Estimate Homography to do 2D to 3D integration (10): Extract known points in pairs automatically

I. Re-making color markers because of the unstable result in last week

   - Modified the size: 150x150 pixels in circle
   - Choose recognizable colors via eye-tracker (...which has lower brightness):
                yellow (255, 255, 0);
                red (255, 0, 0);
                light_blue (0; 255, 255);
                green (0, 255, 0)


II. Testing videos

     1. Simple cases (zoom, tilt, viewpoint_change)

     2. Real cases (only show 3 of 4)

III. Experimental results

     1. Simple cases:
    
          - In zoom and tile cases... 1 to 3 pixels in average, 5 to 8 pixels is the worst

          - In viewpoint_change case... 1 to 5 pixels in average, 8 to 12 pixels is the worst
 

 IV. Real-time demo

      - Now, the whole system can execute by directly reading video from a USB Webcam
      - Reading recording videos to run the whole system is not the only choice
      - Issue: delay time while running... because of the massive computation in our proposed system (EPnP -> Ray_tracing)
      - The issue is not the major issue currently, but can try to improve it