// This code demonstrates how to read a 100x300
        // pixel sub-image at position ( 300, 100 ), 
        // ( 600, 200 ).
        //
        //               Primary Image
        //  +----------------------------------------+
        //  |             600                        |
        //  |<-------------------------->            |
        //  |         +----------------+ ^           |
        //  |         |   Sub-Image    | |           |
        //  |   300   |  ( 100x140 )   | |           |
        //  |<------->+----------------+ | 200       |
        //  |        ^                   |           |
        //  |        | 100               |           |
        //  |        V                   V           |
        //  +----------------------------------------+
        //
        #include <iostream>
        #include "CFitsFile.h"

        using namespace std;
        using namespace arc;

        int main()
        {
            long naxes[ CFitsFile::NAXES_SIZE ] = { 0, 0, 0 };

            try {
                CFitsFile cFits( "Image.fit" );

                unsigned short *pBuf = ( unsigned short * )
                                        cFits.ReadSubImage( 100, 300, 200, 600 );

                if ( pBuf == NULL )
                {
                    cerr << "Error: NULL image buffer!" << endl;
                    exit( 1 );
                }

                cFits.GetParameters( naxes );

                for ( int r=0; r<( 200 - 100 ); r++ )
                {
                    for ( int c=0; c<( 600 - 300 ); c++ )
                    {
                        cout << "pix[ " << ( c + r * naxes[ CFitsFile::NAXES_COL ] )
                             << " ]: " << pBuf[ c + r * naxes[ CFitsFile::NAXES_COL ] ]
                             << endl;
                    }
                }
            }
            catch ( std::exception &e )
            {
                cerr << "Exception Occurred: " << e.what() << endl;
            }
        }