opencv读取一张图片的时间过长，

[冽夏]

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <iostream>
#include <stdio.h>
#include <windows.h>
using namespace std;
// LPCWSTR转string
std::string WChar2Ansi(LPCWSTR pwszSrc)
{
int nLen = WideCharToMultiByte(CP_ACP, 0, pwszSrc, -1, NULL, 0, NULL, NULL);

if (nLen <= 0) return std::string("");

char* pszDst = new char[nLen];
if (NULL == pszDst) return std::string("");

WideCharToMultiByte(CP_ACP, 0, pwszSrc, -1, pszDst, nLen, NULL, NULL);
pszDst[nLen - 1] = 0;

std::string strTemp(pszDst);
delete[] pszDst;

return strTemp;
}

// 利用winWIN32_FIND_DATA读取文件下的文件名
void readImgNamefromFile(char* fileName, vector <string> &imgNames)
{
// vector清零 参数设置
imgNames.clear();
WIN32_FIND_DATA file;
int i = 0;
char tempFilePath[MAX_PATH + 1];
char tempFileName[50];
// 转换输入文件名
sprintf_s(tempFilePath, "%s/*", fileName);
// 多字节转换
WCHAR wstr[MAX_PATH] = { 0 };
MultiByteToWideChar(CP_ACP, 0, tempFilePath, -1, wstr, sizeof(wstr));
// 查找该文件待操作文件的相关属性读取到WIN32_FIND_DATA
HANDLE handle = FindFirstFile(wstr, &file);
if (handle != INVALID_HANDLE_VALUE)
{
FindNextFile(handle, &file);
FindNextFile(handle, &file);
// 循环遍历得到文件夹的所有文件名
do
{
sprintf(tempFileName, "%s", fileName);
imgNames.push_back(WChar2Ansi(file.cFileName));
imgNames[i].insert(0, tempFileName);
i++;
} while (FindNextFile(handle, &file));
}
FindClose(handle);
}
int main()
{
// 设置读入图像序列文件夹的路径
char* fileName = "G:\\2018-08-06\\";
std::vector <string> imgNames;
// 获取对应文件夹下所有文件名
readImgNamefromFile(fileName, imgNames);
// 遍历对应文件夹下所有文件名
for (int i = 0; i < imgNames.size(); i++)
{
double Time = (double)cvGetTickCount();
string ss =imgNames[i];
cv::Mat img = cv::imread(ss);
Time = (double)cvGetTickCount() - Time;
printf("run time = %gms\n", Time / (cvGetTickFrequency() * 1000));//毫秒
if (!img.data)
return -1;
/* 可添加图像处理算法code*/
cv::imshow("im", img);
cv::waitKey(0);
}
return 0;
}
opencv无规则批量读取图片，读取一张图片需要0.5s.请教一下为什么时间那么长啊，有什么解决办法吗