Horn and schunck Combine gradient constraint with a global smoothness term, minimizing 「(Vv+4)2+(+)k n=0.5 instead of 2=100 Ⅰ(Ⅰv+Ⅰ uk+=ukx v=10=0 a2+2+ k+1 k(1n+1v+1) a2+2+ⅠHorn and Schunck • Combine gradient constraint with a global smoothness term, minimizing ( ) ( ) 2 2 2 2 D t 2 2   + +  +  I I u v d   v x 0 0 v u = = 0 1 222 1 222 ( ) ( ) k k k k x x y t x y k k k k y x y t x y I I u I v I u u I I I I u I v I v v I I   + + + + = − + + + + = − + +   = = 0.5 instead of 100