Getting the index of a pixel in an indexed image

Question

Hi,
Is it possible to get the index of a pixel in an indexed image? I mean, indexed images (GIF, indexed PNG) are like:
INDEX R G B
0 234 22 143
1 9 123 213
2 56 43 10
etc.
I'm wondering if it exists a GET method to retrieve this INDEX, as getRGB() retrieves the sRGB value of a pixel.
Thanks in advance.

Answer 1

Raster.getSample:
import java.awt.image.*;
import java.io.*;
import java.net.*;
import javax.imageio.*;
public class IndexColorModelTest {
    public static void main(String[] args) throws IOException {
        URL url = new URL("http://forum.java.sun.com/images/reply.gif");
        BufferedImage bi = ImageIO.read(url);
        ColorModel cm = bi.getColorModel();
        if (!(cm instanceof IndexColorModel))
            throw new IOException("ColorModel is " + cm.getClass());
        WritableRaster r = bi.getRaster();
        for(int y=0, uby=r.getHeight(); y<uby; ++y) {
            for(int x=0, ubx=r.getWidth(); x<ubx; ++x) {
                int sample = r.getSample(x, y, 0); //<<--------<<
                //if (sample < 100)
                //    System.out.print(" ");
                if (sample < 10)
                    System.out.print(" ");
                System.out.print(sample);
            System.out.println();
}