python - 在 Python 中使用 UEye API

Question

我目前正在进行一个项目，该项目涉及将 IDS UEye XC 相机连接到 Raspberry Pi 3 以录制视频。我使用 C++、OpenCV 和 IDS API 编写了一个脚本(脚本 1)，并使用 Python 编写了另一个脚本(脚本 2)以使用 Raspberry Pi 上的 GPIO 按钮启动和停止脚本 1。附件是脚本 1 和 2。

脚本 1:

#include "uEye.h"
#include "stdio.h"
#include "stdlib.h"
#include "iostream"
#include "opencv2/highgui.hpp"
#include "opencv2/imgproc.hpp"
#include "opencv2/core.hpp"
#include "opencv2/videoio.hpp"
#include "opencv2/opencv.hpp"

using namespace std;
using namespace cv;

HIDS hCam = 1;
SENSORINFO sensor_info;
CAMINFO camera_info;
int nRet;
int Mode;
char strCamFileName[256];
int img_width=640;
int img_height=480;

int main ()
{
//initialize camera
nRet = is_InitCamera(&hCam, NULL);
cout << "Status Init: " << nRet << endl;

//get sensor info
//nRet = is_GetSensorInfo(hCam, &sensor_info);
//cout << "Sensor Color Mode: " << sensor_info.nColorMode << endl;
//cout << "Camera Model: " << sensor_info.strSensorName << endl;

//get camera info
//nRet = is_GetCameraInfo(hCam, &camera_info);
//cout << "Camera ID: " << camera_info.ID << endl;
//cout << "Camera SerNum: " << camera_info.SerNo << endl;
//cout << "Camera Version: " << camera_info.Version << endl;
//cout << "Camera Type: " << camera_info.Type << endl;

//color mode
Mode = IS_CM_RGB8_PACKED;
nRet = is_SetColorMode(hCam, Mode);
cout << "Color Mode: " << nRet << endl;

UINT formatID = 13;
nRet = is_ImageFormat(hCam, IMGFRMT_CMD_SET_FORMAT, &formatID, 4);
cout << "Status Image Format: " << nRet << endl;

char* pMem = NULL;
int memID = 0;
nRet = is_AllocImageMem(hCam, img_width, img_height, 24, &pMem, &memID);
nRet = is_SetImageMem(hCam, pMem, memID);

//set display mode
Mode = IS_SET_DM_DIB;
nRet = is_SetDisplayMode(hCam, Mode);

//zoom
double dZoomValue = 0;
nRet = is_Zoom(hCam, ZOOM_CMD_DIGITAL_SET_VALUE, (void*)&dZoomValue, sizeof(dZoomValue));
cout << "Zoom: " << dZoomValue << endl;

VideoWriter video("out.avi", CV_FOURCC('X','V','I','D'), 10, Size(img_width, img_height),true);

for(int ii=0; ii<600; ii++)
{
   if(is_FreezeVideo(hCam, IS_WAIT) == IS_SUCCESS){
        void *pMemVoid; //pointer to where the image is stored
        is_GetImageMem (hCam, &pMemVoid);
        Mat img=Mat(Size(img_width,img_height), CV_8UC3, pMemVoid);
    video.write(img);
    namedWindow( "Live Video", WINDOW_NORMAL);
    resizeWindow("Live Video", 320,240);
    imshow("Live Video", img);
    waitKey(1);

   }
}
//exit camera
is_ExitCamera(hCam);

return 0;
}

脚本 2:

import RPi.GPIO as GPIO
import signal
import time
import os
import subprocess
from subprocess import call
import sys
from sys import exit

GPIO.setmode(GPIO.BOARD)

GPIO.setup(12, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setup(16, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setup(18, GPIO.IN, pull_up_down=GPIO.PUD_UP)

set = 0
while True:
    if GPIO.input(12) == False and set == 0:
        print('Starting Video Recording')
        p=subprocess.Popen("./video", shell=False, preexec_fn=os.setsid)
        time.sleep(1)
        set = 1
    if GPIO.input(16) == False and set == 1:
        print('Stopping Video Recording')
        os.killpg(os.getpgid(p.pid), signal.SIGTERM)
        time.sleep(2)
        set = 0
    if GPIO.input(18) == False and set == 0:
        print('Exit Video Recording') 
        time.sleep(1)
        break
GPIO.cleanup()

在尝试将视频文件从 Raspberry 传输到 Windows 7 笔记本电脑之前，我认为一切正常。我发现，如果我让脚本 1 在其整个持续时间内不间断地运行，它将在笔记本电脑上播放，但如果我使用脚本 2 中断脚本 1，然后尝试在笔记本电脑上播放它，它就不会呈现。

这让我相信当我打断它时，相机没有正确地“清理”它。我的意思是，它不会到达完全释放和关闭相机的 is_ExitCamera()。我目前正在使用 os.killpg() 终止程序。有没有办法以某种方式用 is_ExitCamera() 替换它，即使一个是 C++ 而另一个是 Python？

提前致谢。

Answer 1

您可以通过使用“ctypes”调用所有函数来在 python 中使用 uEye API。我不确定您是否可以在第二个脚本中只调用 is_exitCamera 命令，或者您是否需要将所有第一个 c++ 脚本重写为 python。

在 python 中使用 ctypes 的 uEye API 示例:

import ctypes
import numpy as np

uEyeDll = ctypes.cdll.LoadLibrary("ueye_api.dll") #include full path or copy dll into same folder as .py script


#connect camera
cam = ctypes.c_uint32(0)
hWnd = ctypes.c_voidp()
msg=uEyeDll.is_InitCamera(ctypes.byref(cam),hWnd)
ErrChk=uEyeDll.is_EnableAutoExit (cam, ctypes.c_uint(1))
if ~ErrChk:
    print (' Camera Connected')
IS_CM_SENSOR_RAW8  =ctypes.c_int(11)
nRet = uEyeDll.is_SetColorMode(cam,IS_CM_SENSOR_RAW8)
IS_SET_TRIGGER_SOFTWARE = ctypes.c_uint(0x1000)
nRet = uEyeDll.is_SetExternalTrigger(cam, IS_SET_TRIGGER_SOFTWARE)


#allocate memory
width_py = 1600
height_py = 1200
pixels_py =8

width = ctypes.c_int(width_py) #convert python values into c++ integers
height = ctypes.c_int(height_py) 
bitspixel=ctypes.c_int(pixels_py)
pcImgMem = ctypes.c_char_p() #create placeholder for image memory
pid=ctypes.c_int()

ErrChk=uEyeDll.is_AllocImageMem(cam, width, height,  bitspixel, ctypes.byref(pcImgMem), ctypes.byref(pid))


# Get image data    
uEyeDll.is_SetImageMem(cam, pcImgMem, pid)
ImageData = np.ones((height_py,width_py),dtype=np.uint8)

#put these lines inside a while loop to return continuous images to the array "ImageData"  
uEyeDll.is_FreezeVideo (cam, ctypes.c_int(0x0000))  #IS_DONT_WAIT  = 0x0000, or IS_GET_LIVE = 0x8000
uEyeDll.is_CopyImageMem (cam, pcImgMem, pid, ImageData.ctypes.data)