How to edit the pixels in a BufferedImage? - java

After scouring the internet for days, I found a Question that seemed to address my goal. (I'm trying to draw/edit an individual pixel in an image, and render it.) In said question, The ask-er requested code for a Black BufferedImage. The top Answer provided that code, and appears to work beautifully, until you try to change it to something other than black. Here's the Code:
package myProjectPackage;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferInt;
import javax.swing.*;
public class Copypasta {
public static JFrame frame;
BufferedImage img;
public static int WIDTH = 500;
public static int HEIGHT = 500;
public Copypasta() {
}
public static void main(String[] a){
Copypasta t=new Copypasta();
frame = new JFrame("WINDOW");
frame.setVisible(true);
t.start();
frame.add(new JLabel(new ImageIcon(t.getImage())));
frame.pack();
// Better to DISPOSE than EXIT
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
}
public Image getImage() {
return img;
}
public void start(){
img = new BufferedImage(WIDTH, HEIGHT,BufferedImage.TYPE_INT_RGB);
int[] pixels = ((DataBufferInt)img.getRaster().getDataBuffer()).getData();
boolean running=true;
while(running){
BufferStrategy bs=frame.getBufferStrategy();
if(bs==null){
frame.createBufferStrategy(4);
return;
}
for (int i = 0; i < WIDTH * HEIGHT; i++)
pixels[i] = 0; //This is what i've been trying to change.
Graphics g= bs.getDrawGraphics();
g.drawImage(img, 0, 0, WIDTH, HEIGHT, null);
g.dispose();
bs.show();
}
}
}
I Apologize for the indentation errors. I promise it looks right in the editor.
When set to BufferedImage type ARGB, the black background disappears, causing me to believe that the start function isn't drawing to the Image at all, or the drawn image is not being drawn on the screen. Either way, There is something that I don't understand. If you have the time, I would appreciate some help Identifying What is going wrong, if not an explanation of why. Thank you all,
-Navi.
Link to Original Question: drawing your own buffered image on frame

Several things jump out, the use of BufferStrategy is probably overkill. Unless you absolutely must have control over the paint process, you really don't need it. Using a BufferStrategy also precludes the use of Swing based components which might or might not be an issue.
Trying to manipulate the pixel data directly is probably also a little overkill, instead you can use BufferedImage.setRGB(int, int, int), which allows you to set the color of the pixel at the specified x/y position, for example...
img = new BufferedImage(100, 100, BufferedImage.TYPE_INT_RGB);
for (int x = 0; x < img.getWidth(); x++) {
for (int y = 0; y < img.getHeight(); y++) {
img.setRGB(x, y, Color.RED.getRGB());
}
}
But, even this is a little overkill, the same thing can be achieved by using the provided 2D Graphics API...
Graphics2D g2d = img.createGraphics();
g2d.setColor(Color.RED);
g2d.fillRect(0, 0, img.getWidth(), img.getHeight());
g2d.dispose();
Which you will probably find is faster (not just from a coding point of view).
Take a look at:
Performing Custom Painting
Painting in AWT and Swing
2D Graphics
For more details...
Working example...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class TestImage1 {
public static void main(String[] args) {
new TestImage1();
}
public TestImage1() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private BufferedImage img;
public TestPane() {
img = new BufferedImage(100, 100, BufferedImage.TYPE_INT_RGB);
//for (int x = 0; x < img.getWidth(); x++) {
// for (int y = 0; y < img.getHeight(); y++) {
// img.setRGB(x, y, Color.RED.getRGB());
// }
//}
Graphics2D g2d = img.createGraphics();
g2d.setColor(Color.RED);
g2d.fillRect(0, 0, img.getWidth(), img.getHeight());
g2d.dispose();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.drawImage(img, 0, 0, this);
g2d.dispose();
}
}
}

Related

How to crop an image into a circle with java?

