How to use

ImageIO

in

javax.imageio

  image = ImageIO.read(new URL(
      "http://sstatic.net/stackoverflow/img/logo.png"));
} catch (IOException e) {
return new Dimension(image.getWidth(), image.getHeight());
int w = old.getWidth();
int h = old.getHeight();
BufferedImage img = new BufferedImage(
    w, h, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = img.createGraphics();
g2d.drawImage(old, 0, 0, null);
g2d.setPaint(Color.red);
g2d.setFont(new Font("Serif", Font.BOLD, 20));
String s = "Hello, world!";
FontMetrics fm = g2d.getFontMetrics();
int x = img.getWidth() - fm.stringWidth(s) - 5;
int y = fm.getHeight();
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new TextOverlay());
f.pack();
f.setVisible(true);

public void decode(InputStream in, OutputStream out) throws JadxException {
  try {
    byte[] data = IOUtils.toByteArray(in);
    BufferedImage im = ImageIO.read(new ByteArrayInputStream(data));
    int w = im.getWidth();
    int h = im.getHeight();
    BufferedImage im2 = new BufferedImage(w + 2, h + 2, BufferedImage.TYPE_INT_ARGB);
    im2.createGraphics().drawImage(im, 1, 1, w, h, null);
    NinePatch np = getNinePatch(data);
    drawHLine(im2, h + 1, np.padLeft + 1, w - np.padRight);
    drawVLine(im2, w + 1, np.padTop + 1, h - np.padBottom);
    int[] xDivs = np.xDivs;
    for (int i = 0; i < xDivs.length; i += 2) {
      drawHLine(im2, 0, xDivs[i] + 1, xDivs[i + 1]);
    }
    int[] yDivs = np.yDivs;
    for (int i = 0; i < yDivs.length; i += 2) {
      drawVLine(im2, 0, yDivs[i] + 1, yDivs[i + 1]);
    }
    ImageIO.write(im2, "png", out);
  } catch (IOException | NullPointerException ex) {
    throw new JadxException(ex.toString());
  }
}

/**
 * 等比缩放，居中剪切
 *
 * @param src
 * @param dest
 * @param w
 * @param h
 * @throws IOException
 */
public static void scale(String src, String dest, int w, int h) throws IOException {
  if (notImageExtName(src)) {
    throw new IllegalArgumentException("只支持如下几种图片格式：jpg、jpeg、png、bmp");
  }
  Iterator<ImageReader> iterator = ImageIO.getImageReadersByFormatName(getExtName(src));
  ImageReader reader = (ImageReader) iterator.next();
  InputStream in = new FileInputStream(src);
  ImageInputStream iis = ImageIO.createImageInputStream(in);
  reader.setInput(iis);
  BufferedImage srcBuffered = readBuffereImage(reader, w, h);
  BufferedImage targetBuffered = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
  Graphics graphics = targetBuffered.getGraphics();
  graphics.drawImage(srcBuffered.getScaledInstance(w, h, Image.SCALE_DEFAULT), 0, 0, null); // 绘制缩小后的图
  graphics.dispose();
  srcBuffered.flush();
  save(targetBuffered, dest);
  targetBuffered.flush();
}

  @GetMapping("/{processInstanceId}/image")
  @ApiOperation("查看当前流程活动节点流程图")
  @Authorize(action = Permission.ACTION_QUERY)
  public void getProcessImage(@PathVariable String processInstanceId, HttpServletResponse response) throws IOException {
    try (InputStream inputStream = bpmProcessService.findProcessPic(processInstanceId)) {
      response.setContentType(MediaType.IMAGE_PNG_VALUE);
      ImageIO.write(ImageIO.read(inputStream), "png", response.getOutputStream());
    }
  }
}

