Question

为了安全起见，我正在使用MATLAB进行实时运动检测项目并生成警报。我创建了实时视频捕获代码并将其保存到AVI文件中，但我无法在代码运行时读取代码中的实时视频。运动检测无法正常工作。我用两个脚本完成了这个。两个脚本独立工作，但组合时不会读取实时输入。我使用的脚本发布在下面。

Enter code here 1. %code for reading and saving AVI file

function realtime_test()
    global movie name vid;
    % Define frame rate
    NumberFrameDisplayPerSecond=10;

    % Open figure
    hFigure=figure(1);

    % Set-up webcam video input

    vid = videoinput('winvideo', 1);

    % Set parameters for video
    % Acquire only one frame each time
    set(vid,'FramesPerTrigger',1);
    % Go on forever until stopped
    set(vid,'TriggerRepeat',Inf);
    % Get a grayscale image
    set(vid,'ReturnedColorSpace','rgb')
    vidRes = get(vid, 'VideoResolution');
    nBands = get(vid, 'NumberOfBands');
    hImage = imshow( zeros(vidRes(2), vidRes(1), nBands));
    preview(vid,hImage);
    triggerconfig(vid, 'Manual');

    % Set up timer object
    TimerData=timer('TimerFcn', {@FrameRateDisplay,vid},'Period',1/NumberFrameDisplayPerSecond,'ExecutionMode','fixedRate','BusyMode','drop');
    name = 'Realtime';
    movie=avifile(name,'compression','none');

    % Start video and timer object
    start(vid);
    start(TimerData);

    % We go on until the figure is closed
    uiwait(hFigure);

    % Clean up everything
    stop(TimerData);
    delete(TimerData);
    stop(vid);
    delete(vid);
    movie = close(movie);
    % Clear persistent variables
    clear functions;


% This function is called by the timer to display one frame of the figure

function FrameRateDisplay(obj, event,vid)
    global movie frame;

    frame=uint8(getsnapshot(vid));
    movie=addframe(movie,frame);
    persistent IM;
    persistent handlesRaw;
    persistent handlesPlot;
    trigger(vid);
    IM=getdata(vid,1,'uint8');

    if isempty(handlesRaw)
       % if first execution, we create the figure objects
       subplot(2,1,1);
       handlesRaw=imagesc(IM);
       title('CurrentImage');

       % Plot first value
       Values=mean(IM(:));
       subplot(2,1,2);
       handlesPlot=plot(Values);
       title('Average of Frame');
       xlabel('Frame number');
       ylabel('Average value (au)');
    else
       % We only update what is needed
       set(handlesRaw,'CData',IM);
       Value=mean(IM(:));
       OldValues=get(handlesPlot,'YData');
       set(handlesPlot,'YData',[OldValues Value]);
    end

2.％运动检测代码

% This m-file implements the frame difference algorithm for background
% subtraction.

clear all;
close all;

% source = aviread('live.avi');
%source = aviread('test.avi');
%--------------------------------------------------------------------------
[filename, pathname] = uigetfile( ...
   {'*.avi;*.mpg;*.mpeg;.*flv','Video Files (*.avi,*.mpg,*.mpeg,.*flv)';
   '*.*',  'All Files (*.*)'}, ...
  'Select a video file');

mov = mmreader(fullfile(pathname,filename));
implay(filename);
source = aviread(filename);
%--------------------------------------------------------------------------

thresh = 50;

bg = source(1).cdata;           % Read in 1st frame as background frame
bg_bw = rgb2gray(bg);           % Convert background to greyscale

% ----------------------- Set frame size variables -----------------------
fr_size = size(bg);
width = fr_size(2);
height = fr_size(1);
fg = zeros(height, width);

% --------------------- Process frames -----------------------------------

for i = 2:45
    fr = source(i).cdata;       % Read in frame
    fr_bw = rgb2gray(fr);       % Convert frame to grayscale

    fr_diff = abs(double(fr_bw) - double(bg_bw));  % Cast operands as double to avoid negative overflow

    for j=1:width                 % If fr_diff > thresh pixel in foreground
        for k=1:height
            if ((fr_diff(k,j) > thresh))
                fg(k,j) = fr_bw(k,j);

                disp('motion detected');

                %------------------------- Executes alarm ---------------------------------

                  t = 15;
                  Fs = 50;
                  [t,Fs] = wavread('Blip.wav');
                  player = audioplayer(t,Fs);
                  play(player);

                %--------------------------------------------------------------------------
            else
                fg(k,j) = 0;
            end
        end
        disp('motion not detected');
    end

    bg_bw = fr_bw;

    %figure(1), subplot(3,1,1), imshow(fr)
    subplot(3,1,2),imshow(fr_bw)
    subplot(3,1,3),imshow(uint8(fg))
    figure,imshow(uint8(fr_diff))

    %M(i-1)  = im2frame(uint8(fg),gray);        % Put frames into movie
end
fps = 15;
%movie2avi(M,'frame_difference_output', 'fps', 30);           % Save movie as AVI

Answer 1

您可以使用vid = videoinput（'winvideo'，1）直接阅读您的实时网络摄像头，而不是在第二段代码中阅读源代码。我认为它将满足您的要求。试试。

Answer 2

当您出于安全目的这样做时，我猜近实时应该足够好。这是一个应该有效的流程。请注意，我提到的实体可以是线程，cpu甚至是计算机，无论你喜欢什么。

实体1：记录一个短片段并保存（例如每5秒）
实体2：经常检查最新的片段并对其进行分析，包括在需要时发送信号。（例如每秒）

根据我提出的时间，您将无法获得实时结果，但延迟应限制为最多6秒。

使用MATLAB实时运动检测和报警生成

2 个答案: