OpenCV cv.Mat and .txt file data reading and writing operations-Python Tutorial-php.cn

This article mainly introduces the reading and writing operations of OpenCV cv.Mat and .txt file data. Now I will share it with you and give you a reference.

1. .txt file implemented in OpenCV format Reading and writing
can be implemented using cvSave and cvLoad. The format is similar to .xml/.yml. However, if you are dedicated to data reading and writing with OpenCV, it is better to use .xml/.yml file format. I prefer .yml format. , readability is great.
Use cvSave and cvLoad to read and write .txt files. The implementation method and data format are basically the same as those of .yml files.
For example: cvSave("camera_matrix.txt",camera_matrix); //Save the array header of camera_matrix and the data it refers to (a file similar to yml format)

2. Import/export others The program's .txt file data
can be implemented using conventional sprintf_s and fprintf_s, but the efficiency is relatively low. Here is a quick and easy-to-use method that uses std's steam and vector.

#include  #include  #include  #include  using namespace std; /*---------------------------- * 功能 : 将 cv::Mat 数据写入到 .txt 文件 *---------------------------- * 函数 : WriteData * 访问 : public * 返回 : -1：打开文件失败；0：写入数据成功；1：矩阵为空 * * 参数 : fileName [in] 文件名 * 参数 : matData [in] 矩阵数据 */ int WriteData(string fileName, cv::Mat& matData) { int retVal = 0; // 打开文件 ofstream outFile(fileName.c_str(), ios_base::out); //按新建或覆盖方式写入 if (!outFile.is_open()) { cout << "打开文件失败" << endl; retVal = -1; return (retVal); } // 检查矩阵是否为空 if (matData.empty()) { cout << "矩阵为空" << endl; retVal = 1; return (retVal); } // 写入数据 for (int r = 0; r < matData.rows; r++) { for (int c = 0; c < matData.cols; c++) { uchar data = matData.at(r,c); //读取数据，at - type 是矩阵元素的具体数据格式 outFile << data << "\t" ; //每列数据用 tab 隔开 } outFile << endl; //换行 } return (retVal); } /*---------------------------- * 功能 : 从 .txt 文件中读入数据，保存到 cv::Mat 矩阵 * - 默认按 float 格式读入数据， * - 如果没有指定矩阵的行、列和通道数，则输出的矩阵是单通道、N 行 1 列的 *---------------------------- * 函数 : LoadData * 访问 : public * 返回 : -1：打开文件失败；0：按设定的矩阵参数读取数据成功；1：按默认的矩阵参数读取数据 * * 参数 : fileName [in] 文件名 * 参数 : matData [out] 矩阵数据 * 参数 : matRows [in] 矩阵行数，默认为 0 * 参数 : matCols [in] 矩阵列数，默认为 0 * 参数 : matChns [in] 矩阵通道数，默认为 0 */ int LoadData(string fileName, cv::Mat& matData, int matRows = 0, int matCols = 0, int matChns = 0) { int retVal = 0; // 打开文件 ifstream inFile(fileName.c_str(), ios_base::in); if(!inFile.is_open()) { cout << "读取文件失败" << endl; retVal = -1; return (retVal); } // 载入数据 istream_iterator begin(inFile); //按 float 格式取文件数据流的起始指针 istream_iterator end; //取文件流的终止位置 vector inData(begin,end); //将文件数据保存至 std::vector 中 cv::Mat tmpMat = cv::Mat(inData); //将数据由 std::vector 转换为 cv::Mat // 输出到命令行窗口 //copy(vec.begin(),vec.end(),ostream_iterator(cout,"\t")); // 检查设定的矩阵尺寸和通道数 size_t dataLength = inData.size(); //1.通道数 if (matChns == 0) { matChns = 1; } //2.行列数 if (matRows != 0 && matCols == 0) { matCols = dataLength / matChns / matRows; } else if (matCols != 0 && matRows == 0) { matRows = dataLength / matChns / matCols; } else if (matCols == 0 && matRows == 0) { matRows = dataLength / matChns; matCols = 1; } //3.数据总长度 if (dataLength != (matRows * matCols * matChns)) { cout << "读入的数据长度 不满足 设定的矩阵尺寸与通道数要求，将按默认方式输出矩阵！" << endl; retVal = 1; matChns = 1; matRows = dataLength; } // 将文件数据保存至输出矩阵 matData = tmpMat.reshape(matChns, matRows).clone(); return (retVal); }

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