Colors are beautiful Java Tuenti Contest

package colors;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;

import javax.imageio.stream.*;
import javax.imageio.ImageIO;
import java.util.*;
import javax.imageio.ImageReader;
import java.awt.image.BufferedImage;

public class Colors {

    BufferedImage bi; // imagen

    public BufferedImage cargarImagen(String imagen) {

        try {
            FileInputStream inputStream = new FileInputStream(imagen);
            Iterator readers = ImageIO.getImageReadersBySuffix("bmp");
            ImageReader reader = (ImageReader) readers.next();
            ImageInputStream imageInputStream = ImageIO
                    .createImageInputStream(inputStream);
            reader.setInput(imageInputStream, false);
            return reader.read(0);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public int obtenerComponentePixel(int line, int column, int offset) {
        return (bi.getRGB(column, line) >> offset)&255;
    }

    public int obtenerOffset(String componente) {
        if (componente.equals("R")) {
            return 16;
        } else if (componente.equals("G")) {
            return 8;
        }
        return 0;
    }

    public int obtenerSumaLinea(int linea, String componente) {

        if (linea < 0 || linea >= bi.getHeight()) {
            return -1;
        }

        int offset = obtenerOffset(componente);
        int resultado = 0;

        for (int i=0; i<bi.getWidth(); i++) {
            resultado += obtenerComponentePixel(linea, i, offset);
        }

        return resultado;
    }

    public Colors(String ficheroImagen) {
        bi = cargarImagen(ficheroImagen);
    }

    public static void main(String[] args) {

        Colors colors = new Colors("trabaja.bmp");
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        try {

            while (br.ready()) {

                String datos = br.readLine().trim();
                if (!datos.isEmpty()) {
                    String componente = datos.substring(0, 1);
                    int linea = Integer.parseInt(datos.substring(1));
                    System.out.println(colors.obtenerSumaLinea(linea, componente)+1);
                }

            }

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}