Develop Reference

Java Swing image cut off/zoomed

when I try to render a png image in Java Swing, it is cut off/zoomed on all sides. Here is my code:
this.setSize(500, 500);
this.setResizable(false);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
this.getGraphics().drawImage(getImage("IMAGE PATH"), 0, 0, this);
And this is my getImage function
public static Image getImage(String path) {
File file = new File(path);
try {
return ImageIO.read(file);
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
The image I want to render is 500x500, just like my frame, but it still comes out wrong. This also applies to when I use the function like this:
Image image = getImage("Image Path");
assert image != null;
JLabel picLabel = new JLabel(new ImageIcon(image));
Here is one of the images I am trying to render:
Here is the outcome:
It is kind of hard to tell from this example, but the ground should be lower and the trees higher.

Don't set the size of the frame
If your image is 500x500 then how can you expect the image size and frame size to be the same when the frame also has a title bar and borders?
Don't do custom painting`
Instead:
create a JLabel with an ImageIcon.
Add the label to the frame
invoke pack() before making the frame visible.
All the components will get the proper size.
Read the Swing tutorial on How to Use Labels for more information and examples.

Even though #camikr found a solution, I found a better one for my needs.
What I did, was I created a new JPanel and ran setPreferredSize with the dimensions of my JFrame (500x500). Then I overrided the paintComonent function to render the image using the Graphics2D class.
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.util.Objects;
public class MyPanel extends JPanel {
public Image loadedImage = getImage("Image");
public LoadState() {
setPreferredSize(new Dimension(500,500));
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g.create();
g2.drawImage(loadedImage, 0, 0, null);
g2.dispose();
}
}
EDIT: Fix what #Harald K suggested

This was supposed to get an image in the array and resize it before printing it out to the frame

The cods first goes to the array and gets the file name. Then it converts it to a Buffered Image and changes the size of the image. It then sends the array of pictures to the main method where it is converted to a JLabel before adding it to the frame. I understand my programming convesion skills are kinda lacking but it would be nice if you could explain why when i run this i the image isnt resizing
This is the main class
import java.awt.Color;
import java.awt.Image;
import java.io.IOException;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class Frame extends JFrame
{
public Frame(JLabel welcomeImage)
{
setTitle("Tower Defence Game");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setResizable(false);
setSize(750 , 500);
setLocationRelativeTo(null);
setVisible(true);
getContentPane().setBackground(Color.BLACK);
add(welcomeImage);
}
public static JLabel WelcomeImage(Image[] pics)
{
pics[0].getScaledInstance(750, 1000, Image.SCALE_DEFAULT);
ImageIcon WelcomeImage = new ImageIcon(pics[0]);
JLabel JWelcomeImage = new JLabel();
JWelcomeImage.setIcon(WelcomeImage);
return JWelcomeImage;
}
public static void main(String[] args) throws IOException
{
Image[] pics = Images.Image();
JLabel welcomeImage = WelcomeImage(pics);
JFrame frame = new Frame(welcomeImage);
}
}
This is the class that would hold all the images
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
public class Images
{
public static Image[] Image() throws IOException
{
//Getting all the Picture in a png format
String Picture[] = {"apple.png"};
//Getting the Picture as an image
Image[] Pics = new Image[Picture.length];
BufferedImage iPic;
BufferedImage oPic;
//Using a for loop to put the Picture in an array
for(int i = 0; i < Picture.length; i++)
{
iPic = ImageIO.read(new File(Picture[i]));
oPic = new BufferedImage(750 , 500 , iPic.getType());
Pics[i] = (Image) oPic;
}
return Pics;
}
}