I really need some help with that.
I'm trying to crop an image into a circle and it's fine but the pixels outside the circle stay white. How can I put them transparent?
My code it's:
static ColorImage Circulo(ColorImage img, int radius) {
for (int x=0; x < img.getWidth(); x++ ) {
for(int y=0; y < img.getHeight(); y++) {
if((x - (img.getWidth()/2)) * (x - (img.getWidth()/2)) + (y - (img.getHeight()/2) )* (y - (img.getHeight()/2)) <= (radius*radius)) {
img.setColor(x, y, img.getColor(x, y));
}else {
Color c = new Color (255, 255, 255);
img.setColor(x, y, c );
}
}
}
return img;
}
Try this. This will paint the image on the screen inside a circle. If you want to create a new image, get the Graphics context from a BufferedImage and write the image to that instead of the graphics context in paintComponent. Any image format will work as this does not rely on any transparency mode of the graphics image.
The main idea behind this is setting the clip region to that of a circle. Then whatever you paint will only appear in that region.
In this example, I made the diameter of the circle the minimum of the width and height of the image. This way, the entire circle will fit in a rectangle.
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.geom.Ellipse2D;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class ImageInCircle extends JPanel {
JFrame f = new JFrame();
Image img;
int width;
int height;
static String imgFile =
"location/of/image/img.gif";
public static void main(String[] args) {
SwingUtilities.invokeLater(()->new ImageInCircle().start());
}
#Override
public Dimension getPreferredSize() {
return new Dimension(width, height);
}
public ImageInCircle () {
f.add(this);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void start() {
try {
img = ImageIO.read(new File(imgFile));
} catch (IOException fne) {
fne.printStackTrace();
}
width = img.getWidth(null);
height = img.getHeight(null);
revalidate();
f.setVisible(true);
f.pack();
f.setLocationRelativeTo(null);
repaint();
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
setBackground(Color.white);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
int circleDiameter = Math.min(width,height);
Ellipse2D.Double circle = new Ellipse2D.Double(0,0,circleDiameter,circleDiameter);
g2.setClip(circle);
g2.drawImage(img,0,0,this);
}
}

Create Image from Jframe

I created a pie chart using JFrame and swings. But I want to convert the pie chart into the image and save in desktop/local path. But not having idea how to create image using JFrame Pie.
package test;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
class Main1 {
double value;
Color color;
public Main1(double value, Color color) {
this.value = value;
this.color = color;
}
}
class MyComponent extends JComponent {
Main1[] slices = { new Main1(1, Color.black), new Main1(1, Color.green),
new Main1(1, Color.yellow), new Main1(1, Color.red) };
MyComponent() {
}
public void paint(Graphics g) {
drawPie((Graphics2D) g, getBounds(), slices);
}
void drawPie(Graphics2D g, Rectangle area, Main1[] slices) {
double total = 0.0D;
for (int i = 0; i < slices.length; i++) {
total += slices[i].value;
}
double curValue = 0.0D;
int startAngle = 0;
for (int i = 0; i < slices.length; i++) {
startAngle = (int) (curValue * 360 / total);
int arcAngle = (int) (slices[i].value * 360 / total);
g.setColor(slices[i].color);
g.fillArc(area.x, area.y, area.width, area.height, startAngle, arcAngle);
curValue += slices[i].value;
}
}
}
public class Main2 {
public JPanel contentPane;
public static void main(String[] argv) {
JFrame frame = new JFrame();
frame.getContentPane().add(new MyComponent());
frame.setSize(300, 200);
frame.setVisible(true);
}
}
The basic logic for creating an Image of a Swing component is:
Dimension d = component.getSize();
BufferedImage image = new BufferedImage(d.width, d.height, BufferedImage.TYPE_INT_RGB);
Graphics2D g2d = image.createGraphics();
component.print( g2d );
g2d.dispose();
ImageIO.write(image, ".jpg", new File(...));
You can also check out the Screen Image class for convenience methods that paint the entire frame, a component on the frame or a rectangle of a component on the frame.
Note the above suggestion assumes you do the custom painting correctly which means you:
extend JPanel
override paintComponent(...), not paint(...)
invoke super.paintComponent(...)
If you want to extend JComponent then you need to:
override paintComponent(...);
fill the background of your component first before invoking the drawPie(...) method
But I want to convert the pie chart into the image
Create a BufferedImage and paint to it
BufferedImage bi = new BufferedImage(200, 200, BufferedImage.TYPE_INT_RGB);
Graphics2D g2d = bi.createGraphics();
new MyComponent().drawPie(g2d, new Rectangle(0, 0, 200, 200), slices);
g2d.dispose();
and save in desktop/local path
Use ImageIO
ImageIO.write(bi, "jpg", new File("the/path/andName.jpg"));

