LC [n1,n2,...,n15]
n1: Lookup table to change <all>
n2: 100 times power to use <50>
Examples: n2= 50: square root
100: linear stretch
200: squaring
n3: Min. input <min. over image>
n4: Max. input <max. over image>
n5: Min. output <0>
n6: Max. output <255>
n7: Low end control (for when X < n3) <0>
0: F(X) = n5
1: F(X) = n6
2: leave F(X) alone
n8: High end control (for when X > n4) <0>
0: F(X) = n6
1: F(X) = n5
2: leave F(X) alone
n9: Graphic mask for sampling min. and <entire image>
max. input values
n10,n11: Window offset for sampling min. <0,0>
and max. input values
n12,n13: Window size for sampling min. and <rest of image>
max. input values
n14,n15: Percentage left and right trim for <2,2>
sampling min. and max. input values
-1: equal 0 (no trim)
Lookup table n1 is modified with the following power function:
F(X) = A*(X-n3)**P + n
where:
n3 <= X <= n4
P = n2/100
A is a scaling factor calculated such that
F(n3) = n5, and F(n4) = n6.
If n5 < n6, then F(X) is monotonically increasing. If n5 > n6, then
F(X) is monotonically decreasing.If the user types LC with no parameters, a square root enhancement is performed on all lookup tables.