it would be nice if you could explain why when i run this i the image isnt resizing
Well, the first thing is to learn how to display the image at its actual size BEFORE attempting to scale the image. You can't display a scaled image if you don't know how to display the default image.
The problem with your code is that you can't even display the actual image, so trying to display a scaled image has no chance of working.
With that in mind you have several structural issues:
Don't call you class "Frame". There is an AWT component with that name and it is confusing. A class name should be more descriptive.
Don't extend JFrame. You should only extend a class when you add functionality to the class. Adding components to a frame is not adding functionality,
Components need to be added to the frame BEFORE the frame is made visible.
Don't use setSize(). How can the frame size and the image size be the same? The frame contains a titlebar and borders so it must be larger. Instead you should be using pack() before the setVisible(...) statement.
Variable names should NOT start with an upper case character. Be consistent.
Method names should be descriptive. What does the "Image" method do. Nobody could guess by looking at the method name. Maybe something like "readImages" or "loadImages"?
In the Image class:
iPic = ImageIO.read(new File(Picture[i]));
oPic = new BufferedImage(750 , 500 , iPic.getType());
Pics[i] = (Image) oPic;
What is the point of the "oPic" variable. The purpose of this method is to read the image, not scale the image. The "oPic" variable just contains an empty BufferedImage.
So get rid of that variable and just add the "iPic" image to the array.
In the Frame class:
pics[0].getScaledInstance(750, 1000, Image.SCALE_DEFAULT);
ImageIcon WelcomeImage = new ImageIcon(pics[0]);
The above code does nothing because the getScaledInstance(...) returns a new instance of the Image. So you need to assign it to a variable before you can use it:
// pics[0].getScaledInstance(750, 1000, Image.SCALE_DEFAULT);
// ImageIcon WelcomeImage = new ImageIcon(pics[0]);
Image scaled = pics[0].getScaledInstance(750, 1000, Image.SCALE_DEFAULT);
ImageIcon WelcomeImage = new ImageIcon(scaled);
I suggest you learn Swing basics by reading the Swing tutorial. Each section contains examples and the code will be better structured. The examples will show you how to create a class without extending JFrame.

How can I add an image to a panel

edit// my question is simpler than the other one so please just answer here. the other question looks too complicated for me to understand.
I want to add an image to a panel, but not sure how it's done. I don't want to do it from the design page because I didn't Design my panel I only coded it to show up. so does anyone know what code I need to add for an image to show up on there? and where do I save the image so that it can be included. here is the code I've done so far
JFrame frame = new JFrame("JButton");
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(500,200);
JPanel panel = new JPanel();
frame.add(panel);
JButton button = new JButton("London");
panel.add(button);
JLabel label = new JLabel("Click", JLabel.CENTER);

import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.JPanel;
public class ImagePanel extends JPanel{
private BufferedImage image;
public ImagePanel() {
try {
image = ImageIO.read(new File("image name and path"));
} catch (IOException ex) {
// handle exception...
}
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(image, 0, 0, this); // see javadoc for more info on the parameters
}
}

All you need to do is,
Read image file.
Draw image to background with help of Graphics object.
just replace JPanel panel = new JPanel(); with below code.
JPanel panel = new JPanel() {
#Override
protected void paintComponent(Graphics g) {
Image image = null;
try {
image = ImageIO.read(new URL("https://www.google.co.in/images/branding/googlelogo/2x/googlelogo_color_120x44dp.png"));
} catch (IOException e) {
e.printStackTrace();
}
super.paintComponent(g);
g.drawImage(image, 0, 0, null);
}
};

