Sending Screen Image and Showing continuously - java

I am making a project for Controlling a PC from any other PC on a Network.
but when i send the image from server to client, it does not changed, just the first image is displayed.
So i am sending the captured images of server to client using GZIP compression.
Here is the Server's Code:
out = new DataOutputStream(s.getOutputStream());
zipout = new GZIPOutputStream(out);
while(true)
{
img = conn.getScreenImg(new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()));
//Here conn is a Object of Robot Class
ImageIO.write(img, "jpeg", zipout);
Thread.sleep(200);
System.out.println("Success");
}
Client Code: displaying the Images sent by Server.
while(true)
{
try
{
img = ImageIO.read(zipin);
Graphics g = this.getGraphics();
g.drawImage(img, 0, 0, this);
Thread.sleep(100);
}
catch (Exception e)
{
e.printStackTrace();
}
}
I need Help with this. The image doesn't change on client.
and i want to know that if it is good to use GZIP here for compression for images to send over network , will it accelerate the process. or should i use some other method.

The way you are displaying the images on the client doesn't seem right to me. It would be a lot better to write a custom JPanel that would override the paintComponent method and that would handle the image rendering. Something like below:
class ImagePanel extends JPanel {
private BufferedImage image = null;
private void setImage(BufferedImage img) {
image = img;
repaint();
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
if (image != null) {
g2.drawImage(image, 0, 0, null);
}
}
}
Inside your while loop you would call the setImage method on the panel. The panel in of course previously instantiated and added to a container.

Related

PaintComponent not rendering image?

I'm trying to display a small 16x16 pixel image to a JPanel. I've written a simple function that creates and returns a BufferedImage object that I'm then trying to pass to paintComponent, however, nothing is rendering when I launch the program (with no errors being printed to the console). Help?
Thanks!
public BufferedImage loadImage(String filePath) {
BufferedImage img = null;
try {
img = ImageIO.read(new File(filePath));
} catch (IOException e) {
}
return img;
}
public void paintComponent(Graphics g) {
g.drawImage(loadImage("/resources/tile.png"), 0, 0, this);
}
}
we can also use the below source code inside paintComponent to draw an image swing.
public void paintComponent(Graphics g) {
Toolkit t=Toolkit.getDefaultToolkit();
Image image=t.getImage(<path of image>);
g.drawImage(image, 0,0,this);
}
where,
img - the specified image to be drawn. This method does nothing if img is null.
x - the x coordinate.
y - the y coordinate.
observer - object to be notified as more of the image is converted.
in case to load an bufferImage, you can also check the below link contains good amount of details.
https://www.baeldung.com/java-images
Thanks

Java Draw a GIF

I'm trying to draw a GIF using the Java Graphics API, but I'm not able to successfully draw a GIF using my below code. Only the first image or thumbnail of the GIF is drawn but it doesn't play.
public void paintComponent(Graphics g){
super.paintComponent(g);
BufferedImage img = null;
try {
URL url = new URL("GIF URL");
img = ImageIO.read(url);
} catch (Exception e) {
}
g.drawImage(img, 5, 5, this);
}
Essentially I am creating graphics for a login screen and I want to draw a GIF that loops.
EDIT: Updated my code and changed the question a bit.
You can load a gif into a BufferedImage object.
Then we paint the buffered image onto your swing component
Also one must better override the paintComponent method
It's perfectly possible to do this, you just need to have a proper way to load the frames for the image. The code I use to do this, is as so:
private static Image load(final String url) {
try {
final Toolkit tk = Toolkit.getDefaultToolkit();
final URL path = new URL(url); // Any URL would work here
final Image img = tk.createImage(path);
tk.prepareImage(img, -1, -1, null);
return img;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
This uses the Toolkit to load a gif image, since ImageIO can't properly load gifs at this time, if I recall correctly.
From there, it's so simple as doing the following in a (for example) JPanel:
#Override
protected void paintComponent(Graphics g){
super.paintComponent(g); // clear up render
//...
g.drawImage(IMAGE, x, y, this); // ImageObserver necessary here to update
//...
}
Example:
import javax.swing.*;
import java.awt.*;
import java.net.URL;
public class GifAnimation {
public GifAnimation(){
JFrame frame = new JFrame("Gif Animation");
GifPanel panel = new GifPanel(load("http://www.thisiscolossal.com/wp-content/uploads/2013/01/3.gif"));
frame.add(panel);
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
}
private static Image load(final String url) {
try {
final Toolkit tk = Toolkit.getDefaultToolkit();
final Image img = tk.createImage(new URL(url));
tk.prepareImage(img, -1, -1, null);
return img;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
public static void main(String[] args){
EventQueue.invokeLater(new Runnable() {
public void run() {
new GifAnimation();
}
}
}
public class GifPanel extends JPanel {
private final Image image;
public GifPanel(Image image){
this.image = image;
}
#Override
protected void paintComponent(Graphics g){
super.paintComponent(g);
g.drawImage(image, 10, 10, this);
}
#Override
public Dimension getPreferredSize(){
return new Dimension(660, 660);
}
}
}
GIF animation is not directly possible by using paint method of JPanel.
I would suggest inserting a JEditorPane in the panel whenever you want to display it and show GIF in it using HTML.
Refer showing images on jeditorpane (java swing)
Although some might criticize it as a crude way, the animation works perfectly.
Hope this helps.

