Imager::File::WEBP provides file format support for Google's webp image file format to Imager. You will need at least version 0.5.0 of libwebp installed, including libwebpmux which is packaged with libwebp. To build Imager::File::WEBP you will also need the development headers installed. For Debian you can install all of that with: apt-get install libwebp-dev which will also install the needed runtime libraries. I haven't tried this on Win32.