DP for stitching

Theory

1. At each p(r, c),
2. for each shift d(dr, dc), there are
   
1. a corr score with the image being compared
2. a global cost value: the gap(row(i-1), row(i)). We want the gap < 0
   
3. #2 is under the assumptions:
1. after shift, for all rows, gap(row(i-1), row(i)) < 0;
   
2. from current FOV on, everything goes with 20% overlap, meaning a global corresponding d(dr, dc) shift for all of them.
3. maximize overall correlation
4. minimize cost