Where does matrix B fits best in Matrix A

I have a matrix A (200x200) and a matrix B (200x50).

I want to know now where B fits best in A. Maybe the nearest neighbour method can help?

Here an example what I mean:

[Stephen23]

@Lucas Kellermann: do you have the Image Processing toolbox?

[Lucas Kellermann]

Yes

[Stephen23]

@Lucas Kellermann: does the "best fit" require 100% overlap, or can the "best fit" occur over the matrix edges?

For example, where is the "best fit" for these matrices?:

A = [999,999,999,999;999,999,999,999;999,999,1,1;999,999,1,1]

A = 4×4

999 999 999 999 999 999 999 999 999 999 1 1 999 999 1 1

B = [1,1,1;1,1,1;1,1,1]

B = 3×3

1 1 1 1 1 1 1 1 1

[Lucas Kellermann]

I have to do both but first step is an 100% overlap.

Answer 1

[KSSV]

A = 5*ones(8) ;
A(4:6,4:6) = [3 4 2; 1 1 1; 2 3 3] ;
B = ones(3) ;

[m,n] = size(A) ;
count = 0 ; 
v = zeros(3,3,[]) ; 
R = zeros([],1) ; 
for i = 1:3:(m-3)
    for j = 1:3:(n-4)
        count = count+1 ;
        M = A(i:(i+3-1),j:(j+3-1)) ; 
        v(:,:,count) = M ; 
        R(count) = sqrt(mean((M(:) - B(:)).^2)) ;
    end
end
[val,idx] = min(R) ;
iwant = v(:,:,idx)

iwant = 3×3

3 4 2 1 1 1 2 3 3