image4j

Overview

The image4j library allows you to read and write certain image formats in 100% pure Java.

Currently the following formats are supported:

• BMP (Microsoft bitmap format - uncompressed; 1, 4, 8, 24 and 32 bit)
• ICO (Microsoft icon format - 1, 4, 8, 24 and 32 bit [XP uncompressed, Vista compressed])

Purpose

This project aims to provide:

• an open source library for handling various image formats in Java
• with a commercial-friendly license
• using only Java code, ie. without using any JNI hacks
• with no dependencies on third-party libraries (where possible)

License

The image4j library is licensed under the GNU LGPL v2.1 so you are free to use it in your Free Software and Open Source projects, as well as commercial projects, under the terms of the LGPL v2.1.

History

This project began after I spent hours searching for a library that would meet the above criteria and found that there is probably no such thing - or at least, not any more. The only support I could find for the ICO format was read-only, so doing cool stuff - like generating favicons on the fly - using only Java code was not possible.

QuickStart

It is possible to decode/encode BMP and ICO files with just one line of code!

The image4j library consists of only Java code and has no dependencies on third-party libraries, so you just add it to the classpath and you're good to go.

Although the code is compatible with Java 1.5.0 or later, it should be relatively simple to port the code to an older version, eg. 1.4.2.

BMP

Decode

BufferedImage image = BMPDecoder.read(new File("input.bmp"));

Encode

BMPEncoder.write(image, new File("output.bmp"));

ICO

Decode

List<BufferedImage> image = ICODecoder.read(new File("input.ico"));

Encode

ICOEncoder.write(images, new File("output.ico"));

Documentation

Browse the API Javadocs online.

Download

Download the latest version at SourceForge.net or from the Github release page.

Credits

• The File Formats page at DaubNET for information on various image formats.
• GIMP, which I use for editing images

Disclaimer

To my knowledge, there are no patents on either the BMP or ICO formats.