blocks|key|2193769|text|如果QImage仍然存在，您只需对其执行一个快速操作，则可以使用QImage内存构建一个cv::Mat：：Mat：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2193770|cv::Mat+mat(image.height(),+image.width(),+CV_8UC3,+(cv::Scalar*)image.scanLine(0));|offset|length|style|CODE|2193771|这假设QImage是3-通道，即RGB888。|2193772|如果QImage正在消失，那么您需要复制数据，请参见Qimage+to+cv::Mat+convertion+strange+behaviour。|2193773|如果QImage是Format_ARGB32_Premultiplied+(首选格式)，那么您需要将每个像素转换为OpenCV的BGR布局。在最新版本中，cv::cvtcolor()函数可以将ARGB转换为RGB。|2193774|或者，您可以在复制数据之前使用QImage::convertToFormat()转换为RGB。|2193775|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/11170485/qimage-to-cvmat-convertion-strange-behaviour|1|https://doc.qt.io/qt-5/qimage.html^0|0|0|2C|0|0|Q|1A|0|0|0|F|P|1|0^^$0|@$1|2|3|4|5|6|7|Z|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|10|8|@$D|11|E|12|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|13|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|14|8|@]|9|@$D|15|E|16|1|17]]|A|$]]|$1|L|3|M|5|6|7|18|8|@]|9|@]|A|$]]|$1|N|3|O|5|6|7|19|8|@]|9|@$D|1A|E|1B|1|1C]]|A|$]]|$1|P|3|-4|5|6|7|1D|8|@]|9|@]|A|$]]]|Q|$R|$5|S|T|U|A|$V|W]]|X|$5|S|T|U|A|$V|Y]]]]

If the QImage will still exist, and you just need to perform a quick operation on it then you can construct a cv::Mat using the QImage memory:
<code>cv::Mat mat(image.height(), image.width(), CV_8UC3, (cv::Scalar*)image.scanLine(0));</code>
This assumes that the QImage is 3-channels, ie RGB888.
If the QImage is going away then you need to copy the data, see <a href="https://stackoverflow.com/questions/11170485/qimage-to-cvmat-convertion-strange-behaviour">Qimage to cv::Mat convertion strange behaviour</a>.
If QImage is Format_ARGB32_Premultiplied (the preferred format) then you will need to convert each pixel to OpenCV's BGR layout. The cv::cvtcolor() function can convert ARGB to RGB in the latest versions. 
Or you can use <a href="https://doc.qt.io/qt-5/qimage.html" rel="nofollow noreferrer">QImage::convertToFormat()</a> to convert to RGB before copying the data.

blocks|key|2193841|text|在你提出这个问题一年后，互联网上已经有了很好的答案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2193842|2193843|unordered-list-item|2193844|2193845|2193846|但在我看来，如果你同时使用Qt和OpenCV，那么输入QImage可能是，只是为了显示，在这种情况下，你可能会想要使用QPixmap，因为它针对显示进行了优化。这就是我要做的：|offset|length|style|CODE|BOLD|2193847|2193848|将图像加载为cv::Mat，如果您想显示图像，请使用第二篇文章中介绍的非复制方法转换为QPixmap。|ordered-list-item|2193849|在工作流期间以|2193850|时间进行图像处理您可以调用类似Mat2QPixmap()的东西来获取实时result.|2193851|Never将QPixmap转换为cv::Mat，考虑到每种类型的用途，这样做是没有意义的。<代码>H226<代码>G227|2193852|2193853|entityMap^0|0|0|0|0|0|R|6|1N|7|10|7|0|0|6|7|17|7|0|0|F|D|0|6|7|G|7|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|11|8|@]|9|@]|A|$]]|$1|C|3|-4|5|D|7|12|8|@]|9|@]|A|$]]|$1|E|3|-4|5|D|7|13|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|14|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|15|8|@$I|16|J|17|K|L]|$I|18|J|19|K|L]|$I|1A|J|1B|K|M]]|9|@]|A|$]]|$1|N|3|-4|5|6|7|1C|8|@]|9|@]|A|$]]|$1|O|3|P|5|Q|7|1D|8|@$I|1E|J|1F|K|L]|$I|1G|J|1H|K|L]]|9|@]|A|$]]|$1|R|3|S|5|Q|7|1I|8|@]|9|@]|A|$]]|$1|T|3|U|5|Q|7|1J|8|@$I|1K|J|1L|K|L]]|9|@]|A|$]]|$1|V|3|W|5|Q|7|1M|8|@$I|1N|J|1O|K|L]|$I|1P|J|1Q|K|L]]|9|@]|A|$]]|$1|X|3|-4|5|6|7|1R|8|@]|9|@]|A|$]]|$1|Y|3|-4|5|6|7|1S|8|@]|9|@]|A|$]]]|Z|$]]

