acquire a pixel around the sample point    angle and rad ( is the image size)  Step 2. If the value of the pixel is 0 i.e. ,  goto Step 3. Otherwise, increase and with a step of 1 and then go to Step 1  Step 3. Check the values of 8 neighbors of the pixel , if it holds  ,  is the set of 8 neighbors of the pixel .  Insert the point into the array of palm mask points.  Step 4. Increase and , and then goto Step 1  (i) Continue to search the nearest boundary point of another sampled point until all  the sampled points are scanned.  (ii) Connect all the points recorded in the array of palm mask points to yield the palm mask. 