/**
 * 根据给定的图片格式或者扩展名获取{@link ImageWriter}，如果未找到合适的Writer，返回null
 * 
 * @param formatName 图片格式或扩展名，例如"jpg"、"png"
 * @return {@link ImageWriter}
 * @since 4.3.2
 */
public static ImageWriter getWriter(String formatName) {
  ImageWriter writer = null;
  Iterator<ImageWriter> iter = ImageIO.getImageWritersByFormatName(formatName);
  if (iter.hasNext()) {
    writer = iter.next();
  }
  if (null == writer) {
    // 尝试扩展名获取
    iter = ImageIO.getImageWritersBySuffix(formatName);
    if (iter.hasNext()) {
      writer = iter.next();
    }
  }
  return writer;
}

public static Point getImageSizeFromStream(InputStream is) {
 if (!initialized) {
  // Stops ImageIO from creating temp files when reading images
  // from input stream.
  ImageIO.setUseCache(false);
  initialized = true;
 }
 try {
  ImageInputStream imageStream = ImageIO.createImageInputStream(is);
  Iterator<ImageReader> readers = ImageIO.getImageReaders(imageStream);
  if (!readers.hasNext()) return null;
  ImageReader reader = readers.next();
  try {
   reader.setInput(imageStream);
   return new Point(reader.getWidth(0), reader.getHeight(0));
  } finally {
   reader.dispose();
  }
 } catch (IOException e) {
  throw new RuntimeException(e);
 }
}

Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(new Color(0xFFAA00));
g2d.drawRoundRect(3, 3, getWidth()-4, getHeight()-4, archH, archH);
setLayout(new GridBagLayout()); 
add(usrNameLabel, labCnst);
add(usrNameFeild, txtCnst);
Graphics2D g2d = (Graphics2D) g.create();
if(gradientImage==null || gradientImage.getHeight() != getHeight())
MainContainer.textureImg = ImageIO.read(new URL("http://www.brewsterwallcovering.com/data/default/images/catalog/original/289-5757.jpg"));
System.out.println("Loading finished. Starting the Demo!");
    JFrame frame = new JFrame("Demo: LogIn Dialogue");
    frame.setSize(new Dimension(500, 300)); 
    MainContainer container = new MainContainer();
    frame.add(new MainContainer());
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);

ORIGINAL = ImageIO.read(
    ImageManipulationDemo.class.getResource("../resources/whitefro1.jpg"));
ALTERED = config.createCompatibleImage(
    ORIGINAL.getWidth(), 
    ORIGINAL.getHeight() + 20);
Graphics2D g2 = ALTERED.createGraphics();
g2.setColor(Color.WHITE);
g2.fillRect(0, 0, ALTERED.getWidth(), 20);
g2.drawImage(ORIGINAL, 0, 20, null);
g2.dispose();
ImageIO.write(ALTERED, "PNG", new File("alteredImage.png"));
final JFrame frame = new JFrame("Image Manipulation Demo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setBackground(Color.BLUE.darker());
frame.getContentPane().setLayout(new FlowLayout());
frame.getContentPane().add(new JLabel(new ImageIcon(ORIGINAL)));
frame.getContentPane().add(new JLabel(new ImageIcon(ALTERED)));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);

JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(new GridLayout(1, 1));
  image = convertToARGB(ImageIO.read(new File("lena512color.png")));
panel.add(createComponent("Original", image));
panel.add(createComponent("Flipped", createFlipped(image)));
panel.add(createComponent("Rotated", createRotated(image)));
panel.add(createComponent("Inverted", createInverted(image)));
frame.getContentPane().add(panel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
Graphics2D g = newImage.createGraphics();
g.transform(at);
g.drawImage(image, 0, 0, null);
g.dispose();
return newImage;

Component component) {
BufferedImage image = new BufferedImage(
 component.getWidth(),
 component.getHeight(),
component.paint( image.getGraphics() ); // alternately use .printAll(..)
return image;
Runnable r = new Runnable() {
 public void run() {
  final JFrame f = new JFrame("Test Screenshot");
       new ImageIcon(
        img.getScaledInstance(
         img.getWidth(null)/2,
     try {
      ImageIO.write(
       img,
       "png",
  JMenuBar mb = new JMenuBar();
  mb.add(menu);
  f.setJMenuBar(mb);

