Java JPEG Writer
Java’s built-in ImageIO has limited support for writing JPEG files and provides little control over encoding quality and format-specific options. JDeli is a 100% Java JPEG writer that gives you full encoding control with no dependencies.
Getting started
Add JDeli to your project via Maven or Gradle, or see using JDeli with Java modules.
Key features:
- 100% Java solution. No dlls or dependencies on native code
- Fast and easy to use
- Supports quality settings
Quick start or to replace in existing code using ImageIO:
JDeli.write(myBufferedImage, "jpg", outputStreamOrFile);
or
byte[] outputData = JDeli.write(myBufferedImage, "jpg");
Simple usage
JDeli.write(myBufferedImage, OutputFormat.JPEG, outputStreamOrFile);
OutputFormat allows setting of any supported Image Format
For complete control of output:
final JpegEncoderOptions options = new JpegEncoderOptions();
//set any options in options instance - examples below
options.setQuality(100);//0-100
//write out
JDeli.write(myBufferedImage, options, outputStreamOrFile);
JpegEncoderOptions allows setting of specific options.
Various image processing operations can be conducted on the image, detailed documentation can be found here.
Performance comparisons:
These figures were generated using jmh (as documented on our blog) with a standard set of images (also documented). They should be easy to replicate if you wish to validate, the code is on GitHub.
The higher the number, the better.
Mode: Throughput Count: 25 Units: ops/s
| Benchmark | Score | Error |
|---|---|---|
| ImageIO | 13.345 | ± 0.049 |
| ImageIO_high | 10.049 | ± 0.033 |
| ImageIO_low | 13.989 | ± 0.040 |
| JDeli | 28.073 | ± 0.513 |
| JDeli_high | 15.778 | ± 0.126 |
| JDeli_low | 29.451 | ± 0.491 |
Number of files: 166
| Benchmark | Size | unreadable output | AVG SSIM score | AVG Similarity |
|---|---|---|---|---|
| ImageIO | 201.10KB | 36 | 0.9843408924688256 | Very similar (high quality) |
| ImageIO_high | 922.64KB | 36 | 0.9955252550315202 | Identical or virtually identical |
| ImageIO_low | 110.37KB | 36 | 0.753963280422963 | Moderately similar (visible differences) |
| JDeli | 232.06KB | 0 | 0.9635278566129812 | Very similar (high quality) |
| JDeli_high | 1,484.97KB | 0 | 0.9824853317459952 | Very similar (high quality) |
| JDeli_low | 132.199KB | 0 | 0.7308454760175299 | Moderately similar (visible differences) |
Tested on 2020 13inch M1 MacBook Pro using JDK 18.0.1.1
Frequently asked questions
Does JDeli produce better JPEG output than Java ImageIO?
Yes. While ImageIO can write JPEG, JDeli gives you full control over encoding options such as compression and quality, and produces more consistent output across platforms.
Does writing JPEG in Java require native libraries?
No. JDeli is a 100% Java library with no dependencies. It runs on any platform where the JVM runs with no additional installation.
What output types does JDeli support for writing JPEG?
JDeli can write JPEG to a File, OutputStream, or return the encoded data as a byte array.