Question

我有以下代码：

a = imaqhwinfo;
%[camera_name, camera_id, format] = getCameraInfo(a);


% Capture the video frames using the videoinput function
% You have to replace the resolution & your installed adaptor name.
% vid = videoinput('winvideo', 1);
vid = VideoReader('C:\VHDL Project\VHDL Course\Logtel\Image processing\Sacramento Kings vs Golden State Warriors.mp4')

% Set the properties of the video object
set(vid, 'FramesPerTrigger', Inf);
set(vid, 'ReturnedColorspace', 'rgb')
vid.FrameGrabInterval = 5;

%start the video aquisition here
start(vid)

% Set a loop that stop after 100 frames of aquisition
while(vid.FramesAcquired<=200)

    % Get the snapshot of the current frame
    data = getsnapshot(vid);

    % Now to track red objects in real time
    % we have to subtract the red component 
    % from the grayscale image to extract the red components in the image.
    diff_im = imsubtract(data(:,:,1), rgb2gray(data));
    %Use a median filter to filter out noise
    diff_im = medfilt2(diff_im, [3 3]);
    % Convert the resulting grayscale image into a binary image.
    diff_im = im2bw(diff_im,0.18);

    % Remove all those pixels less than 300px
    diff_im = bwareaopen(diff_im,300);

    % Label all the connected components in the image.
    bw = bwlabel(diff_im, 8);

    % Here we do the image blob analysis.
    % We get a set of properties for each labeled region.
    stats = regionprops(bw, 'BoundingBox', 'Centroid');

    % Display the image
    imshow(data)

    hold on

    %This is a loop to bound the red objects in a rectangular box.
    for object = 1:length(stats)
        bb = stats(object).BoundingBox;
        bc = stats(object).Centroid;
        rectangle('Position',bb,'EdgeColor','r','LineWidth',2)
        plot(bc(1),bc(2), '-m+')
        a=text(bc(1)+15,bc(2), strcat('X: ', num2str(round(bc(1))), '    Y: ', num2str(round(bc(2)))));
        set(a, 'FontName', 'Arial', 'FontWeight', 'bold', 'FontSize', 12, 'Color', 'yellow');
    end

    hold off
end
% Both the loops end here.

% Stop the video aquisition.
stop(vid);

% Flush all the image data stored in the memory buffer.
flushdata(vid);

% Clear all variables
clear all
sprintf('%s','That was all about Image tracking, Guess that was pretty easy :) ')

我尝试读取MP4文件，运行它并找到红色对象。不幸的是，该工具会弹出以下错误：

使用VideoReader / set

时出错

名称＆＃39; FramesPerTrigger＆＃39;不是类＆＃39; VideoReader＆＃39;的实例的可访问属性。

RedObjectTracking错误（第11行）

设置（vid，＆＃39; FramesPerTrigger＆＃39;，Inf）;

如果有人可以告诉我我的错误

，我会很高兴

感谢您的帮助。

Answer 1

如果您查看the documentation for VideoReader，您会看到（如您的错误所示）FramesPerTrigger未列为有效财产。基于FramesPerTrigger FramesPerTrigger，它是一个仅用于图像采集工具箱中的视频设备的属性（类似于之前在线上注释的more of the documentation。所以当您仅使用通过VideoReader输入的视频文件时，您尝试设置VideoReader值的行不应该存在。

这也是有道理的，因为您的图像采集系统将具有触发器，并且MATLAB知道每个触发器要抓取多少帧是很重要的。另一方面，视频文件（VideoReader打算处理）没有触发器，并且文件本身可以随时获得帧信息。

根据您的代码，您认为只是将videoinput替换为function add_copyright_text() { if (is_single()) { ?> <script type='text/javascript'> function addLink() { if ( window.getSelection().containsNode( document.getElementsByClassName('post')[0], true)) { var body_element = document.getElementsByTagName('body')[0]; var selection; selection = window.getSelection(); var oldselection = selection; var pagelink = "<br /><br /> Read full forex article here: <?php the_title(); ?> <a href='<?php echo get_permalink(get_the_ID()); ?>'><?php echo get_permalink(get_the_ID()); ?></a>"; //Change this if you like var copy_text = selection + pagelink; var new_div = document.createElement('div'); new_div.style.left='-99999px'; new_div.style.position='absolute'; body_element.appendChild(new_div ); new_div.innerHTML = copy_text ; selection.selectAllChildren(new_div ); window.setTimeout(function() { body_element.removeChild(new_div ); },0); } } document.oncopy = addLink; </script> <?php } } add_action( 'wp_head', 'add_copyright_text');，但这不起作用，因此您的代码中有很多点会导致错误。

名称＆＃39; FramesPerTrigger＆＃39;对于类＆＃39; VideoReader＆＃39;的实例而言，它不是可访问的属性。

1 个答案: