一. 場景說明

已知某個物體的四個角點(比如：車牌、表格等)坐標和對應的圖片，如何通過透視變換獲得矯正的圖片。
原理解析：

對四個點進行排序(四個點可能是亂序的)；

獲得透視變換矩陣；

獲得矯正的圖片；

二. 代碼實現

#include <iostream> #include <string> #include "opencv2/core.hpp" #include "opencv2/imgproc.hpp" #include "opencv2/highgui.hpp"int sort_points(cv::Point2f points[]) {cv::Point2f tempPoint;// 按照x軸坐標從小到大排序for(int i=0; i<3; i++){for(int j=i+1; j<4; j++){if(points[i].x > points[j].x){tempPoint = points[i];points[i] = points[j];points[j] = tempPoint;}}}// 按照縱坐標排序，坐標順序為：0左下角 1左上角 2右上角 3右下角if(points[0].y < points[1].y){tempPoint = points[0];points[0] = points[1];points[1] = tempPoint;}if(points[2].y > points[3].y){tempPoint = points[2];points[2] = points[3];points[3] = tempPoint;}return 0; }cv::Mat warp_img(cv::Point2f points[], const cv::Mat image) {cv::Point2f pts_src[4] = {points[0], points[1], points[2], points[3]};int img_crop_height = int(sqrt(pow(pts_src[0].x - pts_src[1].x, 2) +pow(pts_src[0].y - pts_src[1].y, 2)));int img_crop_width = int(sqrt(pow(pts_src[1].x - pts_src[2].x, 2) +pow(pts_src[1].y - pts_src[2].y, 2)));cv::Point2f pts_dst[4];pts_dst[0] = cv::Point2f(0, img_crop_height - 1);pts_dst[1] = cv::Point2f(0, 0);pts_dst[2] = cv::Point2f(img_crop_width - 1, 0);pts_dst[3] = cv::Point2f(img_crop_width - 1, img_crop_height - 1);cv::Mat M = cv::getPerspectiveTransform(pts_src, pts_dst);cv::Mat crop_image;cv::warpPerspective(image, crop_image, M,cv::Size(img_crop_width, img_crop_height),cv::BORDER_REPLICATE);return crop_image; }int main() {std::string img_path = "../test.jpg";cv::Mat image = cv::imread(img_path);cv::Mat image2 = image.clone();cv::Point2f points[4];points[0] = cv::Point2f(464, 2862);points[1] = cv::Point2f(2697, 2925);points[2] = cv::Point2f(2706, 3566);points[3] = cv::Point2f(431, 3487);sort_points(points);for(int i=0; i<4; i++){cv::circle(image, points[i], 20, cv::Scalar(0,0,255), cv::FILLED, 0);std::cout << "points:" << points[i] << std::endl;}cv::imwrite("../result.jpg", image);cv::Mat crop_img = warp_img(points, image2);cv::imwrite("../crop_img.jpg", crop_img);return 0; }

三. 效果展示

原圖：

坐標顯示：

透視變換后的圖：

歡迎技術交流：

總結

以上是生活随笔為你收集整理的透视变换 c++实现的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。