背景改为半透明

app/src/main/cpp/PhoneDevice.cpp

@@ -1572,7 +1572,13 @@ bool CPhoneDevice::OnImageReady(cv::Mat& mat)
     cv::Point lt(0, mat.rows - fs - 20 * ratio);
     cv::Point lt2(0, lt.y - 2 * ratio);
     cv::Point rb(0 + textSize.width, lt2.y + textSize.height + 8 * ratio);
-    cv::rectangle(mat, lt2, rb,cv::Scalar(255, 255, 255), -1);
+
+    cv::Mat roi = mat(cv::Rect(lt2, rb));
+    cv::Mat clrMat(roi.size(), CV_8UC3, cv::Scalar(255, 255, 255));
+    double alpha = 0.1;
+    cv::addWeighted(clrMat, alpha, roi, 1.0 - alpha , 0.0, roi);
+
+    // cv::rectangle(mat, lt2, rb,cv::Scalar(255, 255, 255), -1);
     ft2->putText(mat, str, lt, fs, scalarRed, -1, cv::LINE_AA, false);
     // DrawOutlineText(ft2, mat, str, cv::Point(0, mat.rows - fs - 20 * ratio), fs, scalar, 1);