[Java] Read RGB values from raw image file

import java.io.*;

public class ReadRawImage {

    private byte[] all;
    /*
     * Channel[0] for red channel, Channel[1] for green channel, Channel[2]
     * for blue channel
     */
    private int[][][] Channel;

    private FileInputStream stream = null;

    public ReadRawImage(File raw_image, int width, int height) {
        try {
            /* Read the raw image file into memory */
            stream = new FileInputStream(raw_image);
            all = new byte[width * height * 3];
            Channel = new int[3][][];
            stream.read(all);

            /* dispatch pixel values to each array of channel */
            ByteArrayInputStream bytestream = new ByteArrayInputStream(all);

            byte [] temp  = new byte[width * height];

            bytestream.read(temp, 0, width * height);
            Channel[0] = new int[height][width];
            for(int i = 0; i < width * height; i++) {
                /*
                 * extends the byte value to integer value by
                 * performing the "and" operation with 0x000000ff
                 */
                Channel[0][i / width][i%width] = temp[i] & 0x000000ff;
            }

            bytestream.read(temp, 0, width * height);
            Channel[1] = new int[height][width];
            for(int i = 0; i < width * height; i++) {
                Channel[1][i / width][i%width] = temp[i] & 0x000000ff;
            }

            bytestream.read(temp, 0, width * height);
            Channel[2] = new int[height][width];
            for(int i = 0; i < width * height; i++) {
                Channel[2][i / width][i%width] = temp[i] & 0x000000ff;
            }

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

    public int[][][] getRGBValue() {
        return Channel;
    }
}