BGR별 히스토그램 구하기

코드

#include<iostream>

#include<opencv2\core.hpp>

#include<opencv\cv.h>

#include<opencv2\highgui.hpp>

#include<opencv2\imgproc.hpp>

using namespace cv;

using namespace std;

int main(){

Mat inputImg = imread("image/humming_bird.jpg", CV_LOAD_IMAGE_COLOR);

MatND histogramB, histogramG, histogramR;

int channel_B[] = { 0 };  // Blue

int channel_G[] = { 1 };  // Green

int channel_R[] = { 2 };  // Red

float channel_range[2] = {0.0 , 255.0};

const float* channel_ranges[1] = { channel_range };

int histSize[1] = { 256 };

// R, G, B별로 각각 히스토그램을 계산한다.

calcHist(&inputImg, 1, channel_B, Mat(), histogramB, 1, histSize, channel_ranges);

calcHist(&inputImg, 1, channel_G, Mat(), histogramG, 1, histSize, channel_ranges);

calcHist(&inputImg, 1, channel_R, Mat(), histogramR, 1, histSize, channel_ranges);

// Plot the histogram

int hist_w = 512; int hist_h = 400;

int bin_w = cvRound((double)hist_w / histSize[0]);

Mat histImageB(hist_h, hist_w, CV_8UC3, Scalar(0, 0, 0));

normalize(histogramB, histogramB, 0, histImageB.rows, NORM_MINMAX, -1, Mat());

Mat histImageG(hist_h, hist_w, CV_8UC3, Scalar(0, 0, 0));

normalize(histogramG, histogramG, 0, histImageG.rows, NORM_MINMAX, -1, Mat());

Mat histImageR(hist_h, hist_w, CV_8UC3, Scalar(0, 0, 0));

normalize(histogramR, histogramR, 0, histImageR.rows, NORM_MINMAX, -1, Mat());

for (int i = 1; i < histSize[0]; i++)

{

line(histImageB, Point(bin_w*(i - 1), hist_h - cvRound(histogramB.at<float>(i - 1))),

Point(bin_w*(i), hist_h - cvRound(histogramB.at<float>(i))),

Scalar(255, 0, 0), 2, 8, 0);

line(histImageG, Point(bin_w*(i - 1), hist_h - cvRound(histogramG.at<float>(i - 1))),

Point(bin_w*(i), hist_h - cvRound(histogramG.at<float>(i))),

Scalar(0, 255, 0), 2, 8, 0);

line(histImageR, Point(bin_w*(i - 1), hist_h - cvRound(histogramR.at<float>(i - 1))),

Point(bin_w*(i), hist_h - cvRound(histogramR.at<float>(i))),

Scalar(0, 0, 255), 2, 8, 0);

}

namedWindow("Original", CV_WINDOW_AUTOSIZE);

namedWindow("HistogramB", CV_WINDOW_AUTOSIZE);

namedWindow("HistogramG", CV_WINDOW_AUTOSIZE);

namedWindow("HistogramR", CV_WINDOW_AUTOSIZE);

moveWindow("Original", 100, 100);

moveWindow("HistogramB", 110, 110);

moveWindow("HistogramG", 120, 120);

moveWindow("HistogramR", 130, 130);

imshow("Original", inputImg);

imshow("HistogramB", histImageB);

imshow("HistogramG", histImageG);

imshow("HistogramR", histImageR);

waitKey(0);

return 0;

}

결과