function?PhiUnwrap?=?cunwrap（Psi?options）
%?PhiUnwrap?=?cunwrap（Psi?options）
%
%?Purpose:?Costantini‘s?2D?unwrapping?based?on?Minimum?Network?Flow
%
%?INPUTS:
%???-?Psi:?2D-array?wrapped?phase?（radian）
%???-?options:?optional?structure?used?to?modify?the?behavior?of?the?
%??????????????unwrapping?algorithm.?All?fields?are?optional.
%??????????????The?fieldname?does?not?need?to?exactly?case-matched.
%???????Weight:?array?of?same?dimension?as?the?Psi?with?is?used?as
%???????????????the?positive?weight?of?the?L1?norm?of?the?residual?（to?be
%???????????????minimized）.?For?example?user?can?provide?WEIGHT?as?function
%???????????????of?the?interference?amplitude?or?function?of?phase
%???????????????measurement?quality?（e.g.?fringe?contrast）.
%???????????????By?default:?all?internal?pixels?have?the?same?weight?of?1
%???????????????0.5?for?edge-pixels?and?0.25?for?corner-pixels.?
%???????CutSize:?even?integer?scalar?default?[4]:?the?width?（in?pixel）?of
%????????????????the?Gaussian?kernel?use?to?lower?the?weight?around?pixels
%????????????????that?do?not?fulfill?rotational?relation.
%????????????????If?CutSize?is?0?no?rotational-based?weighting?will?be
%????????????????carried?out.
%???????RoundK:?Boolean?[false]?by?default.?When?ROUNDK?is?true?CUNWRAP
%???????????????forces?the?partial?derivative?residuals?K1/K2?to?be
%???????????????integers.
%???????MaxBlockSize:?scalar?default?[125]?target?linear?blocksize.
%?????????????????????Set?to?Inf?for?single-block?global?unwrapping.
%?????????????????????Note:?network?flow?is?costly?in?CPU?for?large?size.
%???????Overlap:?scalar?default?[0.25]?fractional?overlapping?between?two
%????????????????neighboring?blocks.
%???????Verbose:?logical?[true]?control?printout?information.
%???????LPoption:?LINPROG?option?structure?as?return?by?OPTIMSET（...）.
%?OUTPUT:
%???-?Phi:?2D-array?unwrapped?phase?（radian）
%
%?Minimum?network?flow?computation?engine?is?Matlab?LINPROG?（optimization
%???toolbox?is?required）
%
%?References:
%???-?http://earth.esa.int/workshops/ers97/papers/costantini/
%???-?Costantini?M.?（1998）?A?novel?phase?unwrapping?method?based?on?network
%???programming.?IEEE?Tran.?on?Geoscience?and?Remote?Sensing?36?813-821.
%
%?Author:?Bruno?Luong?
%?History:
%???Orginal:?27-Aug-2009
%???????28-Aug-2009:?modification?in?block?splitting?default?size?changes
%????????????????????to?125?x?125
%???????28-Aug-2009:?correct?a?serious?indexing?bug

if?nargin<2
????options?=?struct（）;
end

if?ndims（Psi）>2
????error（‘CUNWRAP:?input?Psi?must?be?2D?array.‘）;
end

[ny?nx]?=?size（Psi）;

if?nx<2?||?ny<2
????error（‘CUNWRAP:?size?of?Psi?must?be?larger?than?2‘）;
end

roundK?=?getoption（options?‘roundk‘?false）;

verbose?=?getoption（options?‘verbose‘?true）;

%?Default?weight
w1?=?ones（ny1）;?w1（[1?end]）?=?0.5;
w2?=?ones（1nx）;?w2（[1?end]）?=?0.5;
weight?=?w1*w2;?%?tensorial?product
weight?=?getoption（options?‘weight‘