Question

我知道这可能是重复的，但我实际上已经在SO上发了几个帖子来尝试解决这个问题

我在OpenCV和C ++中有以下代码

test.cpp

#include "opencv2/core/core_c.h"
#include "opencv2/core/core.hpp"
#include "opencv2/flann/miniflann.hpp"
#include "opencv2/imgproc/imgproc_c.h"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/video/video.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/objdetect/objdetect.hpp"
#include "opencv2/calib3d/calib3d.hpp"
#include "opencv2/ml/ml.hpp"
#include "opencv2/highgui/highgui_c.h"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/contrib/contrib.hpp"
#include <stdio.h>
#include <iostream>
#include <vector>
#include <math.h>
#include <string.h>
#include "draw_shapes.h"
using namespace cv;
using namespace std;

int main(){
    Mat normal = imread("/INPUT 2.jpg");
    Mat gray;
        cvtColor(normal, gray,CV_RGB2GRAY);
        Mat binary = gray > 128;

    Point start = cv::Point(5.0,5.0);
    Point end = cv::Point(200.0,200.0);
        draw_line(binary, start, end, 0, 255, 0);
    imshow("Draw_Line", binary);
    while(waitKey(0)!=27){
        ;
    }
        return 0;
}

draw_shapes.cpp

#include "opencv2/core/core_c.h"
#include "opencv2/core/core.hpp"
#include "opencv2/flann/miniflann.hpp"
#include "opencv2/imgproc/imgproc_c.h"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/video/video.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/objdetect/objdetect.hpp"
#include "opencv2/calib3d/calib3d.hpp"
#include "opencv2/ml/ml.hpp"
#include "opencv2/highgui/highgui_c.h"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/contrib/contrib.hpp"
#include <stdio.h>
#include <iostream>
#include <vector>
#include <math.h>
#include <string.h>
#include "draw_shapes.h"

void draw_line(cv::Mat img, cv::Point start, cv::Point end, int B, int G, int R){
        int thickness = 2;
    int lineType = 8;
    line(img,start,end,Scalar(B,G,R),thickness,lineType);
}

void draw_rectangle(cv::Mat img, cv::Point p1, cv::Point p2, int B, int G, int R){
    int thickness = 2;
    int lineType = 8;
    rectangle(img, p1, p2, Scalar(B,G,R),thickness, lineType);
}

draw_shapes.h

#ifndef DRAWSHAPES_H
#define DRAWSHAPES_H

void draw_line(cv::Mat, cv::Point, cv::Point, int, int, int);
void draw_rectangle(cv::Mat, cv::Point, cv::Point, int, int, int);

#endif

compile_opencv.sh

#!/bin/bash
echo "compiling $1"
if [[ $1 == *.c ]]
then
    gcc -ggdb `pkg-config --cflags opencv` -o `basename $1 .c` $1 `pkg-config --libs      opencv`;
elif [[ $1 == *.cpp ]]
then
    g++ -ggdb `pkg-config --cflags opencv` -o `basename $1 .cpp` $1 `pkg-config --libs     opencv`;
else
    echo "Please compile only .c or .cpp files"
fi
echo "Output file => ${1%.*}"
./${1%.*}

我几乎经历了StackOverflow上与头文件相关的所有帖子，包括来自外部CPP文件的函数，这就是我所得到的。现在，当我编译时，我得到了 undefined reference to 'draw_line(cv::Mat, cv::Point_<int>, cv::Point_<int>, int, int, int)'

我正在疯狂地猜测，这可能是因为我没有单独编译draw_shapes.cpp，但我在C文件中尝试了一个简单的int add(int x, int y)，它直接起作用。我在哪里错了？

Answer 1

（根据Ben的评论）

此命令应该有效：

g++ -ggdb `pkg-config --cflags opencv` test.cpp draw_shapes.cpp `pkg-config --libs opencv`

请注意＆＃34; pkg-config --cflags opencv＆＃34;和＆＃34; pkg-config --libs opencv＆＃34;。 Reqular引用（＆＃39;），不会起作用 - 你真的需要在这里引用反引号（`）。反引号键位于＆＃34; Esc＆＃34;关键在大多数键盘上。或者只是从脚本中复制粘贴它们。

Answer 2

就像@Ben提到的那样，你需要编译draw_shapes.cpp文件。如果您想单独编译您的文件，那么您需要将它们编译为具有-c开关的对象，然后将它们链接在一起。 Further explanation in Your second thread

在C ++和OpenCV中调用其他文件中的函数

2 个答案: