Files

1027 lines
25 KiB
HTML

<!DOCTYPE html>
<html class="theme-next mist use-motion" lang="zh-Hans">
<head>
<meta charset="UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1"/>
<meta name="theme-color" content="#222">
<meta http-equiv="Cache-Control" content="no-transform" />
<meta http-equiv="Cache-Control" content="no-siteapp" />
<link href="/lib/fancybox/source/jquery.fancybox.css?v=2.1.5" rel="stylesheet" type="text/css" />
<link href="/lib/font-awesome/css/font-awesome.min.css?v=4.6.2" rel="stylesheet" type="text/css" />
<link href="/css/main.css?v=5.1.4" rel="stylesheet" type="text/css" />
<link rel="apple-touch-icon" sizes="180x180" href="/images/apple-touch-icon-next.png?v=5.1.4">
<link rel="icon" type="image/png" sizes="32x32" href="/images/favicon-32x32-next.png?v=5.1.4">
<link rel="icon" type="image/png" sizes="16x16" href="/images/favicon-16x16-next.png?v=5.1.4">
<link rel="mask-icon" href="/images/logo.svg?v=5.1.4" color="#222">
<meta name="keywords" content="Hexo, NexT" />
<meta name="description" content="种一棵树最好的时间是十年前其次是现在">
<meta property="og:type" content="website">
<meta property="og:title" content="Cai MY&#39;s blog">
<meta property="og:url" content="https://c-my.github.io/index.html">
<meta property="og:site_name" content="Cai MY&#39;s blog">
<meta property="og:description" content="种一棵树最好的时间是十年前其次是现在">
<meta property="og:locale" content="zh-Hans">
<meta name="twitter:card" content="summary">
<meta name="twitter:title" content="Cai MY&#39;s blog">
<meta name="twitter:description" content="种一棵树最好的时间是十年前其次是现在">
<script type="text/javascript" id="hexo.configurations">
var NexT = window.NexT || {};
var CONFIG = {
root: '/',
scheme: 'Mist',
version: '5.1.4',
sidebar: {"position":"left","display":"post","offset":12,"b2t":false,"scrollpercent":false,"onmobile":false},
fancybox: true,
tabs: true,
motion: {"enable":true,"async":false,"transition":{"post_block":"fadeIn","post_header":"slideDownIn","post_body":"slideDownIn","coll_header":"slideLeftIn","sidebar":"slideUpIn"}},
duoshuo: {
userId: '0',
author: '博主'
},
algolia: {
applicationID: 'DUS4TVPYHE',
apiKey: '6d7f7739988e2ebdc24d007e30e7917b',
indexName: 'blog',
hits: {"per_page":10},
labels: {"input_placeholder":"Search for Posts","hits_empty":"We didn't find any results for the search: ${query}","hits_stats":"${hits} results found in ${time} ms"}
}
};
</script>
<link rel="canonical" href="https://c-my.github.io/"/>
<title>Cai MY's blog</title>
</head>
<body itemscope itemtype="http://schema.org/WebPage" lang="zh-Hans">
<div class="container sidebar-position-left
page-home">
<div class="headband"></div>
<header id="header" class="header" itemscope itemtype="http://schema.org/WPHeader">
<div class="header-inner"><div class="site-brand-wrapper">
<div class="site-meta ">
<div class="custom-logo-site-title">
<a href="/" class="brand" rel="start">
<span class="logo-line-before"><i></i></span>
<span class="site-title">Cai MY's blog</span>
<span class="logo-line-after"><i></i></span>
</a>
</div>
<p class="site-subtitle"></p>
</div>
<div class="site-nav-toggle">
<button>
<span class="btn-bar"></span>
<span class="btn-bar"></span>
<span class="btn-bar"></span>
</button>
</div>
</div>
<nav class="site-nav">
<ul id="menu" class="menu">
<li class="menu-item menu-item-home">
<a href="/" rel="section">
<i class="menu-item-icon fa fa-fw fa-home"></i> <br />
首页
</a>
</li>
<li class="menu-item menu-item-tags">
<a href="/tags/" rel="section">
<i class="menu-item-icon fa fa-fw fa-tags"></i> <br />
标签
</a>
</li>
