goldsteinunwrap2d.m

a usefull source code from internet

function out=GoldsteinUnwrap2D(IM)

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% GoldsteinUnwrap2D implements 2D Goldstein branch cut phase unwrapping algorithm.
%
% References::
% 1. R. M. Goldstein, H. A. Zebken, and C. L. Werner, Satellite radar interferometry:
%    Two-dimensional phase unwrapping, Radio Sci., vol. 23, no. 4, pp. 713�720, 1988.
% 2. D. C. Ghiglia and M. D. Pritt, Two-Dimensional Phase Unwrapping:
%    Theory, Algorithms and Software. New York: Wiley-Interscience, 1998.
%
% Inputs: 1. Complex image in .mat double format
%         2. Binary mask (optional)          
% Outputs: 1. Unwrapped phase image
%          2. Phase quality map
%
% This code can easily be extended for 3D phase unwrapping.
% Posted by Bruce Spottiswoode on 22 December 2008
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Edited by K. Van Caekenberghe on 17/03/2009
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

IM_mask=ones(size(IM));                     %Mask (if applicable)
IM_mag=abs(IM);                             %Magnitude image
IM_phase=angle(IM);                         %Phase image

%%  Set parameters
max_box_radius=4;                           %Maximum search box radius (pixels)
threshold_std=5;                            %Number of noise standard deviations used for thresholding the magnitude image

%% Unwrap
residue_charge=PhaseResidues(IM_phase, IM_mask);                            %Calculate phase residues
branch_cuts=BranchCuts(residue_charge, max_box_radius, IM_mask);            %Place branch cuts
[IM_unwrapped, rowref, colref]=FloodFill(IM_phase, branch_cuts, IM_mask);   %Flood fill phase unwrapping
tempmin=min(min(IM_unwrapped));
temp=(IM_unwrapped==0);
temp_IM=IM_unwrapped;
temp_IM(temp)=tempmin;
out=temp_IM;