cvNorm isn't recognized as OpenCV function

Question

I'm trying to compare to images in my phone's SDcard, so I wrote this piece of code.

package com.example.test;

import java.io.File;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    File img1=new File("mnt/sdcard/xx/IMG-20130123-WA0004.jpg");
    File img2=new File("mnt/sdcard/xx/IMG-20130124-WA0000.jpg");
    double l2_norm = cvNorm( img1, img2 );
}
}

I have imported OpenCV as a project in my Eclipse Workspace and set it as a library. My test project uses this library.

Now, I get this error The method cvNorm(File, File) is undefined for the type MainActivity

I searched for over 3 hours for the proper code or method but none seem to work and Eclipse isn't suggesting the correct imports. Could someone tell me the correct code?

Answer 1

This is Java. You have to import classes and refer to them by package.

import android.os.Bundle;
import android.app.Activity;
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.highgui.Highgui;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Mat img1 = Highgui.imread("mnt/sdcard/xx/IMG-20130123-WA0004.jpg");
        Mat img2 = Highgui.imread("mnt/sdcard/xx/IMG-20130124-WA0000.jpg");
        double l2_norm = Core.norm(img1, img2);
    }
}