使用Matlab重新建立新的特征点'；视觉功能

我使用Matlab的内置视觉功能和预先制作的示例代码来跟踪特征点。在我的示例视频中，相机水平平移，将新对象和景物引入视野，而以前的对象和景物移出视野

当摄影机在场景中平移时，尝试识别新的特征点时会出现问题。我在视频步进循环中使用“detectMinEigenFeatures”功能，以便在经过指定数量的帧后查找新的特征点。但是，这样做对重新建立新的特征点毫无帮助

一些快速信息：使用GoPro视频，采样至720p并保存为.avi

代码发布在下面，我很乐意提供更多的信息来帮助理解或解决这个问题

谢谢

clc;clear all;close all;

videoFileReader = vision.VideoFileReader('GoProFlyingMidFlightResized.avi');

videoFrame = step(videoFileReader);

%Create Video writer
TrackingVideo = VideoWriter('TrackingVideo.avi');

open(TrackingVideo);

% Detect feature points
points = detectMinEigenFeatures(rgb2gray(videoFrame),'MinQuality',0.04,'FilterSize',3);
% points = detectMinEigenFeatures(rgb2gray(videoFrame));

% Create a point tracker
pointTracker = vision.PointTracker('NumPyramidLevels',7,'MaxBidirectionalError', 8, 'MaxIterations',70,'BlockSize',[5 5]);

% Initialize the tracker with the initial point locations and the initial
% video frame.
points = points.Location;
initialize(pointTracker, points, videoFrame);

videoPlayer  = vision.VideoPlayer('Position',[100 100 [size(videoFrame, 2), size(videoFrame, 1)]+30]);

% Make a copy of the points for transformation between the consecutive feature points
oldPoints = points;
FrameCount=0; %For identifying that new feature points must be obtain

while ~isDone(videoFileReader)
    % get the next frame
    FrameCount=FrameCount+1;
    videoFrame = step(videoFileReader);

    if FrameCount==30  %If 30 frame have stepped though, find new feature points
        disp('help')
        points = detectMinEigenFeatures(rgb2gray(videoFrame),'MinQuality',0.04,'FilterSize',3);
        points = points.Location;
        FrameCount=0;
    end

    % Track the points.
    [points, isFound] = step(pointTracker, videoFrame);
    visiblePoints = points(isFound, :);
    oldInliers = oldPoints(isFound, :);

    if size(visiblePoints, 1) >= 2 % need at least 2 points

        % Estimate the geometric transformation between the old points
        % and the new points and eliminate outliers
        [xform, oldInliers, visiblePoints] = estimateGeometricTransform(oldInliers,   visiblePoints, 'similarity', 'MaxDistance', 10);

        % Display tracked points
        videoFrame = insertMarker(videoFrame, visiblePoints, '+','Color', 'red');

        % Reset the points
        oldPoints = visiblePoints;
        setPoints(pointTracker, oldPoints);
    end

    % Display video frame using the video player
    writeVideo(TrackingVideo,videoFrame);
    step(videoPlayer, videoFrame);
end

% Clean up
release(videoFileReader);
release(videoPlayer);
release(pointTracker);
close(TrackingVideo);

---

在if语句中，检测到新点：

    if FrameCount==30  %If 30 frame have stepped though, find new feature points
        disp('help')
        points = detectMinEigenFeatures(rgb2gray(videoFrame),'MinQuality',0.04,'FilterSize',3);
        points = points.Location;
        FrameCount=0;
    end

setPoints(tracker, points);

现在，在相同的

if

中，您必须告诉点跟踪器有关这些新点的信息：

    if FrameCount==30  %If 30 frame have stepped though, find new feature points
        disp('help')
        points = detectMinEigenFeatures(rgb2gray(videoFrame),'MinQuality',0.04,'FilterSize',3);
        points = points.Location;
        FrameCount=0;
    end

setPoints(tracker, points);

否则，变量

点

将被下一行覆盖：

[points, isFound] = step(pointTracker, videoFrame);

---

这就是为什么您从未看到新检测到的点。

谢谢Dima，这确实是问题所在。我感谢你的帮助！不客气。我很好奇，8是点跟踪器的

'MaxBidirectionalError'

参数的合理值吗？你不觉得这样会有很多不好的音轨吗？确实是这样，但这只是为了测试的目的，让我对这个特定视频的属性敏感度有一个很好的了解。我使用2进行实际的测试运行。