How to overlay text on image when working with cv::Mat type

Question

I am using opencv 2.1. In my code I have a few images stored as Mat objects initialized like this:

Mat img1 = imread(\"img/stuff.pgm\", CV_LOAD_IMAGE_GRAYSCA         


        

Answer 1

If you are using OpenCV 3.x or 4.0, you have to replace CV_AA by LINE_AA. So, the complete call would be:

cv::putText(yourImageMat, 
            "Text to add",
            cv::Point(5,5), // Coordinates
            cv::FONT_HERSHEY_COMPLEX_SMALL, // Font
            1.0, // Scale. 2.0 = 2x bigger
            cv::Scalar(255,255,255), // BGR Color
            1, // Line Thickness (Optional)
            cv::LINE_AA); // Anti-alias (Optional)

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