“一点点”数字运算可以定义图像中特定颜色的区域或形状。EG 从这个开始：

_{原始图像，裁剪并缩小为二值（2 色）图像，然后海洋洪水填满。除了在 Java 代码中完成的洪水填充之外的所有内容均未显示。}

然后根据接近白色的颜色运行形状算法（请耐心等待 - 这需要一段时间），将产生一系列用于在顶部渲染的区域。添加了鼠标运动侦听器以将指针下方的区域着色为深绿色。

这是生成该图像的代码。鼠标指针当前指向中国。

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.awt.image.BufferedImage;
import java.net.URL;
import java.util.ArrayList;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
import javax.imageio.ImageIO;

/* 
 Outline code from:
 /sf/ask/505281661/
 */
public class WorldMapArea {

    private JComponent ui = null;
    JLabel output = new JLabel();
    public static final int SIZE = 750;
    BufferedImage image;
    Area area;
    ArrayList<Shape> shapeList;

    public WorldMapArea() {
        try {
            initUI();
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    public final void initUI() throws Exception {
        if (ui != null) {
            return;
        }
        URL url = new URL("https://i.stack.imgur.com/N4eOn.png");
        image = ImageIO.read(url);
        long then = System.currentTimeMillis();
        System.out.println("" + then);
        area = getOutline(Color.WHITE, image, 12);
        long now = System.currentTimeMillis();
        System.out.println("Time in mins: " + (now - then) / 60000d);
        shapeList = separateShapeIntoRegions(area);
        ui = new JPanel(new BorderLayout(4, 4));
        ui.setBorder(new EmptyBorder(4, 4, 4, 4));

        output.addMouseMotionListener(new MousePositionListener());

        ui.add(output);

        refresh();
    }

    public Area getOutline(Color target, BufferedImage bi, int tolerance) {
        // construct the GeneralPath
        GeneralPath gp = new GeneralPath();

        boolean cont = false;
        for (int xx = 0; xx < bi.getWidth(); xx++) {
            for (int yy = 0; yy < bi.getHeight(); yy++) {
                if (isIncluded(new Color(bi.getRGB(xx, yy)), target, tolerance)) {
                    //if (bi.getRGB(xx,yy)==targetRGB) {
                    if (cont) {
                        gp.lineTo(xx, yy);
                        gp.lineTo(xx, yy + 1);
                        gp.lineTo(xx + 1, yy + 1);
                        gp.lineTo(xx + 1, yy);
                        gp.lineTo(xx, yy);
                    } else {
                        gp.moveTo(xx, yy);
                    }
                    cont = true;
                } else {
                    cont = false;
                }
            }
            cont = false;
        }
        gp.closePath();

        // construct the Area from the GP & return it
        return new Area(gp);
    }

    public static ArrayList<Shape> separateShapeIntoRegions(Shape shape) {
        ArrayList<Shape> regions = new ArrayList<>();

        PathIterator pi = shape.getPathIterator(null);
        GeneralPath gp = new GeneralPath();
        while (!pi.isDone()) {
            double[] coords = new double[6];
            int pathSegmentType = pi.currentSegment(coords);
            int windingRule = pi.getWindingRule();
            gp.setWindingRule(windingRule);
            if (pathSegmentType == PathIterator.SEG_MOVETO) {
                gp = new GeneralPath();
                gp.setWindingRule(windingRule);
                gp.moveTo(coords[0], coords[1]);
            } else if (pathSegmentType == PathIterator.SEG_LINETO) {
                gp.lineTo(coords[0], coords[1]);
            } else if (pathSegmentType == PathIterator.SEG_QUADTO) {
                gp.quadTo(coords[0], coords[1], coords[2], coords[3]);
            } else if (pathSegmentType == PathIterator.SEG_CUBICTO) {
                gp.curveTo(
                        coords[0], coords[1],
                        coords[2], coords[3],
                        coords[4], coords[5]);
            } else if (pathSegmentType == PathIterator.SEG_CLOSE) {
                gp.closePath();
                regions.add(new Area(gp));
            } else {
                System.err.println("Unexpected value! " + pathSegmentType);
            }

            pi.next();
        }

        return regions;
    }

    class MousePositionListener implements MouseMotionListener {

        @Override
        public void mouseDragged(MouseEvent e) {
            // do nothing
        }

        @Override
        public void mouseMoved(MouseEvent e) {
            refresh();
        }
    }

    public static boolean isIncluded(Color target, Color pixel, int tolerance) {
        int rT = target.getRed();
        int gT = target.getGreen();
        int bT = target.getBlue();
        int rP = pixel.getRed();
        int gP = pixel.getGreen();
        int bP = pixel.getBlue();
        return ((rP - tolerance <= rT) && (rT <= rP + tolerance)
                && (gP - tolerance <= gT) && (gT <= gP + tolerance)
                && (bP - tolerance <= bT) && (bT <= bP + tolerance));
    }

    private void refresh() {
        output.setIcon(new ImageIcon(getImage()));
    }

    private BufferedImage getImage() {
        BufferedImage bi = new BufferedImage(
                2 * SIZE, SIZE, BufferedImage.TYPE_INT_RGB);

        Graphics2D g = bi.createGraphics();
        g.drawImage(image, 0, 0, output);
        g.setColor(Color.ORANGE.darker());
        g.fill(area);
        g.setColor(Color.RED);
        g.draw(area);
        try {
            Point p = MouseInfo.getPointerInfo().getLocation();
            Point p1 = output.getLocationOnScreen();
            int x = p.x - p1.x;
            int y = p.y - p1.y;
            Point pointOnImage = new Point(x, y);
            for (Shape shape : shapeList) {
                if (shape.contains(pointOnImage)) {
                    g.setColor(Color.GREEN.darker());
                    g.fill(shape);
                    break;
                }
            }
        } catch (Exception doNothing) {
        }

        g.dispose();

        return bi;
    }

    public JComponent getUI() {
        return ui;
    }

    public static void main(String[] args) {
        Runnable r = () -> {
            try {
                UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
            } catch (Exception ex) {
                ex.printStackTrace();
            }
            WorldMapArea o = new WorldMapArea();

            JFrame f = new JFrame(o.getClass().getSimpleName());
            f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
            f.setLocationByPlatform(true);

            f.setContentPane(o.getUI());
            f.setResizable(false);
            f.pack();

            f.setVisible(true);
        };
        SwingUtilities.invokeLater(r);
    }
}

• (1+) worth the wait...
• ...............wow