wolffd@0: function [overlap, normoverlap] = rectintSparseC(A,B)
wolffd@0: %
wolffd@0: % function [area, normarea] = rectintSparseC(A,B)
wolffd@0: % A(i,:) = [x y w h]
wolffd@0: % B(j,:) = [x y w h]
wolffd@0: % out(i,j) = area of intersection
wolffd@0: %
wolffd@0: % Same as built-in rectint, but uses less memory.
wolffd@0: % Also, returns area of overlap normalized by area of patch.
wolffd@0: % See rectintSparse
wolffd@0: 
wolffd@0: if isempty(A) | isempty(B)
wolffd@0:   overlap = [];
wolffd@0:   normoverlap = [];
wolffd@0:   return;
wolffd@0: end
wolffd@0: 
wolffd@0: leftA = A(:,1);
wolffd@0: bottomA = A(:,2);
wolffd@0: rightA = leftA + A(:,3);
wolffd@0: topA = bottomA + A(:,4);
wolffd@0: 
wolffd@0: leftB = B(:,1)';
wolffd@0: bottomB = B(:,2)';
wolffd@0: rightB = leftB + B(:,3)';
wolffd@0: topB = bottomB + B(:,4)';
wolffd@0: 
wolffd@0: numRectA = size(A,1);
wolffd@0: numRectB = size(B,1);
wolffd@0: 
wolffd@0: verbose = 0;
wolffd@0: [overlap, normoverlap] = rectintSparseLoopC(leftA, rightA, topA, bottomA, leftB, rightB, topB, bottomB, verbose);