Answer to Question #277570 in C++ for Ana

Question

Data collected by sensor devices may contain noise and need smoothing. One simple

approach to smooth out data is to replace each value with the average of the value and its two

neighboring values (or one neighboring value if it is at either end of the array). Write a program that

inputs 4*3 array of integers and smooth out the values. You should not create another array in your

solution. Also, you will use all neighbors to for smoothing. For example, for smoothing Red cell, you will

use values of all orange cells. You will use updated value of cells for smoothing.

Answer 1

#include <iostream>
#include <fstream>
#include <sstream>
using namespace std;
 
/* Function to sort an array using insertion sort*/
void insertionSort(int arr[], int n)
{
    int i, key, j;
    for (i = 1; i < n; i++)
    {
        key = arr[i];
        j = i - 1;
 
        /* Move elements of arr[0..i-1], that are
        greater than key, to one position ahead
        of their current position */
        while (j >= 0 && arr[j] > key)
        {
            arr[j + 1] = arr[j];
            j = j - 1;
        }
        arr[j + 1] = key;
    }
}
 
int array[2000][2000];
int arr[2000][2000];
int main()
{
    int window[9],row = 0, col = 0, numrows = 0, numcols = 0,MAX=0;
    ifstream infile("Saltpepper.pgm");
    stringstream ss;
    string inputLine = "";
 
    // First line : version
    getline(infile,inputLine);
    if(inputLine.compare("P2") != 0) cerr << "Version error" << endl;
    else cout << "Version : " << inputLine << endl;
 
    // Continue with a stringstream
    ss << infile.rdbuf();
 
    // Secondline : size of image
    ss >> numcols >> numrows >> MAX;
 
    //print total number of rows, columns and maximum intensity of image
    cout << numcols << " columns and " << numrows << " rows" <<endl<<"
    Maximium Intesity "<< MAX <<endl;
 
 
    //Initialize a new array of same size of image with 0
    for(row = 0; row <= numrows; ++row)
        array[row][0]=0;
    for( col = 0; col<=numcols; ++col )
        array[0][col]=0;
 
    // Following lines : data
    for(row = 1; row <= numrows; ++row)
    {
        for (col = 1; col <= numcols; ++col)
        {
            //original data store in new array
            ss >> array[row][col];
        }
    }
 
 
    // Now print the array to see the result
    for(row = 1; row <= numrows; ++row)
    {
        for(col = 1; col <= numcols; ++col)
        {
            //neighbor pixel values are stored in window including this pixel
            window[0] = array[row-1][col-1];
            window[1] = array[row-1][col];
            window[2] = array[row-1][col+1];
            window[3] = array[row][col-1];
            window[4] = array[row][col];
            window[5] = array[row][col+1];
            window[6] = array[row+1][col-1];
            window[7] = array[row+1][col];
            window[8] = array[row+1][col+1];
 
            //sort window array
            insertionSort(window,9);
            //put the median to the new array
            arr[row][col]=window[4];   
        }
    }
 
    ofstream outfile;
     
    //new file open to store the output image
    outfile.open("Medianfilter.pnm");
    outfile<<"P2"<<endl;
    outfile<<numcols<<" "<<numrows<<endl;
    outfile<<"255"<<endl;
     
    for(row = 1; row <= numrows; ++row)
    {
        for (col = 1; col <= numcols; ++col)
        {
            //store resultant pixel values to the output file
            outfile << arr[row][col]<<" ";
        }
    }
     
    outfile.close();
    infile.close();
    return 0 ;
}