Alright, there are 2 ways to add your image:
Using custom painting by overriding JPanel#paintComponent(...) method.
Using a JLabel to display the image and applying to it various layout managers to get the desired GUI.
I'm going to expand on how to use the 1st way with some comments in the code, the original idea was given in this answer so, be sure to give credits to the author.
You need to either:
Create a custom JPanel object
Create a class that extends JPanel
In any case you need to override the paintComponent(...) method.
Later, in that paintComponent() method you need to draw the image using Graphics#drawImage(...) method. This will make the JPanel to draw the image as the background.
After that you should override your JPanel's getPreferredSize() method, so you can call JFrame#pack(), which will resize your JFrame's size to its preferred size (which is the minimum size where all your components are visible).
After doing that, you can easily add components as you've always done:
panel.add(...);
And the second way is to make a JLabel to act as a Container, where you can add more Components to it (just like you do in a JPanel) (As shown in this answer)
The way to do this is:
Create a JLabel with an ImageIcon
Set its layout manager
Add components to it
Depending on which one you choose you have some differences:
Using the custom painting option, you need to take care of the preferred size of your container but you have more control over your component. However the image will fill all the space available on the window.
Using the JLabel option you can simply call pack() on your JFrame and it will resize to the image size, but if your image is too big your JFrame will be the same size too. If you resize your window to be shorter the image will be cropped and show "white" space if you make your window bigger.
This is how the image looks like with the 2 options, on the left the custom painting, on the right the label approach. At first they both look the same...
But... If we resize the window, this is what we get:
I like the custom painting approach more, but it depends on your needs and likes.
The code that produces the above output is:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.BoxLayout;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class JPanelWithBackgroundImageExample {
private JFrame frame; //Our window
private JPanel panel; //The panel where we're going to draw the background image
private Image image;
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new JPanelWithBackgroundImageExample().createAndShowGui();
}
});
}
public void createAndShowGui() {
frame = new JFrame(getClass().getSimpleName());
try {
image = ImageIO.read(new URL("https://i.stack.imgur.com/XZ4V5.jpg")); //We read the image from the Internet
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
panel = new JPanel() { //We need to open the curly braces so we can change the default behavior of the JPanel
/*
* This method is the one that paints the background, by default it paints it with gray color,
* so, we need to tell it to draw an image instead. (This method belongs to JPanel already, so we need to add
* "#Override" before it, so the compiler knows we're overriding it
*/
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g); //Never forget this line or you could break the paint chain
/*
* This method belongs to the Graphics class and draws an image, this is what we want the JPanel to draw as our background
* The parameters are: the image to be drawn, the starting position (x, y) coords, the width and height and the observer
*/
g.drawImage(image, 0, 0, this.getWidth(), this.getHeight(), this);
}
/*
* This method is part of the JPanel, we're overriding it's preferred size and return the size we want
*/
#Override
public Dimension getPreferredSize() {
return new Dimension(300, 200);
}
};
JLabel label = new JLabel(new ImageIcon(image)); //We create a JLabel that will act as a container for our components
panel.setBorder(BorderFactory.createLineBorder(Color.WHITE)); //We create a border just for visibility of both ways
label.setBorder(BorderFactory.createLineBorder(Color.WHITE)); //We create a border just for visibility of both ways
label.setLayout(new BoxLayout(label, BoxLayout.PAGE_AXIS)); //We set the layout manager for the label
label.add(new JLabel("I'm a label inside a label")); //We add a new label to our label (that is acting as a container)
label.add(new JButton("I'm a button inside a label")); //We add a button to our label (that is acting as a container)
//You can add your components to the panel, as you always do it
panel.add(new JButton("HEY! I'm a button!")); //We add a button to our jpanel
panel.add(new JLabel("Click the button next to me! :D")); //We add a label to our jpanel
frame.add(panel, BorderLayout.WEST); //We add the pane which has a size of 300 x 200 to the left part of our JFrame
frame.add(label, BorderLayout.EAST); //We add the label (which acts as a container / jpanel) to the right part of our JFrame
frame.pack(); //We pack the frame, so it takes its preferred size (and as we only added a single component to it (the JPanel)
//As the panel has a size of 300 x 200, the frame will also have this size
frame.setVisible(true); //We set the visibility of the frame
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
Now, as a general tip, place your program on the Event Dispatch Thread (EDT) by changing your main() method as follows:
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
//Your constructor here
}
});
}
And now, to answer your question in the comments:
everything works except the image because I don't have that image. so I copied an image url from google and pasted it in and it didn't appear? what can I do
Well, I think you took the code from the linked answer and changed this line:
frame.setContentPane(new JLabel(new ImageIcon("C:/Users/Frakcool/workspace/StackOverflowProjects/src/test/Air.jpg")));
To something like this:
frame.setContentPane(new JLabel(new ImageIcon("https://i.stack.imgur.com/XZ4V5.jpg")));
Well in that case, it's obvious that the code won't work that way, Swing doesn't know how to interpret a http in a String, but URL class does, and thus, you should change the above line like:
frame.setContentPane(new JLabel(new ImageIcon(new URL("https://i.stack.imgur.com/XZ4V5.jpg"))));
And import:
import java.net.URL;
In your class.
I hope this helps you in understanding how the code works, if not, well, I think you need to put more effort in understanding it.

Java - How do I get an image to display?

