虽然手机上Barcode应用已经非常流行,但是工作的时候还是用Webcam比较方便。比如需要检测Barcode,我只需要拿Webcam对着电脑屏幕或者纸张扫一下就可以了。今天分享下如何轻松使用OpenCV控制Webcam,以及如何获取一帧图像做Barcode检测。
参考原文:Reading Barcode with Webcam in OpenCV and Python
作者:Xiao Ling
翻译:yushulx
软件安装
- Dynamsoft Barcode SDK: http://www.dynamsoft.com/Downloads/Dynamic-Barcode-Reader-Download.aspx
- Python: https://www.python.org/ftp/python/
- NumPy: http://sourceforge.net/projects/numpy/files/NumPy/
- SciPy: http://sourceforge.net/projects/scipy/files/scipy/
- OpenCV: http://sourceforge.net/projects/opencvlibrary/files/opencv-win/
控制Webcam,读取Barcode
基本步骤:
- 拷贝<opencv_installation_dir>\build\python\2.7\x86\cv2.pyd到 <Python27>\Lib\site-packages\cv2.pyd。
- 创建一个工程目录。
- 构建Python Barcode动态链接库。
- 拷贝所有依赖的动态链接库到工程目录。
- 把Webcam连接到PC上。
- 创建Python脚本控制Webcam,捕捉Webcam图像,并使用Python Barcode库来读取图像中的Barcode。
使用Dynamsoft Barcode SDK创建Python Barcode动态链接库
编译Python Barcode动态链接库。
#include "Python.h" #include "If_DBR.h" #include "BarcodeFormat.h" #include "BarcodeStructs.h" #include "ErrorCode.h" #ifdef _WIN64 #pragma comment(lib, "DBRx64.lib") #else #pragma comment(lib, "DBRx86.lib") #endif void SetOptions(pReaderOptions pOption, int option_iMaxBarcodesNumPerPage, int option_llBarcodeFormat){ if (option_llBarcodeFormat > 0) pOption->llBarcodeFormat = option_llBarcodeFormat; else pOption->llBarcodeFormat = OneD; if (option_iMaxBarcodesNumPerPage > 0) pOption->iMaxBarcodesNumPerPage = option_iMaxBarcodesNumPerPage; else pOption->iMaxBarcodesNumPerPage = INT_MAX; } static PyObject * initLicense(PyObject *self, PyObject *args) { char *license; if (!PyArg_ParseTuple(args, "s", &license)) { return NULL; } printf("information: %s\n", license); int ret = DBR_InitLicense(license); printf("return value = %d", ret); return Py_None; } static PyObject * decodeFile(PyObject *self, PyObject *args) { char *pFileName; int option_iMaxBarcodesNumPerPage = -1; int option_llBarcodeFormat = -1; if (!PyArg_ParseTuple(args, "s", &pFileName)) { return NULL; } pBarcodeResultArray pResults = NULL; ReaderOptions option; SetOptions(&option, option_iMaxBarcodesNumPerPage, option_llBarcodeFormat); int ret = DBR_DecodeFile( pFileName, &option, &pResults ); if (ret == DBR_OK){ int count = pResults->iBarcodeCount; pBarcodeResult* ppBarcodes = pResults->ppBarcodes; pBarcodeResult tmp = NULL; PyObject* list = PyList_New(count); PyObject* result = NULL; for (int i = 0; i < count; i++) { tmp = ppBarcodes[i]; result = PyString_FromString(tmp->pBarcodeData); PyList_SetItem(list, i, Py_BuildValue("iN", (int)tmp->llFormat, result)); } // release memory DBR_FreeBarcodeResults(&pResults); return list; } return Py_None; } static PyMethodDef methods[] = { { "initLicense", initLicense, METH_VARARGS, NULL }, { "decodeFile", decodeFile, METH_VARARGS, NULL }, { NULL, NULL } }; PyMODINIT_FUNC initDynamsoftBarcodeReader(void) { Py_InitModule("DynamsoftBarcodeReader", methods); }
具体请参考GitHub上的源码。编译成功之后请记得拷贝DynamsoftBarcodeReader.pyd和DynamsoftBarcodeReaderx64.dll /DynamsoftBarcodeReaderx86.dll到工程目录中。
使用OpenCV打开Webcam
import cv2.cv as cv title = "Dynamsoft Barcode Reader" cv.NamedWindow(title, 1) capture = cv.CaptureFromCAM(0) while True: img = cv.QueryFrame(capture) cv.ShowImage(title, img)
使用OpenCV绘制显示结果
line_type = cv.CV_AA font = cv.InitFont(cv.CV_FONT_HERSHEY_COMPLEX, 0.1, 1, 1, 1, line_type) fileName = ‘test.jpg‘ img = cv.QueryFrame(capture) cv.SaveImage(fileName, img) results = DynamsoftBarcodeReader.decodeFile(fileName) top = 30 increase = 20 if results: for result in results: barcode_format = "Format: " + formats[result[0]] barcode_value = "Value: " + result[1] cv.PutText(img, barcode_format, (10, top), font, (254, 142, 20)) top += increase cv.PutText(img, barcode_value, (10, top), font, (254, 142, 20)) top += increase cv.PutText(img, "************************", (10, top), font, (254, 142, 20)) top += increase cv.ShowImage(title, img)
源码
https://github.com/yushulx/webcam-barcode-reader
时间: 2024-11-08 22:17:31