java by 26 comments

How to convert byte[] to BufferedImage in Java

This article shows how to convert a byte[] to a BufferedImage in Java.


  InputStream is = new ByteArrayInputStream(bytes);
  BufferedImage bi = ImageIO.read(is);

The idea is puts the byte[] into an ByteArrayInputStream object, and we can use ImageIO.read to convert it to a BufferedImage.

1. Convert byte[] to BufferedImage.

The below example shows how to convert BufferedImage to byte[] and vice versa.

ImageUtils.java

package com.mkyong.io.image;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;
import java.nio.file.Path;
import java.nio.file.Paths;

public class ImageUtils {

    public static void main(String[] args) throws IOException {

        Path source = Paths.get("c:\\test\\mkyong.png");
        Path target = Paths.get("c:\\test\\mkyong-new.png");

        BufferedImage bi = ImageIO.read(source.toFile());

        // convert BufferedImage to byte[]
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ImageIO.write(bi, "png", baos);
        byte[] bytes = baos.toByteArray();

        // convert byte[] back to a BufferedImage
        InputStream is = new ByteArrayInputStream(bytes);
        BufferedImage newBi = ImageIO.read(is);

        // add a text on top on the image, optional, just for fun
        Graphics2D g = newBi.createGraphics();
        g.setFont(new Font("TimesRoman", Font.BOLD, 30));
        g.setColor(Color.BLACK);
        g.drawString("Hello World", 100, 100);

        // save it
        ImageIO.write(newBi, "png", target.toFile());

    }
}

Download Source Code

$ git clone https://github.com/mkyong/core-java

$ cd java-io

References

26 comments on “How to convert byte[] to BufferedImage in Java”

  2. hi i have image that stored in mongodb as byte format looking for separate decoder for that.

    File image = new File(“mongodb://localhost:27017//test-db//user”);
    Tesseract tessInst = new Tesseract();
    tessInst.setDatapath(“C:\\Users\\Administrator\\Desktop\\tessdata”);
    try {
    String result= tessInst.doOCR(image);
    System.out.println(result);
    } catch (TesseractException e) {
    System.err.println(e.getMessage());
    }

    }
    }

    Reply

  4. Do we have any other option otherthan ImageIO.read for converting Bytes to BufferedImage
    Because when reading via ImageIO.read,image size is increasing…

    Reply

  7. I have image in binary format file how to get back image .there is concpt of ImageIO and ByteBuffer .but How i use this

    Reply

    1. Import the following classes :
      import java.awt.Graphics;
      import java.awt.image.BufferedImage;
      import javax.imageio.ImageIO;

      Then use the following piece of code:
      Graphics g;
      Supposing you have image’s byte code in
      byte[] img;

      Now, this will get you the image.
      InputStream in = new ByteArrayInputStream(imgData);
      BufferedImage bImageFromConvert = ImageIO.read(in);
      g = bImageFromConvert.getGraphics();

      // optional statements
      g.setColor(Color.red); // to set color
      g.setFont(g.getFont().deriveFont(100f)); // to set font style
      g.drawString(“Hello”, 100, 200); // to draw any string on it
      g.dispose();

      Reply

  10. Hi,
    this solution is only valid when you read image from a file. But when reading a byte array from a database the following error shows up:

    Exception in thread “main” java.lang.IllegalArgumentException: im == null!
    at javax.imageio.ImageIO.write(Unknown Source)
    at javax.imageio.ImageIO.write(Unknown Source)

    Reply

  11. Hi, I use richfaces treenode because there are some problems on primefaces treenode. I need to load an image inside from a byte array (blob type in my database).

    Is it necessary to declare the icon url into iconLeaf param?
    I mean, is it necessary to create an image file to get it inside the treenode or can i get a buffered image directly from the bean?
    BR.

    Reply

  16. i need help on showing images from database to my jsp page. I am using Spring+Hibernate Framework. i am getting String when i get the blob from the pojo. can i get image directly from the pojo? thanks

    Reply

  18. Hello All,
    I want to convert raw file to jpg.
    I have file name ss.raw. I want to convert it into ss.jpg. Please help me.
    Thanks in Advance.

    Reply

  20. hi,
    how can i read image in byte array from socket and write a jpeg file, please help me here is my email umer_rock_12[at]hotmail.com

    Thanks and Regards

    umer

    Reply

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