1
)
∑
s
=
i
−
n
i
n
∑
k
=
j
−
m
j
m
f
(
s
,
k
)
M(i,j)=\frac{1}{(2n+1)(2m+1)}\sum_{s=i-n}{i+n}\sum_{k=j-m}{j+m}f(s,k)
M(i,j)=(2n+1)(2m+1)1s=i−n∑i+nk=j−m∑j+mf(s,k)
σ
2
(
i
,
j
)
=
1
(
2
n
1
)
(
2
m
1
)
∑
s
=
i
−
n
i
n
∑
k
=
j
−
m
j
m
(
f
(
s
,
k
)
−
M
(
i
,
j
)
)
2
\sigma {2}(i,j)=\frac{1}{(2n+1)(2m+1)}\sum_{s=i-n}{i+n}\sum_{k=j-m}{j+m}(f(s,k)-M(i,j)){2}
σ2(i,j)=(2n+1)(2m+1)1s=i−n∑i+nk=j−m∑j+m(f(s,k)−M(i,j))2
上述式子中,
f
(
s
,
k
)
f(s,k)
f(s,k)代表坐标为
(
s
,
k
<