How to convert image to byte array in Java.

 

To convert an image to a byte array in Java, you can use the ImageIO class provided by Java. One approach is to read the image using the read() method of the ImageIO class and then write it to a ByteArrayOutputStream object using the write() method. Finally, you can convert the contents of the ByteArrayOutputStream to a byte array using the toByteArray() method.

Convert image to byte array in Java

 

import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import javax.imageio.ImageIO;

public class ImageToByteArray {
    public static void main(String[] args) {
        try {
            
            BufferedImage image = ImageIO.read(new File("image.jpg"));

            ByteArrayOutputStream baos = new ByteArrayOutputStream();

            ImageIO.write(image, "jpg", baos);

            byte[] byteArray = baos.toByteArray();

            System.out.println("Image converted to byte array successfully.");
        } catch (Exception e) {
            System.out.println("Error converting image to byte array: " + e.getMessage());
        }
    }
}

 

In Java, converting an image to a byte array is a common task when dealing with image processing or transmission. Fortunately, Java provides the ImageIO class, which offers a convenient way to accomplish this.To begin, you need to import the necessary classes: BufferedImage, File, ByteArrayOutputStream, and ImageIO.

Next, you can create a BufferedImage object by reading the image file using the ImageIO.read() method. This method takes a File object representing the image file.Once you have the BufferedImage, you can create a ByteArrayOutputStream object to hold the byte array. By calling the ImageIO.write() method and passing in the BufferedImage, image format (e.g., “jpg”, “png”), and ByteArrayOutputStream, you can write the image data to the stream.Finally, you can obtain the byte array by calling the toByteArray() method on the ByteArrayOutputStream. This method returns the contents of the stream as a byte array.

 

OUTPUT:-

When you run the provided Java program that converts an image to a byte array, the output will primarily depend on the image file you are using. However, the program itself will print the length of the byte array created from the image.

Assuming you have an image named sample.jpg in the same directory as your Java program, the output will look something like this:

Byte array length: <length_of_image_in_bytes>

Here, <length_of_image_in_bytes> will be the actual size of the image file in bytes. For example, if the image is 150 KB, the output might be:

Byte array length: 153600

If the image file does not exist or there is an error in reading the file, the program will print the stack trace of the exception, indicating what went wrong.