Incorrect Value for "Core.NATIVE_LIBRARY_NAME"

[aji4032]

Hi,

I was facing the below error while trying to use Highgui.imread(String) function:
"java.lang.UnsatisfiedLinkError: org.opencv.highgui.Highgui.imread_1".

On searching, I found out that I might have to use "System.loadLibrary(Core.NATIVE_LIBRARY_NAME);" to load the library. But now, it gives the below error:
"java.lang.UnsatisfiedLinkError: no opencv_java248 in java.library.path"

The jar file contains opencv_java320.dll for 64bit windows machine but the value for Core.NATIVE_LIBRARY_NAME is "opencv_java320". Is this the reason why I am getting this error? Also, can you help me on how to resolve this above error also I'm receiving?

Issue Found in below Maven Dependency:

org.openpnp
opencv
3.2.0-1

[vonnieda]

Hi @aji4032,

Did you call loadShared() first? Typically you should load this library like this:

    static {
        nu.pattern.OpenCV.loadShared();
        System.loadLibrary(org.opencv.core.Core.NATIVE_LIBRARY_NAME);
    }

Try that and let me know if you are still having problems.

In addition, unless you actually need features from 3.x, I recommend using 2.4.13 instead. The Java bindings for 3.x are pretty buggy.

[aji4032]

Hi @vonnieda ,
I tried adding the static block and downgraded it to 2.4.13 as you said. Still receiving below error :(.
java.lang.UnsatisfiedLinkError: no opencv_java248 in java.library.path on trying to execute loadShared();

public class TemplateMatching {
static {
nu.pattern.OpenCV.loadShared();
System.loadLibrary("opencv_java2413");
}
public static void run() {
String templateFileName = "C:\Users\aji4032\Desktop\outfile.png";
Mat img = Highgui.imread(templateFileName);
}
}

[vonnieda]

Hi @aji4032,

A few things:

This works for me:

package org.openpnp;

import org.opencv.core.Mat;
import org.opencv.highgui.Highgui;

public class OpenCvTest {
    static {
        nu.pattern.OpenCV.loadShared();
        System.loadLibrary(org.opencv.core.Core.NATIVE_LIBRARY_NAME);
    }
    
    public static void main(String[] args) {
        String filename = "/Users/jason/Desktop/Screen Shot 2017-09-15 at 8.57.47 AM.png";
        Mat mat = Highgui.imread(filename);
    }
}

using this Maven dependency:

		<dependency>
			<groupId>org.openpnp</groupId>
			<artifactId>opencv</artifactId>
			<version>2.4.11-2</version>
		</dependency>

I'm not sure why you are getting an error that opencv_java248 is not available when you are calling for opencv_java2413. It makes me think you either have a broken Maven dependency or are using non-Maven version of the library.

If you are using Maven, can you please just zip up your entire test project and send it over to me? I can test it locally and see if I get the same error.

I don't believe this is an error with the library, it looks environmental to me.

[vonnieda]

Closing as this doesn't seem like a library issue. Feel free to reopen if you still are having trouble.