Facial detection - null pointer error

asked 2014-06-09 12:55:32 -0500

razvangabriel gravatar image

updated 2014-06-09 16:16:37 -0500

Hello,

I've followed this quide to detect faces using OpenCV: http://docs.opencv.org/doc/tutorials/introduction/desktop_java/java_dev_intro.html# The same code in the quide gave me the following error:

Exception in thread "main" java.lang.Error: Unresolved compilation problems: Cannot make a static reference to the non-static method getClass() from the type Object Cannot make a static reference to the non-static method getClass() from the type Object

at faced.DetectFaceDemo.main(DetectFaceDemo.java:23)

I have changed the lines with errors: CascadeClassifier faceDetector = new CascadeClassifier(DetectFaceDemo.class.getResource("/lbpcascade_frontalface.xml").getPath()); Mat image = Highgui.imread(DetectFaceDemo.class.getResource("/lena.png").getPath());

Now I have the following errors:

Running DetectFaceDemo Exception in thread "main" java.lang.NullPointerException at faced.DetectFaceDemo.main(DetectFaceDemo.java:26)

My code is:

package faced;

import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.MatOfRect;
import org.opencv.core.Point;
import org.opencv.core.Rect;
import org.opencv.core.Scalar;
import org.opencv.highgui.Highgui;
import org.opencv.objdetect.CascadeClassifier;

//
//Detects faces in an image, draws boxes around them, and writes the results
//to "faceDetection.png".
//
class DetectFaceDemo {
public static void main(String[] args) {
    System.loadLibrary( Core.NATIVE_LIBRARY_NAME );
 System.out.println("\nRunning DetectFaceDemo");

 // Create a face detector from the cascade file in the resources
 // directory.
//CascadeClassifier faceDetector = new CascadeClassifier(getClass().getResource("/lbpcascade_frontalface.xml").getPath());
//Mat image = Highgui.imread(getClass().getResource("/lena.png").getPath());

 CascadeClassifier faceDetector = new CascadeClassifier(DetectFaceDemo.class.getResource("/lbpcascade_frontalface.xml").getPath());
 Mat image = Highgui.imread(DetectFaceDemo.class.getResource("/lena.png").getPath());


 // Detect faces in the image.
 // MatOfRect is a special container class for Rect.
 MatOfRect faceDetections = new MatOfRect();
 faceDetector.detectMultiScale(image, faceDetections);

 System.out.println(String.format("Detected %s faces", faceDetections.toArray().length));

 // Draw a bounding box around each face.
 for (Rect rect : faceDetections.toArray()) {
     Core.rectangle(image, new Point(rect.x, rect.y), new Point(rect.x + rect.width, rect.y + rect.height), new Scalar(0, 255, 0));
 }

 // Save the visualized detection.
 String filename = "faceDetection.png";
 System.out.println(String.format("Writing %s", filename));
 Highgui.imwrite(filename, image);
}
}

So, why it dowsn't find my xml? Or what should I do? I have tryed to coppy the xml and lena's image from home/src/main/resources as they say in the guide to home/workspace/face_detection/src/faced where I have the file "DetectFaceDemo.java" that I'm trying to run. I am using eclipse for my project. I am sorry if the way I wrote is not arranged.

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Comments

Is the .xml where your .class is?

thdrksdfthmn gravatar imagethdrksdfthmn ( 2014-06-11 06:10:54 -0500 )edit