Question

I am reading a .jpg image and accesing the pixels as:

if (type == BufferedImage.TYPE_3BYTE_BGR) {
   System.out.println("type.3byte.bgr");
   byte[] pixels = (byte[]) sourceImage.getData().getDataElements(0, 0, w, h, null);
}

// process this array called pixels and display the resulting image
// first i convert it to integer

int offseet=0;
   int[] data=new int[width*height*3];
   for ( i = 0; i < data.length; i++) { 
       data[i] = pixels[offset++] & 0xff;
     }

// and then process this array. For now I am not processing it. Now when i create a buffered
//image from data array and display it the image displayed is not the same.
// the code i use is

 writeEdges(data);


private BufferedImage edgesImage;   
private void writeEdges(int arb[]) {
    if (edgesImage == null) {
    edgesImage = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
    }

    edgesImage.getWritableTile(0, 0).setDataElements(0, 0, width,height, arb);
 }

// for the penguins.jpg image(provided in sample pictures in windows 7)!

the output i get is

Answer 1

I do not know how is your code running because it would not compile as jcomeau_ictx pointed out. The problem is that you use different image type for reading and writing.
Here is a code snippet that would generate the same image as the input.

public static void main(String[] args) {

        BufferedImage sourceImage = null;
        try {
            sourceImage = ImageIO.read(new File("IScSH.jpg"));
        } catch (IOException e) {
        }

        int type = sourceImage.getType();
        int w = sourceImage.getWidth();
        int h = sourceImage.getHeight();
        byte[] pixels = null;
        if (type == BufferedImage.TYPE_3BYTE_BGR) {
            System.out.println("type.3byte.bgr");
            pixels = (byte[]) sourceImage.getData().getDataElements(0, 0, w, h, null);
        }
        try {
            BufferedImage edgesImage = new BufferedImage(w, h, BufferedImage.TYPE_3BYTE_BGR);
            edgesImage.getWritableTile(0, 0).setDataElements(0, 0, w, h, pixels);
            ImageIO.write(edgesImage, "jpg", new File("nvRhP.jpg"));
        } catch (IOException e) {
        }
    }