COMPASSEDGE_BASE - Base function for COMPASSEDGE.

Contents

Syntax

   [S, O, A, U] = COMPASSEDGE_BASE(I, R, Angles, wedges, gray);

Acknowledgment

This function calls the mex functions implemented in the original [COMPASS] code by Ruzon & Tomasi (available at http://ai.stanford.edu/~ruzon/compass/).

See also

Ressembles: COMPASSEDGE, EDGECORNER_BASE, CANNYEDGE_BASE, ROTHWELLEDGE_BASE, CONGRUENCYEDGE_BASE, ANISOEDGE_BASE, ELDERZUCKEREDGE_BASE, KOETHEDGE_BASE, SDGDEDGE_BASE, PETROUEDGE_BASE. Requires: GREYCOMPASS_MEX, COMPASS_MEX.

Function implementation

function [S, O, A, U] = compassedge_base(I, R, Angles, wedges, gray)

dealing with multichannel images

C = size(I,3);

if C>1 && (C~=3 || (C==3 && islogical(gray) && gray))
    % process channel by channel
    S = zeros(size(I));
    if nargout>=2, varargout{1}= cell(C,1);
        if nargout>=3, varargout{2} = zeros(size(I));
            if nargout==4, varargout{3} = cell(C,1); end
        end
    end
    for c=1:C
        [S(:,:,c), O, A, U] = ...
            compassedge_base(I(:,:,c), R, Angles, wedges, gray);
        if nargout>=2, varargout{1}{c} = O;
            if nargout>=3, varargout{2}(:,:,c) = A;
                if nargout==4, varargout{3}{c} = U; end
            end
        end
    end
    return;

end

run the mex files

maxradius = ceil(3 * R); % see functions compass_mex.c & compass.c
A = padarray(I,[maxradius maxradius],'replicate','both');

% check  again the size of the input image
C = size(I,3);

% default parameters
spc = 1; % spacing at each scale
Is = 0; % the compass operator is applied on the entire image.

if C==3
    [S, O, A, U] = compass_mex(A, R, spc, Is, Angles, wedges);

else % note that we have necessarly C=1 at this stage
     [S, O, A, U] = greycompass_mex(A, R, spc, Is, Angles, wedges);
end

refine outputs

S = S(1:end-1,1:end-1);
A = A(1:end-1,1:end-1);
O = O(1:end-1,1:end-1,:);
U = U(1:end-1,1:end-1,:);

end % end of compassedge_base