v01

thirdparty/opengv/matlab/helpers/create2D2DExperiment.m

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+function [v1, v2, t, R ] = create2D2DExperiment( pt_number, cam_number, noise, outlier_fraction )
+
+%% generate the camera system
+
+avg_cam_distance = 0.5;
+cam_offsets = zeros(3,cam_number);
+%cam_rotations = zeros(3,cam_number*3);
+
+if cam_number == 1
+    cam_offsets = zeros(3,1);
+    %cam_rotations = eye(3);
+else
+    for i=1:cam_number
+        cam_offsets(:,i) = avg_cam_distance * generateRandomR() * [1.0; 0.0; 0.0];
+        %cam_rotations(:,(i-1)*3+1:(i-1)*3+3) = generateRandomR();
+    end
+end
+
+%% generate random view-points
+
+max_parallax = 2.0;
+max_rotation = 0.5;
+
+position1 = zeros(3,1);
+rotation1 = eye(3);
+
+position2 = max_parallax * 2.0 * (rand(3,1) - repmat(0.5,3,1));
+rotation2 = generateBoundedR(max_rotation);
+
+%% Generate random point-cloud
+
+minDepth = 4.0;
+maxDepth = 8.0;
+
+normalizedPoints = 2.0*(rand(3,pt_number)-repmat(0.5,3,pt_number));
+norms = sqrt(sum(normalizedPoints.*normalizedPoints));
+directions = normalizedPoints./repmat(norms,3,1);
+points = (maxDepth-minDepth) * normalizedPoints + minDepth * directions;
+
+%% Now create the correspondences by looping through the cameras
+
+focal_length = 800.0;
+
+v1 = zeros(6,pt_number);
+v2 = zeros(6,pt_number);
+cam_correspondence = 1;
+cam_correspondences = zeros(1,pt_number);
+
+for i=1:pt_number
+    
+    cam_offset = cam_offsets(:,cam_correspondence);
+    %cam_rotation = cam_rotations(:,(cam_correspondence-1)*3+1:(cam_correspondence-1)*3+3);
+    
+    body_point1 = rotation1' * (points(:,i)-position1);
+    body_point2 = rotation2' * (points(:,i)-position2);
+    
+    % we actually omit the can rotation here by unrotating the bearing
+    % vectors already
+    bearingVector1 = body_point1 - cam_offset;
+    bearingVector2 = body_point2 - cam_offset;
+    bearingVector1_norm = norm(bearingVector1);
+    bearingVector2_norm = norm(bearingVector2);
+    bearingVector1 = bearingVector1/bearingVector1_norm;
+    bearingVector2 = bearingVector2/bearingVector2_norm;
+    
+    % add noise to the bearing vectors here
+    bearingVector1_noisy = addNoise(bearingVector1,focal_length,noise);
+    bearingVector2_noisy = addNoise(bearingVector2,focal_length,noise);
+    
+    % store the normalized bearing vectors along with the cameras they are
+    % being seen (we create correspondences that always originate from the
+    % same camera, you can change this if you want)
+    bearingVector1_norm = norm(bearingVector1_noisy);
+    bearingVector2_norm = norm(bearingVector2_noisy);
+    
+    v1(:,i) = [bearingVector1_noisy./bearingVector1_norm; cam_offset];
+    v2(:,i) = [bearingVector2_noisy./bearingVector2_norm; cam_offset];
+    
+    % change the camera correspondence
+    cam_correspondences(1,i) = cam_correspondence;
+    cam_correspondence = cam_correspondence + 1;
+    if cam_correspondence > cam_number
+        cam_correspondence = 1;
+    end
+end
+
+%% Add outliers
+number_outliers = floor(outlier_fraction*pt_number);
+
+if number_outliers > 0
+for i=1:number_outliers
+    
+    cam_correspondence = cam_correspondences(1,i);
+    
+    cam_offset = cam_offsets(:,cam_correspondence);
+    %cam_rotation = cam_rotations(:,(cam_correspondence-1)*3+1:(cam_correspondence-1)*3+3);
+    
+    %generate random point
+    normalizedPoint = 2.0*(rand(3,1)-repmat(0.5,3,1));
+    norm1 = sqrt(sum(normalizedPoint.*normalizedPoint));
+    direction = normalizedPoint./norm1;
+    point = (maxDepth-minDepth) * normalizedPoint + minDepth * direction;
+    
+    body_point2 = rotation2' * (point-position2);
+    
+    % store the point (no need to add noise)
+    bearingVector2 = body_point2 - cam_offset;
+    
+    % store the normalized bearing vectors along with the cameras they are
+    % being seen (we create correspondences that always originate from the
+    % same camera, you can change this if you want)
+    bearingVector2_norm = norm(bearingVector2);
+    
+    v2(:,i) = [bearingVector2./bearingVector2_norm; cam_offset];
+end
+end
+
+%% compute relative translation and rotation
+
+R = rotation1' * rotation2;
+t = rotation1' * (position2 - position1);
+
+%% Cut the cam offset in the single camera case (e.g. central)
+
+if cam_number == 1
+    v1 = v1(1:3,:);
+    v2 = v2(1:3,:);
+end