opencv--常用库调用

时不时用到Opencv里面的各种库，每次都是现查，各种版本都有，实在受不了自己写个文档记录一下。毫无逻辑、毫无美感，纯为了查阅方便。(●ˇ∀ˇ●)

Opencv + SVM

cv::Mat train_data, train_label;

train_data.convertTo(train_data, CV_32FC1);
train_label.convertTo(train_label, CV_32FC1);

Ptr<SVM> svm = SVM::create();
svm->setType(SVM::C_SVC);
svm->setKernel(SVM::RBF);

svm->setTermCriteria(TermCriteria(TermCriteria::MAX_ITER, 1000, 1e-5));
svm->train(train_data, ROW_SAMPLE, train_label);
svm->save("svm.xml");

Opencv + ANN

Mat layers_size = (Mat_<int>(1, 4) << 500,200,10,1);

////模型创建和参数设置
Ptr<ml::ANN_MLP> ann = ml::ANN_MLP::create();//创建一个空模型
ann->setLayerSizes(layers_size);
ann->setTrainMethod(ml::ANN_MLP::BACKPROP, 0.1, 0.1);
ann->setActivationFunction(ml::ANN_MLP::SIGMOID_SYM);
ann->setTermCriteria(TermCriteria(TermCriteria::MAX_ITER, 1000, 1e-4));

////设置训练数据并训练分类器
Ptr<ml::TrainData> tData = ml::TrainData::create(train_data, ml::ROW_SAMPLE, train_label);

ann->train(tData);
ann->save("model_ann.xml");

Opencv + json(第三方库)

https://github.com/nlohmann/json/tree/develop/single_include/nlohmann/json.hpp
(include/lib啥的自己配置属性表)

#include "nlohmann/json.hpp" 
#include <fstream>              // ifstream, ofstream

string json_name;

std::ifstream fin(json_name);   // 注意此处是相对路径
json j;
fin >> j;
fin.close();

std::cout << j["shapes"][0]["label"] << std::endl;  // 根据自己的json文件改
string image_name = j["imagePath"];

Opencv + PCA

Mat input_data;
//-> save pca file
PCA pca(input_data, Mat(), PCA::DATA_AS_ROW,500);
FileStorage fs("pca.xml", FileStorage::WRITE);
pca.write(fs);
fs.release();

//->load pca file
FileStorage fs("pca.xml", FileStorage::READ);
cv::PCA pca;
pca.read(fs.root());
fs.release();

//->project the input vector
input_data = pca.project(input_data);

C++ 指定字符分割字符串

vector<string> _split(const string& s, const string& seperator) 
{
vector<string> result;
typedef string::size_type string_size;
string_size i = 0;

while (i != s.size()) {
//找到字符串中首个不等于分隔符的字母；
int flag = 0;
while (i != s.size() && flag == 0) {
      flag = 1;
      for (string_size x = 0; x < seperator.size(); ++x)
           if (s[i] == seperator[x]) {
              ++i;
              flag = 0;
              break;
           }
     }

//找到又一个分隔符，将两个分隔符之间的字符串取出；
flag = 0;
string_size j = i;
while (j != s.size() && flag == 0) {
    for (string_size x = 0; x < seperator.size(); ++x)
             if (s[j] == seperator[x]) {
                  flag = 1;
                  break;
             }
            if (flag == 0)
                  ++j;
        }
       if (i != j) {
           result.push_back(s.substr(i, j - i));
           i = j;
       }
   }
   return result;
}

C++ 获取系统时间转为字符串

string getCurTime()
{
    time_t now = time(0);
    char dt[50];
    ctime_s(dt,50,&now);
    string ans;
    ans= dt;
    return ans;
}