can't find dependent library javacv

Question

I have this code:

package javacv;
import static com.googlecode.javacv.cpp.opencv_core.*;
import static com.googlecode.javacv.cpp.opencv_imgproc.*;
import static com.googlecode.javacv.cpp.opencv_highgui.*;
import javax.swing.JOptionPane;

/**
 *
 * @author (Mahdi)
 */
public class JavaCv {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        try {
              IplImage img = cvLoadImage("mehdi.jpg");  
                cvShowImage("Hellow", img);
                cvSmooth(img, img, CV_GAUSSIAN, 13);
                cvShowImage("Blur", img);
                cvWaitKey();
                cvReleaseImage(img);

        } catch (Exception e) {
            JOptionPane.showMessageDialog(null, e.getMessage());
        }



    }
}

after run throw this exception:

Exception in thread "main" java.lang.UnsatisfiedLinkError: C:\Users\(Mahdi)\AppData\Local\Temp\javacpp66820482987315\jniopencv_core.dll: Can't find dependent libraries
    at java.lang.ClassLoader$NativeLibrary.load(Native Method)
    at java.lang.ClassLoader.loadLibrary1(ClassLoader.java:1939)
    at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1864)
    at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1825)
    at java.lang.Runtime.load0(Runtime.java:792)
    at java.lang.System.load(System.java:1059)
    at com.googlecode.javacpp.Loader.loadLibrary(Loader.java:566)
    at com.googlecode.javacpp.Loader.load(Loader.java:489)
    at com.googlecode.javacpp.Loader.load(Loader.java:431)
    at com.googlecode.javacv.cpp.opencv_core.<clinit>(opencv_core.java:136)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:266)
    at com.googlecode.javacpp.Loader.load(Loader.java:453)
    at com.googlecode.javacv.cpp.opencv_imgproc.<clinit>(opencv_imgproc.java:97)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:266)
    at com.googlecode.javacpp.Loader.load(Loader.java:453)
    at com.googlecode.javacv.cpp.opencv_highgui.<clinit>(opencv_highgui.java:85)
    at javacv.JavaCv.main(JavaCv.java:23)
Caused by: java.lang.UnsatisfiedLinkError: no opencv_core244 in java.library.path
    at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1860)
    at java.lang.Runtime.loadLibrary0(Runtime.java:845)
    at java.lang.System.loadLibrary(System.java:1084)
    at com.googlecode.javacpp.Loader.loadLibrary(Loader.java:593)
    at com.googlecode.javacpp.Loader.load(Loader.java:481)
    ... 11 more
Java Result: 1

any idea?

Answer 1

Java is trying to find required dlls in ${java.library.path} but it is not defined. So you should:

1. Set location of opencv_java244.dll in %PATH% ("c:\opencv\build\java\x64\" for example).
2. Create in your project dir "lib" dir.
3. Put there:
   • javacpp.jar
   • javacv.jar
   • javacv-windows-x86_64.jar
   • opencv-2.4.4-windows-x86_64.jar
   • opencv-244.jar

If your platform's bitness is 32 then use *x86.jar versions.

And then you may use this modified ant script from opencv/samples/java/ant/ to run your app:

<project name="JavaCv" basedir="." default="rebuild-run">

<property name="src.dir" value="src"/>
<property name="lib.dir" value="lib"/>
<path id="classpath">
    <fileset dir="${lib.dir}" includes="**/*.jar"/>
</path>

<property name="build.dir"   value="build"/>
<property name="classes.dir" value="${build.dir}/classes"/>
<property name="jar.dir"     value="${build.dir}/jar"/>

<property name="main-class"  value="${ant.project.name}"/>


<target name="clean">
    <delete dir="${build.dir}"/>
</target>

<target name="compile">
    <mkdir dir="${classes.dir}"/>
    <javac includeantruntime="false" srcdir="${src.dir}" destdir="${classes.dir}" classpathref="classpath"/>
</target>

<target name="jar" depends="compile">
    <mkdir dir="${jar.dir}"/>
    <jar destfile="${jar.dir}/${ant.project.name}.jar" basedir="${classes.dir}">
        <manifest>
            <attribute name="Main-Class" value="${main-class}"/>
        </manifest>
    </jar>
</target>

<target name="run" depends="jar">
    <java fork="true" classname="${main-class}">
        <classpath>
            <path refid="classpath"/>
            <path location="${jar.dir}/${ant.project.name}.jar"/>
        </classpath>
    </java>
</target>

<target name="rebuild" depends="clean,jar"/>

<target name="rebuild-run" depends="clean,run"/>

Or you may define ${java.library.path} in your ant script like this:

<target name="run" depends="jar">
    <java fork="true" classname="${main-class}">
        <sysproperty key="java.library.path" path="PUT_YOUR_PATH_HERE"/>
        <classpath>
            <path refid="classpath"/>
            <path location="${jar.dir}/${ant.project.name}.jar"/>
        </classpath>
    </java>
</target>

Answer 2

Did you try extracting the opencv directory as c:\opencv? That is an easy way to fix this.

Answer 3

There is a problem of the version of java cv and OpenCV.

If you use the OpenCV 2.4.7 then you should use the java cv 0.6 and if you use OpenCV 2.4.8 then you should use javacv 0.7.