I have spent a really long time trying to find a way to display an image in a Java program (I'm trying to learn how to make a 2D Java game) an nothing that I've tried works. I'm using Eclipse Mars and the latest of everything else. Here is my code:
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class Main extends JFrame {
public static void main(String[] args0) {
JFrame frame = new JFrame();
ImageIcon image = new ImageIcon("background.bmp");
JLabel imageLabel = new JLabel(image);
frame.add(imageLabel);
frame.setLayout(null);
imageLabel.setLocation(0, 0);
imageLabel.setSize(1000, 750);
imageLabel.setVisible(true);
frame.setVisible(true);
frame.setSize(1000, 750);
frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
}
}
Please, just tell me how to correct the code so that the image actually displays. Thank you ahead of time.
(P.S. the "background.bmp" file is in the "default package" if that changes anything)

The image with .bmp suffix can't be displayed in your code. Try to modify
ImageIcon image = new ImageIcon("background.bmp");
to
ImageIcon image = new ImageIcon("background.png");
and change the image name to background.png.
However, if you just want to use background.bmp, you need to modify your code like this and background image will be displayed.
import java.awt.Image;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class Main extends JFrame {
public static void main(String[] args0) {
try {
JFrame frame = new JFrame();
File imageFile = new File("background.bmp");
Image i = ImageIO.read(imageFile);
ImageIcon image = new ImageIcon(i);
JLabel imageLabel = new JLabel(image);
frame.add(imageLabel);
frame.setLayout(null);
imageLabel.setLocation(0, 0);
imageLabel.setSize(1000, 750);
imageLabel.setVisible(true);
frame.setVisible(true);
frame.setSize(1000, 750);
frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
Here is the effect with new code:
Hope it helps.
BTW, I've put the image at the root directory of the project.

Read the section from the Swing tutorial on How to Use Icons. The examples their show you how to load the images as resources. When you use resources the classpath will be searched to find the file.
//frame.setLayout(null);
//imageLabel.setLocation(0, 0);
//imageLabel.setSize(1000, 750);
Don't use a null layout and attempt to set the size/location of the label. Let the layout manager do its job. The label will be the size of the image.
//frame.setSize(1000, 750);
frame.pack();
Don't use frame.setSize(...). Instead you use frame.pack() then the frame will be the size of the image plus the size of the frame borders and title. Let Swing and its layout managers do the work for you.

As a beginer, I found that is easy to see the picture you draw:
Source code
public class CheckCodeTest {
private int width = 100, height = 50;
private BufferedImage image = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);
#Test
public void drawGraphicsTest() throws IOException {
Graphics graphics = image.createGraphics();
// draw an orange rectangle
graphics.setColor(Color.orange);
graphics.fillRect(0,0,width,height);
// layout the picture right now!
graphics.drawImage(image,0,0,null);
ImageIO.write(image, "png", new File("checkcode.png"));
}
}
Output
It produce a picture file under your projects content.
output-picture
Then you can see what change after adding draw code in small window, it is more convenient than closing an jump-out Frame / Label window:
output-picture-in-editor

Draw string to image in Java

I need to draw a string to a BufferedImage in Java. The way this is done doesn't matter, however the image should take up only the space it needs, like in the example below.
I need a new BufferedImage created containing only the string. Extra space above the string and on the right side of the string could be tolerated, but I can't have extra space below and left of the drawn string.
Is something like this possible? I have tried to do it myself, but I always end up having extra space which is not what I want. Any help would be appreciated.

You can use Graphics2D#drawString method:
import java.awt.Container;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import javax.swing.JComponent;
import javax.swing.JFrame;
public class MainClass{
public static void main(String[] args) {
JFrame jf = new JFrame("Demo");
Container cp = jf.getContentPane();
MyCanvas tl = new MyCanvas();
cp.add(tl);
jf.setSize(300, 200);
jf.setVisible(true);
}
}
class MyCanvas extends JComponent {
public void paint(Graphics g) {
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
Font font = new Font("Serif", Font.PLAIN, 96);
g2.setFont(font);
g2.drawString("Test string", 40, 120);
}
}

I need to draw a string to an image in Java. I have tried to do it myself, but I always end up having extra space
I can't tell if you are trying to create an image of a String or add some text to an existing image. Since you say you have extra space I assume you are trying to create an image of the text and you don't know how big to make the BufferedImage that you are drawing on.
Create a JLabel with the text you want. Then you can use the Screen Image class to create an image of the label component. The the image will be the exact size pf the text.