Task E. Scale 200% Program scale.cpp. Scale the original picture to 200% of its

Question

Task E. Scale 200%

Program scale.cpp. Scale the original picture to 200% of its size. It can be done by increasing the size of the picture by the factor of 2, and copying each pixel of the input as a small 2x2 square in the output. (We don’t do any interpolation of colors as more advanced scaling procedures would do.)

I`m adding the code and you just need to do something in the main function, I tried but looks like it`s not working...If you could comment what you did to make it work....

#include <iostream>

#include <cassert>

#include <cstdlib>

#include <fstream>

using namespace std;

const int MAX_H = 512;

const int MAX_W = 512;

// Reads a PGM file.

// Notice that: height and width are passed by reference!

void readImage(int image[MAX_H][MAX_W], int &height, int &width) {

char c;

int x;

ifstream instr;

instr.open("inImage.pgm");

// read the header P2

instr >> c;

assert(c == 'P');

instr >> c;

assert(c == '2');

// skip the comments (if any)

while ((instr>>ws).peek() == '#') {

instr.ignore(4096, ' ');

}

instr >> width;

instr >> height;

assert(width <= MAX_W);

assert(height <= MAX_H);

int max;

instr >> max;

assert(max == 255);

for (int row = 0; row < height; row++)

for (int col = 0; col < width; col++)

instr >> image[row][col];

instr.close();

return;

}

// Writes a PGM file

// Need to provide the array data and the image dimensions

void writeImage(int image[MAX_H][MAX_W], int height, int width) {

ofstream ostr;

ostr.open("outImage.pgm");

if (ostr.fail()) {

cout << "Unable to write file ";

exit(1);

};

// print the header

ostr << "P2" << endl;

// width, height

ostr << width << ' ';

ostr << height << endl;

ostr << 255 << endl;

for (int row = 0; row < height; row++) {

for (int col = 0; col < width; col++) {

assert(image[row][col] < 256);

assert(image[row][col] >= 0);

ostr << image[row][col] << ' ';

ostr << endl;

}

}

ostr.close();

return;

}

int main() {

int img[MAX_H][MAX_W];

int h, w;

int avg = 0;

readImage(img, h, w); // read it from the file "inImage.pgm"

// h and w were passed by reference and

// now contain the dimensions of the picture

// and the 2-dimesional array img contains the image data

// Now we can manipulate the image the way we like

// for example we copy its contents into a new array

int out[MAX_H][MAX_W];

for(int row = 0; row < h; row++) {

for(int col = 0; col < w; col ++) {

avg = (out[row][col] + out[row][col + 1] + out[row + 1][col] + out[row + 1][col + 1])/4; // find ave

out[row][col] = out[row][col + 1] = out[row + 1][col] = out[row + 1][col + 1] = avg;

col += 2; // skip a col

row += 2; // skip a row

}

}

// and save this new image to file "outImage.pgm"

writeImage(out, h, w);

}

Example

Explanation / Answer

#include #include #include #include using namespace std; const int MAX_H = 512; const int MAX_W = 512; // Reads a PGM file. // Notice that: height and width are passed by reference! void readImage(int image[MAX_H][MAX_W], int& height, int& width) { char c; int x; ifstream instr; instr.open("inImage.pgm"); // read the header P2 instr >> c; assert(c == 'P'); instr >> c; assert(c == '2'); // skip the comments (if any) while ((instr >> ws).peek() == '#') { instr.ignore(4096, ' '); } instr >> width; instr >> height; assert(width max; assert(max == 255); for (int row = 0; row image[row][col]; instr.close(); return; } // Writes a PGM file // Need to provide the array data and the image dimensions void writeImage(int image[MAX_H][MAX_W], int height, int width) { ofstream ostr; ostr.open("outImage.pgm"); if (ostr.fail()) { cout

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