%MATCHSHAPES  Compares two shapes
%
%    d = cv.matchShapes(object1, object2)
%    d = cv.matchShapes(object1, object2, 'OptionName', optionValue, ...)
%
% ## Input
% * __object1__ First contour or grayscale image. If it's contour, a cell array
%         of 2-element vectors or 1-by-N-by-2 numeric array are accepted.
% * __object2__ Second contour or grayscale image. If it's contour, a cell array
%         of 2-element vectors or 1-by-N-by-2 numeric array are accepted.
%
% ## Output
% * __d__ Output score.
%
% ## Options
% * __Method__ Comparison method. One of {'I1','I2','I3'}. default I1.
% * __Parameter__ Parameter value used in comparison.
%
% The function compares two shapes. All three implemented methods use the Hu
% invariants (see HuMoments() ) as follows (`A` denotes object1,`B` denotes
% object2):
%
%    'I1'    I_1(A,B) = \sum_{i=1,...,7} | 1/m_i^A - 1/m_i^B |
%    'I2'    I_2(A,B) = \sum_{i=1,...,7} | m_i^A - m_i^B |
%    'I3'    I_3(A,B) = \sum_{i=1,...,7} | m_i^A - m_i^B | / | m_i^A |
%
% where
%
%           m_i^A = sign(h_i^A) log h_i^A
%           m_i^B = sign(h_i^B) log h_i^B
%
% and `h_i^A`, `h_i^B` are the Hu moments of `A` and `B`, respectively.
%