<li class="menu-item menu-item-categories">
<a href="/categories/" rel="section">
<i class="menu-item-icon fa fa-fw fa-th"></i> <br />
分类
</a>
</li>
<li class="menu-item menu-item-archives">
<a href="/archives/" rel="section">
<i class="menu-item-icon fa fa-fw fa-archive"></i> <br />
归档
</a>
</li>
<li class="menu-item menu-item-search">
<a href="javascript:;" class="popup-trigger">
<i class="menu-item-icon fa fa-search fa-fw"></i> <br />
搜索
</a>
</li>
</ul>
<div class="site-search">
<div class="algolia-popup popup search-popup">
<div class="algolia-search">
<div class="algolia-search-input-icon">
<i class="fa fa-search"></i>
</div>
<div class="algolia-search-input" id="algolia-search-input"></div>
</div>
<div class="algolia-results">
<div id="algolia-stats"></div>
<div id="algolia-hits"></div>
<div id="algolia-pagination" class="algolia-pagination"></div>
</div>
<span class="popup-btn-close">
<i class="fa fa-times-circle"></i>
</span>
</div>
</div>
</nav>
</div>
</header>
<main id="main" class="main">
<div class="main-inner">
<div class="content-wrap">
<div id="content" class="content">
<section id="posts" class="posts-expand">
<article class="post post-type-normal" itemscope itemtype="http://schema.org/Article">
<div class="post-block">
<link itemprop="mainEntityOfPage" href="https://c-my.github.io/2018/04/08/利用OpenCV提取图像中的矩形区域(PPT屏幕等)/">
<span hidden itemprop="author" itemscope itemtype="http://schema.org/Person">
<meta itemprop="name" content="Cai.MY">
<meta itemprop="description" content="">
<meta itemprop="image" content="/images/avatar.gif">
</span>
<span hidden itemprop="publisher" itemscope itemtype="http://schema.org/Organization">
<meta itemprop="name" content="Cai MY's blog">
</span>
<header class="post-header">
<h1 class="post-title" itemprop="name headline">
<a class="post-title-link" href="/2018/04/08/利用OpenCV提取图像中的矩形区域(PPT屏幕等)/" itemprop="url">利用OpenCV提取图像中的矩形区域(PPT屏幕等)</a></h1>
<div class="post-meta">
<span class="post-time">
<span class="post-meta-item-icon">
<i class="fa fa-calendar-o"></i>
</span>
<span class="post-meta-item-text">发表于</span>
<time title="创建于" itemprop="dateCreated datePublished" datetime="2018-04-08T13:36:17+08:00">
2018-04-08
</time>
</span>
<span class="post-category" >
<span class="post-meta-divider">|</span>
<span class="post-meta-item-icon">
<i class="fa fa-folder-o"></i>
</span>
<span class="post-meta-item-text">分类于</span>
<span itemprop="about" itemscope itemtype="http://schema.org/Thing">
<a href="/categories/图像处理/" itemprop="url" rel="index">
<span itemprop="name">图像处理</span>
</a>
</span>
</span>
<span class="post-comments-count">
<span class="post-meta-divider">|</span>
<span class="post-meta-item-icon">
<i class="fa fa-comment-o"></i>
</span>
<a href="/2018/04/08/利用OpenCV提取图像中的矩形区域(PPT屏幕等)/#comments" itemprop="discussionUrl">
<span class="post-comments-count disqus-comment-count"
data-disqus-identifier="2018/04/08/利用OpenCV提取图像中的矩形区域(PPT屏幕等)/" itemprop="commentCount"></span>
</a>
</span>
<span id="/2018/04/08/利用OpenCV提取图像中的矩形区域(PPT屏幕等)/" class="leancloud_visitors" data-flag-title="利用OpenCV提取图像中的矩形区域(PPT屏幕等)">
<span class="post-meta-divider">|</span>
<span class="post-meta-item-icon">
<i class="fa fa-eye"></i>
</span>
<span class="post-meta-item-text">阅读次数&#58;</span>
<span class="leancloud-visitors-count"></span>
</span>
</div>
</header>
<div class="post-body" itemprop="articleBody">
<h2 id="前言"><a href="#前言" class="headerlink" title="前言"></a>前言</h2><p>最近参加了大创项目,题目涉及到计算机视觉,学姐发了个修正图像的博客链接,于是打算用这个题目入门OpenCV。</p>
