package com.zhou.opencv.example;

import com.zhou.opencv.example.common.ListDisplayPanel;
import com.zhou.opencv.example.utils.BufferImageUtil;
import com.zhou.opencv.example.utils.ShowImages;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.core.Scalar;
import org.opencv.highgui.HighGui;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;

import java.io.File;
import java.io.IOException;
import java.util.Arrays;
import java.util.Comparator;

/**
 * 图像灰度变换
 *
 * @author zhoucq
 * @date 2023/10/25
 */
public class OpencvGrayImage {
    private static final String imageResultPath = "image/result/";
    private static final String imagePath = "image/cat.jpg";

    public static void main(String[] args) throws Exception {
        //取消热部署，防止opencv加载报错，没有热部署可忽略
        System.setProperty("spring.devtools.restart.enabled", "false");
        //加载绝对路径下的dll
        System.load("E:\\workspace\\opencv\\lib\\opencv_java455.dll");
        grayImage(imagePath);
    }

    /**
     * opencv自带HighGui显示图片
     *
     * @param filePath
     * @throws Exception
     */
    public static void showImage(String filePath) throws Exception {
        ListDisplayPanel gui = new ListDisplayPanel();
        //读取图片
        Mat src = Imgcodecs.imread(filePath, Imgcodecs.IMREAD_COLOR);
        //创建显示窗口，不加这行代码，也能显示，默认窗口大小不能改变
        HighGui.namedWindow("原图");
        //在窗口显示图像
        HighGui.imshow("原图", src);

        //检测图像是否加载成功
        if (src.empty()) {
            System.out.println("not find the image");
            return;
        }

        File file = new File(imageResultPath);
        if (!file.isDirectory()) {
            if (!file.mkdirs()) {
                throw new Exception("文件夹创建失败：" + imageResultPath);
            }
        }

        //图像保存
        Imgcodecs.imwrite(String.format(imageResultPath + "save.jpg"), src);
        //暂停，保持图像显示，等待按键结束
        HighGui.waitKey(0);
    }

    /**
     * 灰度三种测试，opencv默认是加权平均值法
     *
     * @throws IOException
     */
    public static void grayImage(String filePath) throws IOException {
        ListDisplayPanel gui = new ListDisplayPanel();
        Mat src = Imgcodecs.imread(filePath, Imgcodecs.IMREAD_COLOR);
        //检测图像是否加载成功
        if (src.empty()) {
            System.out.println("not find the image");
            return;
        }
        gui.addImage("原图", BufferImageUtil.mat2BufferedImage(src));

        //自定义空白单通道图像，用于存放灰度图
        Mat dst = new Mat(src.size(), CvType.CV_8UC1);
        dst.setTo(new Scalar(255, 255, 255));
        Imgproc.cvtColor(src, dst, Imgproc.COLOR_BGR2GRAY);
        gui.addImage("opencv默认灰度", BufferImageUtil.mat2BufferedImage(dst));

        for (int row = 0; row < src.rows(); row++) {
            for (int col = 0; col < src.cols(); col++) {
                if (src.channels() == 3) {
                    double[] colors = src.get(row, col);
                    //加权平均值法D=0.299R+0.587G+0.114*B
                    double color = colors[0] * 0.114 + colors[1] * 0.587 + colors[2] * 0.299;
                    dst.put(row, col, color);
                }
            }
        }
        gui.addImage("加权平均值法", BufferImageUtil.mat2BufferedImage(dst));
        //平均值法
        for (int row = 0; row < src.rows(); row++) {
            for (int col = 0; col < src.cols(); col++) {
                if (src.channels() == 3) {
                    double[] colors = src.get(row, col);
                    double color = Math.floorDiv((long) (colors[0] + colors[1] + colors[2]), 3);
                    dst.put(row, col, color);
                }
            }
        }
        gui.addImage("平均值法", BufferImageUtil.mat2BufferedImage(dst));
        //最大值
        for (int row = 0; row < src.rows(); row++) {
            for (int col = 0; col < src.cols(); col++) {
                if (src.channels() == 3) {
                    double[] colors = src.get(row, col);
                    Double color = Arrays.stream(colors).boxed().max(Comparator.comparing(x -> x)).orElse(null);
                    dst.put(row, col, color);
                }
            }
        }
        gui.addImage("最大值法", BufferImageUtil.mat2BufferedImage(dst));
        ShowImages.showWindow(gui, "灰度的三种测试", true);
    }
}