You can add text to an image using the putText() method of the org.opencv.imgproc.Imgproc class. This method renders the specified text in the given image. It accepts −
An empty mat object to store the source image.
A string object to specify the desired text.
A Point object specifying the position of the text.
Integer constant specifying the font of the text.
scale factor that is multiplied by the font-specific base size.
A Scalar object specifying the color of the text.
An integer value specifying the color of the text
Example
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.Point;
import org.opencv.core.Scalar;
import org.opencv.highgui.HighGui;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
public class AddingText {
public static void main(String args[]) throws Exception {
//Loading the OpenCV core library
System.loadLibrary( Core.NATIVE_LIBRARY_NAME );
//Reading the contents of the image
String file ="D:\\Images\\shapes.jpg";
Mat src = Imgcodecs.imread(file);
//Preparing the arguments
String text = "JavaFX 2D shapes";
Point position = new Point(170, 280);
Scalar color = new Scalar(0, 0, 255);
int font = Imgproc.FONT_HERSHEY_SIMPLEX;
int scale = 1;
int thickness = 3;
//Adding text to the image
Imgproc.putText(src, text, position, font, scale, color, thickness);
//Displaying the resultant Image
HighGui.imshow("Contours operation", src);
HighGui.waitKey();
}
}Input Image

Output