<h2 id="分析问题"><a href="#分析问题" class="headerlink" title="分析问题"></a>分析问题</h2><p>照片中的PPT区域总是沿着x,y,z三个轴都有倾斜(如下图),要想把照片翻转到平行位置,需要进行透视变换,而透视变换需要同一像素点变换前后的坐标。由此可以想到,提取矩形区域四个角的坐标作为变换前的坐标,变换后的坐标可以设为照片的四个角落,经过投影变换,矩形区域将会翻转并充满图像。<br>
<!--noindex-->
<div class="post-button text-center">
<a class="btn" href="/2018/04/08/利用OpenCV提取图像中的矩形区域(PPT屏幕等)/#more" rel="contents">
阅读全文 &raquo;
</a>
</div>
<!--/noindex-->
</div>
<footer class="post-footer">
<div class="post-eof"></div>
</footer>
</div>
</article>
<article class="post post-type-normal" itemscope itemtype="http://schema.org/Article">
<div class="post-block">
<link itemprop="mainEntityOfPage" href="https://c-my.github.io/2018/04/08/hello-world/">
<span hidden itemprop="author" itemscope itemtype="http://schema.org/Person">
<meta itemprop="name" content="Cai.MY">
<meta itemprop="description" content="">
<meta itemprop="image" content="/images/avatar.gif">
</span>
<span hidden itemprop="publisher" itemscope itemtype="http://schema.org/Organization">
<meta itemprop="name" content="Cai MY's blog">
</span>
<header class="post-header">
<h1 class="post-title" itemprop="name headline">
<a class="post-title-link" href="/2018/04/08/hello-world/" itemprop="url">Hello World</a></h1>
<div class="post-meta">
<span class="post-time">
<span class="post-meta-item-icon">
<i class="fa fa-calendar-o"></i>
</span>
<span class="post-meta-item-text">发表于</span>
<time title="创建于" itemprop="dateCreated datePublished" datetime="2018-04-08T12:37:28+08:00">
2018-04-08
</time>
</span>
<span class="post-comments-count">
<span class="post-meta-divider">|</span>
<span class="post-meta-item-icon">
<i class="fa fa-comment-o"></i>
</span>
<a href="/2018/04/08/hello-world/#comments" itemprop="discussionUrl">
<span class="post-comments-count disqus-comment-count"
data-disqus-identifier="2018/04/08/hello-world/" itemprop="commentCount"></span>
</a>
</span>
<span id="/2018/04/08/hello-world/" class="leancloud_visitors" data-flag-title="Hello World">
<span class="post-meta-divider">|</span>
<span class="post-meta-item-icon">
<i class="fa fa-eye"></i>
</span>
<span class="post-meta-item-text">阅读次数&#58;</span>
<span class="leancloud-visitors-count"></span>
</span>
</div>
</header>
<div class="post-body" itemprop="articleBody">
<p>Welcome to <a href="https://hexo.io/" target="_blank" rel="noopener">Hexo</a>! This is your very first post. Check <a href="https://hexo.io/docs/" target="_blank" rel="noopener">documentation</a> for more info. If you get any problems when using Hexo, you can find the answer in <a href="https://hexo.io/docs/troubleshooting.html" target="_blank" rel="noopener">troubleshooting</a> or you can ask me on <a href="https://github.com/hexojs/hexo/issues" target="_blank" rel="noopener">GitHub</a>.</p>
<h2 id="Quick-Start"><a href="#Quick-Start" class="headerlink" title="Quick Start"></a>Quick Start</h2><h3 id="Create-a-new-post"><a href="#Create-a-new-post" class="headerlink" title="Create a new post"></a>Create a new post</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">$ hexo new <span class="string">"My New Post"</span></span><br></pre></td></tr></table></figure>
<p>More info: <a href="https://hexo.io/docs/writing.html" target="_blank" rel="noopener">Writing</a></p>
<h3 id="Run-server"><a href="#Run-server" class="headerlink" title="Run server"></a>Run server</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">$ hexo server</span><br></pre></td></tr></table></figure>
<p>More info: <a href="https://hexo.io/docs/server.html" target="_blank" rel="noopener">Server</a></p>
