Resizing image in Java

Question

I have a PNG image and I want to resize it. How can I do that? Though I have gone through this I can't understand the snippet.

Do you want to generate a resized version of the original png, or just paint a resized version somewhere in your UI? — dcn, May 05 '11 at 10:03

score 90 · Accepted Answer · edited Jan 10 '22 at 20:48

If you have an java.awt.Image, resizing it doesn't require any additional libraries. Just do:

Image newImage = yourImage.getScaledInstance(newWidth, newHeight, Image.SCALE_DEFAULT);

Obviously, replace newWidth and newHeight with the dimensions of the specified image.
Notice the last parameter: it tells the runtime the algorithm you want to use for resizing.

There are algorithms that produce a very precise result, however these take a large time to complete.
You can use any of the following algorithms:

Image.SCALE_DEFAULT: Use the default image-scaling algorithm.
Image.SCALE_FAST: Choose an image-scaling algorithm that gives higher priority to scaling speed than smoothness of the scaled image.
Image.SCALE_SMOOTH: Choose an image-scaling algorithm that gives higher priority to image smoothness than scaling speed.
Image.SCALE_AREA_AVERAGING: Use the Area Averaging image scaling algorithm.
Image.SCALE_REPLICATE: Use the image scaling algorithm embodied in the ReplicateScaleFilter class.

See the Javadoc for more info.

The doc link refers to older version use this instead: http://download.oracle.com/javase/6/docs/api/java/awt/Image.html — Harry Joy, May 05 '11 at 10:57

score 23 · Answer 2 · answered May 05 '11 at 10:03

We're doing this to create thumbnails of images:

  BufferedImage tThumbImage = new BufferedImage( tThumbWidth, tThumbHeight, BufferedImage.TYPE_INT_RGB );
  Graphics2D tGraphics2D = tThumbImage.createGraphics(); //create a graphics object to paint to
  tGraphics2D.setBackground( Color.WHITE );
  tGraphics2D.setPaint( Color.WHITE );
  tGraphics2D.fillRect( 0, 0, tThumbWidth, tThumbHeight );
  tGraphics2D.setRenderingHint( RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR );
  tGraphics2D.drawImage( tOriginalImage, 0, 0, tThumbWidth, tThumbHeight, null ); //draw the image scaled

  ImageIO.write( tThumbImage, "JPG", tThumbnailTarget ); //write the image to a file

score 10 · Answer 3 · answered May 05 '11 at 10:03

10

Try this:

ImageIcon icon = new ImageIcon(UrlToPngFile);
Image scaleImage = icon.getImage().getScaledInstance(28, 28,Image.SCALE_DEFAULT);

answered May 05 '11 at 10:03

Harry Joy

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IIRC, this way (getSclaedInstance()) is not advised due to its lack of performance (I think I read that, a long time ago, in "Filthy Rich Clients"). – jfpoilpret May 05 '11 at 10:22
1

There's no need to use an `ImageIcon`, you can directly do `ImageIO.read(...)`. – Alba Mendez May 07 '11 at 14:59
1

@AndrewThompson Your link seems to be out-of-date. The new location is: https://community.oracle.com/docs/DOC-983611 – Brian Matthews Dec 30 '17 at 23:13
1

Thanks @BrianMatthews. Unfortunately I'm unable to edit the original comment so I'll update it here: For more info. see [The Perils of Image.getScaledInstance()](https://community.oracle.com/docs/DOC-983611). – Andrew Thompson Dec 31 '17 at 00:37

Radadiya Nikunj · Answer 4 · 2019-03-27T13:57:39.433

Resize image with high quality:

private static InputStream resizeImage(InputStream uploadedInputStream, String fileName, int width, int height) {

        try {
            BufferedImage image = ImageIO.read(uploadedInputStream);
            Image originalImage= image.getScaledInstance(width, height, Image.SCALE_DEFAULT);

            int type = ((image.getType() == 0) ? BufferedImage.TYPE_INT_ARGB : image.getType());
            BufferedImage resizedImage = new BufferedImage(width, height, type);

            Graphics2D g2d = resizedImage.createGraphics();
            g2d.drawImage(originalImage, 0, 0, width, height, null);
            g2d.dispose();
            g2d.setComposite(AlphaComposite.Src);
            g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION,RenderingHints.VALUE_INTERPOLATION_BILINEAR);
            g2d.setRenderingHint(RenderingHints.KEY_RENDERING,RenderingHints.VALUE_RENDER_QUALITY);
            g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);

            ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();

            ImageIO.write(resizedImage, fileName.split("\\.")[1], byteArrayOutputStream);
            return new ByteArrayInputStream(byteArrayOutputStream.toByteArray());
        } catch (IOException e) {
            // Something is going wrong while resizing image
            return uploadedInputStream;
        }
    }

why are you setting rendering hints after drawImage() and dispose()? — ykaganovich, Jun 07 '19 at 17:57

score 1 · Answer 5 · edited Dec 02 '20 at 18:29

Simple way in Java

public void resize(String inputImagePath,
            String outputImagePath, int scaledWidth, int scaledHeight)
            throws IOException {
        // reads input image
        File inputFile = new File(inputImagePath);
        BufferedImage inputImage = ImageIO.read(inputFile);
 
        // creates output image
        BufferedImage outputImage = new BufferedImage(scaledWidth,
                scaledHeight, inputImage.getType());
 
        // scales the input image to the output image
        Graphics2D g2d = outputImage.createGraphics();
        g2d.drawImage(inputImage, 0, 0, scaledWidth, scaledHeight, null);
        g2d.dispose();
 
        // extracts extension of output file
        String formatName = outputImagePath.substring(outputImagePath
                .lastIndexOf(".") + 1);
 
        // writes to output file
        ImageIO.write(outputImage, formatName, new File(outputImagePath));
    }

score 1 · Answer 6 · answered May 07 '20 at 08:10

            int newHeight = 150;
            int newWidth = 150; 
            holder.iv_arrow.requestLayout();
            holder.iv_arrow.getLayoutParams().height = newHeight;
            holder.iv_arrow.getLayoutParams().width = newWidth;
            holder.iv_arrow.setScaleType(ImageView.ScaleType.FIT_XY);
            holder.iv_arrow.setImageResource(R.drawable.video_menu);

score 0 · Answer 7 · answered Sep 09 '22 at 18:41

Design jLabel first:

JLabel label1 = new JLabel("");
label1.setHorizontalAlignment(SwingConstants.CENTER);
label1.setBounds(628, 28, 169, 125);
frame1.getContentPane().add(label1);   //frame1 = "Jframe name"

Then you can code below code:

ImageIcon imageIcon1 = new ImageIcon(new ImageIcon("add location url").getImage().getScaledInstance(100, 100, Image.SCALE_DEFAULT)); //100, 100 add your own size
label1.setIcon(imageIcon1);

Resizing image in Java

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