Gudubeth

Here you can find a simple image utility class to do some simple image operations in Java. ImageUtil class can find image width, height, file size and it can convert images to other formats. Some other functionalities like resizing image are coming soon. This class uses standard Java classes like ImageIO or BufferedImage, so you can learn basic image operations by examining this class.

Methods

All the documentation is inside the class in JavaDoc format but simple class outline is like this:

Sample

You can find the code below inside the main method of the class.

try{

	String filePath="d:/_dev/temp/"; //!!!do not forget to change this and the filename!!!
	File f = new File(filePath+"test.png");
	System.out.println("test.png: "+ImageUtil.findWidth(f)+"x"+ImageUtil.findHeight(f));

	f=ImageUtil.convertTo(f, new File(filePath+"/test.gif"), ImageUtil.GIF);
	System.out.println("test.gif: "+ImageUtil.findWidth(f)+"x"+ImageUtil.findHeight(f));

	f=ImageUtil.convertTo(f, new File(filePath+"/test.bmp"), ImageUtil.BMP);
	System.out.println("test.bmp: "+ImageUtil.findWidth(f)+"x"+ImageUtil.findHeight(f));

	f=ImageUtil.convertToJpg(f, new File(filePath+"/test.jpg"), 0.9f);
	System.out.println("test.jpg: "+ImageUtil.findWidth(f)+"x"+ImageUtil.findHeight(f));

}
catch(Exception e){
	e.printStackTrace();
}

Download The Class

Download the class code from here.

ImageUtil Class Code

package net.gudubeth.common;

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

import javax.imageio.ImageIO;

import com.sun.image.codec.jpeg.ImageFormatException;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGEncodeParam;
import com.sun.image.codec.jpeg.JPEGImageDecoder;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
import java.io.FileOutputStream;

/**
 * Image utility class. it can find image width, height, file size
 * and it can convert images to other formats. Images are used as File objects.
 * How to create a File object from file name:
 *  File file=new File("/path/to/image.jpg");
 *
 *
 * @author gudubeth
 * @since 20-01-2010
 */
public class ImageUtil{

    public static final String JPG="jpg";
    public static final String GIF="gif";
    public static final String BMP="bmp";
    public static final String PNG="png";

    /**
     * creates BufferedImage from file. this object is used for other image operations
     * @param imageFile
     * @return image
     * @throws ImageFormatException
     * @throws IOException
     */
    public static BufferedImage findBufferedImage(File imageFile) throws ImageFormatException, IOException{
            return ImageIO.read(imageFile);
    }

    /**
     * creates BufferedImage from jpg file. this object is used for other image operations
     * @param imageFile
     * @return image
     * @throws ImageFormatException
     * @throws IOException
     */
    public static BufferedImage findBufferedImageForJpeg(File imageFile) throws ImageFormatException, IOException{
            JPEGImageDecoder jpegDecoder = JPEGCodec.createJPEGDecoder(new FileInputStream(imageFile.getPath()));
            return jpegDecoder.decodeAsBufferedImage();
    }

    /**
     * gets the width of image.
     * @param imageFile these formats are ok: jpg,tif,png,bmp,gif. test for other formats
     * @return image width in int
     * @throws ImageFormatException
     * @throws IOException
     */
    public static int findWidth(File imageFile) throws ImageFormatException, IOException {
            return findBufferedImage(imageFile).getWidth();
    }

    /**
     * gets the height of image
     * @param imageFile. these formats are ok: jpg,tif,png,bmp,gif. test for other formats
     * @return image height in int
     * @throws ImageFormatException
     * @throws IOException
     */
    public static int findHeight(File imageFile) throws ImageFormatException, IOException{
            return findBufferedImage(imageFile).getHeight();
    }

    /**
     * find image width and height. this is faster than calling
     * findHeight and findWidth separately
     * @param imageFile
     * @return  int array containing width and height
     * @throws ImageFormatException
     * @throws IOException
     */
    public static int[] findWidthAndHeight(File imageFile) throws ImageFormatException, IOException{
            BufferedImage buffy = findBufferedImage(imageFile);
            return new int[]{buffy.getWidth(), buffy.getHeight()};
    }

    /**
     * find file size in bytes
     * @param imageFile
     * @return
     * @throws IOException
     */
    public static long findFileSize(File imageFile) throws IOException{
            return imageFile.length();
    }

    /**
     * convert image file to another format.  possible formats are jpg, png, gif, bmp
     *
     * @param input File        file to convert. any format read by ImageIO is OK
     * @param output File       output file
     * @param format String     one of jpg, png, gif, bmp
     * @return output file
     * @throws IOException
     */
    public static File convertTo(File input, File output, String format) throws IOException{
        ImageIO.write(ImageIO.read(input), format, output);
        return output;
    }

    /**
     * convert image to gif
     * @param input     file to convert
     * @param output    output file
     * @return output file
     * @throws IOException
     */
    public static File convertToGif(File input, File output) throws IOException{
        return convertTo(input, output, GIF);
    }

    /**
     * convert image to bmp
     * @param input     file to convert
     * @param output    output file
     * @return output file
     * @throws IOException
     */
    public static File convertToBmp(File input, File output) throws IOException{
        return convertTo(input, output, BMP);
    }

    /**
     * convert image to png
     * @param input     file to convert
     * @param output    output file
     * @return output file
     * @throws IOException
     */
    public static File convertToPng(File input, File output) throws IOException{
        return convertTo(input, output, PNG);
    }

    /**
     * convert image to jpg with specified quality
     * @param input     file to convert
     * @param output    output file
     * @param quality   jpeg quality. any float between 0 and 1.
     * @return output file
     * @throws ImageFormatException, IOException
     */
    public static File convertToJpg(File input, File output, float quality) throws ImageFormatException, IOException {
        if(quality>1 || quality<=0) throw new IllegalArgumentException("quality must be between 0 and 1"); 

        BufferedImage bim = findBufferedImage(input);
        FileOutputStream fos = new FileOutputStream(output);
        JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(fos);
        JPEGEncodeParam encodeParams = encoder.getDefaultJPEGEncodeParam(bim);
        encodeParams.setQuality(quality, false);
        encoder.setJPEGEncodeParam(encodeParams);
        encoder.encode(bim);
        fos.close();
        return output;
    }

    /**
     *
     */
    public static void main(String[] args) {
        try{

            String filePath="d:/_dev/temp/"; //!!!do not forget to change this and the filename!!!
            File f = new File(filePath+"test.png");
            System.out.println("test.png: "+ImageUtil.findWidth(f)+"x"+ImageUtil.findHeight(f));

            f=ImageUtil.convertTo(f, new File(filePath+"/test.gif"), ImageUtil.GIF);
            System.out.println("test.gif: "+ImageUtil.findWidth(f)+"x"+ImageUtil.findHeight(f));

            f=ImageUtil.convertTo(f, new File(filePath+"/test.bmp"), ImageUtil.BMP);
            System.out.println("test.bmp: "+ImageUtil.findWidth(f)+"x"+ImageUtil.findHeight(f));

            f=ImageUtil.convertToJpg(f, new File(filePath+"/test.jpg"), 0.9f);
            System.out.println("test.jpg: "+ImageUtil.findWidth(f)+"x"+ImageUtil.findHeight(f));

        }
        catch(Exception e){
            e.printStackTrace();
        }
    }

}