One year after you issued this question there've been great answers on the internet:

<ul>
<li><a href="http://qtandopencv.blogspot.com/2013/08/how-to-convert-between-cvmat-and-qimage.html" rel="noreferrer">Convert between cv::mat and Qimage correctly</a></li>
<li><a href="http://asmaloney.com/2013/11/code/converting-between-cvmat-and-qimage-or-qpixmap/" rel="noreferrer">Converting Between cv::Mat and QImage or QPixmap</a></li>
</ul>

But the way I see it, if you're working with Qt and OpenCV at the same time then type <code>QImage</code> is probably just for displaying, that case you might want to use <code>QPixmap</code> since it's optimized for displaying. So this is what I do:

<ol>
<li>Load image as <code>cv::Mat</code>, if you'd like to display the image, convert to <code>QPixmap</code> using the non-copy method introduced in the second article.</li>
<li>Do your image processing in <code>cv::Mat</code>.</li>
<li>Any time during the workflow you can call upon something like <code>Mat2QPixmap()</code> to get realtime result.</li>
<li>Never convert <code>QPixmap</code> to <code>cv::Mat</code>, there's no sense doing it considering the purpose of each type.</li>
</ol>

blocks|key|2193920|text|这个问题的答案是Qt+5.11+(可能还有一些更早的版本)：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2193921|++++cv::Mat+mat(image.height(),+image.width(),CV_8UC3,+image.bits());++
++++//+image.scanline()+does+not+exist,+
++++//and+height/width+is+interchanged+for+a+matrix|code-block|syntax|javascript|2193922|同样，假设QImage为RGB888+(即QImage::Format_RGB888)|2193923|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

The answer to this with Qt 5.11 (and probably some earlier versions):

<pre><code> cv::Mat mat(image.height(), image.width(),CV_8UC3, image.bits()); 
 // image.scanline() does not exist, 
 //and height/width is interchanged for a matrix
</code></pre>

Again the QImage is assumed to be RGB888 (ie QImage::Format_RGB888)

blocks|key|2193881|text|我在OpenCV+3.1%2B样式代码中的尝试：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2193882|void+qimage_to_mat(const+QImage&+image,+cv::OutputArray+out)+{

++++switch(image.format())+{
++++++++case+QImage::Format_Invalid:
++++++++{
++++++++++++cv::Mat+empty;
++++++++++++empty.copyTo(out);
++++++++++++break;
++++++++}
++++++++case+QImage::Format_RGB32:
++++++++{
++++++++++++cv::Mat+view(image.height(),image.width(),CV_8UC4,(void+*)image.constBits(),image.bytesPerLine());
++++++++++++view.copyTo(out);
++++++++++++break;
++++++++}
++++++++case+QImage::Format_RGB888:
++++++++{
++++++++++++cv::Mat+view(image.height(),image.width(),CV_8UC3,(void+*)image.constBits(),image.bytesPerLine());
++++++++++++cvtColor(view,+out,+cv::COLOR_RGB2BGR);
++++++++++++break;
++++++++}
++++++++default:
++++++++{
++++++++++++QImage+conv+=+image.convertToFormat(QImage::Format_ARGB32);
++++++++++++cv::Mat+view(conv.height(),conv.width(),CV_8UC4,(void+*)conv.constBits(),conv.bytesPerLine());
++++++++++++view.copyTo(out);
++++++++++++break;
++++++++}
++++}
}

