idst2(A)

Calculate the inverse sine transform of 2D matrix A

function out = idst2(A)
% Calculate the inverse sine transform of 2D matrix A
N = length(A) + 1;
U = zeros(N,N);
for i = 1:N
for j = 1:N
holder = 0;
for m = 1:length(A)
for n = 1:length(A)
holder = holder + ...
A(m,n) * ...
sin(pi * m * (i-1) / (N - 1)) * ...
sin(pi * n * (j-1) / (N - 1));
end
end
U(i,j) = holder;
end
end
out = U;