ImageReader et ImageIO

 
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;

public class ImageReader {

    public ImageReader() {
        super();
    }

    /**
     * Method to read an image from the file system, store the result whith a
     * BufferedImage object
     *
     * @param filename
     *            the filename of the picture to read
     * @return the representation of the file read with a BuffereadImage object
     */
    public BufferedImage readImageFile(String filename) {
        try {
            File f = new File(filename);
            return ImageIO.read(f);
        } catch (IOException ioe) {
            ioe.printStackTrace();
            return null;
        }
    }

    /**
     * Method to write a BufferedImage on the file system
     *
     * @param buffer
     *            the buffer representing the picture to write
     * @param filename
     *            the name of the output picture
     * @param format
     *            the format of the picture (could be bmp, jpg, gif, png, ...)
     */
    public void writeImageFile(BufferedImage buffer, String filename,
            String format) {
        try {
            File f = new File(filename);
            ImageIO.write(buffer, format, f);
        } catch (IOException ioe) {
            ioe.printStackTrace();
        }
    }

    /**
     * Method to convert a BufferedImage to an integer array, each integer
     * represent a pixel
     *
     * @param bufferedImage
     * @return a pixel map (int[]) representing each pixel of the picture
     */
    public int[] bufferedImage2IntArray(BufferedImage bufferedImage) {
        int w = bufferedImage.getWidth();
        int h = bufferedImage.getHeight();
        int[] pixelMap = new int[w * h];
        bufferedImage.getRGB(0, 0, w, h, pixelMap, 0, w);
        return pixelMap;
    }

    /**
     * Method to convert a pixel matrix to a BufferedImage
     *
     * @param pixelMap
     *            the pixel map representing the picture
     * @param width
     *            the width of the picture
     * @param height
     *            the height of the picture
     * @return the BufferedImage of the picture
     */
    public BufferedImage IntArray2BufferedImage(int[] pixelMap, int width,
            int height) {
        BufferedImage bufferedImage = new BufferedImage(width, height,
                BufferedImage.TYPE_3BYTE_BGR);
        bufferedImage.setRGB(0, 0, width, height, pixelMap, 0, width);
        return bufferedImage;
    }

    public static void main(String[] args) {
       
        String filename = "imageOrigine.JPG";
       
        ImageReader imageReader = new ImageReader();
        BufferedImage bufferedImage = imageReader.readImageFile(filename);

  int width = bufferedImage.getWidth();
        int height = bufferedImage.getHeight();
       
        int[] pixelMap = imageReader.bufferedImage2IntArray(bufferedImage);
       
     BufferedImage NEWbufferedImage = imageReader.IntArray2BufferedImage(pixelMap,width,height) ;

        imageReader.writeImageFile(NEWbufferedImage, "Sortie.jpg", "png");
    }
}