Java PNG Reader
The JDeli Java image library includes a PNG Reader to read PNG images into Java. The PNG Decoder is written in 100% Java and provides PNG support with no dependencies.
What is supported
The JDeli PNG reader supports the following features:
| Feature | Support |
|---|---|
| Compression - NONE | yes |
| Compression - 8bit Quantised | yes |
| Compression - Zlib | yes |
| Alpha | yes |
| RGB | yes |
| Palette | yes |
| Grayscale | yes |
| Filtering | yes |
| ICC | yes |
| Metadata | EXIF |
| Takes file input | Yes |
| Takes InputStream input | Yes |
| Takes byte[] input | Yes |
| Pure Java implementation | Yes |
Quick start:
Add JDeli to your project via Maven or Gradle, or see using JDeli with Java modules.
JDeli can automatically detect the file type and will use the PNG File Reader
BufferedImage image = JDeli.read(pngImageFile);
or
PngDecoder decoder = new PngDecoder();
BufferedImage image = decoder.read(pngData);
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 |
|---|---|---|
| Apache | 1151.556 | ± 12.405 |
| ImageIO | 296.915 | ± 12.564 |
| JDeli | 2160.496 | ± 43.874 |
| ICafe | 184.446 | ± 0.917 |
Tested on 2021 14inch M1 MacBook Pro using JDK 18.0.1.1
Frequently asked questions
Does JDeli produce better PNG reading and decoding than Java ImageIO?
Yes. While ImageIO can read PNG, JDeli provides better compatibility, more consistent output across platforms, and access to format-specific decoding options.
Does reading or decoding PNG in Java with JDeli require additional 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 input types does JDeli support for reading PNG?
JDeli can read and decode PNG from a File, InputStream, or byte array.