OpenCV cv.Mat and .txt file data reading and writing operations

不言
Release: 2018-05-03 13:51:02
Original
3530 people have browsed it

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 <iostream> 
#include <fstream> 
#include <iterator> 
#include <vector> 
 
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<uchar>(r,c); //读取数据,at<type> - 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<float> begin(inFile);  //按 float 格式取文件数据流的起始指针 
  istream_iterator<float> end;     //取文件流的终止位置 
  vector<float> 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<double>(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); 
}
Copy after login

Related recommendations:

Read txt text line by line under python3.4.3 and remove duplicates Methods

The above is the detailed content of OpenCV cv.Mat and .txt file data reading and writing operations. For more information, please follow other related articles on the PHP Chinese website!

Related labels:
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template