OPenCV特征提取代码总结

特征提取代码总结

颜色提取

颜色直方图提取：

Code:

#include <cv.h>

#include <highgui.h>

#include <iostream>

using namespace std;

IplImage* h_plane = cvCreateImage( cvGetSize(src), 8, 1 );

IplImage* s_plane = cvCreateImage( cvGetSize(src), 8, 1 );

IplImage* v_plane = cvCreateImage( cvGetSize(src), 8, 1 );

IplImage* planes[] = { h_plane, s_plane };

/** H 分量划分为 16 个等级，S 分量划分为 8 个等级*/

int h_bins = 16, s_bins = 8;

int hist_size[] = {h_bins, s_bins};

/** H 分量的变化范围*/

/** 输入图像转换到 HSV 颜色空间*/

cvCvtColor( src, hsv, CV_BGR2HSV );

cvCvtPixToPlane( hsv, h_plane, s_plane, v_plane, 0 );

/** 创建直方图，二维, 每个维度上均分*/

CvHistogram * hist = cvCreateHist( 2, hist_size, CV_HIST_ARRAY, ranges, 1 );

/** 根据 H,S 两个平面数据统计直方图*/

cvCalcHist( planes, hist, 0, 0 );

/** 获取直方图统计的最大值，用于动态显示直方图*/

int width = (h_bins*s_bins*6);

IplImage* hist_img = cvCreateImage( cvSize(width,height), 8, 3 );

cvZero( hist_img );

/** 用来进行 HSV 到 RGB 颜色转换的临时单位图像*/

IplImage * hsv_color = cvCreateImage(cvSize(1,1),8,3);

IplImage * rgb_color = cvCreateImage(cvSize(1,1),8,3);

int bin_w = width / (h_bins * s_bins);

for(int h = 0; h < h_bins; h++)

{

/** 获得当前直方图代表的颜色，转换成 RGB 用于绘制*/

cvSet2D(hsv_color,0,0,cvScalar(h*180.f / h_bins,s*255.f/s_bins,255,0));

cvCvtColor(hsv_color,rgb_color,CV_HSV2BGR);

CvScalar color = cvGet2D(rgb_color,0,0);

cvRectangle( hist_img, cvPoint(i*bin_w,height),

cvPoint((i+1)*bin_w,height - intensity),

color, -1, 8, 0 );

}

cvNamedWindow( "Source", 1 );

cvShowImage( "Source", src );

cvNamedWindow( "H-S Histogram", 1 );

形状提取

Candy 算子对边缘提取：

Code：

#include "cv.h"

#include "cxcore.h"

#include "highgui.h"

int main( int argc, char** argv )

{

//声明 IplImage 指针

//canny 边缘检测

cvCanny(pImg, pCannyImg, 50, 150, 3);

//创建窗口

cvNamedWindow("src", 1);

//销毁窗口

cvDestroyWindow( "src" );

cvDestroyWindow( "canny" );

//释放图像

cvReleaseImage( &pImg );

cvReleaseImage( &pCannyImg );

return 0;

}

运行效果截图：

角点提取：

Code：

#include <stdio.h>

#include "cv.h"

#include "highgui.h"

#define MAX_CORNERS 100

int cornersCount=MAX_CORNERS;//得到的角点数目

CvPoint2D32f corners[MAX_CORNERS];//输出角点集合

IplImage *srcImage = 0,*grayImage = 0,*corners1 = 0,*corners2 = 0;

int i;

//复制并转为灰度图像

cvCvtColor(srcImage,grayImage,CV_BGR2GRAY);

//create empty images os same size as the copied images

//两幅临时位浮点图像，cvGoodFeaturesToTrack 会用到

corners1 = cvCreateImage(cvGetSize(srcImage),IPL_DEPTH_32F,1);

corners2 = cvCreateImage(cvGetSize(srcImage),IPL_DEPTH_32F,1);

cvGoodFeaturesToTrack(grayImage,corners1,corners2,corners,&cornersCount,0.05,

30,//角点的最小距离是

0,//整个图像

3,0,0.4);

cvCircle(srcImage,cvPoint((int)(corners[i].x),(int)(corners[i].y)),2,color,2,CV_AA,

0);

}

}

cvShowImage("image",srcImage);

cvSaveImage("imagedst.png",srcImage);

cvReleaseImage(&srcImage);

cvReleaseImage(&grayImage);

cvReleaseImage(&corners1);

cvReleaseImage(&corners2);