how to use the below code to embed and extract the fragile watermark

clc; clear all; close all; I = imread('circuit.tif'); corners = detectFASTFeatures(I,'MinContrast',0.1); J = insertMarker(I,corners,'circle'); imshow(J)

original = imread('cameraman.tif'); figure; imshow(original);

scale = 1.3; J = imresize(original,scale); theta = 31; distorted = imrotate(J,theta); figure imshow(distorted)

ptsOriginal = detectSURFFeatures(original); ptsDistorted = detectSURFFeatures(distorted);

[featuresOriginal,validPtsOriginal] = ... extractFeatures(original,ptsOriginal); [featuresDistorted,validPtsDistorted] = ... extractFeatures(distorted,ptsDistorted);

        indexPairs = matchFeatures(featuresOriginal,featuresDistorted);

        matchedOriginal  = validPtsOriginal(indexPairs(:,1));
matchedDistorted = validPtsDistorted(indexPairs(:,2));

figure showMatchedFeatures(original,distorted,matchedOriginal,matchedDistorted) title('Candidate matched points (including outliers)')

[tform, inlierDistorted,inlierOriginal] = ... estimateGeometricTransform(matchedDistorted,... matchedOriginal,'similarity');

            figure
showMatchedFeatures(original,distorted,inlierOriginal,inlierDistorted)
title('Matching points (inliers only)')
legend('ptsOriginal','ptsDistorted')

outputView = imref2d(size(original)); recovered = imwarp(distorted,tform,'OutputView',outputView);

figure imshowpair(original,recovered,'montage')

original = imread('cameraman.tif'); figure; imshow(original); text(size(original,2),size(original,1)+15, ... 'Image courtesy of Massachusetts Institute of Technology', ... 'FontSize',7,'HorizontalAlignment','right');

scale = 1.3; J = imresize(original, scale);

theta = 31; distorted = imrotate(J,theta); figure imshow(distorted)

ptsOriginalBRISK = detectBRISKFeatures(original,'MinContrast',0.01); ptsDistortedBRISK = detectBRISKFeatures(distorted,'MinContrast',0.01);

ptsOriginalSURF = detectSURFFeatures(original); ptsDistortedSURF = detectSURFFeatures(distorted);

[featuresOriginalFREAK,validPtsOriginalBRISK] = ... extractFeatures(original,ptsOriginalBRISK); [featuresDistortedFREAK,validPtsDistortedBRISK] = ... extractFeatures(distorted,ptsDistortedBRISK);

[featuresOriginalSURF,validPtsOriginalSURF] = ... extractFeatures(original,ptsOriginalSURF); [featuresDistortedSURF,validPtsDistortedSURF] = ... extractFeatures(distorted,ptsDistortedSURF);

    indexPairsBRISK = matchFeatures(featuresOriginalFREAK,...
            featuresDistortedFREAK,'MatchThreshold',40,'MaxRatio',0.8);

indexPairsSURF = matchFeatures(featuresOriginalSURF,featuresDistortedSURF);

matchedOriginalBRISK = validPtsOriginalBRISK(indexPairsBRISK(:,1)); matchedDistortedBRISK = validPtsDistortedBRISK(indexPairsBRISK(:,2));

matchedOriginalSURF = validPtsOriginalSURF(indexPairsSURF(:,1)); matchedDistortedSURF = validPtsDistortedSURF(indexPairsSURF(:,2));

figure showMatchedFeatures(original,distorted,matchedOriginalBRISK,... matchedDistortedBRISK) title('Putative matches using BRISK & FREAK') legend('ptsOriginalBRISK','ptsDistortedBRISK')

matchedOriginalXY = ... [matchedOriginalSURF.Location; matchedOriginalBRISK.Location]; matchedDistortedXY = ... [matchedDistortedSURF.Location; matchedDistortedBRISK.Location];

[tformTotal,inlierDistortedXY,inlierOriginalXY] = ... estimateGeometricTransform(matchedDistortedXY,... matchedOriginalXY,'similarity');

    figure
showMatchedFeatures(original,distorted,inlierOriginalXY,inlierDistortedXY)
title('Matching points using SURF and BRISK (inliers only)')
legend('ptsOriginal','ptsDistorted')

outputView = imref2d(size(original)); recovered = imwarp(distorted,tformTotal,'OutputView',outputView);

figure; imshowpair(original,recovered,'montage')

[John D'Errico]

Contact the author. You got the code from someone. So ask that person.