Grabcut example

[Larienas]

Hello,

  I am using grabcut as shown in the example https://github.com/bytedeco/javacv-examples/blob/master/OpenCV_Cookbook/src/main/scala/opencv_cookbook/chapter05/Ex5GrabCut.scala

  I have done one to one translation from scala example to java as show below

import java.io.File;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;

import javax.swing.WindowConstants;

import org.bytedeco.javacpp.BytePointer;

import org.bytedeco.javacpp.annotation.ByVal;

import org.bytedeco.javacpp.indexer.FloatIndexer;

import org.bytedeco.javacpp.indexer.IntIndexer;

import org.bytedeco.javacpp.indexer.UByteIndexer;

import org.bytedeco.javacv.CanvasFrame;

import org.bytedeco.javacv.OpenCVFrameConverter;

import org.bytedeco.javacv.OpenCVFrameConverter.ToMat;

import org.bytedeco.opencv.global.opencv_imgproc;

import org.bytedeco.opencv.opencv_core.*;

import org.bytedeco.opencv.opencv_imgproc.*;

import static org.bytedeco.opencv.global.opencv_core.*;

import static org.bytedeco.opencv.global.opencv_imgcodecs.*;

import static org.bytedeco.opencv.global.opencv_imgproc.*;

public class GrabcutExample {

public static void main(String[] args) {

String file = "group.jpg";

Mat src = OpenCVUtilsJava.loadAndShowOrExit(new File(file), IMREAD_COLOR);

Rect rect = new Rect(10, 100, 380, 180);

Mat result = new Mat();

int iterCount = 5;

int mode = GC_INIT_WITH_RECT;

Mat bgdModel = new Mat();

Mat fgdModel = new Mat();

grabCut(src, result, rect, bgdModel, fgdModel, iterCount, mode);

threshold(result, result, GC_PR_FGD - 0.5, GC_PR_FGD + 0.5, THRESH_BINARY);

display(result, "Result foreground mask");

}

static void display(Mat image, String caption) {

// Create image window named "My Image".

final CanvasFrame canvas = new CanvasFrame(caption, 1.0);

// Request closing of the application when the image window is closed.

canvas.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

// Convert from OpenCV Mat to Java Buffered image for display

final OpenCVFrameConverter converter = new OpenCVFrameConverter.ToMat();

// Show image on window.

canvas.showImage(converter.convert(image));

}

}

The result I am getting is just a black screen. Could anyone help me to get it right. I have also attached "group.jpg" pic if anyone tries to execute the code

With Regards,

Larienas

[Samuel Audet]

On 4/6/20 10:23 AM, Larienas wrote:
>   I am using grabcut as shown in the example
> https://github.com/bytedeco/javacv-examples/blob/master/OpenCV_Cookbook/src/main/scala/opencv_cookbook/chapter05/Ex5GrabCut.scala
>
>   I have done one to one translation from scala example to java as show below

I would recommend to take a look at the original sample in C++ here:
https://github.com/opencv/opencv/blob/master/samples/cpp/grabcut.cpp

If it's still not clear what you're missing, please ask again! Thanks

Samuel

[larien...@gmail.com]

Hello Samuel,

I am very new to Open CV and I am not an expert in C/C++. I know Java that’s why I using JAVACV, otherwise I would have used OpenCV in C++ itself.

I really don’t know what I should look for in the original code to make my Java code work.

When I went through the original code it is also calling " grabCut" function.

As you are the expert it would be very much helpful to get a working example of grabcut

With Regards,
Lariena

[Samuel Audet]

From the Scala example, it just looks like you forgot the call to
toMat8U(). Try adding that and it should work!

[larien...@gmail.com]

Hello Samuel,

It is working 😊 Thank you so much. Much appreciated

With Regards,
Larienas