The following code runs with an NullPointerException

rectangle(frame,
                                new Point(result.x, result.y),
                                new Point(result.x + result.width, result.y + result.height),
                                Scalar.MAGENTA, 2, LINE_8, 0);

java.lang.NullPointerException: Pointer address of argument 3 is NULL.
at org.bytedeco.opencv.global.opencv_imgproc.rectangle(Native Method) ~[opencv-4.4.0-1.5.4.jar:4.4.0-1.5.4]

argument 3 isScalar.MAGENTA，What did I write wrong?