Linux C读取并处理文件夹下的所有文件，定义传递参数使用的结构体：头文件

#ifndef _PARAM_H_
#define _PARAM_H_

typedef struct str_1_param
{
char *str;
void *param;
} STR_1_PARAM, *pSTR_1_PARAM;

#endif

使用方法：遍历文件夹下图片，提起hog特征：

#include
#include
#include "param.h"
#include "procdir.h"
#include "cv.h"
#include "opencv2/opencv.hpp"

using namespace cv;

typedef struct MY_PARAM
{
IplImage *img;
IplImage *dst;
HOGDescriptor *hog;
FILE *pout;
vector descriptors;
} MY_PARAM, *pMY_PARAM;

void extr_hog(void *s1p)
{
STR_1_PARAM *str1param = (STR_1_PARAM*)s1p;
MY_PARAM *my_param = (MY_PARAM*)str1param->param;
my_param->img = cvLoadImage(str1param->str,0);
cvSmooth(my_param->img, my_param->dst, CV_GAUSSIAN, 3, 3);
my_param->hog->compute(my_param->dst, my_param->descriptors, Size(1,1), Size(0,0));
for(int i=0;idescriptors.size();i++)
{
fprintf(my_param->pout, "%f ", my_param->descriptors[i]);
}
fprintf(my_param->pout, "\n");
cvReleaseImage(&my_param->img);
}

int main(int argc, char **argv)
{
if(argc != 5 )
{
printf("Usage:\n%s [-d InputBaseDir] [-o OutputFile]\n", argv[0]);
return -1;
}

char tmp, *base, *output;
while((tmp=getopt(argc,argv,"d:o:"))!=-1)
{
switch(tmp)
{
case 'd':
base = optarg;
break;
case 'o':
output = optarg;
break;
}
}

FILE *pOutFile;
pOutFile = fopen(output,"w");
if(!pOutFile)
{
printf("Open/create file %s failed!\n", output);
return -1;
}

MY_PARAM my_param;
my_param.dst = cvCreateImage(cvSize(64,64),8,1);
my_param.pout = pOutFile;
my_param.hog = new HOGDescriptor(cvSize(64,64),cvSize(16,16),cvSize(8,8),cvSize(8,8),9);
STR_1_PARAM str1param;
str1param.param = &my_param;

   int rval = procdir(base, extr_hog, &str1param, 1);

fclose(pOutFile);

return 0;
}