How to convert webp to png/jpg/gif in MacOS

Environment

I'm using OS X 10.11.4 and have homebrew 1.0.5 installed.

Introduction

I recently downloaded several pictures from Google Plus to use them as my wallpaper galaxy. But the images are all in webp format. MacOS doesn't support webp as a valid wallpaper format.

WebP is an image format employing both lossy and lossless compression. WebP supports for animation as an alternative to the popular GIF format, citing the advantages of 24-bit color with transparency, combining frames with lossy and lossless compression in the same animation, and as well as support for seeking to specific frames. It has been reported by Google that it has a 64% reduction in file size for images converted from animated GIFs to lossy WebP, and a 19% reduction when converted to lossless WebP.

Steps

Make sure you have [homebrew](http://brew.sh/) installed

# using brew
/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Install webp

To convert from webp, webp support should be available

brew install webp

Batch using script

1 the package contains several commands

ls /usr/local/Cellar/webp/0.5.1/bin/
# cwebp   dwebp   webpmux

for i in *.webp; do
    dwebp $i -o ${i//webp/png} $i &>/dev/null
    echo "Done with $i"
done
# using for-loop
# using dwebp of package webp
# Or one-liner
for i in *.webp; do dwebp $i -o ${i//webp/png} $i &>/dev/null; echo "Done with $i"; done