BufferedImage doesn't draw from 0,0

I hope my first post isn't too basic for y'all.
I'm trying to do some per-pixel drawing on a JCanvas using a BufferedImage (using setRGB()). I thought I would test all was working with a single diagonal line from the origin to the width/height of the JCanvas. The trouble is that I get a strange offset in the x axis that I can't seem to fix!
Here's a link to the problem:
http://i811.photobucket.com/albums/zz31/bohngy/problemMandel_zpsae20713a.jpeg
Here's the code:
public class Mandelbrot extends JFrame {
private BufferedImage I;
public Mandelbrot() {
super("Mandelbrot Set");
setSize(600, 600);
setResizable(false);
setDefaultCloseOperation(EXIT_ON_CLOSE);
I = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_RGB);
for (int x = 0; x < getHeight(); x++) {
for (int y = 0; y < getWidth(); y++) {
I.setRGB(x, x, Color.GREEN.getRGB());
}
}
}
#Override
public void paint(Graphics g) {
g.drawImage(I, 0, 0, this);
}
public static void main(String[] args) {
new Mandelbrot().setVisible(true);
}
}
General issues
Don't extend JFrame (particularly, don't override the paint method of JFrame). Instead, do the painting in the paintComponent method a class that extends JPanel
Create the GUI from the Event Dispatch Thread
The main reason for the unexpected result is that you are creating an image that has the size of the frame - but the frame also has a title bar and a border, and these are "covering" parts of the image. The size of the area that is actually available for painting is smaller than the total frame size. Additionally, the getWidth() and getHeight() methods may return garbage as long as the frame is not yet visible on the screen.
One approach considering all this could look like in this snippet:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.image.BufferedImage;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class Mandelbrot
{
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
#Override
public void run()
{
createAndShowGUI();
}
});
}
private static void createAndShowGUI()
{
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(new GridLayout(1, 1));
BufferedImage image = createImage(500, 500);
ImagePanel imagePanel = new ImagePanel(image);
frame.getContentPane().add(imagePanel);
frame.pack();
frame.setVisible(true);
}
private static BufferedImage createImage(int w, int h)
{
BufferedImage image = new BufferedImage(w, h,
BufferedImage.TYPE_INT_RGB);
for (int x = 0; x < w; x++)
{
image.setRGB(x, x, Color.GREEN.getRGB());
}
return image;
}
static class ImagePanel extends JPanel
{
private final BufferedImage image;
ImagePanel(BufferedImage image)
{
this.image = image;
}
#Override
public Dimension getPreferredSize()
{
if (super.isPreferredSizeSet())
{
return super.getPreferredSize();
}
return new Dimension(image.getWidth(), image.getHeight());
}
#Override
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
g.drawImage(image, 0, 0, null);
}
}
}
All BufferedImage objects have an upper left corner coordinate of (0, 0). Any Raster used to construct a BufferedImage must therefore have minX=0 and minY=0.
Therein lies your problem.
JavaDoc for BufferedImage
Edit:
Also remove this from your loop:
for (int y = 0; y < getWidth(); y++) {
I.setRGB(x, x, Color.GREEN.getRGB());
}

