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How to increase the quality of the Java Netbeans Icons

How can I enhance the sharpness of an image that has been scaled down from 100px to 25px using an image scaler, as it appears to be heavily pixelated?
The rescale code I am using:
public ImageIcon scaleImage(String location, int size){
BufferedImage img = null;
try {
img = ImageIO.read(new File(location));
} catch (IOException e) {
e.printStackTrace();
}
Image dimg = img.getScaledInstance(size, size, Image.SCALE_SMOOTH);
ImageIcon p = new ImageIcon(dimg);
return p;
}
Using a non-resized picture makes the navigation bar larger and does not fit the label.
Pictures scaled down using other applications look the same.

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

How to change Inset color in GRAL?

I'm trying to create GRAL graphs and export them as JPGs.
Not sure why, but the color of the 'Inset' areas (outside the border) seems to be defaulting to black. This is particularly confusing, as the docs seem to indicate that insets default to being white.
How can I change the color of the Inset?
Here is how I'm exporting the jpg
private void getJpg(BarPlot plot) {
BufferedImage bImage = new BufferedImage(800, 600, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = (Graphics2D) bImage.getGraphics();
DrawingContext context = new DrawingContext(g2d);
plot.draw(context);
DrawableWriter wr = DrawableWriterFactory.getInstance().get("image/jpeg");
try {
wr.write(plot, new FileOutputStream("/path/out.jpg"), 800, 600);
} catch (IOException err) {
System.out.println(err);
}
}
Here is my current result (using white text on black bg for now, but want black text on white bg). current output

I figured it out! (with the help of a co-worker)
The Inset area defaults to being transparent black (RGBA(0,0,0,0)). Because of this, when the graph is exported as JPEG (which does not support transparency) it drops the alpha value and renders it all as black. By exporting as a png, I was able to preserve transparency and the graphs now look good when embedded into a document with a white background.
private static void getPng(XYPlot plot, String fileName) {
BufferedImage bImage = new BufferedImage(800, 600, BufferedImage.TYPE_INT_RGB);
Graphics2D g2d = (Graphics2D) bImage.getGraphics();
DrawingContext context = new DrawingContext(g2d);
plot.draw(context);
DrawableWriter wr = DrawableWriterFactory.getInstance().get("image/png");
try {
wr.write(plot, new FileOutputStream(fileName + ".png"), 800, 600);
} catch (IOException err) {
System.out.println(err);
}
}

Sending Screen Image and Showing continuously

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.

How to rescale and save an BufferedImage

I got a BufferedImage and want to rescale it before saving it as an jpg/png.
I got the following code:
private BufferedImage rescaleTo(BufferedImage img,int minWidth,int minHeight) {
BufferedImage buf = toBufferedImage(img.getScaledInstance(minWidth, minHeight, Image.SCALE_DEFAULT));
BufferedImage ret = new BufferedImage(buf.getWidth(null),buf.getHeight(null),BufferedImage.TYPE_INT_ARGB);
return ret;
}
public BufferedImage toBufferedImage(Image img) {
BufferedImage ret = new BufferedImage(img.getWidth(null),img.getHeight(null),BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = ret.createGraphics();
g2.drawImage(img,0,0,null);
return ret;
}
public String saveTo(BufferedImage image,String URI) throws UtilityException {
try {
if(image == null)
System.out.println("dododod");
ImageIO.write(image, _type, new File(URI));
} catch (IOException e) {
throw new UtilityException(e.getLocalizedMessage());
}
return URI;
}
But as an result I just get a black picture. It must have to do with the rescaling as when I skip it I can save the expected picture.

As a test, set _type="png" and also use file extension .png when you make the call to ImageIO.write(image, _type, new File(URI));. I had issues like you describe and I started writing type PNG and all works fine. Unfortunately, I never went back to debug why I could not write type JPG, GIF etc.