diff --git a/EXP_four.m b/EXP_four.m
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+% 读取图片
+image = imread('EXP_3_4/test.jpg');
+image_airport = imread('EXP_3_4/airport.jpg');
+image_circuit = imread('EXP_3_4/circuit.png');
+image_circle = imread('EXP_3_4/circle.jpg');
+
+% 灰度化
+image_gray = rgb2gray(image);
+image_airport_gray = rgb2gray(image_airport);
+image_circle_gray = rgb2gray(image_circle);
+
+% log算法
+image_log = edge(image_gray, 'log');
+
+% canny算法
+image_canny = edge(image_gray, 'canny');
+image_circuit_canny = edge(image_circuit, 'canny');
+
+% 角点检测
+image_corners = corner(image_airport_gray, 'Harris');
+
+% Hough参数
+[Hough, theta, rho] = hough(image_circuit_canny);
+
+% Hough 峰值
+P = houghpeaks(Hough, 10, 'Threshold', ceil(0.3 * max(Hough(:))));  % 取前10个峰
+
+% 峰值中提取图像中的直线
+lines = houghlines(image_circuit_canny, theta, rho, P, 'FillGap', 20, 'MinLength', 30);
+
+% 圆特征提取
+[centers, radii] = imfindcircles(image_circle_gray, [50 100], 'ObjectPolarity', 'bright', 'Sensitivity', 0.92);
+
+% 展示照片
+figure;
+subplot(1,3,1);
+imshow(image);
+title('Original Image'); % 原图
+subplot(1,3,2);
+imshow(image_log);
+title('Log Edge Detection'); % Log边缘检测
+subplot(1,3,3);
+imshow(image_canny);
+title('Canny Edge Detection'); % Canny边缘检测
+
+figure;
+subplot(1,2,1);
+imshow(image_airport);
+title('Original Image'); % 原图
+subplot(1,2,2);
+imshow(image_airport);
+title('Corner Detection'); % 角点检测
+hold on;
+plot(image_corners(:,1), image_corners(:,2), 'r*');
+
+% 显示图像与直线
+figure;
+imshow(image_circuit);
+hold on;
+title('Line Edge Detection'); %直线边缘检测
+
+for k = 1:length(lines)
+    xy = [lines(k).point1; lines(k).point2];  % 两端点
+    plot(xy(:,1), xy(:,2), 'LineWidth', 2, 'Color', 'green');
+
+    % 可视化端点
+    plot(xy(1,1), xy(1,2), 'x', 'Color', 'yellow');
+    plot(xy(2,1), xy(2,2), 'x', 'Color', 'red');
+end
+
+figure;
+subplot(1,2,1);
+imshow(image_circle);
+title('Original Image'); % 原图
+subplot(1,2,2);
+imshow(image_circle);
+title('Coin Edge Detection'); % 硬币边缘检测
+hold on;
+viscircles(centers, radii, 'EdgeColor', 'r');
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