Notes

#include <iostream>
#include <opencv2opencv.hpp>
#include <opencv2corecore.hpp>
#include <opencv2highguihighgui.hpp>

using namespace cv;
using namespace std;

int main(int argc, char *argv[]) {
if (argc != 2) {
cout << "Usage: display_Image ImageToLoadandDisplay" << endl;
return -1;
}
Mat image;
Mat gray;

image = imread(argv[1], IMREAD_COLOR); //read the files
if (!image.data) //check for invalid input
{
cout << "Could not open or find the image" << endl;
return -1;
}
int h = image.rows;
int w = image.cols;
Mat gr(h, w, CV_8UC1, Scalar(0));

for (int i = 0;i < h;i++) {
for (int j = 0;j < w;j++) {
gr.at<uchar>(i, j) = uchar(0.114*image.at<Vec3b>(i, j)[0]) + uchar(0.587*image.at<Vec3b>(i, j)[1]) + uchar(0.299*image.at<Vec3b>(i, j)[2]);
}
}

cvtColor(image, gray, CV_BGR2GRAY);



// ******************* READ the Pixel intensity *********************
// single channel grey scale image (type 8UC1) and pixel coordinates x=5 and y=2
// by convention, {row number = y} and {column number = x}
// intensity.val[0] contains a value from 0 to 255


int his1[256];
double prob[256];
double cprob[256];


for (int i = 0; i < 256; i++) {
his1[i] = 0;
prob[i] = 0.0;

}
int val = 0;

for (int i = 0;i < h; i++) {
for (int j = 0;j < w; j++) {
val = gr.at<uchar>(i, j); //assigning the pixel value to val

his1[val] = his1[val] + 1; //increasing the value of bin by 1

}
}
for (int i = 0; i < 256; i++) {

prob[i] = (double)his1[i] / (h*w);
if(i==0)
{
cprob[0] = prob[0];

}
else
{
cprob[i] = cprob[i-1] + prob[i];

}

cout << "cprob" << i << ": " << cprob[i] << std::endl;

}

//int max = 0;
//for (int i = 0; i < 256; i++) {

// cout << "Bin" << i << ": " << his1[i] << std::endl;
// if (max < his1[i])
// max = his1[i];
//}

//cout << max;
//Mat him(301, 260, CV_8UC1, Scalar(255));
//int hist[256]; // integer array
//double maxd = max;
//for (int i = 0;i < 255; i++) {

// hist[i] = cvRound(double(his1[i] / maxd) * 300); //calculating histogram bin value
// Point pt1 = Point(i, 300 - hist[i]);
// Point pt2 = Point(i, 300);
// line(him, pt1, pt2, Scalar(0), 1, 8, 0); //scalar 0 = black colour, we are drawing in black colour





//}



namedWindow("Display window", WINDOW_AUTOSIZE);//Create window for
imshow("Display window", gr); //show out the image inside it
//namedWindow("Display window1", WINDOW_AUTOSIZE);
//imshow("Display window1", him); //wait for the user to press a key in the GUI window
cvWaitKey(0);
image.release(); //free memory
gray.release(); //free memory
gr.release();
//him.release();
return 0;
}