image-manipulation/ReadImageHeader.cpp at master · robertroeder/image-manipulation · GitHub

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#include <iostream>
#include <fstream>
#include <stdlib.h>
#include <stdio.h>

using namespace std;

#include "image.h"

void readImageHeader(char fname[], int& N, int& M, int& Q, bool& type, bool& fileRead)
{
 int i, j;
 unsigned char *charImage;
 char header [100], *ptr;
 ifstream ifp;

 ifp.open(fname, ios::in | ios::binary);

 if (!ifp) {
   cout << "Can't read image: " << fname << endl;
   //exit(1); <---- Gives the user a chance to re-enter their filename if this is commented out.
	 fileRead = false;
	 return;
 }

 // read header

 type = false; // PGM

 ifp.getline(header,100,'\n');
 if ( (header[0] == 80) &&  /* 'P' */
      (header[1]== 53) ) {  /* '5' */
      type = false;
	  fileRead = true;
 }
 else if ( (header[0] == 80) &&  /* 'P' */
      (header[1] == 54) ) {        /* '6' */
      type = true;
	  fileRead = true;
 }
 else {
   cout << "Image " << fname << " is not PGM or PPM" << endl;
	 // exit(1);  <---- Gives the user a chance to re-enter their filename if this is commented out.
	 fileRead = false;
	 return;
 }

ifp.getline(header,100,'\n');
 while(header[0]=='#')
   ifp.getline(header,100,'\n');

 M=strtol(header,&ptr,0);
 N=atoi(ptr);

 ifp.getline(header,100,'\n');

 Q=strtol(header,&ptr,0);

 ifp.close();


}