python调用c++接口传递opencv格式图像

迷南。 2022-02-14 09:07 449阅读 0赞

关于python调用c++接口的方法，网上有好多例子，不在赘述了。

文件结构如下：

![20190426101215991.png][]

直接上代码：

opencvcall.cpp

#include <opencv2/opencv.hpp>
    
    using namespace cv;
    
    extern "C"
    {
        void test(int height, int width, uchar* frame_data)
        {
            int count = 0;
    
            Mat image(height, width, CV_8UC3);
            uchar* pxvec =image.ptr<uchar>(0);
            
            for(int row = 0; row < height; row++)
            {
                pxvec = image.ptr<uchar>(row);
                for(int col = 0; col < width; col++)
                {
                    for(int c = 0; c < 3; c++)
                    {
                        pxvec[col*3+c] = frame_data[count];
                        count++;
                    }
                }
            }
    
            imshow("result", image);
            waitKey(0);
            return;
        }
    }

makefile

libopencvcall.so:
    	g++ -o libopencvcall.so -shared -fPIC opencvcall.cpp -lopencv_core -lopencv_highgui -lopencv_imgcodecs

pycall.py

import cv2   
    import ctypes
    import numpy as np
    
    ll = ctypes.cdll.LoadLibrary
    lib = ll("./libopencvcall.so")
    lib.test.restype = ctypes.c_float
    frame = cv2.imread('1.jpg')
    frame_data = np.asarray(frame, dtype=np.uint8)
    frame_data = frame_data.ctypes.data_as(ctypes.c_char_p)
    lib.test(frame.shape[0], frame.shape[1], frame_data)

首先执行make，当前目录下会生成libopencvcall.so动态库文件，然后执行pycall.py，读取当前目录下的1.jpg图片，通过libopencvcall.so生成的接口调用opencvcall.cpp中的test接口，显示图片：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaWNhbzE5OTA_size_16_color_FFFFFF_t_70][]

[20190426101215991.png]: /images/20220214/d3ec44a9246041b4bfbcce8ffeb8ddc2.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaWNhbzE5OTA_size_16_color_FFFFFF_t_70]: /images/20220214/f066818dd3eb4ada94d4bb24e8b16d76.png