<h3 id="Generate-static-files"><a href="#Generate-static-files" class="headerlink" title="Generate static files"></a>Generate static files</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">$ hexo generate</span><br></pre></td></tr></table></figure>
<p>More info: <a href="https://hexo.io/docs/generating.html" target="_blank" rel="noopener">Generating</a></p>
<h3 id="Deploy-to-remote-sites"><a href="#Deploy-to-remote-sites" class="headerlink" title="Deploy to remote sites"></a>Deploy to remote sites</h3><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">$ hexo deploy</span><br></pre></td></tr></table></figure>
<p>More info: <a href="https://hexo.io/docs/deployment.html" target="_blank" rel="noopener">Deployment</a></p>
</div>
<footer class="post-footer">
<div class="post-eof"></div>
</footer>
</div>
</article>
</section>
</div>
</div>
<div class="sidebar-toggle">
<div class="sidebar-toggle-line-wrap">
<span class="sidebar-toggle-line sidebar-toggle-line-first"></span>
<span class="sidebar-toggle-line sidebar-toggle-line-middle"></span>
<span class="sidebar-toggle-line sidebar-toggle-line-last"></span>
</div>
</div>
<aside id="sidebar" class="sidebar">
<div class="sidebar-inner">
<section class="site-overview-wrap sidebar-panel sidebar-panel-active">
<div class="site-overview">
<div class="site-author motion-element" itemprop="author" itemscope itemtype="http://schema.org/Person">
<p class="site-author-name" itemprop="name">Cai.MY</p>
<p class="site-description motion-element" itemprop="description">种一棵树最好的时间是十年前</br>其次是现在</p>
</div>
<nav class="site-state motion-element">
<div class="site-state-item site-state-posts">
<a href="/archives/">
<span class="site-state-item-count">2</span>
<span class="site-state-item-name">日志</span>
</a>
</div>
<div class="site-state-item site-state-categories">
<a href="/categories/index.html">
<span class="site-state-item-count">1</span>
<span class="site-state-item-name">分类</span>
</a>
</div>
<div class="site-state-item site-state-tags">
<a href="/tags/index.html">
<span class="site-state-item-count">2</span>
<span class="site-state-item-name">标签</span>
</a>
</div>
</nav>
<div class="links-of-author motion-element">
<span class="links-of-author-item">
<a href="https://github.com/c-my" target="_blank" title="GitHub">
<i class="fa fa-fw fa-github"></i>GitHub</a>
</span>
<span class="links-of-author-item">
<a href="mailto:cmy1113@outlook.com" target="_blank" title="E-Mail">
<i class="fa fa-fw fa-envelope"></i>E-Mail</a>
</span>
</div>
</div>
</section>
</div>
</aside>
</div>
</main>
<footer id="footer" class="footer">
<div class="footer-inner">
<div class="copyright">&copy; <span itemprop="copyrightYear">2018</span>
<span class="with-love">
<i class="fa fa-user"></i>
</span>
<span class="author" itemprop="copyrightHolder">Cai.MY</span>
</div>
<div class="powered-by">由 <a class="theme-link" target="_blank" href="https://hexo.io">Hexo</a> 强力驱动</div>
<span class="post-meta-divider">|</span>
<div class="theme-info">主题 &mdash; <a class="theme-link" target="_blank" href="https://github.com/iissnan/hexo-theme-next">NexT.Mist</a> v5.1.4</div>
</div>
</footer>
<div class="back-to-top">
<i class="fa fa-arrow-up"></i>
</div>
</div>
<script type="text/javascript">
if (Object.prototype.toString.call(window.Promise) !== '[object Function]') {
window.Promise = null;
}
</script>
<script type="text/javascript" src="/lib/jquery/index.js?v=2.1.3"></script>
<script type="text/javascript" src="/lib/fastclick/lib/fastclick.min.js?v=1.0.6"></script>
