Java实现图片模糊效果详解

import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
 
public class BlurImageEffect extends JPanel {
    private BufferedImage image; // 原始图片
    private BufferedImage blurredImage; // 模糊后的图片
    private final int PANEL_WIDTH = 800; // 面板宽度
    private final int PANEL_HEIGHT = 600; // 面板高度
 
    public BlurImageEffect() {
        this.setPreferredSize(new Dimension(PANEL_WIDTH, PANEL_HEIGHT));
        this.setBackground(Color.WHITE);
 
        // 加载图片
        image = new ImageIcon("image.jpg").getImage(); // 请替换为实际图片路径
        blurredImage = new BufferedImage(image.getWidth(null), image.getHeight(null), BufferedImage.TYPE_INT_ARGB);
 
        // 创建模糊后的图片
        applyGaussianBlur();
 
        // 添加按钮，用于应用效果
        JButton button = new JButton("应用模糊效果");
        button.setBounds(10, PANEL_HEIGHT - 40, 200, 30);
        button.addActionListener(e -> {
            applyGaussianBlur();
            repaint(); // 更新界面
        });
        this.setLayout(null);
        this.add(button);
    }
 
    // 高斯模糊处理方法
    private void applyGaussianBlur() {
        int width = image.getWidth(null);
        int height = image.getHeight(null);
 
        // 高斯模糊核
        int size = 5; // 核的大小，影响模糊的程度
        double[][] kernel = createGaussianKernel(size, 1.0); // 创建高斯核，1.0是标准差
 
        // 对每个像素进行高斯模糊处理
        for (int y = size / 2; y < height - size / 2; y++) {
            for (int x = size / 2; x < width - size / 2; x++) {
                // 计算像素的新值
                int newColor = applyKernel(x, y, kernel, size, width, height);
                blurredImage.setRGB(x, y, newColor);
            }
        }
    }
 
    // 创建高斯核
    private double[][] createGaussianKernel(int size, double sigma) {
        double[][] kernel = new double[size][size];
        double sum = 0.0;
        int center = size / 2;
 
        // 创建高斯核
        for (int x = -center; x <= center; x++) {
            for (int y = -center; y <= center; y++) {
                kernel[x + center][y + center] = Math.exp(-(x * x + y * y) / (2 * sigma * sigma));
                sum += kernel[x + center][y + center];
            }
        }
 
        // 归一化，使得权重和为1
        for (int i = 0; i < size; i++) {
            for (int j = 0; j < size; j++) {
                kernel[i][j] /= sum;
            }
        }
        return kernel;
    }
 
    // 应用高斯核对图像进行模糊处理
    private int applyKernel(int x, int y, double[][] kernel, int size, int width, int height) {
        double r = 0, g = 0, b = 0;
 
        // 对周围像素应用高斯核
        int halfSize = size / 2;
        for (int ky = -halfSize; ky <= halfSize; ky++) {
            for (int kx = -halfSize; kx <= halfSize; kx++) {
                int pixel = new Color(image.getRGB(x + kx, y + ky)).getRGB();
                double weight = kernel[kx + halfSize][ky + halfSize];
 
                r += ((pixel >> 16) & 0xFF) * weight; // 红色通道
                g += ((pixel >> 8) & 0xFF) * weight;  // 绿色通道
                b += (pixel & 0xFF) * weight;          // 蓝色通道
            }
        }
 
        // 限制颜色值范围 [0, 255]
        r = Math.min(Math.max(r, 0), 255);
        g = Math.min(Math.max(g, 0), 255);
        b = Math.min(Math.max(b, 0), 255);
 
        // 返回新的像素值
        return (int)(r << 16) | (int)(g << 8) | (int)b;
    }
 
    // 绘制原始图片和模糊后的图片
    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
 
        // 绘制原始图片
        g.drawImage(image, 0, 0, PANEL_WIDTH / 2, PANEL_HEIGHT, this);
 
        // 绘制模糊后的图片
        g.drawImage(blurredImage, PANEL_WIDTH / 2, 0, PANEL_WIDTH / 2, PANEL_HEIGHT, this);
    }
 
    // 主方法，创建窗口并显示模糊效果
    public static void main(String[] args) {
        JFrame frame = new JFrame("图片模糊效果");
        BlurImageEffect imagePanel = new BlurImageEffect();
        frame.add(imagePanel);
        frame.pack();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }
}