目前可用的选项包括：gd，imagick，cwebp（exec-call）或调用云服务。我在github上创建了一个库'webp-convert'，它尝试了所有方法。自述文件描述了每种方法的优缺点。它可以在这里找到： https://github.com/rosell-dk/webp-convert

The options currently available are: gd, imagick, cwebp (exec-call) or calling a cloud service. I have created a library 'webp-convert' on github which tries all methods. The readme-file describes the pros and cons of each method. Its available here: https://github.com/rosell-dk/webp-convert