I37A Answer ― Image Halving

/*Halve Images */
void halveImage( image full, image *half)
{
  int r, c, p ;

  /* construct an image structure of the appropriate size */
  if ( !newImage( half, full.nrows/2, full.ncols/2 ) )
  {
    printf("halveImages(): newImage() failed\n" );
    system( "pause" );
    exit( EXIT_FAILURE );
  }

  for ( r=0; r<full.nrows; r+=2 )
    for ( c=0; c<full.ncols; c+=2 )
    {
      p = getPixel( full, r, c ) ;
      setPixel( *half, r/2, c/2, (unsigned char)p );
    }
}

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