Opencv矩阵的访问(通过指针

指针

mat.data.ptr 

把数据块切分成一个一个的字节，方便转换

 

#include "stdafx.h"

#include "cv.h"

#include "highgui.h"

#include "cxcore.h"

int main(int argc, char* argv[])

{

                 //数?y据Y

        float data[18] =

        {

        30,60,40,60, 50,40,

        67,88,55,33, 22,97,

        59,69,32,46, 25,45

        };

                

                CvMat mat;

                 //cvInitMatHeader(&mat,3,6,CV_32FC1,data);

                cvInitMatHeader(&mat,3,3,CV_32FC2,data);

                 int y=2,x=3;

                 int nChannels = 2;

                

                 for (y=0;y<mat.rows;y++)

                {

                                 float * p_float = (float *)(mat.data.ptr + y*mat.step);

                                 for (x=0;x<mat.cols;x++)

                                {

                                                 //float value = *(p_float+x);

                                                 //printf("(%f ) ",value);

                                                 float value[2];

                                                value[0] = *(p_float+x*nChannels);

                                                value[1] = *(p_float+x*nChannels+1);

                                                printf( "(%f %f) " ,value[0],value[1]);

                                }

                                printf( "\n" );

                }

                 return 0;

}