page.imageName = outputFile.getName();
BufferedImage canvas = new BufferedImage(width, height, getBufferedImageType(settings.format));
Graphics2D g = (Graphics2D)canvas.getGraphics();
if (!settings.silent) System.out.println("Writing " + canvas.getWidth() + "x" + canvas.getHeight() + ": " + outputFile);
  if (settings.outputFormat.equalsIgnoreCase("jpg") || settings.outputFormat.equalsIgnoreCase("jpeg")) {
    BufferedImage newImage = new BufferedImage(canvas.getWidth(), canvas.getHeight(), BufferedImage.TYPE_3BYTE_BGR);
    newImage.getGraphics().drawImage(canvas, 0, 0, null);
    canvas = newImage;
    Iterator<ImageWriter> writers = ImageIO.getImageWritersByFormatName("jpg");
    ImageWriter writer = writers.next();
    ImageWriteParam param = writer.getDefaultWriteParam();
    param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
    param.setCompressionQuality(settings.jpegQuality);
    ios = ImageIO.createImageOutputStream(outputFile);
    writer.setOutput(ios);
    writer.write(null, new IIOImage(canvas, null, null), param);
  } else {
    if (settings.premultiplyAlpha) canvas.getColorModel().coerceData(canvas.getRaster(), true);
    ImageIO.write(canvas, "png", outputFile);

BufferedImage originalImage = ImageIO.read(url);
final BufferedImage textImage = new BufferedImage(
  originalImage.getWidth(),
  originalImage.getHeight(),
  BufferedImage.TYPE_INT_ARGB);
Graphics2D g = textImage.createGraphics();
int yOff = 80+(int)-box.getY();
Shape shape = gv.getOutline(xOff,yOff);
g.setClip(shape);
g.drawImage(originalImage,0,0,null);
g.setClip(null);
g.setStroke(new BasicStroke(2f));
g.setColor(Color.BLACK);
ImageIO.write(textImage,"png",file);
Desktop.getDesktop().open(file);

BufferedImage image = ImageIO.read(inFile);
BufferedImage resultImage1 = ImageToBufferedImage(transpImg1, image.getWidth(), image.getHeight());
ImageIO.write(resultImage1, "PNG", outFile1);
BufferedImage resultImage2 = ImageToBufferedImage(transpImg2, image.getWidth(), image.getHeight());
ImageIO.write(resultImage2, "PNG", outFile2);
  width, height, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = dest.createGraphics();
g2.drawImage(image, 0, 0, null);
g2.dispose();
return dest;

public static int[] ratio(String src) throws IOException {
  BufferedImage bufferedImage = ImageIO.read(new File(src));
  int width = bufferedImage.getWidth();
  int height = bufferedImage.getHeight();
  return new int[]{width, height};
}

BufferedImage red = ImageIO.read(redResource.getInputStream());
BufferedImage goodImage = ImageIO.read(goodPic);
BufferedImage qrCodeImage = ImageIO.read(qrCodeImg);
BufferedImage baseImage = new BufferedImage(red.getWidth(), red.getHeight(), BufferedImage.TYPE_4BYTE_ABGR_PRE);
BufferedImage result = new BufferedImage(baseImage.getWidth(), baseImage
    .getHeight(), BufferedImage.TYPE_3BYTE_BGR);
result.getGraphics().drawImage(baseImage, 0, 0, null);
ByteArrayOutputStream bs = new ByteArrayOutputStream();
ImageIO.write(result, "jpg", bs);

