How to get the r,g,b value of a pixel in a picture

Question

Hi, there
How can I get the integer value of the r, g, b value of a pixel in a picture. This picture is loaded from a file, such as jpg or gif. That means the absolute position of the left corner of the picture may be float when you change the size of the window.
Thanks in advance.

Answer 1

Hi, there
I try the way that you suggested, but it still cannot work. I attach the fragment code here. If anyone have time, please help me to check why I always get 0 for the r,g and b value.
Thanks in advance
public class cc
{   public static void main(String[] args)
{   PFrame frame = new PFrame();
frame.setTitle("Pixels");
frame.setSize(200,200);
frame.setBackground(Color.blue);
frame.show();
class PFrame extends JFrame implements ActionListener
{   DrawPanel dp;
JButton clickButton;
JTextField rgbTextField;
public PFrame()
{   dp = new DrawPanel();
clickButton = new JButton("Show RGB");
clickButton.addActionListener(this);
rgbTextField = new JTextField("RGB show here");
Container contentPane = getContentPane();
contentPane.add(clickButton, "North");
contentPane.add(rgbTextField, "South");
contentPane.add(dp, "Center");
public void actionPerformed(ActionEvent ae)
{   BufferedImage bi = new BufferedImage(10,10,BufferedImage.TYPE_INT_ARGB);
int rgb = bi.getRGB(5,5);
//int red = (rgb & 0xff0000) >> 16;
//int green = (rgb & 0xff00) >> 8;
//int blue = rgb & 0xff;
int red = new Color(rgb).getRed();
int green = new Color(rgb).getGreen();
int blue = new Color(rgb).getBlue();
rgbTextField.setText("Red = " + red + " Green = " + green + " Blue = " + blue);
class DrawPanel extends JPanel
{   public void paintComponent(Graphics g)
{   super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setColor(new Color(10,20,39));
g2.fillRect(0,0,10,10);
g2.setColor(Color.red);
g2.fillRect(60,60,20,20);