Motion Based multi object tracking

Subscripted assignment between dissimilar structures.

Error in MotionBasedMultiObjectTracking/createNewTracks (line 130)

tracks(end + 1)= newTrack;

Error in MotionBasedMultiObjectTracking (line 15)

createNewTracks();

this is the error Im getting----- and I've also attached the code please help.....!

function MotionBasedMultiObjectTracking()

obj = setupSystemObjects();

tracks = initializeTracks();

nextId=1;

while ~isDone(obj.reader)

frame=readFrame();

[centroids,bboxes,mask]=detectObjects(frame);

predictNewLocationOfTracks();

[assignments,unassignedTracks,unassignedDetections] = ...

detectionToTrackAssignment();

updateAssignedTracks();

updateUnassignedTracks();

deleteLostTracks();

createNewTracks();

displayTrackingResults();

end

function obj = setupSystemObjects()

obj.reader=vision.VideoFileReader('test.avi');

obj.maskPlayer=vision.VideoPlayer('Position',[740, 400, 700,400]);

obj.videoPlayer=vision.VideoPlayer('Position',[20, 400, 700, 400]);

obj.detector = vision.ForegroundDetector('NumGaussians',3,...

'NumTrainingFrames',40,'MinimumBackgroundRatio',0.7);

obj.blobAnalyser = vision.BlobAnalysis('BoundingBoxOutputPort',true,...

'AreaOutputPort',true,'CentroidOutputPort',true,...

'MinimumBlobArea',400);

end

function tracks = initializeTracks()

tracks = struct(...

'id',{},...

'bbox',{},...

'kalmanFilter',{},...

'age',{},...

'totalVisibleCount',{},...

'consecutiveInvisibleCount',{});

end

function frame= readFrame()

frame = obj.reader.step;

end

function [centroids, bboxes, mask] = detectObjects(frame)

mask = obj.detector.step(frame);

mask= imopen(mask,strel('rectangle',[3,3]));

mask= imclose(mask,strel('rectangle',[15, 15]));

mask= imfill(mask,'holes');

[~,centroids,bboxes]=obj.blobAnalyser.step(mask);

end

function predictNewLocationOfTracks()

for i=1:length(tracks)

bbox=tracks(i).bbox;

predictedCentroid = predict(tracks(i).kalmanFilter);

tracks(i).bbox=[predictedCentroid,bbox(3:4)];

end

end

function [assignments,unassignedTracks,unassignedDetections]=...

detectionToTrackAssignment()

nTracks = length(tracks);

nDetections = size(centroids,1);

cost=zeros(nTracks,nDetections);

for i=1:nTracks

cost(1,:)=distance(tracks(i).kalmanFilter,centroids);

end

costOfNonAssignment =20;

[assignments,unassignedTracks,unassignedDetections]=...

assignDetectionsToTracks(cost,costOfNonAssignment);

end

function updateAssignedTracks()

numAssignedTracks=size(assignments,1);

for i =1:numAssignedTracks

trackIdx=assignments(i,1);

detectionIdx=assignments(i,2);

centroid=centroids(detectionIdx,:);

bbox=bboxes(detectionIdx,:);

correct(tracks(trackIdx).kalmanFilter,centroid);

tracks(trackIdx).bbox=bbox;

tracks(trackIdx).age=tracks(trackIdx).age + 1;

tracks(trackIdx).totalVisbleCount=...

tracks(trackIdx).totalVisibleCount + 1;

tracks(trackIdx).consecutiveInvisibleCount = 0;

end

end

function updateUnassignedTracks()

for i=1:length(unassignedTracks)

ind=assignedTracks(i);

tracks(ind).age=tracks(ind).age+1;

tracks(ind).consecutiveInvisibleCount=...

tracks(ind).consecutiveInvisibleCount+1;

end

end

function deleteLostTracks()

if isempty(tracks)

return

end

invisibleForTooLong = 20;

ageThreshold = 8;

ages=[tracks(:).age];

totalVisibleCounts = [tracks(:).totalVisibleCount];

visibility = totalVisibleCounts ./ ages;

lostInds = (ages < ageThreshold & visibility <0.6) | ...

[tracks(:).consecutiveInvisibleCount] >=invisibleForTooLong;

tracks = tracks(~lostInds);

end

function createNewTracks()

centroids = centroids(unassignedDetections,:);

bboxes = bboxes(unassignedDetections,:);

for i = 1:size(centroids, 1)

centroid = centroids(1,:);

bbox=bboxes(i,:);

kalmanFilter = configureKalmanFilter('ConstantVelocity',...

centroid,[200, 50],[100, 25],100);

newTrack = struct(...

'id',nextId,...

'bbox',bbox,...

'kalmanFilter',kalmanFilter,...

'age',1,...

'totalVisibleCount',1,...

'consecutiveInvisibleCount',0);

tracks(end + 1)= newTrack;

nextId = nextId + 1;

end

end

function displayTrackingResults()

frame = im2uint8(frame);

mask = uint8(repmat(mask,[1, 1, 3])) .* 225;

minVisibleCount = 8;

if ~isempty(tracks)

reliableTrackInds = ...

[tracks(:).totalVisibleCount] > minVisibleCount;

reliableTracks = tracks(reliableTrackInds);

if ~isempty(reliableTracks)

bboxes = cat(1,reliableTracks.bbox);

ids=int32([reliableTracks(:).id]);

labels = cellstr(int2str(ids'));

predictedTracksInds = ...

[reliableTracks(:).consecutiveInvisbleCount] > 0;

isPredicted = cell(size(labels));

isPredicted(predictedTracksInds) = {'predicted'};

labels = strcat(labels,isPredicted);

frame = insertObjectAnnotation(frame,'rectangle',...

bboxes,labels);

mask = insertObjectAnnotation(mask,'rectangle',...

bboxes,labels);

end

end

obj.maskPlayer.step(mask);

obj.videoPlayer.step(frame);

end

end