fix: add option to use RANSAC to reject false matches

.gitignore

@@ -270,4 +270,5 @@ __pycache__/
 *.dll
 *.exe
 ~case-cuhk_lib/
-case*
+case*
+build

Stitching-1.1.0/RANSAC/SURF2.m

@@ -51,7 +51,7 @@
                 threshold = threshold - 10;                    
                 pNew = detectSURFFeatures(I, 'ROI', roi, 'MetricThreshold', threshold); 
             end
-            while nMore * 2 < size(pNew, 1) && threshold < 200;
+            while nMore * 2 < size(pNew, 1) && threshold < 200
                 threshold = threshold + 20;                    
                 pNew = detectSURFFeatures(I, 'ROI', roi, 'MetricThreshold', threshold);                     
             end

Stitching-1.1.0/RunStitching.m

@@ -25,12 +25,13 @@
 TracksPerFrame = 600; % # of trajectories in a frame
 TrackWindowSize = 40; % the window size for motion segmentation
 % ---------------
-MeshSize = 8; % The mesh size of bundled camera path, 5 - 10 is OK
-MaxIte = 15; % Number of iterations of the optimization scheme, 10 - 15 is OK
-Smoothness = 1; % adjust how stable the output is, 0.5 - 3 is OK
-Cropping = 1; % adjust how similar the result to the original video, usually set to 1;
-Stitchness = 20; % adjust the weight of stitching term, 10 - 30 is OK
+MeshSize = 8;                        % The mesh size of bundled camera path, 5 - 10 is OK
+MaxIte = 15;                         % Number of iterations of the optimization scheme, 10 - 15 is OK
+Smoothness = 3;                      % adjust how stable the output is, 1 - 4 is OK
+Cropping = 1;                        % adjust how similar the result to the original video, usually set to 1;
+Stitchness = 20;                     % adjust the weight of stitching term, 10 - 30 is OK
 SKIP_BACKGROUND_SEGMENTATION = true; % skip the background segmentation - treat all tracks as background.
+RANSAC = true;                       % use RANSAC to remove wrong sparse correspondences, set to true if overlap is small and stitch fails. 
 % ---------------
 OutputPadding = 500; % the padding around the video
 OutputPath = 'res_demo'; % the directory to store the output frames, auto create it if not exist
@@ -90,7 +91,7 @@
 %% Matching SIFT in every frame pair
 tic;
 if ~exist([data 'ControlPoints' int2str(PointsPerFrame) '.mat'], 'file')
-    [CP, ppf] = getControlPoints([data input_A], [data input_B], 500);
+    [CP, ppf] = getControlPoints([data input_A], [data input_B], PointsPerFrame, RANSAC);
     save([data 'ControlPoints' int2str(PointsPerFrame) '.mat'], 'CP', 'ppf');
 else
     load([data 'ControlPoints' int2str(PointsPerFrame) '.mat']);

Stitching-1.1.0/stitch/getControlPoints.m

@@ -1,10 +1,10 @@
-function [CP, ppf] = getControlPoints( input_A, input_B, maxppf )
+function [CP, ppf] = getControlPoints( input_A, input_B, maxppf, ransac)
     disp('Detecting and Matching SIFT features...');
     fileListA = dir(input_A);
     fileListA = fileListA(3:length(fileListA));
     fileListB = dir(input_B);
     fileListB = fileListB(3:length(fileListB));
-    nFrames = min(length(fileListA), length(fileListB))
+    nFrames = min(length(fileListA), length(fileListB));
     CP = zeros(nFrames, maxppf, 4);
     ppf = zeros(nFrames, 1);
     trackerA = vision.PointTracker('MaxBidirectionalError', 1);
@@ -14,113 +14,88 @@
         if mod(frameIndex, 20) == 0
             fprintf('\n') ;
         end
-        
+
         fileNameA = fileListA(frameIndex).name;
         fileNameB = fileListB(frameIndex).name;
         IA = imread([input_A fileNameA]);
         IB = imread([input_B fileNameB]);
-        
+
         [H, W, ~] = size(IA);
-        
+
         if frameIndex > 1
             setPoints(trackerA, trackA);
-            [trackAcont, validityA] = step(trackerA, IA);             
+            [trackAcont, validityA] = step(trackerA, IA);
             setPoints(trackerB, trackB);
-            [trackBcont, validityB] = step(trackerB, IB); 
+            [trackBcont, validityB] = step(trackerB, IB);
             trackAcont = trackAcont(validityA & validityB, :);
             trackBcont = trackBcont(validityA & validityB, :);
         end
-
-%         [~, ~, HH] = SURF(IA, IB);
-        HH = eye(3);
-%         IApre = imwarp(IA, projective2d(HH'), 'OutputView', imref2d(size(IA)));
-        IApre = IA;
-%         [trackApresift, trackBsift] = SIFT(IApre, IB);
-
-        [trackApresurf, trackBsurf] = SURF2(IApre, IB);
-%         trackerAB = vision.PointTracker('MaxBidirectionalError', 0.1);
-%         trackApre = getMorePoints(IApre, 20, 2000);
-%         initialize(trackerAB, trackApre, IApre);
-%         [trackB, validity] = step(trackerAB, IB);
-
-%         if length(trackB) > maxppf - length(trackBsurf)
-%             ordering = randperm(length(trackB));
-%             trackApre = trackApre(ordering(1:maxppf - length(trackBsurf)), :); 
-%             trackB = trackB(ordering(1:maxppf - length(trackBsurf)), :); 
-%             validity = validity(ordering(1:maxppf - length(trackBsurf)));
-%         end
-
-%         trackB = [trackB(validity, :); trackBsurf];
-%         trackApre = [trackApre(validity, :); trackApresurf];
+        if ransac
+            [trackAsurf, trackBsurf] = SURF(IA, IB);
+        else
+            [trackAsurf, trackBsurf] = SURF2(IA, IB);
+        end
 