Getting a black screen after trying to resize an image

I am currently trying to resize a picture that I am downloading from the web and putting it into a JPanel.
First, I am using the following code to download the image from the web:
public static Image MSImageHigh(){
URL imageUrl = null;
try {
imageUrl = new URL("http://www.hmdb.ca/labm/metabolites/"
+ HMDB + "/ms/spectraH/" + HMDB + "H.png");
} catch (MalformedURLException e) {
e.printStackTrace();
}
Image image = Toolkit.getDefaultToolkit().createImage(imageUrl);
return image;
}
Then I made a new method that resizes the image:
public static BufferedImage resizeImage() {
final BufferedImage bufferedImage = new BufferedImage(300, 500,BufferedImage.TYPE_INT_RGB);
final Graphics2D graphics2D = bufferedImage.createGraphics();
graphics2D.setComposite(AlphaComposite.Src);
graphics2D.drawImage(MSImageHigh(), 0, 0, 200, 200, null);
graphics2D.dispose();
return bufferedImage;
}
This should produce s a new image that is resized to 200x200 px. What it in fact does is give me a black screen that is 200x200px in size. Btw, I also tried using TYPE_INT_ARGB instead of TYPE_INT_RGB, and this produces a totally transparent image, so that is not working either.
I used ImageIO.read(imageUrl) instead of Toolkit.getDefaultToolkit().createImage(imageUrl) and that solved the problem. Thanks #Hovercraft Full Of Eels!

How to set a background image to JSlider?

I have an applet. I set its image background. It works fine.
Now I want to set a background image to a JSlider.
How can I do that?
You will need to create a custom JSlider class and override the paintComponent method. Be sure to call setOpaque(false) on your slider object.
public class CustomSlider extends JSlider
{
private Image img = null;
public CustomSlider()
{
try
{
img = ImageIO.read(new File("background.jpg"));
}
catch (IOException e)
{
e.printStackTrace();
}
}
#Override
public void paintComponent(Graphics g)
{
// Draw the previously loaded image to Component
g.drawImage(img, 0, 0, null);
super.paintComponent(g);
}
}

LWUIT Painter : How to make an image the background?

I am trying to use Painter to make a certain jpg become my background.
mapScreen = new Form("Map");
try
{
Image image = Image.createImage("/res/try.jpg");
map = new Map(image);
mapScreen.addComponent(map);
} catch (Exception e)
{
System.out.print("Error\n\n"+e.getMessage());
mapScreen.addComponent(new Label(e.getMessage()));
}
And for the map class,
public Map(Image image)
{
this.mapImage = image;
painter = new Painter()
{
public void paint(Graphics g, Rectangle clippingRect)
{
g.clipRect(0, 0, getWidth(), getHeight());
g.drawImage(mapImage, getX(), getY());
}
};
}
public void initComponent()
{
setX(0);
setY(0);
getSelectedStyle().setBgTransparency(0);
getSelectedStyle().setBgPainter(painter);
getUnselectedStyle().setBgTransparency(0);
getUnselectedStyle().setBgPainter(painter);
}
The problem with this is that the image doesn't show up at all and when I try to debug, It doesn't even enter the paint(Graphics g, Rectangle clippingRect)...
The code
try
{
Image image = Image.createImage("/res/try.jpg");
map = new Map(image);
mapScreen.addComponent(map);
}
is successful.
Can anyone tell me how to do it properly?
And also, if anyone know how to do panning on an image larger than the size of the screen, Can you help me with that also? Thanks.
Use setBgTransparency to 255 and don't call the clipRect method.
You can look at the bg painter code within Component.java which is pretty flexible.

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