opencv mat to QbyteArray Unsupported image format

Question

Hi I am trying to draw a contour to a base64 encoded qbytearray by converting it to cv mat and revert it back to qbyte array to display on qml. While the first part is working correclty, I can't seem to convert the cv mat to qbytearray back properly

the code that I am using now is

cv::Mat final_img;
        cv::Mat dst;
        cv::resize(final_img, final_img, final_img.size());
        cv::cvtColor(final_img, dst, cv::COLOR_BGR2BGRA);
        QByteArray data = QByteArray::fromRawData(reinterpret_cast<char*>(dst.data), 592355);
        decoded_image = "data:image/jpeg;base64,";
        decoded_image.append(QString::fromLatin1(data.toBase64().data()));

I get a correct format of base64encoded bytearray but gets the following error

Unsupported image format

Any help will be appreciated! Thanks