OpenCV分通道显示图片，灰度，融合，直方图,彩色直方图

代码有参考跟整合：没有一一列出出处

// split_rgb.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <iostream>
#include <vector>

#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"

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

using namespace std;
using namespace cv;

#pragma comment(lib,"opencv_highgui244d.lib")
#pragma comment(lib,"opencv_core244d.lib")
#pragma comment(lib,"opencv_imgproc244d.lib")

void split_image(const char* image_name)
{
	Mat image_src = imread(image_name);
	Mat image_dst;
	vector<Mat> bgr;

	//颜色通道分离
	//输入图像
	//分离后各通道
	split(image_src,bgr);

	//颜色通道合成
	//输入各通道
	//输入图像
	merge(bgr,image_dst);

	//用彩色图像形象的表示一下,除了原通道保留，其余两通道置0
	Mat tmp(image_src.size(),CV_8U,Scalar(0));
	vector<Mat> b,g,r;   //用来表示的彩色图像

	for(int i=0;i<3;i++)
	{
		if(i==0)
			b.push_back(bgr[0]);
		else
			b.push_back(tmp);

		if(i==1)
			g.push_back(bgr[1]);
		else
			g.push_back(tmp);

		if(i==2)
			r.push_back(bgr[2]);
		else
			r.push_back(tmp);
	}
	Mat image_b,image_g,image_r;

	merge(b,image_b);
	merge(g,image_g);
	merge(r,image_r);

	namedWindow( "b", CV_WINDOW_AUTOSIZE );
	namedWindow( "g", CV_WINDOW_AUTOSIZE );
	namedWindow( "r", CV_WINDOW_AUTOSIZE );
	namedWindow( "dst", CV_WINDOW_AUTOSIZE );
	imshow("b",image_b);

	imshow("g",image_g);

	imshow("r",image_r);

	imshow("dst",image_dst);
	moveWindow("dst", 1,1);
	moveWindow("b",800,1);
	moveWindow("g",1,500);
	moveWindow("r",900,500);

	//waitKey(1);
	//waitKey(0);

}

void split_image_gray(const char* image_name)
{
	Mat image_src = imread(image_name);
	Mat image_dst;
	vector<Mat> bgr;

	//颜色通道分离
	//输入图像
	//分离后各通道
	split(image_src,bgr);

	//颜色通道合成
	//输入各通道
	//输入图像

	imshow("B_channel",bgr[0]);
	imshow("G_channel",bgr[1]);
	imshow("R_channel",bgr[2]);
	//waitKey(1);

}

//计算和绘制直方图（R,G,B）
/* img 通道图像
 * hist_img: 直方图的绘图图像
 * pstrWndName: 绘图窗口
 */
void draw_histogram(IplImage* img,IplImage* hist_img,const char* pstrWndName)
{

	CvHistogram* hist = NULL;

	int bin_count = 256;
	float range[] = {0,255};
	float* ranges[]={range};

	hist = cvCreateHist(1,         //一维
		&bin_count, //每一维上bin（直方柱）的个数， 此处为 256 【由上述两个参数，函数/就会创建一个1*256的矩阵】
		CV_HIST_ARRAY,
		ranges,
		1);
	cvClearHist(hist);   //防止初始化时有其它数据，先清理一下	

	cvCalcHist(&img,hist,0,0);

	//得到直方图的最值及标号
	float min,max;
	int min_idx,max_idx;
	cvGetMinMaxHistValue(hist,&min,&max,&min_idx,&max_idx);

	//cout<<"min: "<<min<<"  max:"<<max<<endl;
	if(max == 0) {cout<<"max =0 err!"<<endl;max = 100;}

	//缩放直方图的大小，和图像相适应
	cvScale(hist->bins,hist->bins,((double)hist_img->height)/max,0);

	//设置所有的直方图的数值为255
	cvSet(hist_img,cvScalarAll(255),0);

	// 平均每个直放柱的宽度
	int bin_w=cvRound((double)hist_img->width/bin_count);

	//画直方图
	for(int i=0;i<bin_count;i++)
	{
	   cvRectangle(hist_img,
		cvPoint(i*bin_w,hist_img->height),  //左下角的点（i*bin_w，height）
		cvPoint((i+1)*bin_w, hist_img->height-cvRound(cvGetReal1D(hist->bins,i))),//右上角的点((i+1)*bin_w,图像高度-直方柱的高度)
		 cvScalarAll(0),
		-1,
		8,
		0);
	}

	//显示直方图
	cvShowImage(pstrWndName,hist_img);
	cvWaitKey(1);
}

void historgram_channel(const char* image_name)
{
	IplImage* image_src = cvLoadImage(image_name,1);

	//创建窗口
	const char* pstrBHistWnd = "b plane";
	const char* pstrGHistWnd = "g plane";
	const char* pstrRHistWnd = "r plane";
	cvNamedWindow(pstrBHistWnd,1);
	cvNamedWindow(pstrGHistWnd,1);
	cvNamedWindow(pstrRHistWnd,1);

	//B G R 通道
	CvSize img_size;img_size.width = image_src->width;img_size.height = image_src->height;
	IplImage* b = cvCreateImage(img_size,8,1);
	IplImage* g = cvCreateImage(img_size,8,1);
	IplImage* r = cvCreateImage(img_size,8,1);
	//分割BGR通道
	cvSplit(image_src,b,g,r,0);

	CvSize size;size.width = image_src->width;size.height = image_src->height;
	IplImage* b_hist_img = cvCreateImage(size,8,1);
	IplImage* g_hist_img = cvCreateImage(size,8,1);
	IplImage* r_hist_img = cvCreateImage(size,8,1);

	//绘制直方图
	draw_histogram(b,b_hist_img,pstrBHistWnd);
	draw_histogram(g,g_hist_img,pstrGHistWnd);
	draw_histogram(r,r_hist_img,pstrRHistWnd); 

}

int _tmain(int argc, _TCHAR* argv[])
{
	char* image_name = "swan.jpg";
	split_image(image_name);
	split_image_gray(image_name);
	historgram_channel(image_name);

	waitKey(0);

	getchar();
	return 0;
}

实现效果：

彩色直方图：

#include <cv.h>
#include <highgui.h>
#include <iostream>
using namespace std;

int main( int argc, char** argv )
{
	IplImage * src= cvLoadImage("F:\\test3.jpg");

	IplImage* hsv = cvCreateImage( cvGetSize(src), 8, 3 );
	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 */
	float h_ranges[] = { 0, 180 }; 

	/** S 分量的变化范围*/
	float s_ranges[] = { 0, 255 };
	float* ranges[] = { h_ranges, s_ranges };

	/** 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 */
	float max_value;
	cvGetMinMaxHistValue( hist, 0, &max_value, 0, 0 );

	/** 设置直方图显示图像 */
	int height = 240;
	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++)
	{
		for(int s = 0; s < s_bins; s++)
		{
			int i = h*s_bins + s;
			/** 获得直方图中的统计次数，计算显示在图像中的高度 */
			float bin_val = cvQueryHistValue_2D( hist, h, s );
			int intensity = cvRound(bin_val*height/max_value);

			/** 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 );
	cvShowImage( "H-S Histogram", hist_img );

	cvWaitKey(0);
}

输入图像：

输出直方图：