tianai-captcha/src/main/java/cloud/tianai/captcha/template/slider/CaptchaImageUtils.java

package cloud.tianai.captcha.template.slider;

import lombok.SneakyThrows;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.Area;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.PixelGrabber;
import java.awt.image.WritableRaster;
import java.io.InputStream;
import java.net.URL;
import java.util.ArrayList;

/**
 * @Author: 天爱有情
 * @date 2022/2/16 9:46
 * @Description image Utils
 */
public class CaptchaImageUtils {

    @SneakyThrows
    public static BufferedImage wrapFile2BufferedImage(URL resourceImage) {
        if (resourceImage == null) {
            throw new IllegalArgumentException("包装文件到 BufferedImage 失败， file不能为空");
        }
        return ImageIO.read(resourceImage);
    }

    @SneakyThrows
    public static BufferedImage wrapFile2BufferedImage(InputStream resource) {
        if (resource == null) {
            throw new IllegalArgumentException("包装文件到 BufferedImage 失败， file不能为空");
        }
        return ImageIO.read(resource);
    }


    /**
     * 图片覆盖（覆盖图压缩到width*height大小，覆盖到底图上）
     *
     * @param baseBufferedImage  底图
     * @param coverBufferedImage 覆盖图
     * @param x                  起始x轴
     * @param y                  起始y轴
     */
    public static void overlayImage(BufferedImage baseBufferedImage, BufferedImage coverBufferedImage,
                                    int x, int y) {
        // 创建Graphics2D对象，用在底图对象上绘图
        Graphics2D g2d = baseBufferedImage.createGraphics();
        // 绘制
        g2d.drawImage(coverBufferedImage, x, y, coverBufferedImage.getWidth(), coverBufferedImage.getHeight(), null);
        // 释放图形上下文使用的系统资源
        g2d.dispose();
    }

    /**
     * 将Image图像中的透明/不透明部分转换为Shape图形
     *
     * @param img         图片信息
     * @param transparent 是否透明
     * @return Shape
     * @throws InterruptedException 异常
     */
    public static Shape getImageShape(Image img, boolean transparent) throws InterruptedException {
        ArrayList<Integer> x = new ArrayList<>();
        ArrayList<Integer> y = new ArrayList<>();
        int width = img.getWidth(null);
        int height = img.getHeight(null);

        // 首先获取图像所有的像素信息
        PixelGrabber pgr = new PixelGrabber(img, 0, 0, -1, -1, true);
        pgr.grabPixels();
        int[] pixels = (int[]) pgr.getPixels();

        // 循环像素
        for (int i = 0; i < pixels.length; i++) {
            // 筛选，将不透明的像素的坐标加入到坐标ArrayList x和y中
            int alpha = (pixels[i] >> 24) & 0xff;
            if (alpha != 0) {
                x.add(i % width > 0 ? i % width - 1 : 0);
                y.add(i % width == 0 ? (i == 0 ? 0 : i / width - 1) : i / width);
            }
        }

        // 建立图像矩阵并初始化(0为透明,1为不透明)
        int[][] matrix = new int[height][width];
        for (int i = 0; i < height; i++) {
            for (int j = 0; j < width; j++) {
                matrix[i][j] = 0;
            }
        }

        // 导入坐标ArrayList中的不透明坐标信息
        for (int c = 0; c < x.size(); c++) {
            matrix[y.get(c)][x.get(c)] = 1;
        }

        /*
         * 逐一水平"扫描"图像矩阵的每一行，将透明（这里也可以取不透明的）的像素生成为Rectangle，
         * 再将每一行的Rectangle通过Area类的rec对象进行合并， 最后形成一个完整的Shape图形
         */
        Area rec = new Area();
        int temp = 0;
        //生成Shape时是1取透明区域还是取非透明区域的flag
        int flag = transparent ? 0 : 1;

        for (int i = 0; i < height; i++) {
            for (int j = 0; j < width; j++) {
                if (matrix[i][j] == flag) {
                    if (temp == 0) {
                        temp = j;
                    }
                } else {
                    if (temp != 0) {
                        rec.add(new Area(new Rectangle(temp, i, j - temp, 1)));
                        temp = 0;
                    }
                }
            }
            temp = 0;
        }
        return rec;
    }

    /**
     * 深度拷贝图片
     *
     * @param bi 原图片
     * @return BufferedImage
     */
    public static BufferedImage deepCopyBufferedImage(BufferedImage bi) {
        ColorModel cm = bi.getColorModel();
        boolean isAlphaPremultiplied = cm.isAlphaPremultiplied();
        WritableRaster raster = bi.copyData(bi.getRaster().createCompatibleWritableRaster());
        return new BufferedImage(cm, raster, isAlphaPremultiplied, null);
    }

    /**
     * 通过模板图片抠图（不透明部分）
     *
     * @param origin   源图片
     * @param template 模板图片
     * @param x        坐标轴x
     * @param y        坐标轴y
     * @return BufferedImage
     */
    @SneakyThrows
    public static BufferedImage cutImage(BufferedImage origin, BufferedImage template, int x, int y) {
        int bw = template.getWidth(null);
        int bh = template.getHeight(null);
        int lw = origin.getWidth(null);
        int lh = origin.getHeight(null);
        //得到透明的区域(人物轮廓)
        Shape imageShape = getImageShape(template, false);
        //合成后的图片
        BufferedImage image = new BufferedImage(bw, bh, BufferedImage.TYPE_INT_ARGB);
        Graphics2D graphics = image.createGraphics();
        //设置画布为透明
        image = graphics.getDeviceConfiguration().createCompatibleImage(bw, bh, Transparency.TRANSLUCENT);
        graphics.dispose();
        Graphics2D graphics2 = image.createGraphics();
        //取交集(限制可以画的范围为shape的范围)
        graphics2.clip(imageShape);
        //抗锯齿
        graphics2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        graphics2.setStroke(new BasicStroke(5, BasicStroke.CAP_BUTT, BasicStroke.JOIN_BEVEL));
        graphics2.drawImage(origin, -x, -y, lw, lh, null);
        graphics2.dispose();
        return image;
    }


}