java - 如何使用opencv java识别黑色

Question

我正在进行图像处理，以识别 quartz sample 上的铁颗粒，为此，我必须识别浅灰色背景中的黑色 Blob 。我建立了一个java程序来做到这一点。然而该程序没有识别图像中的黑点。请帮我解决这个问题。

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package imageprocessing;

import java.awt.image.BufferedImage;
import java.awt.image.DataBufferByte;
import java.io.File;
import java.util.ArrayList;
import java.util.List;
import javax.imageio.ImageIO;
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.core.MatOfPoint;
import org.opencv.core.Point;
import org.opencv.core.Rect;
import org.opencv.core.Scalar;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;

/**
 *
 * @author My Kindom
 */
public class imageprocessingf extends javax.swing.JFrame {

    /**
     * Creates new form imageprocessingf
     */
    double sum =0;
    public imageprocessingf() {
        initComponents();
    }
    public double imageprocessing1(){
        try{
            System.loadLibrary( Core.NATIVE_LIBRARY_NAME);
            //BufferedImage image= ImageIO.read(new File("C:\\Users\\My Kindom\\Desktop\\printscreen.JPG"));
            BufferedImage image= ImageIO.read(new File("C:\\Users\\Samarasinghe\\Downloads\\IS_1.jpg"));      
            byte[] data =((DataBufferByte) image.getRaster().getDataBuffer()).getData();
                    Mat mat = new Mat(image.getHeight(),image.getWidth(), CvType.CV_8UC3);
                    mat.put(0, 0, data);

                    Mat mat1 = new Mat(image.getHeight(), image.getWidth(), CvType.CV_8UC3);
                    Imgproc.cvtColor(mat, mat1, Imgproc.COLOR_RGB2HSV);

                    byte[] data1 = new byte[mat1.rows()*mat1.cols()*(int)(mat1.elemSize())];
                    mat1.get(0, 0, data1);
                    BufferedImage image1 = new BufferedImage(mat1.cols(), mat1.rows(), 5);
                    image1.getRaster().setDataElements(0, 0, mat1.cols(), mat1.rows(), data1);

                    ImageIO.write(image1, "jpg", new File("C:\\Users\\Samarasinghe\\Desktop\\hsv.jpg"));
                    Mat source = Imgcodecs.imread("C:\\Users\\Samarasinghe\\Desktop\\hsv.jpg",Imgcodecs.CV_LOAD_IMAGE_COLOR);
                    Mat destination = new Mat(source.rows(),source.cols(),source.type());
                    destination = source;


                    Scalar lowerb=new Scalar (0,0,0);
                    Scalar upperb=new Scalar (180,255,30);

                    Core.inRange(source, lowerb, upperb, destination);
                    Imgcodecs.imwrite("C:\\Users\\Samarasinghe\\Desktop\\ThreshZero.jpg", destination);


                    List<MatOfPoint> contours= new ArrayList<>();
                    Mat hierarchy =new Mat();

                    Imgproc.findContours(destination, contours, hierarchy,Imgproc.RETR_EXTERNAL,Imgproc.CHAIN_APPROX_SIMPLE);
                    for(int j=0;j<contours.size();j++){
                          double[] d= hierarchy.get(0, j);
                          Rect rect = Imgproc.boundingRect(contours.get(j));
                          Point pt1=new Point(rect.x,rect.y);
                          Point pt2=new Point(rect.x+rect.width,rect.y+rect.height);
                          Scalar  eder=new Scalar(0,255,0);
                          Imgproc.rectangle(destination, pt1, pt2, eder,2);
                          Mat contour = contours.get(j);
                          double contourarea=Imgproc.contourArea(contour);
                          sum = sum + contourarea;

                    }System.out.println("Sum"+sum);



        }catch(Exception e){

        }
        return sum ;

    };

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jButton1 = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jButton1.setText("jButton1");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap(272, Short.MAX_VALUE)
                .addComponent(jButton1)
                .addGap(55, 55, 55))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap(164, Short.MAX_VALUE)
                .addComponent(jButton1)
                .addGap(113, 113, 113))
        );

        pack();
    }// </editor-fold>                        

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        imageprocessing1();
    }                                        

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(imageprocessingf.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(imageprocessingf.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(imageprocessingf.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(imageprocessingf.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>
        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new imageprocessingf().setVisible(true);

            }
        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JButton jButton1;
    // End of variables declaration                   
}

Answer 1

我猜你的图像背景中有一些阴影，全局阈值不会给出预期的结果!

您可以尝试使用自适应阈值或 top/bottom-hat transformation + 分割粒子的全局阈值。因此，将图像加载为灰度，忘记 Imgproc.cvtColor并将 Core.InRange 替换为您的分段方法，例如 threshold、adaptiveThreshold 或其他；)

这是一些 C++ 示例代码:

//Binarization using fixed threshold -> failed because of shading background
threshold(source,otsu, 0, max_value, THRESH_OTSU);
//Adaptive threshold
adaptiveThreshold(source, adaptive, 255, ADAPTIVE_THRESH_MEAN_C,CV_THRESH_BINARY, 25, 11);

//Segmentation with Black-Hat to uniform background
int const morph_size = 20;
Mat element = getStructuringElement(CV_SHAPE_ELLIPSE, Size(2 * morph_size + 1, 2 * morph_size + 1), Point(morph_size, morph_size));
morphologyEx(source, morph, MORPH_BLACKHAT, element);
threshold(morph, destination, 16, 255, THRESH_BINARY_INV);

大津: 自适应: 黑帽: