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<div style="margin:0px;padding:0px;border:0px;font-size:14px;line-height:inherit;font-family:helvetica,Arial,'Hiragino Sans GB','Microsoft YaHei',simsun;vertical-align:baseline;color:rgb(89,89,89);"><div class="wrap1 sclearfix" style="margin:5px auto;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-size:0px;line-height:inherit;font-family:inherit;vertical-align:baseline;width:1000px;background-color:rgb(255,255,255);"><div class="center" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;"><div class="container-main" style="margin:0px auto 0px 0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;float:left;width:700px;"><div class="article-detail" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;"><div class="article-content" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-size:18px;line-height:1.5;vertical-align:baseline;color:rgb(93,93,93);"><div style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:1.5;vertical-align:baseline;"><p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;"> 
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<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">当然，媒体也无济于事，他们将危言耸听每一个小场景。从冻伤的家庭在寒风中露营整晚，到瞒姗老太在大门打开后被蜂拥而入的低价抢购人群踩踏，就像侏罗纪公园中似鸡龙的蹂躏。这所有的一切只是因为她想为9岁的孙女蒂米买到最新的光晕游戏，而蒂米的父母，在去年的这个时候离世了，就在沃尔玛，在这黑色星期五。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
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<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;"><span style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:700;line-height:inherit;font-family:inherit;vertical-align:baseline;">用 Python 和 OpenCV 检测图片上的的条形码<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">这篇博文的目的是应用计算机视觉和图像处理技术，展示一个条形码检测的基本实现。我所实现的算法本质上基于StackOverflow 上的这个问题，浏览代码之后，我提供了一些对原始算法的更新和改进。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">首先需要留意的是，这个算法并不是对所有条形码有效，但会给你基本的关于应用什么类型的技术的直觉。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">假设我们要检测下图中的条形码：<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">图1：包含条形码的示例图片<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">现在让我们开始写点代码，新建一个文件，命名为detect_barcode.py，打开并编码：<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">我们首先做的是导入所需的软件包，我们将使用NumPy做数值计算，argparse用来解析命令行参数，cv2是OpenCV的绑定。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">然后我们设置命令行参数，我们这里需要一个简单的选择，–image是指包含条形码的待检测图像文件的路径。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">现在开始真正的图像处理：<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">12~13行：从磁盘载入图像并转换为灰度图。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">17~18行：使用Scharr操作（指定使用ksize = -1）构造灰度图在水平和竖直方向上的梯度幅值表示。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">21~22行：Scharr操作之后，我们从x-gradient中减去y-gradient，通过这一步减法操作，最终得到包含高水平梯度和低竖直梯度的图像区域。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">上面的gradient表示的原始图像看起来是这样的：<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
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<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">25行：我们要做的第一件事是使用9*9的内核对梯度图进行平均模糊，这将有助于平滑梯度表征的图形中的高频噪声。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">26行：然后我们将模糊化后的图形进行二值化，梯度图中任何小于等于255的像素设为0（黑色），其余设为255（白色）。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">模糊并二值化后的输出看起来是这个样子：<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
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<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">29行：我们首先使用cv2.getStructuringElement构造一个长方形内核。这个内核的宽度大于长度，因此我们可以消除条形码中垂直条之间的缝隙。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">30行：这里进行形态学操作，将上一步得到的内核应用到我们的二值图中，以此来消除竖杠间的缝隙。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">现在，你可以看到这些缝隙相比上面的二值化图像基本已经消除：<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
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<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">我们这里所做的是首先进行4次腐蚀（erosion），然后进行4次膨胀（dilation）。腐蚀操作将会腐蚀图像中白色像素，以此来消除小斑点，而膨胀操作将使剩余的白色像素扩张并重新增长回去。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">如果小斑点在腐蚀操作中被移除，那么在膨胀操作中就不会再出现。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">经过我们这一系列的腐蚀和膨胀操作，可以看到我们已经成功地移除小斑点并得到条形码区域。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
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<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">图6：成功检测到示例图像中的条形码<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">下一部分，我们将尝试更多图像。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;"><span style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:700;line-height:inherit;font-family:inherit;vertical-align:baseline;">成功的条形码检测<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">要跟随这些结果，请使用文章下面的表单去下载本文的源码以及随带的图片。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">一旦有了代码和图像，打开一个终端来执行下面的命令：<blockquote style="margin:1em 10px 0px;padding:0px 0px 0px 10px;border-width:0px 0px 0px 4px;border-left-style:solid;border-left-color:rgb(238,238,238);font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;"><p style="margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">$python detect_barcode.py --image images/barcode_02.jpg<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">图7：使用OpenCV检测图像中的一个条形码<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">检测椰油瓶子上的条形码没有问题。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">让我们试下另外一张图片：<blockquote style="margin:1em 10px 0px;padding:0px 0px 0px 10px;border-width:0px 0px 0px 4px;border-left-style:solid;border-left-color:rgb(238,238);font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;"><p style="margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">$ python detect_barcode.py --image images/barcode_03.jpg<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
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<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">图10：使用计算机视觉和图像处理检测包裹上的条形码<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">我们的算法再次成功检测到条形码。<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">最后，我们再尝试一张图片，这个是我最爱的意大利面酱—饶氏自制伏特加酱（Rao’s Homemade Vodka Sauce）:<blockquote style="margin:1em 10px 0px;padding:0px 0px 0px 10px;border-width:0px 0px 0px 4px;border-left-style:solid;border-left-color:rgb(238,238);font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;"><p style="margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">$python detect_barcode.py --image images/barcode_06.jpg<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
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<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;"><span style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:700;line-height:inherit;font-family:inherit;vertical-align:baseline;">源码下载：http://pan.baidu.com/s/1jGMfcBs<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">欢迎关注我的博客哦：https://home.cnblogs.com/u/sm123456/<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;"><span style="color:rgb(0,0);font-family:Verdana,Helvetica,sans-serif;font-size:14px;text-align:left;background-color:rgb(238,238);">?欢迎加入千人交流，资源共享群：125240963
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