提供了直线检测python与C++版本，用于检测竖直线与横线，主要流程为：图像二值化+Canny边缘检测+霍夫直线变换直线检测

一、python实现

import shutilimport osimport cv2
import numpy as npfilename = "20230525-173637.jpg"
file_ext = ".jpg"src_path = "./" + filename
dirpath = "./"
print(src_path)
# TODO: 在此处添加对图片的处理代码new_filename = filename.split('.')[0] + '_result.' + file_extnew_file_path = os.path.join(dirpath, new_filename)img_path = src_path# 读取图像
img2 = cv2.imread(img_path)
img = cv2.imread(img_path,0)lower = 25
upper = 255# 将图像二值化到指定范围内
binary_img = cv2.inRange(img, lower, upper)
#  # 显示结果
cv2.imshow('Binary Image', binary_img)
cv2.waitKey(0)
cv2.destroyAllWindows()cv2.imwrite(new_file_path,binary_img)# 边缘检测
edges = cv2.Canny(binary_img, 50, 150, apertureSize=3)# 使用霍夫直线变换检测直线
lines = cv2.HoughLinesP(edges, rho=1, theta=0.5*np.pi/180, threshold=50, minLineLength=1000, maxLineGap=80)# shutil.copy2(src_path, new_file_path)# 遍历所有直线，绘制竖直方向的直线
for line in lines:x1, y1, x2, y2 = line[0]# 计算直线的斜率# print(x2-x1)# k = (y2 - y1) / (x2 - x1)# 当斜率大于0.5时，认为是竖直方向的直线if x2 -x1 == 0 :# img = cv2.cvtColor(img, cv2.COLOR_GRAY2BGR)cv2.line(img2, (x1, y1), (x2, y2), (0, 0, 255), 5)# print(6666)cv2.imwrite(new_file_path,img2)

二、C++实现

#include <iostream>
#include <string>
#include <opencv2/opencv.hpp>
#include <cmath>
const std::string file_ext = ".jpeg";
const int lower = 10;
const int upper = 255;double distance(int x1, int y1, int x2, int y2)
{// 计算两点直线距离double dx = x1 - x2;double dy = y1 - y2;return std::sqrt(dx*dx + dy*dy);
}int main()
{std::string src_path = "../1/top3.jpeg";// 读取图片// cv::Mat img = cv::imread(src_path, 0);cv::Mat img2 = cv::imread(src_path);cv::Mat img;cv::cvtColor(img2, img, cv::COLOR_BGR2GRAY);// 判断是否读取成功if (img.empty()) {std::cout << "read image failed" << std::endl;return -1;}// 将图像二值化到指定范围内cv::Mat binary_img;cv::inRange(img, lower, upper, binary_img);// 边缘检测cv::Mat edges;cv::Canny(binary_img, edges, 50, 150, 3);// 使用霍夫直线变换检测直线std::vector<cv::Vec4i> lines;cv::HoughLinesP(edges, lines, 1, 0.5*CV_PI/180, 50, 1000, 80);// 遍历所有直线，绘制竖直方向的直线bool ifLeft = false;bool iRight = false;for (auto line : lines){int x1 = line[0], y1 = line[1], x2 = line[2], y2 = line[3];// 当斜率大于0.5时，认为是竖直方向的直线if (x2 - x1 == 0){double dis = distance(x1, y1, x2, y2);if ((630 < x1 && x1 < 650) && (dis > 1000)){cv::line(img2, cv::Point(x1, y1), cv::Point(x2, y2), cv::Scalar(0, 0, 255), 5);std::cout << x1 << std::endl;ifLeft = true;// cv::imwrite(new_file_path, img2);}if ((1270 < x1 && x1 < 1290) && (dis > 1000)){cv::line(img2, cv::Point(x1, y1), cv::Point(x2, y2), cv::Scalar(0, 0, 255), 5);std::cout << x1 << std::endl;iRight = true;}}}// cv::imshow("image", img2);// cv::waitKey(0);if( ifLeft && iRight){std::cout << 2 << std::endl;return 2;}if( ifLeft && !iRight){std::cout << 1 << std::endl;return 1;}std::cout << 0 << std::endl;return 0;cv::imshow("image", img2);cv::waitKey(0);
}

cmake

# For more information about using CMake with Android Studio, read the
# documentation: https://d.android.com/studio/projects/add-native-code.html# Sets the minimum version of CMake required to build the native library.
project("linedetector")
cmake_minimum_required(VERSION 3.4.1)# Declares and names the project.set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fexceptions")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fexceptions" )# 添加opencv
set(thirdPath ${CMAKE_SOURCE_DIR}/thirdParty)
set(OPENCV_ANDROID_SDK_PATH ${thirdPath}/opencv/)
include_directories(${OPENCV_ANDROID_SDK_PATH}/native/jni/include)
add_library(opencvSHAREDIMPORTED)
set_target_properties(opencvPROPERTIESIMPORTED_LOCATION${OPENCV_ANDROID_SDK_PATH}/native/libs/${ANDROID_ABI}/libopencv_java3.so)# 添加自定义文件
set(INTERFACE_SRC ${CMAKE_SOURCE_DIR}/src/main/cpp)
include_directories(${INTERFACE_SRC}/)file(GLOB_RECURSE INTERFACE_SRC${INTERFACE_SRC}/linedetector.cpp)add_library(linedetector SHARED ${INTERFACE_SRC})find_library( # Sets the name of the path variable.log-lib# Specifies the name of the NDK library that# you want CMake to locate.log)# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, prebuilt third-party libraries, or system libraries.target_link_libraries( # Specifies the target library.linedetectoropencvjnigraphics# Links the target library to the log library# included in the NDK.${log-lib})

编译运行：

mkdir build
cd build
cmake ..
make
./linedetector