Estimate Homography to do 2D to 3D integration (17): Extract known points in pairs automatically

I. Draft code for compute "Precision and Accuracy" of these 5 videos of demo:

    [ Precision Part ]
    * There are 8 rows in the picture marked "Precision".  Each of them are corresponding to 1 color marker
    * The order of these color markers are: yellow, red, blue, green
    * Precision_2D_PPAF is related to the precision in 2D; Precision_3D_PPAF is related to 3D

    [ Accuracy Part ]
    * There are 4 rows of 2 "ans" in the picture marked "Accuracy".  Each of them are corresponding to 1 color marker
    * The order of these color markers are: yellow, red, blue, green
    * nframes: total frames in that video which are used for experiments (including the 1st initial frames, but in the following computation, the 1st frame is not included)
    * The information of accuracy_2D includes the following stuffs:
       - 1 column: offset <= 3 pixels in 2D, after executing "2D-to-3D Re-projection" computation
       - 2 column: offset <= 5 pixels
       - 3 column: offset <= 8 pixels
       - 4 column: offset <= 10 pixels
       - 5 column: offset <= 15 pixelsi
       - 6 column: offset <= 20 pixels
       - 7 column: offset > 20 pixels



   - Zoom:

Precision: 1st 4 values of ans are in 2D, 2nd 4 values of ans are in 3D

Accuracy: offset of 4 color markers [ <=3 pixels | <=5 pixels | <=8 pixels | <=10 pixels | <=15 pixels | <=20 pixels | >20 pixels ]

   - Viewpoint_change:

Precision: 1st 4 values of ans are in 2D, 2nd 4 values of ans are in 3D

Accuracy: offset of 4 color markers [ <=3 pixels | <=5 pixels | <=8 pixels | <=10 pixels | <=15 pixels | <=20 pixels | >20 pixels ]

   - Tilt:

Precision: 1st 4 values of ans are in 2D, 2nd 4 values of ans are in 3D

Accuracy: offset of 4 color markers [ <=3 pixels | <=5 pixels | <=8 pixels | <=10 pixels | <=15 pixels | <=20 pixels | >20 pixels ]

   - Real case 2:

Precision: 1st 4 values of ans are in 2D, 2nd 4 values of ans are in 3D

Accuracy: offset of 4 color markers [ <=3 pixels | <=5 pixels | <=8 pixels | <=10 pixels | <=15 pixels | <=20 pixels | >20 pixels ]

   - Real case 3:

Precision: 1st 4 values of ans are in 2D, 2nd 4 values of ans are in 3D

Accuracy: offset of 4 color markers [ <=3 pixels | <=5 pixels | <=8 pixels | <=10 pixels | <=15 pixels | <=20 pixels | >20 pixels ]