Hi, I am new to openCV. Please help me resolve "null pointer exception" issue when I execute the below code.
Thanks in advance.
/**
Program
**/
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.MatOfFloat;
import org.opencv.core.MatOfInt;
import org.opencv.imgproc.Imgproc;
import java.io.File;
import java.io.IOException;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import static org.opencv.core.Core.split;
import static org.opencv.imgcodecs.Imgcodecs.imread;
public class Manu {
static{
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
System.out.println("Executing library "+Core.NATIVE_LIBRARY_NAME);
}
public static void main(String[] args) {
System.out.println("Welcome to OpenCV " + Core.VERSION);
Path p = null;
try {
p = Paths.get(new File(".").getCanonicalPath() + "/src/resource/ostracon - design.png");
} catch (IOException e) {
e.printStackTrace();
}
Mat src, dst;
src = imread(p.toString()+" ");
if(src.empty()){
System.out.println("Image could not be loaded..");
System.exit(1);
}
ArrayList rgb_planes = new ArrayList(3);
split(src,rgb_planes);
int histSize = 256;
float range[] = {0,256};
float histRange[][] = {range};
boolean uniform = true;
boolean accumulate = false;
Mat rHist = null,gHist,bHist;
Imgproc.calcHist(rgb_planes,new MatOfInt(1),new Mat(),rHist, new MatOfInt(histSize),new MatOfFloat(range),accumulate);
}
}
**Error that I am facing -**
Executing library opencv_java310
Welcome to OpenCV 3.1.0
Exception in thread "main" java.lang.NullPointerException
at org.opencv.imgproc.Imgproc.calcHist(Imgproc.java:1487)
at master.Manu.main(Manu.java:51)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
Process finished with exit code 1
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