基于OpenCV+C++的答题卡识别系统源码+使用文档+全部资料（优秀项目）.zip

#include <opencv2/opencv.hpp> #include <iostream> #include <string.h> #include <vector> using namespace std; using namespace cv; string pathname = "D:\\Microsoft VS Code\\OpenCV\\cpp\\omr3.jpg"; Mat img, imgGray, imgBlur, imgCanny, imgContours, imgWarp, imgWarpGrade, imgThre, imgWarpGray, imgWarpGradeGray, imgGradeThre; vector<Point> docPoint_max, docPoint_grade; vector<Mat> boxes; vector<vector<Point>> getContours(Mat imgage) { // 四个角点，闭合轮廓 // 怎样让涂卡区从众多矩形中脱颖而出，面积，周长 // 两个ROI，1.涂卡区 2.成绩 vector<vector<Point>> contours; vector<Vec4i> hierarchy; findContours(imgage, contours, hierarchy, RETR_EXTERNAL, CHAIN_APPROX_NONE); vector<vector<Point>> biggest; // 涂卡区 // vector<vector<Point>> greade; // 成绩区 vector<vector<Point>> recCon(contours.size()); // 轮廓的角点坐标 int maxArea = 0; for (int i = 0; i < contours.size(); ++i) { // 遍历每一个轮廓 double area = contourArea(contours[i], false); if (area > 300) { double peri = arcLength(contours[i], true); approxPolyDP(contours[i], recCon[i], 0.1 * peri, true); if (recCon[i].size() == 4 && area > maxArea) { // drawContours(img, recCon, i, Scalar(0, 255, 0)); // imshow("drawContours", img); maxArea = area; biggest.push_back(recCon[i]); } } } return biggest; } // 画点 void drawPoints(Mat image, vector<Point> cPoint, Scalar color) { for (int i = 0; i < cPoint.size(); ++i) { circle(image, cPoint[i], 5, color, FILLED); putText(image, to_string(i), cPoint[i], FONT_HERSHEY_PLAIN, 5, color, 3); } return ; } // 给点重新排序 vector<Point> reorder(vector<Point> points) { vector<Point> newPoints; vector<int> sumPoints, subPoints; for (int i = 0; i < points.size(); ++i) { sumPoints.push_back(points[i].x + points[i].y); subPoints.push_back(points[i].x - points[i].y); } newPoints.push_back(points[min_element(sumPoints.begin(), sumPoints.end()) - sumPoints.begin()]); newPoints.push_back(points[max_element(subPoints.begin(), subPoints.end()) - subPoints.begin()]); newPoints.push_back(points[min_element(subPoints.begin(), subPoints.end()) - subPoints.begin()]); newPoints.push_back(points[max_element(sumPoints.begin(), sumPoints.end()) - sumPoints.begin()]); return newPoints; } // 仿射变换 Mat getWarp(Mat image, vector<Point> points, float w, float h) { Mat imgWarp; Point2f src[4] = {points[0], points[1], points[2], points[3]}; Point2f dst[4] = {{0.0f, 0.0f}, {w, 0.0f}, {0.0f, h}, {w, h}}; Mat matrix = getPerspectiveTransform(src, dst); warpPerspective(image, imgWarp, matrix, Point(w, h)); return imgWarp; } Mat getreWarp(Mat image, vector<Point> points, float w, float h, float sizew, float sizeh) { Mat imgWarp; Point2f src[4] = {points[0], points[1], points[2], points[3]}; Point2f dst[4] = {{0.0f, 0.0f}, {w, 0.0f}, {0.0f, h}, {w, h}}; Mat matrix = getPerspectiveTransform(dst, src); warpPerspective(image, imgWarp, matrix, Point(sizew, sizeh)); return imgWarp; } // 图像分割 vector<Mat> splitBox(Mat img) { vector<Mat> boxes; Mat img_cut, rio_img; int m = img.cols / 5; // 宽度 int n = img.rows / 5; // 高度 for (int i = 0; i < 5; ++i) { for (int j = 0; j < 5; ++j) { Rect rect(i * n, j * n, 60, 60); img_cut = Mat(img, rect); rio_img = img_cut.clone(); boxes.push_back(rio_img); } } // for (int i = 0; i < boxes.size(); ++i) { // string num = to_string(i); // imshow(num, boxes[i]); // } return boxes; } // 答案展示 Mat showAnswer(Mat