// image.cpp
// Functions required for MSc Project
// Do not alter the contents of this file - simply compile with your program
// if your program is called histo, then to compile:
// g++ -o histo histo.cpp image.cpp

#include <string.h>
#include <iostream.h>
#include "image.h"

void write_image(ofstream &fo, unsigned char image[][256])
{
	int i;

	fo << "P5\n";
	fo << "256\t256\n255\n";

        for (i = 0;i < 256; i++)
        {
		 fo.write((const char *) image[i],256); 
        }

}


void read_image(ifstream  &fi,  unsigned char image[][256])
{
		char buff[100];
		int i;

		next_line(fi,buff);
                if (strncmp("P5",buff,2)!=0)
                {
                        cerr << "wrong input file format\n";
                        exit(1);
                }

		next_line(fi, buff);

		next_line(fi, buff);

		for (i=0; i< 256 ; i++)
		{
			fi.read((char *) image[i],  256);

		}
}
void next_line (ifstream &fptr, char *s)
{
	 // Ignores #lines and returns next line of input file in char_buff[] 
	do {
    		fptr.getline(s,100);
    	} while (s[0]=='#');
}