java调用opencv测量右下颌角角度

以下是一个Java程序，它可以使用OpenCV库来测量右下颌角的角度。

import org.opencv.core.*;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
import org.opencv.objdetect.CascadeClassifier;

public class JawAngleMeasurement {
    
    public static void main(String[] args) {
        
        // Load the OpenCV library
        System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
        
        // Load the image
        Mat image = Imgcodecs.imread("path/to/image.jpg");
        
        // Convert the image to grayscale
        Mat grayImage = new Mat();
        Imgproc.cvtColor(image, grayImage, Imgproc.COLOR_BGR2GRAY);
        
        // Load the cascade classifier for detecting faces
        CascadeClassifier faceDetector = new CascadeClassifier("path/to/haarcascade_frontalface_default.xml");
        
        // Detect faces in the image
        MatOfRect faceDetections = new MatOfRect();
        faceDetector.detectMultiScale(grayImage, faceDetections);
        
        // Get the first face detection (assuming there is only one face in the image)
        Rect face = faceDetections.toArray()[0];
        
        // Extract the region of interest (ROI) corresponding to the lower part of the face
        int x = face.x;
        int y = (int) (face.y + face.height * 0.6);
        int width = face.width;
        int height = (int) (face.height * 0.4);
        Rect jawROI = new Rect(x, y, width, height);
        Mat jawImage = new Mat(grayImage, jawROI);
        
        // Threshold the jaw image to obtain a binary image
        Mat binaryImage = new Mat();
        Imgproc.threshold(jawImage, binaryImage, 0, 255, Imgproc.THRESH_BINARY_INV | Imgproc.THRESH_OTSU);
        
        // Find the contours in the binary image
        Mat contoursImage = new Mat();
        binaryImage.copyTo(contoursImage);
        Mat hierarchy = new Mat();
        MatOfPoint2f maxContour = new MatOfPoint2f();
        Imgproc.findContours(contoursImage, new ArrayList<>(), hierarchy, Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE);
        double maxArea = 0;
        for (MatOfPoint contour : contours) {
            MatOfPoint2f contour2f = new MatOfPoint2f(contour.toArray());
            double area = Imgproc.contourArea(contour2f);
            if (area > maxArea) {
                maxArea = area;
                contour2f.convertTo(maxContour, CvType.CV_32FC2);
            }
        }
        
        // Fit an ellipse to the max contour
        RotatedRect ellipse = Imgproc.fitEllipse(maxContour);
        
        // Get the angle of the major axis of the ellipse
        double angle = ellipse.angle;
        if (angle < -45) {
            angle += 90;
        }
        
        // Print the angle
        System.out.println("Right jaw angle: " + angle);
        
    }
    
}

请注意，此程序假定图像中只有一个人脸，并且只测量右下颌角的角度。如果需要在多个人脸中测量右下颌角的角度，您需要修改程序以在每个人脸上运行相同的算法。