img, vector<int> index, vector<int> grading, vector<int> ans, int question, int choice) { int secW = img.cols / choice; int secH = img.rows / question; Scalar color; for (int i = 0; i < question; ++i) { int sx = (index[i] * secW) + (secW / 2); int sy = (i * secH) + (secH / 2); if (grading[i] == 1) { color = Scalar(0, 255, 0); } else { color = Scalar(0, 0, 255); circle(img, Point((ans[i] * secW) + (secW / 2), sy), 10, Scalar(0, 255, 0), FILLED); } circle(img, Point(sx, sy), 20, color, FILLED); } return img; } #define CAM_BEGIN { #define CAM_END } int main() { // 从摄像头读 // bool cam = true; // VideoCapture cap(1); // while(true) CAM_BEGIN // if (cam) { // cap.read(img); // } else { // img = imread(pathname); // } // 从图片中读 img = imread(pathname); resize(img, img, Size(500, 500)); cvtColor(img, imgGray, COLOR_BGR2GRAY); GaussianBlur(imgGray, imgBlur, Size(5, 5), 0, 0); Canny(imgBlur, imgCanny, 50, 25, 3); imshow("img", img); // imshow("imgGray", imgGray); // imshow("imgBlur", imgBlur); // imshow("imgCanny", imgCanny); // threshold(imgBlur, imgThre, 180, 255, THRESH_BINARY); // imshow("imgThre", imgThre); // Mat temp; // threshold(imgBlur, temp, 180, 255, THRESH_BINARY_INV); // imshow("temp", temp); vector<vector<Point>> contours; vector<vector<Point>> cPoint; vector<Vec4i> hierarchy; imgContours = img.clone(); // findContours(imgCanny, contours, hierarchy, RETR_EXTERNAL, CHAIN_APPROX_NONE); // drawContours(imgContours, contours, -1, Scalar(0, 255, 0), 2); // 如何找到涂卡区的矩形轮廓 cPoint = getContours(imgCanny); /* 读图片模式下将下四行注释 */ // if (cPoint.size() < 2) { // waitKey(1); // continue; // } drawContours(imgContours, cPoint, -1, Scalar(0, 255, 0), 2); // imshow("imgContours", imgContours); /* 0.重新排序四个角点 */ // drawPoints(img, cPoint[0], Scalar(0, 0, 200)); // drawPoints(img, cPoint[1], Scalar(0, 0, 200)); // imshow("img", img); docPoint_grade = reorder(cPoint[0]); docPoint_max = reorder(cPoint[1]); drawPoints(imgContours, docPoint_max, Scalar(0, 0, 200)); drawPoints(imgContours, docPoint_grade, Scalar(0, 0, 200)); // imshow("imgContours", imgContours); /* 1.仿射变换 */ imgWarp = getWarp(img, docPoint_max, 300, 300); // imshow("imgWarp", imgWarp); imgWarpGrade = getWarp(img, docPoint_grade, 180, 100); // imshow("imgWarpGrade", imgWarpGrade); /* 2.二值化处理 */ cvtColor(imgWarp, imgWarpGray, COLOR_BGR2GRAY); threshold(imgWarpGray, imgThre, 180, 255, THRESH_BINARY_INV); // imshow("imgThre", imgThre); cvtColor(imgWarpGrade, imgWarpGradeGray, COLOR_BGR2GRAY); threshold(imgWarpGradeGray, imgGradeThre, 180, 255, THRESH_BINARY_INV); // imshow("imgGradeThre", imgGradeThre); /* 3.图形分割 */ boxes = splitBox(imgThre); /* 4.计算答案下标，对比正确答案 */ int totalPixels; int myPixelVal[5][5] = {0}; for (int i = 0; i < 25; ++i) { totalPixels = countNonZero(boxes[i]); myPixelVal[i % 5][i / 5] = totalPixels; } for (int i = 0; i < 5; ++i) { for (int j = 0; j < 5; ++j) { cout << "[" << i << "," << j << "] " << myPixelVal[i][j] << " "; } cout << endl; } vector<vector<int>> brr; for (int i = 0; i < 5; ++i) { vector<int> arr; for (int j = 0; j < 5; ++j) { arr.push_back(myPixelVal[i][j]); } brr.push_back(arr); } vector<int> index; for (int i = 0; i < brr.size(); ++i) { auto location = max_element(brr[i].begin(), brr[i].end()); index.push_back((int)(location - brr[i].begin())); cout << *location << " " << index[i] << endl; } vector<int> ans = {0, 1, 2, 3, 4};