Image to WebP

This project consists of a Java library for images (jpeg, png, tiff, webp) to WebP conversion and a Spring Service. The Spring service offers both, a REST API and a traditional web interface to the library.

You can use the lib standalone. The lib is a wrapper around the "cwebp"-executable (the official webp converter) with easy input and output interface and error/success feedback. You call the converter with a byte[] array and a working directory of your choice. The library creates the file out of the byte[]-array (which is for example a jpeg, png or tiff image, or even another webp image) and writes it to the given working directory. Then cwebp is executed in this directory with a chosen quality factor (1 - 100).

The website and the REST API can be found here: https://webp.phip1611.dev

REST-Interface

Input: POST-Request to /convert

{
    "fileExtension": string; // e.g. "jpeg"
    "base64String": string;
    [optional] "quality": integer; // 1 - 100; Default-Value is 82
}

Output: Response from /convert

{
    "success": boolean;
    "size": number;
    "oldSize": number;
    "savingsInPercent": number;
    "base64String": string;
    "quality": integer;
}

Build and Run

Minimum Supported Java Version

The minimum supported Java version is Java 21.

Nix

To build the project via the Nix flake:

• Spring Service Jar:
  $ nix build .#\jar
• Spring Service run script (with runtime dependencies):
  $ nix build .#\serviceScript
  • as binary package:
    $ nix build .#\serviceScriptBin or $ nix run .#\serviceScriptBin
• Docker Container:
  $ nix build .#\dockerImage

Regular

• install cwebp on your machine, e.g. via https://developers.google.com/speed/webp/docs/precompiled and make sure it's in your PATH variable, or $ sudo apt install webp
• mvn clean install
• cd target && java -jar ....jar starts by default on Port 8080; change for example with -Dserver.port=1337 (or any other spring configuration method you like)