Algorithm 2. Mismatch Elimination Based on Matching Direction

1. Calculate the matching direction of each match.

2. Encode every match using its matching direction.

3. For every code, count the number of matches with this code to create the histogram of matching direction.

4. Find the maximum value of histogram $M_1$ and the secondary maximum value $M_2$.

5. If $M_1>\alpha \cdot M_2$, save the matches with code of the maximum; otherwise, abandon all.