MATLAB: Invalid indexing operation- drawing epipolar lines

Question

Hello

I am creating Stereo images processing project modeled on Matlab's examples. A copy pasted code from one of them not works well.

    I1 = rgb2gray(imread('viprectification_deskLeft.png'));
    I2 = rgb2gray(imread('viprectification_deskRight.png'));
    points1 = detectHarrisFeatures(I1);
    points2 = detectHarrisFeatures(I2);
    [features1, valid_points1] = extractFeatures(I1, points1);
    [features2, valid_points2] = extractFeatures(I2, points2);
    indexPairs = matchFeatures(features1, features2);
    matchedPoints1 = valid_points1(indexPairs(:, 1),:);
    matchedPoints2 = valid_points2(indexPairs(:, 2),:);
    figure; showMatchedFeatures(I1, I2, matchedPoints1, matchedPoints2);
 load stereoPointPairs
 [fLMedS, inliers] = estimateFundamentalMatrix(matchedPoints1,matchedPoints2,'NumTrials',4000);
 figure;
 subplot(121); imshow(I1);
 title('Inliers and Epipolar Lines in First Image'); hold on;
 plot(matchedPoints1(inliers,1), matchedPoints1(inliers,2), 'go');

An error:

Error using epilineTest (line 23) Invalid indexing operation.

Best regards

EDIT:// I deleted if/end, this was unnecessary

Answer 1

IT WORKS! So a conversion to arrays of double is done. Thank you for help! My full-working code:

I1 = rgb2gray(imread('viprectification_deskLeft.png'));
I2 = rgb2gray(imread('viprectification_deskRight.png'));
points1 = detectHarrisFeatures(I1);
points2 = detectHarrisFeatures(I2);
[features1, valid_points1] = extractFeatures(I1, points1);
[features2, valid_points2] = extractFeatures(I2, points2);
%Use the sum of absolute differences (SAD) metric to determine indices of matching features.
indexPairs = matchFeatures(features1, features2);
%Retrieve locations of matched points for each image
matched_points1 = valid_points1(indexPairs(:, 1), :);
matched_points2 = valid_points2(indexPairs(:, 2), :);
[fLMedS, inliers] = estimateFundamentalMatrix(matched_points1, matched_points2, 'NumTrials', 4000);
%%%%conversion of matched_points1 to matrix
sS = 13;
xm1 = matched_points1.selectStrongest(sS);
m1 = zeros(sS,2,'double');
newInliners = logical(sS);
wielCP = size(matched_points1);
wielCP = wielCP(1,1);
for y = 1:sS
  am1 = xm1(y);
  m1(y,1) = am1.Location(1,1);
  m1(y,2) = am1.Location(1,2);
    for z = 1 : wielCP
        b = matched_points1(z);
        temp_a1 = am1.Location(1,1);
        temp_a2 = am1.Location(1,2);
        temp_b1 = b.Location(1,1);
        temp_b2 = b.Location(1,2);
        if temp_a1 == temp_b1 && temp_a2 == temp_b2
            newInliners(y) = inliers(z);
        end
    end
  end
newInliners = newInliners';
%%%%conversion of matched_points2 to matrix
xm2 = matched_points2.selectStrongest(sS);
m2 = zeros(sS,2,'double');
for y = 1:sS
  am2 = xm2(y);
  m2(y,1) = am2.Location(1,1);
  m2(y,2) = am2.Location(1,2); 
end
%%%%%%%%
figure;
subplot(121); imshow(I1);
title('Inliers and Epipolar Lines in First Image'); hold on;
plot(m1(newInliners,1), m1(newInliners,2), 'go')
% Compute the epipolar lines in the first image.
epiLines = epipolarLine(fLMedS', m2(newInliners, :));
% Compute the intersection points of the lines and the image border.
pts = lineToBorderPoints(epiLines, size(I1));
% Show the epipolar lines in the first image
line(pts(:, [1,3])', pts(:, [2,4])');
% Show the inliers in the second image.
subplot(122); imshow(I2); title('Inliers and Epipole Lines in Second Image'); hold on;
plot(m2(newInliners,1), m2(newInliners,2), 'ro')
% Compute and show the epipolar lines in the second image.
epiLines = epipolarLine(fLMedS, m1(newInliners, :));
pts = lineToBorderPoints(epiLines, size(I2));
line(pts(:, [1,3])', pts(:, [2,4])');
truesize;