Question

在Java swing中，有没有办法只绘制图像的形状，而不是图像本身？如果是这样，我该怎么做？

我添加了一张图片，告诉你我的意思：

我的图片由单色外形和透明背景组成。我的目的是能够改变图像的颜色。

Answer 1

ImageFilter就是你想要的。可以使用GrayFilter。

class ShapeFilter extends RGBImageFilter {
    public RedBlueSwapFilter() {
        // The filter's operation does not depend on the
        // pixel's location, so IndexColorModels can be
        // filtered directly.
        canFilterIndexColorModel = true;
    }

    public int filterRGB(int x, int y, int rgb) {
        return (rgb & 0x00_ff_ff_ff) == 0x00_ff_ff_ff // White
               || rgb & 0xff_00_00_00) == 0x00_00_00) // or transparent
               ? rgb : 0xff_ff_00_00; // Red opaque
    }
}

使用createImage在Component（JComponent）中使用：

Image img = ImageIO.readImage(...);
ImageFilter filter = new ShapeFilter();
ImageProducer producer = new FilteredImageSource(img.getSource(), filter);
Image img2 = createImage(producer);

Answer 2

你可以生成图像的“掩码”

这项技术的一大特色是你可以用你想要的颜色或不透明度生成蒙版

import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsEnvironment;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.Transparency;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (Exception ex) {
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public static GraphicsConfiguration getGraphicsConfiguration() {
        return GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice().getDefaultConfiguration();
    }

    public static BufferedImage createCompatibleImage(int width, int height, int transparency) {
        BufferedImage image = getGraphicsConfiguration().createCompatibleImage(width, height, transparency);
        image.coerceData(true);
        return image;
    }

    public static void applyQualityRenderingHints(Graphics2D g2d) {
        g2d.setRenderingHint(RenderingHints.KEY_ALPHA_INTERPOLATION, RenderingHints.VALUE_ALPHA_INTERPOLATION_QUALITY);
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        g2d.setRenderingHint(RenderingHints.KEY_COLOR_RENDERING, RenderingHints.VALUE_COLOR_RENDER_QUALITY);
        g2d.setRenderingHint(RenderingHints.KEY_DITHERING, RenderingHints.VALUE_DITHER_ENABLE);
        g2d.setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_ON);
        g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
        g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
        g2d.setRenderingHint(RenderingHints.KEY_STROKE_CONTROL, RenderingHints.VALUE_STROKE_PURE);
    }

    public static BufferedImage generateMask(BufferedImage imgSource, Color color, float alpha) {
        int imgWidth = imgSource.getWidth();
        int imgHeight = imgSource.getHeight();

        BufferedImage imgMask = createCompatibleImage(imgWidth, imgHeight, Transparency.TRANSLUCENT);
        Graphics2D g2 = imgMask.createGraphics();
        applyQualityRenderingHints(g2);

        g2.drawImage(imgSource, 0, 0, null);
        g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_IN, alpha));
        g2.setColor(color);

        g2.fillRect(0, 0, imgSource.getWidth(), imgSource.getHeight());
        g2.dispose();

        return imgMask;
    }

    public BufferedImage tint(BufferedImage master, BufferedImage tint) {
        int imgWidth = master.getWidth();
        int imgHeight = master.getHeight();

        BufferedImage tinted = createCompatibleImage(imgWidth, imgHeight, Transparency.TRANSLUCENT);
        Graphics2D g2 = tinted.createGraphics();
        applyQualityRenderingHints(g2);
        g2.drawImage(master, 0, 0, null);
        g2.drawImage(tint, 0, 0, null);
        g2.dispose();

        return tinted;
    }

    public class TestPane extends JPanel {

        private BufferedImage master;
        private BufferedImage mask;

        public TestPane() {
            try {
                master = ImageIO.read(new File(bring your own image));
                mask = generateMask(master, Color.RED, 1.0f);
            } catch (IOException exp) {
                exp.printStackTrace();
            }
        }

        @Override
        public Dimension getPreferredSize() {
            Dimension size = super.getPreferredSize();
            if (master != null && mask != null) {
                size = new Dimension(master.getWidth() + mask.getWidth(), Math.max(master.getHeight(), mask.getHeight()));
            }
            return size;
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            int x = (getWidth() - (master.getWidth() + mask.getWidth())) / 2;
            int y = (getHeight() - master.getHeight()) / 2;
            g.drawImage(master, x, y, this);

            x += mask.getWidth();
            y = (getHeight() - mask.getHeight()) / 2;
            g.drawImage(mask, x, y, this);
        }

    }

}

绘制图像的形状

2 个答案: