Linux离线文字识别 C++ 调用easyocr_python easyocr c++

easyocr是一个python文字识别库，支持80种语言。直接用python调用的话，还是很简单的，代码量很少，对用户友好满分。如果需要C++调用，需要用到c-python。这块千万别去chatgpt，有很多坑。

0，github:GitHub - JaidedAI/EasyOCR: Ready-to-use OCR with 80+ supported languages and all popular writing scripts including Latin, Chinese, Arabic, Devanagari, Cyrillic and etc.1，测试及支持语言列表：Jaided AI: EasyOCR demo

2，安装

如果需要GPU版本的easyocr，需要先安装GPU版本的torch库等（这块比较复杂）。如果只是需要CPU版本的easyocr的话，直接一句指令安装即可：

pip3 install easyocr -i https://pypi.tuna.tsinghua.edu.cn/simple --trusted-host pypi.tuna.tsinghua.edu.cn

3，python调用直接识别文件

import easyocr
reader = easyocr.Reader(['en'])
result = reader.readtext('/home/huahua/lpr_eng.jpg)
print(result)

4，python调用识别mat

import easyocr
import cv2
 
reader = easyocr.Reader(['en'])
 
img = cv2.imread('/home/huahua/lpr_eng.jpg')
result = reader.readtext(img)
print(result)

5，python调用增加可选参数白名单

import easyocr
import cv2
 
reader = easyocr.Reader(['en'])
 
img = cv2.imread('/home/huahua/lpr_eng.jpg')
result = reader.readtext(img, allowlist='ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890')
print(result)

6，C++调用直接识别文件

#include <Python.h>
#include <iostream>
 
//编译：g++ -o callEasyOcr callEasyOcr.cpp -I /usr/include/python3.8 -lpython3.8
 
int main() {
    // 初始化Python解释器
    Py_Initialize();
 
    // 导入EasyOCR模块
    PyObject* pModule = PyImport_ImportModule("easyocr");
 
    if (pModule != NULL) {
        std::cout<<"PyImport_ImportModule easyocr success!"<<std::endl;
        // 获取EasyOCR类
        PyObject* pClass = PyObject_GetAttrString(pModule, "Reader");
 
        if (pClass != NULL && PyCallable_Check(pClass)) {
            std::cout<<"PyObject_GetAttrString Reader success!"<<std::endl;
 
            // 准备参数
            PyObject* langs = PyList_New(2);
            PyList_SetItem(langs, 0, PyUnicode_FromString("ch_sim"));
            PyList_SetItem(langs, 1, PyUnicode_FromString("en"));
            PyObject* pArgs = PyTuple_New(1);
            PyTuple_SetItem(pArgs, 0, langs);  
 
            // 创建EasyOCR对象
            PyObject* pInstance = PyObject_CallObject(pClass, pArgs);
 
            if (pInstance != NULL) {
                std::cout<<"PyObject_CallObject pClass success!"<<std::endl;
                
                // 调用EasyOCR对象的readtext方法
                PyObject* pResult = PyObject_CallMethod(pInstance, "readtext", "(s)", "/home/huahua/lpr_ch_en.jpg");
 
                if (pResult != NULL) {
                    std::cerr << "Call readtext success" << std::endl;
                    // 解析结果
                    int resultSize = PyList_Size(pResult);
                    for(int i=0;i<resultSize;i++)
                    {
                        PyObject *listItem = PyList_GetItem(pResult,i);
                        Py_ssize_t listItemsize = PyTuple_Size(listItem);
                        for (Py_ssize_t i = 0; i < listItemsize; ++i) {
                            PyObject* tupleItem = PyTuple_GetItem(listItem, i);
                            if (tupleItem != NULL && PyUnicode_Check(tupleItem)) {
                                const char* text = PyUnicode_AsUTF8(tupleItem);
                                std::cout << text << std::endl;
                            }
                        }
                    }
                    Py_DECREF(pResult);
                } else {
                    std::cerr << "Call croppedImage failed" << std::endl;
                    PyErr_Print();
                }
 
                // 释放EasyOCR对象
                Py_DECREF(pInstance);
            } else {
                std::cerr << "Failed to create instance" << std::endl;
                PyErr_Print();
            }
 
            // 释放EasyOCR类
            Py_DECREF(pClass);
        } else {
            std::cerr << "Class not found" << std::endl;
            PyErr_Print();
        }
 
        // 释放EasyOCR模块
        Py_DECREF(pModule);
    } else {
        PyErr_Print();
        std::cerr << "Module not found" << std::endl;
    }
 
    // 清理Python解释器
    Py_Finalize();
 
    return 0;
}
 

7，C++调用识别mat

#define NPY_NO_DEPRECATED_API NPY_1_7_API_VERSION
 
#include <Python.h>
#include <numpy/arrayobject.h>
#include <opencv2/opencv.hpp>
#include <iostream>
#include <unistd.h>
#include <time.h>
 
//编译：g++ -o easyocr-opencv easyocr-opencv.cpp -I /usr/include/python3.8 -I /home/huahua/.local/lib/python3.8/site-packages/numpy/core/include -lpython3.8  `pkg-config --cflags --libs opencv4`
 
//读取图片
cv::Mat readPictureFile(char* filePath)
{
    // 1. 读取整个图片
    cv::Mat originalImage = cv::imread(filePath, cv::IMREAD_COLOR); // 替换为您的输入图片路径
    if (originalImage.empty())
    {
        std::cerr << "Could not open or find the image" << std::endl;
    }
    return originalImage;
}
 
 
int main() {
    // 初始化Python解释器
    Py_Initialize();
    import_array();//使用numy数组传入图片数据要加的
 
    // 加载EasyOCR模块
    PyObject* easyocr_module = PyImport_ImportModule("easyocr");
    if (easyocr_module == NULL) {
        std::cerr << "Failed to import easyocr module" << std::endl;
        PyErr_Print();
        return 1;
    }
 
    // 获取EasyOCR的Reader类
    PyObject* reader_class = PyObject_GetAttrString(easyocr_module, "Reader");
    if (reader_class == NULL || !PyCallable_Check(reader_class)) {
        std::cerr << "Failed to get easyocr Reader class" << std::endl;
        PyErr_Print();
        Py_XDECREF(easyocr_module);
        return 1;
    }
 
    // 准备参数
    PyObject* langs = PyList_New(2);
    PyList_SetItem(langs, 0, PyUnicode_FromString("ch_sim"));
    PyList_SetItem(langs, 1, PyUnicode_FromString("en"));
    PyObject* pArgs = PyTuple_New(1);
    PyTuple_SetItem(pArgs, 0, langs);  
 
    // 创建Reader对象
    PyObject* reader_instance = PyObject_CallObject(reader_class, pArgs);
    if (reader_instance == NULL) {
        std::cerr << "Failed to create easyocr Reader instance" << std::endl;
        PyErr_Print();
        Py_XDECREF(easyocr_module);
        Py_XDECREF(reader_class);
        return 1;
    }
 
    // 加载并读取截图数据为OpenCV的Mat对象，假设截图数据已经存储在cv::Mat对象image中
    cv::Mat originalImage = readPictureFile("//home/huahua/lpr_croppedImage.jpg");//读文件
    cv::Mat croppedImage;cv::cvtColor(originalImage, croppedImage, cv::COLOR_BGR2RGB);
 
    // 将OpenCV的Mat对象转换为numpy数组对象
    npy_intp dims[] = {croppedImage.rows, croppedImage.cols, croppedImage.channels()};
    PyObject *numpy_array = PyArray_SimpleNewFromData(3, dims, NPY_UINT8, croppedImage.data);//记得加import_array();不然会段错误
 
    // 调用OCR识别
    printTime("readtext begin");
    PyObject* pResult = PyObject_CallMethod(reader_instance, "readtext", "(O)", numpy_array);
    printTime("readtext end");
    Py_XDECREF(numpy_array);
 
    if (pResult == NULL) {
        std::cerr << "Failed to call easyocr readtext method" << std::endl;
        PyErr_Print();
    } else {
        std::cerr << "Call success" << std::endl;
        // 解析结果
        int resultSize = PyList_Size(pResult);
        for(int i=0;i<resultSize;i++)
        {
            PyObject *listItem = PyList_GetItem(pResult,i);
            Py_ssize_t listItemsize = PyTuple_Size(listItem);
            for (Py_ssize_t i = 0; i < listItemsize; ++i) {
                PyObject* tupleItem = PyTuple_GetItem(listItem, i);
                if (tupleItem != NULL && PyUnicode_Check(tupleItem)) {
                    const char* text = PyUnicode_AsUTF8(tupleItem);
                    std::cout << text << std::endl;
                }
            }
        }
    }
    Py_DECREF(pResult);
 
    // 释放资源
    Py_XDECREF(easyocr_module);
    Py_XDECREF(reader_class);
    Py_XDECREF(reader_instance);
 
    // 清理Python解释器
    Py_Finalize();
 
    return 0;
}
 

特征：库加载的时候需要的时间和硬件资源比较多，基本CPU要跑满。

优势：会自动下载新的语言包（需要网络）