Statistical parameters estimation of a image in C

#include<stdio.h>
#include<conio.h>
#include<process.h>
#include<math.h>
#include<iostream.h>
#include<stdlib.h>
#include<graphics.h>

void plot_axis(int type);
void plot_histo(void);
void plot_profile(void);

unsigned char input[128][128];

void main()
{
   int i,j,k;
   char name[20];
   FILE *fp;
   clrscr();
   cout<<"\n program to plot histogram of a given images:";
   cout<<"\n Enter the name of raw file:";
   cin>>name;
   //p//c:\rice.tif";
   fp=fopen(name,"rb");//c:\\rice.tif","rb");
   if(fp==NULL)
    {
     printf("\n unabel to open the file");
     fclose(fp);
     getch();
     exit(1);
     }
     i=0;
     for(i=0;i<128;i++)
      {
       for(j=0;j<128;j++)
	{
	 fscanf(fp,"%c",&input[i][j]);
	}
       }
       plot_axis(0);
       plot_histo();
       getch();
// next:
       closegraph();
       plot_axis(1);
       plot_profile();
       getch();
       //goto next;
}

void plot_axis(int type)
     {
      int i,k;
      float j;
      int gdriver=DETECT,gmode,errorcode;
      float x,y,real,imaginary,denominator,w;
      initgraph(&gdriver, &gmode, "E:\\TC\\BGI ");
      errorcode=graphresult();
      if(errorcode!=grOk)
	 {
	 printf("graphics error: %s\n",grapherrormsg(errorcode));
	 printf("press any key to halt:");
	 getch();
	 exit(1);
	 }
	  j=150;
	  setcolor(7);
	  line(50,70,50,400);
	  line(50,400,600,400);
	  for(i=1;i<6;i++);
	   {
	   line(j,395,j,405);
	   j+=100;
	   }
	  if(type==0)
	    {
	      outtextxy(150,405,"50");
	      outtextxy(250,405,"100");
	      outtextxy(350,405,"150");
	      outtextxy(450,405,"200");
	      outtextxy(550,405,"250");
	      outtextxy(400,10,"HISTOGRAM PLOT");
	      outtextxy(400,20,"==================");
	      outtextxy(450,425,"Gray level");
	      outtextxy(5,100,"freq");
	      outtextxy(20,370,"150");
	    }
	     j=400;
	     for(i=0;i<11;i++)
	      {
		line(50,j,55,j);
		j-=30;
	      }
		if(type==1)
		 {
		   outtextxy(150,405,"25");
		   outtextxy(250,405,"50");
		   outtextxy(350,405,"75");
		   outtextxy(450,405,"100");
		   outtextxy(550,405,"125");
		   outtextxy(5,50,"Gray level");
		   outtextxy(20,370,"40");
		   outtextxy(400,10,"PROFILE PLOT");
		   outtextxy(400,20,"==================");
		   outtextxy(450,425,"Pixel number");
		 }
}

void plot_histo(void)
{
		 int counter[256];
		 int i,j;
		 float x,y,mean,temp,sd,var;
		 for(i=0;i<256;i++)

		   counter[i]=0;
		  mean=0;
		  sd=0;
		   for(i=0;i<128;i++)
			{
			 for(j=0;j<128;j++)
			  {
			   counter[int(input[i][j])]++;
			   mean+=int(input[i][j]);
			   }
			  }
			 setcolor(15);
			 for(i=0;i<256;i++)
			 {
			 temp=counter[i];
			 y=400-(30*temp/150);
			 x=50+(i*2);
			 line(x,400,x,y);
			 }
			 mean=mean/16384;
			 for(i=0;i<128;i++)
			 {
			  for(j=0;j<128;j++)
			   {
			temp=int(input[i][j])-mean;
			sd+=temp*temp;
			}
			   }
			 sd=sd/16384;
			 sd=sqrt(sd);
			 var=sd*sd;
			 cout<<"\n Mean"<<mean;
			 cout<<"\n S.D."<<sd;
			 cout<<"\n VARIANCE"<<var;

}
			//Function to plot profile of a given row
		 void plot_profile(void)
		{
			int i,x,y,row;
		    cout<<"\n enter the row number (200 to exit):";
		    cin>>row;
		    if(row!=200)
		     {
		     for(i=0;i<128;i++)
		      {
		      y=int(input[row][i]);
		      y=400-(y*30/40);
		      x=50+(i*4);
		      setcolor(15);
		      line(x,400,x,y);
		       }//for
		   }//if


		   if(row==200)
		   exit(0);
}