Unable Take screenshot of JFrame Java Swing

I have tried to save the JFrame as an image using the following approach.
try
{
BufferedImage image = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_RGB);
this.paint(image.getGraphics());
ImageIO.write(image,"png", new File("Test.png"));
}
catch(Exception exception)
{
//code
System.out.print("Exception unable to write image");
}
I am trying to save a screenshot as follows:
I would like to have even the title in my screenshot
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.geom.AffineTransform;
import java.awt.geom.Path2D;
import java.awt.geom.Point2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class DividedSquare {
public static void main(String[] args) {
new DividedSquare();
}
public DividedSquare() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private TriangleShape baseTriangle;
private Color[] colors;
public TestPane() {
colors = new Color[]{Color.RED, Color.GREEN, Color.BLUE, Color.MAGENTA};
}
#Override
public void invalidate() {
super.invalidate();
baseTriangle = new TriangleShape(
new Point(0, 0),
new Point(getWidth(), 0),
new Point(getWidth() / 2, getHeight() / 2));
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
String text[] = new String[]{
"123.123",
"456.789",
"012.315",
"678.921"
};
FontMetrics fm = g2d.getFontMetrics();
double angel = 0;
for (int index = 0; index < 4; index++) {
g2d.setColor(colors[index]);
Path2D rotated = rotate(baseTriangle, angel);
g2d.fill(rotated);
Rectangle bounds = rotated.getBounds();
int x = bounds.x + ((bounds.width - fm.stringWidth(text[0])) / 2);
int y = bounds.y + (((bounds.height - fm.getHeight()) / 2) + fm.getAscent());
g2d.setColor(Color.WHITE);
g2d.drawString(text[index], x, y);
angel += 90;
}
g2d.setColor(Color.BLACK);
g2d.drawLine(0, 0, getWidth(), getHeight());
g2d.drawLine(getWidth(), 0, 0, getHeight());
g2d.dispose();
try
{
BufferedImage image = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_RGB);
frame.paint(image.getGraphics());
ImageIO.write(image,"png", new File("Practice.png"));
}
catch(Exception exception)
{
//code
System.out.print("Exception to write image");
}
}
public Path2D rotate(TriangleShape shape, double angel) {
Rectangle bounds = shape.getBounds();
int x = bounds.width / 2;
int y = bounds.width / 2;
return new Path2D.Float(shape, AffineTransform.getRotateInstance(
Math.toRadians(angel),
x,
y));
}
}
public class TriangleShape extends Path2D.Double {
public TriangleShape(Point2D... points) {
moveTo(points[0].getX(), points[0].getY());
lineTo(points[1].getX(), points[1].getY());
lineTo(points[2].getX(), points[2].getY());
closePath();
}
}
}
But I the image does not get created. I am unable to understand why.
I looked at this but am unable to understand how to incorporate it in my case.
Edit
Based on comments, I tried using robot class but am unable to know where to call this function from. If I call this function from the paint() method, I am unable to get the colors and text.
void screenshot()
{
try
{
Robot robot = new Robot();
// Capture the screen shot of the area of the screen defined by the rectangle
Point p = frame.getLocationOnScreen();
System.out.print("point" + p);
BufferedImage bi=robot.createScreenCapture(new Rectangle((int)p.getX(),(int)p.getY(),frame.getWidth(),frame.getHeight()));
ImageIO.write(bi, "png", new File("imageTest.png"));
}
catch(Exception exception)
{
//code
System.out.print("Exception to write image");
}
}
There are at least two ways you might achieve this...
You Could...
Use Robot to capture a screen shot. For example
The problem with this is it takes a little effort to target the component you want to capture. It also only captures a rectangular area, so if the component is transparent, Robot won't respect this...
You Could...
Use printAll to render the component to your own Graphics context, typically from a BufferedImage
printAll allows you to print a component, because the intention is not to print this to the screen, printAll disables double buffering, making it more efficient to use when you don't want to render the component to the screen, such printing it to a printer...
Forexample
You can use Robot to capture screenshot. But it not gives Jframe Screenshot. We need to give correct coordinates and refer the frame. gFrame is my frame name and below code works for only Jframe area screenshot.
try {
Robot cap=new Robot();
Rectangle rec=new Rectangle(gFrame.getX(),gFrame.getY(),gFrame.getWidth(),gFrame.getHeight());
BufferedImage screenshot=cap.createScreenCapture(rec);
ImageIO.write(screenshot, "JPG",
new File("C:\\Users\\ruwan\\Downloads\\screenshot.jpg");
} catch (Exception e) {
e.printStackTrace();
}

