Opencv-从数组创建Mat

Question

I try to create mat object from uchar* . I could not find a useful conversion. My code is below ;

uchar* urgbImg; // this value is created another function

Mat img_argb(HEIGHT, WIDTH, CV_8UC4, urgbImg);
Mat img_rgb(HEIGHT, WIDTH, CV_8UC3);
img_argb.convertTo(img_rgb, CV_8UC3);


cv::imwrite("RGB.png", img_rgb);

QImage img1(urgbImg, WIDTH, HEIGHT, QImage::Format_ARGB32);
QImage img2 = img1.convertToFormat(QImage::Format_RGB32);

QFile file2(QString::fromStdString("QRGB.png"));
file2.open(QIODevice::WriteOnly);
img2.save(&file2,"PNG",100);
file2.close();

QRGB file is a fine result but not RGB file. I have uchar array so it is 8 bit.

I tried CV_8UC3(without conversion from CV_8UC4), CV_32SC3 and CV_32SC4. All result are bad. How can I create rgb image from uchar* ?

Answer 1

convertTo() don't convert a CV_8UC4 image to CV_8UC3

you should use cvtColor() function

Mat img_argb(HEIGHT, WIDTH, CV_8UC4, urgbImg);
Mat img_rgb;
cvtColor(img_argb,img_rgb,COLOR_BGRA2BGR);