-%         trackApre = [trackApresurf;trackApresift];
-%         trackB = [trackBsurf;trackBsift];
-        trackApre = trackApresurf;
+        trackA = trackAsurf;
         trackB = trackBsurf;
-        trackA = HH \ [trackApre' ; ones(1, length(trackApre))];
-        trackA(1, :) = trackA(1, :) ./ trackA(3, :);
-        trackA(2, :) = trackA(2, :) ./ trackA(3, :);
-        trackA = trackA(1:2, :);
-        trackA = trackA';
 
         valid = trackA(:, 1) > 0 & trackA(:, 1) < W & trackA(:, 2) > 0 & trackA(:, 2) < H ...
             & trackB(:, 1) > 0 & trackB(:, 1) < W & trackB(:, 2) > 0 & trackB(:, 2) < H;
+
         trackA = trackA(valid, :);
         trackB = trackB(valid, :);
-        
-%         valid = filtermask(IA, trackA);
-%         trackA = trackA(valid, :);
-%         trackB = trackB(valid, :);
-%         valid = filtermask(IB, trackB);
-%         trackA = trackA(valid, :);
-%         trackB = trackB(valid, :);
-        
+
+        valid = filtermask(IA, trackA);
+        trackA = trackA(valid, :);
+        trackB = trackB(valid, :);
+        valid = filtermask(IB, trackB);
+        trackA = trackA(valid, :);
+        trackB = trackB(valid, :);
+
         if frameIndex == 1
-            initialize(trackerA, trackA, IA); 
+            initialize(trackerA, trackA, IA);
             initialize(trackerB, trackB, IB);
         else
+            if length(trackA) + length(trackAcont) > maxppf
+                ordering = randperm(length(trackAcont));
+                trackAcont = trackAcont(ordering(1:maxppf - length(trackA)), :);
+                trackBcont = trackBcont(ordering(1:maxppf - length(trackA)), :);
+            end
             trackA = [trackA ; trackAcont];
             trackB = [trackB ; trackBcont];
         end
-        if length(trackA) > maxppf
-            ordering = randperm(length(trackA));
-            trackA = trackA(ordering(1:maxppf), :); 
-            trackB = trackB(ordering(1:maxppf), :); 
-        end
-
-%         IA = insertMarker(IA, trackA, 'o', 'color', 'red');
-%         IB = insertMarker(IB, trackB, 's', 'color', 'yellow');
-%         figure(1);
-%         imshow(IA);
-%         figure(2);
-%         imshow(IB);
-%         figure(3);
-%         imshow(IApre);
 
+        IA = insertMarker(IA, trackA, 'o', 'color', 'red');
+        IB = insertMarker(IB, trackB, 's', 'color', 'yellow');
+        figure(1);
+        imshow(IA);
+        figure(2);
+        imshow(IB);
+
         if length(trackA) > maxppf
             ppf(frameIndex) = maxppf;
             CP(frameIndex, :, 1:2) = trackA(1:maxppf, :);
             CP(frameIndex, :, 3:4) = trackB(1:maxppf, :);
         else
             ppf(frameIndex) = length(trackA);
             CP(frameIndex, 1:ppf(frameIndex), 1:2) = trackA;
-            CP(frameIndex, 1:ppf(frameIndex), 3:4) = trackB;            
+            CP(frameIndex, 1:ppf(frameIndex), 3:4) = trackB;
         end
 %         CP(frameIndex, :, :) = [featuresA featuresB; zeros(maxppf - ppf(frameIndex), 4)];
-        
+
     end
 end
 
 function valid = filtermask(frame, points_)
     [H, W, ~] = size(frame);
     valid = points_(:, 1) > 0 & points_(:, 1) < W & points_(:, 2) > 0 & points_(:, 2) < H;
-    points_ = points_(valid, :);    
+    points_ = points_(valid, :);
     mask = frame(:, :, 1) < 20 & frame(:, :, 2) < 20 & frame(:, :, 3) < 20;
     mask = imgaussfilt(double(mask), 50);
     videoH = size(frame, 1);
     mask(mask > 0.2) = 1;
     mask(mask ~= 1) = 0;
-    valid = mask(round(points_(:, 1) - 1) * videoH + round(points_(:, 2))) == 0;    
+    valid = mask(round(points_(:, 1) - 1) * videoH + round(points_(:, 2))) == 0;
 end
 
 

Stitching-1.1.0/stitch/getPath.m

@@ -12,7 +12,7 @@
 
     fileList = dir(input);
     fileList = fileList(3:length(fileList));
-    nFrames = length(fileList);
+    nFrames = tracks.nFrame;
     if nFrames < 2
         error('Wrong inputs') ;
     end
@@ -23,7 +23,7 @@
         end
     end
     fprintf('%5d', 1);
-    for frameIndex = 2:length(fileList)
+    for frameIndex = 2:nFrames
         fprintf('%5d', frameIndex);
         if mod(frameIndex, 20) == 0
             fprintf('\n') ;