在使用Qt和OpenCV混合编程时，我们有时需要在两种图片类cv::Mat和QImage之间进行转换
//##### cv::Mat ---> QImage #####
// Shallow copy
QImage mat2qimage_ref(cv::Mat &m, QImage::Format format) {
return QImage(m.data, m.cols, m.rows, m.step, format);
}
// Deep copy
QImage mat2qimage_cpy(cv::Mat &m, QImage::Format format) {
return QImage(m.data, m.cols, m.rows, m.step, format).copy();
}
//##### QImage ---> cv::Mat #####
// Shallow copy
cv::Mat qimage2mat_ref(QImage &img, int format) {
return cv::Mat(img.height(), img.width(), format, img.bits(), img.bytesPerLine());
}
// Deep copy
cv::Mat qimage2mat_ref(QImage &img, int format) {
return cv::Mat(img.height(), img.width(), format, const_cast<uchar*>(img.bits()), img.bytesPerLine()).clone();
}//##### cv::Mat ---> QImage #####
QImage cvMat_to_QImage(const cv::Mat &mat ) {
switch ( mat.type() )
{
// 8-bit, 4 channel
case CV_8UC4:
{
QImage image( mat.data, mat.cols, mat.rows, mat.step, QImage::Format_RGB32 );
return image;
}
// 8-bit, 3 channel
case CV_8UC3:
{
QImage image( mat.data, mat.cols, mat.rows, mat.step, QImage::Format_RGB888 );
return image.rgbSwapped();
}
// 8-bit, 1 channel
case CV_8UC1:
{
static QVector<QRgb> sColorTable;
// only create our color table once
if ( sColorTable.isEmpty() )
{
for ( int i = 0; i < 256; ++i )
sColorTable.push_back( qRgb( i, i, i ) );
}
QImage image( mat.data, mat.cols, mat.rows, mat.step, QImage::Format_Indexed8 );
image.setColorTable( sColorTable );
return image;
}
default:
qDebug("Image format is not supported: depth=%d and %d channels\n", mat.depth(), mat.channels());
break;
}
return QImage();
}
//##### QImage ---> cv::Mat #####
cv::Mat QImage_to_cvMat( const QImage &image, bool inCloneImageData = true ) {
switch ( image.format() )
{
// 8-bit, 4 channel
case QImage::Format_RGB32:
{
cv::Mat mat( image.height(), image.width(), CV_8UC4, const_cast<uchar*>(image.bits()), image.bytesPerLine() );
return (inCloneImageData ? mat.clone() : mat);
}
// 8-bit, 3 channel
case QImage::Format_RGB888:
{
if ( !inCloneImageData ) {
qWarning() << "ASM::QImageToCvMat() - Conversion requires cloning since we use a temporary QImage";
}
QImage swapped = image.rgbSwapped();
return cv::Mat( swapped.height(), swapped.width(), CV_8UC3, const_cast<uchar*>(swapped.bits()), swapped.bytesPerLine() ).clone();
}
// 8-bit, 1 channel
case QImage::Format_Indexed8:
{
cv::Mat mat( image.height(), image.width(), CV_8UC1, const_cast<uchar*>(image.bits()), image.bytesPerLine() );
return (inCloneImageData ? mat.clone() : mat);
}
default:
qDebug("Image format is not supported: depth=%d and %d format\n", image.depth(), image.format();
break;
}
return cv::Mat();
}参考：
https://www.yuque.com/docs/share/c6a6b2da-b430-49fe-9ae6-cd14410408a1