GitHub

FPNG Java

FPNG-Java provides Java wrappers around two native, SIMD-optimised PNG encoders — FPNG (SSE2) and FPNGE (AVX2). Both produce fully compliant PNG files at significantly higher throughput than javax.imageio.

The JDK23+ version of the encoders uses Foreign Function & Memory API and is the fastest. Otherwise JNI is used via JNA, which comes with some overhead.

Latest stable release: fpng-java-1.4.1.jar

GitHub Repository: https://github.com/manticore-projects/fpng-java

Features

  • Two encoders with automatic runtime selection

    • FPNG — SSE2/SSE4.1/PCLMUL, works on any x86-64 CPU

    • FPNGE — AVX2, used automatically when the CPU supports it

  • FFM for JDK22+, JNI/JNA for older JDKs

  • Runtime hasAVX2() CPUID probe — no AVX2 library is loaded on unsupported hardware

  • Encodes BufferedImage directly — 3-channel (RGB) and 4-channel (RGBA)

  • Handles Java’s native TYPE_3BYTE_BGR / TYPE_4BYTE_ABGR channel order in C via SIMD byte shuffles

  • Interleaved Adler32 checksum — no redundant full-image pass

  • PCLMUL-accelerated CRC32

  • Supports Java 8, Java 11, Java 17 and Java 21

  • Platforms: Linux x86-64, Windows x86/x86-64, macOS x86-64

Benchmarks

Run the JMH benchmarks with:

./gradlew jmh

Results are written to benchmark/build/results/jmh/results.json.