package GFX::Enhancer::PNGReader;
sub new {
        my ($class, $name) = @_;
        my $self = $class->SUPER::new;
        $self->{filename} = "";
        $self->{bytes} = 0; ### number which stores all bytes of the png image
        $self->{length} = 0;
}
### public methods
sub read_in_byte_array {
        my $self = shift;
        my $self->{filename} = shift;
        ### FIXME png reader code
        $self->{length} = ;
}
sub get_byte {
        my $self = shift;
        my $index = shift; ### byte index
        return ($self->{bytes} >> ($index-1)*4 - $self->{bytes} >> $index*4); 
}
         
sub get_byte_interval {
        my $self = shift;
        my $i = shift;
        my $j = shift; ### j > i
        return ($self->{bytes} >> $j*4 - $self->{bytes} >> $i*4);     
}
1;