convolution2d.asv

convolution with matlab

in=[0 0 0 0 0 0 ;0 0 0 1 0 0;0 0 0 0 0 0];
kernel=[1 0;0 0];
rows=size(in,1);
cols=size(in,2);
kRows=size(kernel,1);
kCols=size(kernel,2);

% find center position of kernel (half of kernel size)
kCenterX = uint16(kCols / 2;
kCenterY = uint16(kRows / 2;

for i=1:1:rows              %// rows
    for j=1:1:cols
        sum = 0;  
        out(i,j)=0;
        for m=1:1:kRows
            mm = kRows - 1 - m;
            for n=1:1:kCols
                nn = kCols - 1 - n;
                %// index of input signal, used for checking boundary
                ii = i + (m - kCenterY);
                jj = j + (n - kCenterX);
                %// ignore input samples which are out of bound
                if  (ii >= 1) && (ii <= rows) && (jj >= 1) && (jj <= cols) 
                    out(i,j) =out(i,j)+ in(ii,jj) * kernel(mm,nn);
                end
            end
        end
   end
end
[out]