I'm looking for an effective method for automating the conversion of a number of images to the WebP image format. I'm particularly interested in a method that will keep the metadata or allow me to add or edit the metadata.
The easiest way would be <cfexecute> with cwebp https://developers.google.com/speed/webp/docs/precompiled
As for metadata...
WebP format do support EXIF/XMP metadata. The next version of WebP library (libwebp) will have appropriate APIs supporting handling of EXIF/XMP metadata, along with supporting utility binaries to convert JPEG/PNG to WebP format retaining the metadata from original files.
Quoted from WebP Google Group. Meanwhile, follow issue 52 for latest updates? https://code.google.com/p/webp/issues/detail?id=52