Having trouble displaying graphics in Swing

I've been trying to visually simulate a traffic problem, but for some reason I get only blank output in my swing window. Instead of a constantly-moving picture with vehicles, I get only a grey screen.
My drawing class looks as follows:
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JPanel;
public class RoadNetwork extends JPanel {
BufferedImage tempicon = ImageIO.read(getClass().getResource("Truck.png"));
BufferedImage truckicon = new BufferedImage(tempicon.getWidth(), tempicon.getHeight(), BufferedImage.TYPE_INT_ARGB);
public RoadNetwork() throws IOException {
repaint();
}
protected void paintComponent (Graphics g) {
super.paintComponent(g);
g.clearRect(0, 0, 600, 600); // insert window size parameters here
for (int i = 0; i < AMEC.vehiclecounter; i++) {
if (AMEC.vehicle[i].spawned == true && AMEC.vehicle[i].finished == false) { // if the truck is somewhere on the plant
g.drawImage(truckicon, AMEC.getcoord(i)[0], AMEC.getcoord(i)[1], this);
}
}
g.drawImage(truckicon, 100, 100, this);
}
}
The call to the class in my main function is done as follows:
RoadNetwork roadnetwork = new RoadNetwork();
roadnetwork.setVisible(true);
JFrame frame = new JFrame();
frame.add(roadnetwork);
frame.setSize(600, 600);
frame.setVisible(true);
Then, with every iteration of my simulation, I call
roadnetwork.repaint();
What am I missing?
BufferedImage tempicon = ImageIO.read(getClass().getResource("Truck.png"));
BufferedImage truckicon = new BufferedImage(tempicon.getWidth(), tempicon.getHeight(), BufferedImage.TYPE_INT_ARGB);
At the end of the 2nd code line, truckicon is still completely invisible (since it is a transparent image that we have drawn nothing to). Try instead.
BufferedImage truckicon = ImageIO.read(getClass().getResource("Truck.png"));
I hate not knowing why something works. But I remember going through the Graphics totorial and seeing them do this in the constructor where they seem to draw the second image
BufferedImage img = ImageIO.read(imageSrc);
int w = img.getWidth(null);
int h = img.getHeight(null);
BufferedImage bi = new
BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
Graphics g = bi.getGraphics();
g.drawImage(img, 0, 0, null);
Here's the fix I made. I wish I could give more explanation, but feel free to check out the tutorial I linked
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class RoadNetwork extends JPanel {
BufferedImage tempicon;
BufferedImage truckicon;
public RoadNetwork() throws IOException {
tempicon = ImageIO.read(getClass().getResource("resources/stack_reverse.png"));
int w = tempicon.getWidth(null);
int h = tempicon.getHeight(null);
truckicon = new
BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
Graphics g = truckicon.getGraphics();
g.drawImage(tempicon, 0, 0, null);
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
//g.clearRect(0, 0, 600, 600); // insert window size parameters here
// for (int i = 0; i < AMEC.vehiclecounter; i++) {
// if (AMEC.vehicle[i].spawned == true && AMEC.vehicle[i].finished ==
// false) { // if the truck is somewhere on the plant
// g.drawImage(truckicon, AMEC.getcoord(i)[0], AMEC.getcoord(i)[1],
// this);
// }
// }
g.drawImage(truckicon, 100, 100, this);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable(){
public void run() {
try {
RoadNetwork roadnetwork = new RoadNetwork();
roadnetwork.setVisible(true);
JFrame frame = new JFrame();
frame.add(roadnetwork);
frame.setSize(600, 600);
frame.setVisible(true);
} catch (IOException es) {
es.printStackTrace();
}
}
});
}
}
Also, I was going to suggest #AndrewThompson's answer, but because I didn't know the reason you were using two BufferedImages, I didn't want to suggest it. You may have been trying to do what the tutorial was doing.

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