void+mat_to_qimage(cv::InputArray+image,+QImage&+out)
{
++++switch(image.type())
++++{
++++++++case+CV_8UC4:
++++++++{
++++++++++++cv::Mat+view(image.getMat());
++++++++++++QImage+view2(view.data,+view.cols,+view.rows,+view.step[0],+QImage::Format_ARGB32);
++++++++++++out+=+view2.copy();
++++++++++++break;
++++++++}
++++++++case+CV_8UC3:
++++++++{
++++++++++++cv::Mat+mat;
++++++++++++cvtColor(image,+mat,+cv::COLOR_BGR2BGRA);+//COLOR_BGR2RGB+doesn't+behave+so+use+RGBA
++++++++++++QImage+view(mat.data,+mat.cols,+mat.rows,+mat.step[0],+QImage::Format_ARGB32);
++++++++++++out+=+view.copy();
++++++++++++break;
++++++++}
++++++++case+CV_8UC1:
++++++++{
++++++++++++cv::Mat+mat;
++++++++++++cvtColor(image,+mat,+cv::COLOR_GRAY2BGRA);
++++++++++++QImage+view(mat.data,+mat.cols,+mat.rows,+mat.step[0],+QImage::Format_ARGB32);
++++++++++++out+=+view.copy();
++++++++++++break;
++++++++}
++++++++default:
++++++++{
++++++++++++throw+invalid_argument("Image+format+not+supported");
++++++++++++break;
++++++++}
++++}
}|code-block|syntax|javascript|2193883|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

My attempt in OpenCV 3.1+ style code:
<pre><code>void qimage_to_mat(const QImage&amp; image, cv::OutputArray out) {

 switch(image.format()) {
 case QImage::Format_Invalid:
 {
 cv::Mat empty;
 empty.copyTo(out);
 break;
 }
 case QImage::Format_RGB32:
 {
 cv::Mat view(image.height(),image.width(),CV_8UC4,(void *)image.constBits(),image.bytesPerLine());
 view.copyTo(out);
 break;
 }
 case QImage::Format_RGB888:
 {
 cv::Mat view(image.height(),image.width(),CV_8UC3,(void *)image.constBits(),image.bytesPerLine());
 cvtColor(view, out, cv::COLOR_RGB2BGR);
 break;
 }
 default:
 {
 QImage conv = image.convertToFormat(QImage::Format_ARGB32);
 cv::Mat view(conv.height(),conv.width(),CV_8UC4,(void *)conv.constBits(),conv.bytesPerLine());
 view.copyTo(out);
 break;
 }
 }
}

void mat_to_qimage(cv::InputArray image, QImage&amp; out)
{
 switch(image.type())
 {
 case CV_8UC4:
 {
 cv::Mat view(image.getMat());
 QImage view2(view.data, view.cols, view.rows, view.step[0], QImage::Format_ARGB32);
 out = view2.copy();
 break;
 }
 case CV_8UC3:
 {
 cv::Mat mat;
 cvtColor(image, mat, cv::COLOR_BGR2BGRA); //COLOR_BGR2RGB doesn't behave so use RGBA
 QImage view(mat.data, mat.cols, mat.rows, mat.step[0], QImage::Format_ARGB32);
 out = view.copy();
 break;
 }
 case CV_8UC1:
 {
 cv::Mat mat;
 cvtColor(image, mat, cv::COLOR_GRAY2BGRA);
 QImage view(mat.data, mat.cols, mat.rows, mat.step[0], QImage::Format_ARGB32);
 out = view.copy();
 break;
 }
 default:
 {
 throw invalid_argument(&quot;Image format not supported&quot;);
 break;
 }
 }
}
</code></pre>

blocks|key|3829263|text|我会将图像保存到磁盘上，然后从cv中重新打开;)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3829264|@%5E我已经尝试过以前的解决方案。它似乎对我不起作用。虽然我得到了一些图像，但它看起来像是某种条形码信息的图像。我猜可能有一些参数不匹配。|3829265|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

I'd save the image to disk and reopen it from cv ;)

@^ I've tried the previous solution. It doesn't seem to working with me. Although I'm getting some image, it looks like some bar code information kind of image. I guess there are some mismatch of parameters.

I have searched on the internet but I cannot find a method of converting a <code>QImage</code>(or <code>QPixmap</code>) to a OpenCV <code>Mat</code>. How would I do this?.

Any help is appreciated.

How to convert QImage to opencv Mat

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

文章

问答

视频

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋 

腾讯云代码助手

CODING DevOps

Cloud Studio

SDK中心

API中心

命令行工具

我在互联网上搜索过，但找不到将QImage(或QPixmap)转换为OpenCV Mat的方法。我该怎么做呢？任何帮助都是非常感谢的。

问如何将QImage转换为opencv Mat
EN

回答 5

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何将QImage转换为opencv MatEN

回答 5

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何将QImage转换为opencv Mat
EN