序贯航迹关联算法Matlab代码

以下是一个简单的基于Matlab的序贯航迹关联算法的实现示例：

function [assignments, unassignedTracks, unassignedDetections] = ...
    detectionToTrackAssignment(costMatrix, costOfNonAssignment)
 
    % 初始化输入参数
    [numTracks, numDetections] = size(costMatrix);
    assignments = zeros(1, numTracks);
    unassignedTracks = [];
    unassignedDetections = [];
    
    % 对于每个跟踪器，选择最小代价的检测，并将其分配给该跟踪器
    [cost, trackIndices] = min(costMatrix, [], 2);
    for i = 1:numTracks
        % 如果最小代价大于阈值，则认为该跟踪器未匹配到检测
        if cost(i) > costOfNonAssignment
            unassignedTracks = [unassignedTracks i];
        else
            assignments(i) = trackIndices(i);
        end
    end
    
    % 对于未分配的检测，选择最小代价的跟踪器，并将其分配给该检测
    unassignedDetections = find(assignments==0);
    for i = unassignedDetections
        [~, trackIndex] = min(costMatrix(:,i));
        if cost(trackIndex) <= costOfNonAssignment
            assignments(trackIndex) = i;
        else
            unassignedTracks = [unassignedTracks trackIndex];
        end
    end
end

function tracks = updateAssignedTracks(assignments,centroids,bboxes,scores,tracks)
 
    numAssignedTracks = size(assignments, 2);
    for i = 1:numAssignedTracks
        trackIdx = assignments(1, i);
        detectionIdx = assignments(2, i);
        centroid = centroids(detectionIdx, :);
        bbox = bboxes(detectionIdx, :);
        score = scores(detectionIdx);
 
        % 更新跟踪器状态
        tracks(trackIdx).centroid = centroid;
        tracks(trackIdx).bbox = bbox;
        tracks(trackIdx).score = score;
        tracks(trackIdx).age = tracks(trackIdx).age + 1;
        tracks(trackIdx).consecutiveInvisibleCount = 0;
    end
end

function tracks = updateUnassignedTracks(unassignedTracks,tracks)
 
    for i = 1:length(unassignedTracks)
        ind = unassignedTracks(i);
        tracks(ind).age = tracks(ind).age + 1;
        tracks(ind).consecutiveInvisibleCount = ...
            tracks(ind).consecutiveInvisibleCount + 1;
    end
end

function [tracks,nextId] = createNewTracks(unassignedDetections,centroids,bboxes,scores,tracks,nextId)
 
    centroids = centroids(unassignedDetections, :);
    bboxes = bboxes(unassignedDetections, :);
    scores = scores(unassignedDetections);
    
    for i = 1:size(centroids, 1)
 
        centroid = centroids(i,:);
        bbox = bboxes(i, :);
        score = scores(i);
 
        % 创建一个新跟踪器
        newTrack = struct(...
            'id', nextId, ...
            'centroid', centroid, ...
            'bbox', bbox, ...
            'score', score, ...
            'age', 1, ...
            'consecutiveInvisibleCount', 0);
        
        % 将新跟踪器添加到跟踪器列表
        tracks(end + 1) = newTrack;
 
        % 增加下一个可用ID
        nextId = nextId + 1;
    end
end

function [tracks, nextId] = deleteLostTracks(tracks, nextId)
 
    if isempty(tracks)
        return;
    end
 
    invisibleForTooLong = 20;
    ageThreshold = 8;
 
    ages = [tracks(:).age]';
    totalVisibleCounts = [tracks(:).totalVisibleCount]';
    visibility = totalVisibleCounts ./ ages;
 
    % 删除连续不可见时间超过阈值或者可见次数超过阈值但是跟踪时间太短的跟踪器
    lostInds = (ages >= ageThreshold & visibility < 0.6) | ...
        [tracks(:).consecutiveInvisibleCount]' >= invisibleForTooLong;
 
    % 删除跟踪器列表中对应的跟踪器
    tracks = tracks(~lostInds);
end

function displayTrackingResults(frame, tracks)
 
    % 分别绘制每个跟踪器的轨迹和边框
    for i = 1:length(tracks)
        if tracks(i).age > 1
            % 获取跟踪器的中心点和边框
            centroid = tracks(i).centroid;
            bbox = tracks(i).bbox;
            score = tracks(i).score;
 
            % 绘制跟踪器轨迹
            plot(centroid(1), centroid(2), 'g.', 'MarkerSize', 10);
            text(bbox(1), bbox(2)-20, sprintf('%.1f',score),'BackgroundColor',[.7 .9 .7],'FontSize',6);
            if size(bbox,1)==4
            bbox = [bbox(1),bbox(2),bbox(3)-bbox(1),bbox(4)-bbox(2)];
        end
        rectangle('Position', bbox, 'EdgeColor', 'g', 'LineWidth', 2);
        end
    end
 
    % 显示帧
    imshow(frame);
end

这段代码实现了一个简单的目标跟踪器，使用序贯航迹关联算法将每个帧中的检测结果与之前跟踪的目标进行匹配。完整的示例代码可以在MathWorks网站上找到。