Arrays getting disfigured automatically!

[rghai6]

Hi, i've been trying to create a program for implementing high/low
pass filters on images. I get the data from a 24 bit .bmp file using
the old file handling techniques. The file handling portion of my
program works like a breeze, it is the arrays that are giving me the
problem.

My I/P file:4*4 pixel 24 bit bmp

I've added the output as well at the end to show the difference in
array contents in the start an at the beginning.

I'm really confused as to why the contents of the array are changing ?

PS:I am not doing any processing on the image yet, just trying to get
the pixel color intensities into the array c and use this to output
the pixel intensities to the new file.

code:

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

using namespace std;

int main() {

FILE *fp1,*fp2;
int a,h=0,w=0,t=0;
int j=0,i=0;
//clrscr();

fp1=fopen("rd.bmp","rb");
fp2=fopen("rd2.bmp","wb");
for (i=0;i<54;i++) {
a=getc(fp1);
putc(a,fp2);

if(i>=18&&i<22)
w+=int(a*(pow(256,(i-18))));
if(i>=22&&i<26)
h+=int(a*(pow(256,(i-22))));

}
cout<<endl<<"Pixels to process: "<<h<<" "<<w<<endl;
cout<<"Original image"<<endl;
int *c = new int[w*h*3];
//int c[48]={0};
for (i=0;i<h;i++) {
for (j=0;j<w;j++) {
t=0;
a=getc(fp1);
t+=a;
c[i*w+j]=(int)a;
cout<<c[i*w+j]<<" ";
a=getc(fp1);
t+=a;
c[i*w+j+1]=(int)a;
cout<<c[i*w+j+1]<<" ";
a=getc(fp1);
t=(t+a)/3;
c[i*w+j+2]=(int)a;
cout<<c[i*w+j+2]<<" ";
if(a==-1) break;
}

cout<<endl;
if(a==-1) {
cout<<endl<<"Breaking..."<<i<<" "<<j; break ;
}
}

cout<<endl<<"Processed pixels : "<<i<<" "<<j<<endl;
cout<<endl;
int cn=0;

while((a=getc(fp1))!=-1) {
cout<<" "<<a;
cn++;
}
cout<<endl<<"Pixels not proc : "<<cn/3<<endl;

for (i=0;i<h;i++) {
for (j=0;j<w;j++) {

cout<<c[i*w+j]<<" "<<c[i*w+j+1]<<" "<<c[i*w+j
+2]<<" ";
t=(c[i*w+j]+c[i*w+j+1]+c[i*w+j+2])/3;

putc(t,fp2);
putc(t,fp2);
putc(t,fp2);
}
cout<<endl;
}

Output :

Pixels to process: 4
4
Original
image
0 0 0 255 255 255 0 0 255 255 255
255
255 255 255 255 255 255 255 255 255 255 255
255
255 255 255 255 255 255 255 255 255 255 255
255
255 255 255 255 255 255 255 255 255 255 255
255

Processed pixels : 4
4
Pixels not proc :
0
0 255 0 255 0 255 0 255 255 255 255
255
255 255 255 255 255 255 255 255 255 255 255
255
255 255 255 255 255 255 255 255 255 255 255
255
255 255 255 255 255 255 255 255 255 255 255 255

Thanks
fclose(fp1);
fclose(fp2);
getch();
return 0;
}

[rghai6]

Code got messed up last time. Modified it...

New code:

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

using namespace std;

int main() {

FILE *fp1,*fp2;
int a,h=0,w=0,t=0;
int j=0,i=0;
//clrscr();

fp1=fopen("rd.bmp","rb");
fp2=fopen("rd2.bmp","wb");

for (i=0;i<54;i++) {
a=getc(fp1);
putc(a,fp2);

if(i>=18&&i<22)
w+=int(a*(pow(256,(i-18))));
if(i>=22&&i<26)
h+=int(a*(pow(256,(i-22))));

}

cout<<endl<<"Pixels to process: "<<h<<" "<<w<<endl;
cout<<"Original image"<<endl;
int *c = new int[w*h*3];
//int c[48]={0};

for (i=0;i<h;i++) {
for (j=0;j<w;j++) {
t=0;
a=getc(fp1);
t+=a;
c[i*w+j]=(int)a;
cout<<c[i*w+j]<<" ";
a=getc(fp1);
t+=a;
c[i*w+j+1]=(int)a;
cout<<c[i*w+j+1]<<" ";
a=getc(fp1);
t=(t+a)/3;
c[i*w+j+2]=(int)a;
cout<<c[i*w+j+2]<<" ";
if(a==-1) break;
}

cout<<endl;
if(a==-1) {
cout<<endl<<"Breaking..."<<i<<" "<<j; break ;
}
}

cout<<endl<<"Processed pixels : "<<i<<" "<<j<<endl;
cout<<endl;
int cn=0;

while((a=getc(fp1))!=-1) {
cout<<" "<<a;
cn++;
}
cout<<endl<<"Pixels not proc : "<<cn/3<<endl;

for (i=0;i<h;i++) {
for (j=0;j<w;j++) {

cout<<c[i*w+j]<<" "<<c[i*w+j+1]<<" "<<c[i*w+j
+2]<<" ";
t=(c[i*w+j]+c[i*w+j+1]+c[i*w+j+2])/3;

putc(t,fp2);
putc(t,fp2);
putc(t,fp2);
}
cout<<endl;
}
fclose(fp1);
fclose(fp2);
getch();
return 0;

}

[tragomaskhalos]

On Oct 8, 9:14 am, [e-mail] wrote:

if(i>=18&&i<22)
w+=int(a*(pow(256,(i-18))));
if(i>=22&&i<26)
h+=int(a*(pow(256,(i-22))));

You really don't want to be using pow here; use <<
instead.