在Java中如何在Graphics2D中使用高斯模糊绘制背景

import java.awt.AlphaComposite;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.awt.image.ConvolveOp;
import java.awt.image.Kernel;

BufferedImage background = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);

Graphics2D g2d = background.createGraphics();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);

// 绘制图片示例
g2d.drawImage(image, 0, 0, null);

float radius = 10.0f; // 模糊半径，可以根据需要调整
GaussianBlurFilter filter = new GaussianBlurFilter(radius);

ConvolveOp blurOp = new ConvolveOp(filter);
g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.5f)); // 设置透明度，可以根据需要调整
g2d.drawImage(background, blurOp, 0, 0);

g2d.dispose();

import java.awt.AlphaComposite;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.awt.image.ConvolveOp;
import java.awt.image.Kernel;

public class GaussianBlurExample {
    public static void main(String[] args) {
        int width = 800; // 背景宽度
        int height = 600; // 背景高度

        // 创建背景图片
        BufferedImage background = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);

        // 获取Graphics2D对象，并设置抗锯齿和渲染质量
        Graphics2D g2d = background.createGraphics();
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);

        // 在背景上绘制需要模糊的内容，例如图片或其他图形
        // g2d.drawImage(image, 0, 0, null);

        // 创建高斯模糊滤镜
        float radius = 10.0f; // 模糊半径，可以根据需要调整
        GaussianBlurFilter filter = new GaussianBlurFilter(radius);

        // 创建卷积操作对象，并将其作为参数传递给Graphics2D对象的setComposite方法
        ConvolveOp blurOp = new ConvolveOp(filter);
        g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.5f)); // 设置透明度，可以根据需要调整
        g2d.drawImage(background, blurOp, 0, 0);

        // 释放Graphics2D对象
        g2d.dispose();
    }
}

// 高斯模糊滤镜类
class GaussianBlurFilter extends ConvolveOp {
    public GaussianBlurFilter(float radius) {
        int size = Math.round(radius * 3) * 2 + 1;
        float[] data = new float[size * size];
        float sigma = radius / 3;
        float twoSigmaSquare = 2 * sigma * sigma;
        float sigmaRoot = (float) Math.sqrt(twoSigmaSquare * Math.PI);
        float total = 0;
        int index = 0;
        for (int row = -size / 2; row <= size / 2; row++) {
            for (int col = -size / 2; col <= size / 2; col++) {
                float distance = row * row + col * col;
                data[index] = (float) Math.exp(-distance / twoSigmaSquare) / sigmaRoot;
                total += data[index];
                index++;
            }
        }
        for (int i = 0; i < data.length; i++) {
            data[i] /= total;
        }
        Kernel kernel = new Kernel(size, size, data);
        super(kernel, ConvolveOp.EDGE_NO_OP, null);
    }
}