I'm using ubuntu 12.04.
So far, no example found on the net of converting webp to jpg.
Some webp files can easily converted by using imagemagick with command
convert file.webp file.jpg
but lots of webp files cannot be converted and give error:
convert: no decode delegate for this image format `file.webp' @ error/constitute.c/ReadImage/532. convert: missing an image filename `file.jpg' @ error/convert.c/ConvertImageCommand/3011.
This is the file: http://www.filedropper.com/file_144