imageLabel = new JLabel(new ImageIcon(convertToFromBytes(getImage())));
memory = new JProgressBar(0, (int) Runtime.getRuntime().maxMemory());
p.add(imageLabel, BorderLayout.CENTER);
p.add(memory, BorderLayout.SOUTH);
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setContentPane(p);
f.setLocation(150, 150);
f.pack();
f.setVisible(true);
Runnable r = new Runnable() {
GradientPaint gp = new GradientPaint(0f, 0f, new Color(127 + random.nextInt(128), 127 + random.nextInt(128), 127 + random.nextInt(128)),
    (float) halfScreenSize.width, (float) halfScreenSize.width, new Color(random.nextInt(128), random.nextInt(128), random.nextInt(128)));
BufferedImage bi = new BufferedImage(halfScreenSize.width, halfScreenSize.height, BufferedImage.TYPE_INT_RGB);
Graphics2D g2d = bi.createGraphics();
g2d.setPaint(gp);
g2d.fillRect(0, 0, halfScreenSize.width, halfScreenSize.height);
g2d.setFont(bigFont);
g2d.setColor(Color.BLACK);
if (maxMem < ((int) Runtime.getRuntime().freeMemory())) {
  maxMem = ((int) Runtime.getRuntime().freeMemory());
try {
  ByteArrayOutputStream baos = new ByteArrayOutputStream();
  ImageIO.write(image, "png", baos);
  return Toolkit.getDefaultToolkit().createImage(baos.toByteArray());
} catch (Exception e) {

int w = bi.getWidth();
int h = bi.getHeight();
int step = w/3;
JPanel p = new JPanel(new GridLayout(3,3));
  for (int jj=0; jj<h; jj+=step) {
    Image icon = bi.getSubimage(jj, ii, step, step);
    if (count%2==1) {
      JButton button = new JButton(new ImageIcon(icon));
      p.add(button);
    } else {
      JLabel label = new JLabel(new ImageIcon(icon));
      p.add(label);
center.add(p);
JOptionPane.showMessageDialog(null, center);
final BufferedImage bi = ImageIO.read(url);
SwingUtilities.invokeLater(new Runnable(){
  @Override

  frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
    img = ImageIO.read(new URL("http://images4.wikia.nocookie.net/__cb20120515073660/naruto/images/0/09/Naruto_newshot.png")).getScaledInstance(200, 200, Image.SCALE_SMOOTH);
  } catch (Exception ex) {
    ex.printStackTrace();
  frame.add(jsp);
  frame.pack();
  frame.setVisible(true);
  BufferedImage bi = componentToImage(imagePanel, true);
  try {
    File outputfile = new File("c:/saved.png");
    ImageIO.write(bi, "png", outputfile);
  } catch (IOException e) {
    e.printStackTrace();
    BufferedImage img = new BufferedImage(component.getWidth(), component.getHeight(), BufferedImage.TRANSLUCENT);
    Graphics2D g2d = (Graphics2D) img.getGraphics();
    g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    component.paintAll(g2d);
protected void paintComponent(Graphics grphcs) {
  super.paintComponent(grphcs);
  grphcs.drawImage(bg, 0, 0, null);

  this.image = ImageIO.read(new URL("http://interviewpenguin.com/wp-content/uploads/2011/06/java-programmers-brain.jpg"));
}catch(IOException ex) {
  Logger.getLogger(ScrollImageTest.class.getName()).log(Level.SEVERE, null, ex);
  protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    g.drawImage(image, 0, 0, null);
canvas.add(new JButton("Currently I do nothing"));
canvas.setPreferredSize(new Dimension(image.getWidth(), image.getHeight()));
JScrollPane sp = new JScrollPane(canvas);
setLayout(new BorderLayout());
add(sp, BorderLayout.CENTER);
  public void run() {
    JPanel p = new ScrollImageTest();
    JFrame f = new JFrame();
    f.setContentPane(p);
    f.setSize(400, 300);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setVisible(true);

private void generatePremultiplyAlpha(File out){
  try {
    BufferedImage outImage = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_INT_ARGB);
    float[] color = new float[4];
    WritableRaster raster = image.getRaster();
    WritableRaster outRaster = outImage.getRaster();
    for(int x =0, w = image.getWidth(); x< w; ++x)
      for(int y =0, h = image.getHeight(); y< h; ++y){
        raster.getPixel(x, y, color);
        float alpha = color[3]/255f;
        for(int i=0;i < 3; ++i) 
          color[i] *= alpha;
        outRaster.setPixel(x, y, color);
      }
    ImageIO.write(outImage, "png", out);
  } catch (IOException e) {
    e.printStackTrace();
  }
}