<script type="text/javascript" src="/lib/jquery_lazyload/jquery.lazyload.js?v=1.9.7"></script>
<script type="text/javascript" src="/lib/velocity/velocity.min.js?v=1.2.1"></script>
<script type="text/javascript" src="/lib/velocity/velocity.ui.min.js?v=1.2.1"></script>
<script type="text/javascript" src="/lib/fancybox/source/jquery.fancybox.pack.js?v=2.1.5"></script>
<script type="text/javascript" src="/js/src/utils.js?v=5.1.4"></script>
<script type="text/javascript" src="/js/src/motion.js?v=5.1.4"></script>
<script type="text/javascript" src="/js/src/bootstrap.js?v=5.1.4"></script>
<script id="dsq-count-scr" src="https://blog-eul4knok3t.disqus.com/count.js" async></script>
<link rel="stylesheet" href="/lib/algolia-instant-search/instantsearch.min.css">
<script src="/lib/algolia-instant-search/instantsearch.min.js"></script>
<script src="/js/src/algolia-search.js?v=5.1.4"></script>
<script src="https://cdn1.lncld.net/static/js/av-core-mini-0.6.4.js"></script>
<script>AV.initialize("Y2e5QTjX3wq2puTAGIzfj2Ki-gzGzoHsz", "nsSr52XeeRtKIQ2JVBJdCn9L");</script>
<script>
function showTime(Counter) {
var query = new AV.Query(Counter);
var entries = [];
var $visitors = $(".leancloud_visitors");
$visitors.each(function () {
entries.push( $(this).attr("id").trim() );
});
query.containedIn('url', entries);
query.find()
.done(function (results) {
var COUNT_CONTAINER_REF = '.leancloud-visitors-count';
if (results.length === 0) {
$visitors.find(COUNT_CONTAINER_REF).text(0);
return;
}
for (var i = 0; i < results.length; i++) {
var item = results[i];
var url = item.get('url');
var time = item.get('time');
var element = document.getElementById(url);
$(element).find(COUNT_CONTAINER_REF).text(time);
}
for(var i = 0; i < entries.length; i++) {
var url = entries[i];
var element = document.getElementById(url);
var countSpan = $(element).find(COUNT_CONTAINER_REF);
if( countSpan.text() == '') {
countSpan.text(0);
}
}
})
.fail(function (object, error) {
console.log("Error: " + error.code + " " + error.message);
});
}
function addCount(Counter) {
var $visitors = $(".leancloud_visitors");
var url = $visitors.attr('id').trim();
var title = $visitors.attr('data-flag-title').trim();
var query = new AV.Query(Counter);
query.equalTo("url", url);
query.find({
success: function(results) {
if (results.length > 0) {
var counter = results[0];
counter.fetchWhenSave(true);
counter.increment("time");
counter.save(null, {
success: function(counter) {
var $element = $(document.getElementById(url));
$element.find('.leancloud-visitors-count').text(counter.get('time'));
},
error: function(counter, error) {
console.log('Failed to save Visitor num, with error message: ' + error.message);
}
});
} else {
var newcounter = new Counter();
/* Set ACL */
var acl = new AV.ACL();
acl.setPublicReadAccess(true);
acl.setPublicWriteAccess(true);
newcounter.setACL(acl);
/* End Set ACL */
newcounter.set("title", title);
newcounter.set("url", url);
newcounter.set("time", 1);
newcounter.save(null, {
success: function(newcounter) {
var $element = $(document.getElementById(url));
$element.find('.leancloud-visitors-count').text(newcounter.get('time'));
},
error: function(newcounter, error) {
console.log('Failed to create');
}
});
}
},
error: function(error) {
console.log('Error:' + error.code + " " + error.message);
}
});
}
$(function() {
var Counter = AV.Object.extend("Counter");
if ($('.leancloud_visitors').length == 1) {
addCount(Counter);
} else if ($('.post-title-link').length > 1) {
showTime(Counter);
}
});
</script>
</body>
</html>