视频中直线像素采样（cvInitLineIterator ）把每个像素点的三个值写入csv文件中

#include <cv.h>
#include <highgui.h>
#include <stdio.h>

int main( int argc, char** argv )
{
// 	if( argc != 2 )
// 		return -1;
cvNamedWindow( "Example", CV_WINDOW_AUTOSIZE );
CvCapture* capture = cvCreateFileCapture( "video1.avi" );  //加载视频
if( !capture )
printf( "Couldn't open %s\n", argv[1] );
CvPoint pt1 = cvPoint( 10, 10 );
CvPoint pt2 = cvPoint( 10, 20 );  //直线两个顶点,读取这两个端点连成直线的像素点，总共11个像素点

int max_buffer;
IplImage* rawImage;
int r[10000], g[10000], b[10000];  //存储r,g,b三维的像素值
FILE* fptrb = fopen( "blines.csv","w" );  //创建文件存储数据
FILE* fptrg = fopen( "glines.csv", "w" );  //存储每个通道的像素值
FILE* fptrr = fopen( "rlines.csv", "w" );  //存储为csv文件
CvLineIterator iter;  //采样迭代器

int sign = 0;
for( ;; )
{
if( !cvGrabFrame( capture ) )  //如果没捕捉到帧，退出,视频总共有68帧，30秒的画面
break;
rawImage = cvRetrieveFrame( capture );  //取回由函数cvGrabFrame抓取的图像
max_buffer = cvInitLineIterator( rawImage, pt1, pt2, &iter, 8, 0);  //初始化直线迭代器,返回直线上两端像素点个数，总共11个
cvShowImage( "Example", rawImage );   //显示每一帧，连续显示每一帧就是视频的的原理
//	int c = cvWaitKey(0);
for( int j = 0; j < max_buffer; ++j ) //max_buffer = 11
{
fprintf( fptrb, "%d,", iter.ptr[0] );  //写蓝值
fprintf( fptrg, "%d,", iter.ptr[1] );
fprintf( fptrr, "%d,", iter.ptr[2] );
iter.ptr[2] = 255; //将直线标记为红色
CV_NEXT_LINE_POINT( iter );  //移动指针，指向下一个pixel
}
fprintf( fptrb, "\n" );
fprintf( fptrg, "\n" );
fprintf( fptrr, "\n" );
sign++;
printf("\n\n%d", sign);
}

fclose( fptrb );
fclose( fptrg );
fclose( fptrr );
cvReleaseCapture( &capture );
cvDestroyWindow( "Example" );

return 0;
}