简述

我们使用QT和opencv的过程中经常会碰到这样的问题：Mat怎么转化位QImage？Mat怎么转化为QPixmap？今天我来告诉大家一个比较好的解决方案（以下代码参考了别人的，增加了一些修改）

代码

#include 
   
    #include 
    
     #include 
     
      #include "opencv2/opencv.hpp"// 将Mat转化位QImageQImage  cvMatToQImage( const cv::Mat &inMat ){    switch ( inMat.type() )    {    // 8-bit, 4 channel    case CV_8UC4:    {        QImage image( inMat.data,                      inMat.cols, inMat.rows,                      static_cast
      
       (inMat.step),                      QImage::Format_ARGB32 );        return image;    }    // 8-bit, 3 channel    case CV_8UC3:    {        QImage image( inMat.data,                      inMat.cols, inMat.rows,                      static_cast
       
        (inMat.step),                      QImage::Format_RGB888 );        return image.rgbSwapped();    }    // 8-bit, 1 channel    case CV_8UC1:    {#if QT_VERSION >= QT_VERSION_CHECK(5, 5, 0)        QImage image( inMat.data,                      inMat.cols, inMat.rows,                      static_cast
        
         (inMat.step), QImage::Format_Grayscale8 );//Format_Alpha8 and Format_Grayscale8 were added in Qt 5.5#else//这里还有一种写法，最后给出 static QVector
         
           sColorTable; // only create our color table the first time if ( sColorTable.isEmpty() ) { sColorTable.resize( 256 ); for ( int i = 0; i < 256; ++i ) { sColorTable[i] = qRgb( i, i, i ); } } QImage image( inMat.data, inMat.cols, inMat.rows, static_cast
          
           (inMat.step), QImage::Format_Indexed8 ); image.setColorTable( sColorTable );#endif return image; } default: qWarning() << "CVS::cvMatToQImage() - cv::Mat image type not handled in switch:" << inMat.type(); break; } return QImage();}//将Mat转化为QPixmapQPixmap cvMatToQPixmap( const cv::Mat &inMat ){ return QPixmap::fromImage( cvMatToQImage( inMat ) );}//将QImage转化为Matcv::Mat QImageToCvMat( const QImage &inImage, bool inCloneImageData = true ){ switch ( inImage.format() ) { // 8-bit, 4 channel case QImage::Format_ARGB32: case QImage::Format_ARGB32_Premultiplied: { cv::Mat mat( inImage.height(), inImage.width(), CV_8UC4, const_cast
           
            (inImage.bits()), static_cast
            
             (inImage.bytesPerLine()) ); return (inCloneImageData ? mat.clone() : mat); } // 8-bit, 3 channel case QImage::Format_RGB32: case QImage::Format_RGB888: { if ( !inCloneImageData ) { qWarning() << "CVS::QImageToCvMat() - Conversion requires cloning because we use a temporary QImage"; } QImage swapped = inImage; if ( inImage.format() == QImage::Format_RGB32 ) { swapped = swapped.convertToFormat( QImage::Format_RGB888 ); } swapped = swapped.rgbSwapped(); return cv::Mat( swapped.height(), swapped.width(), CV_8UC3, const_cast
             
              (swapped.bits()), static_cast
              
               (swapped.bytesPerLine()) ).clone(); } // 8-bit, 1 channel case QImage::Format_Indexed8: { cv::Mat mat( inImage.height(), inImage.width(), CV_8UC1, const_cast
               
                (inImage.bits()), static_cast
                
                 (inImage.bytesPerLine()) ); return (inCloneImageData ? mat.clone() : mat); } default: qWarning() << "CVS::QImageToCvMat() - QImage format not handled in switch:" << inImage.format(); break; } return cv::Mat();}//将QPixmap转化为Matcv::Mat QPixmapToCvMat( const QPixmap &inPixmap, bool inCloneImageData = true ){ return QImageToCvMat( inPixmap.toImage(), inCloneImageData );}