Convert Images in Java

An example on converting images between JPG, PNG, GIF formats in Java in two simple steps.

Example

// Import for ImageIO class

import javax.imageio.*;



// Import for BufferedImage

import java.awt.image.*;



// Import for File, IOException is also raised but not used here.

import java.io.*;



class ConvertJPG

{



 public static void main(String args[]) throws Exception

 {

 // Read the input image file using a static method read() in javax.imageio.ImageIO

 BufferedImage bim=ImageIO.read(new File("C:/java/images/icon.png"));



 // Convert the image that is read to PNG and it's name should be icon.png in the current directory

 boolean written=ImageIO.write(bim,"PNG",new File("icon.png"));



 // Convert the image that is read to GIF and it's name should be icon.gif in the current directory

 boolean written1=ImageIO.write(bim,"GIF",new File("icon.gif"));



 // Print whether converted to PNG

 System.out.println("Is file written to PNG (T/F)? "+written);



 // Print whether converted to GIF

 System.out.println("Is file written to GIF (T/F)? "+written1);

 }



}

Explanation

ImageIO is a class in the javax.imageio package.

read() is a static overloaded method in the ImageIO class.

Here, we've used read(File source_image_file) from which the image is read.

The read(File source_image_file) method returns java.awt.image.BufferedImage object representing the image that is read from the file.

java.awt.image.BufferedImage is a class implementing the java.awt.image.RenderedImage interface.

write() is also a overloaded static method of the javax.imageio.ImageIO class.

Here we've used write(RenderedImage img,String convert_format,File destination_image_file)

For the first parameter in write() method, we've sent bim which is an object of the java.awt.image.BufferedImage class representing the image that is read (here C:/java/images/icon.png).

This can be used because BufferedImage implements RenderedImage so a BufferedImage object is also a RenderedImage object.

boolean value is returned which says whether the conversion was successfully completed or not. true is returned when conversion is completed.

Also see my other post on Getting Screen Size and Resolution in Java and Getting Center point of the Screen in Java and also Get All Fonts Installed in a PC in Java