cbir_cosinedist.m

matlab编程

function dist = CBIR_cosinedist(x1, x2)
% EE6850 HW3, Content-Based Image Retrieval
% CBIR_cosinedist() --- Cosine distance of a given feature vector pair
% input:
%   feature vector x1 and x2 (1xN)
% output:
%    their cosine distance (0~1)
% 10-24-2001, [e-mail]

if sum(size(x1)==size(x2))~=2
    error('To calculate cosine distance, matrix dimension must agree');
end

costheta = sum(x1(:).*x2(:))/...
    sqrt( x1(:)'*x1(:) * x2(:)'*x2(:));

dist = acos(costheta)*2/pi;