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Image manipulation with WebP and ImageMagick

WebP conversion​

WebP compression reduces image sizes considerably for web usage while maintaining good enough quality. You can install webp using a package manager or download the binaries for your operating system:

# on macos
brew install webp

# on ubuntu/debian
apt update && apt install -y --no-install-recommends webp

# rhel
dnf in -y epel-release
dnf config-manager --set-enabled crb
dnf in -y libwebp-tools

Or download precompiled binaries for your operation system - https://developers.google.com/speed/webp/docs/precompiled

VERSION="1.6.0"
wget https://storage.googleapis.com/downloads.webmproject.org/releases/webp/libwebp-${VERSION}-linux-x86-64.tar.gz
tar -xf libwebp-${VERSION}-linux-x86-64.tar.gz
rm libwebp-${VERSION}-linux-x86-64.tar.gz
export PATH=${PWD}/libwebp-${VERSION}-linux-x86-64/bin:$PATH

Convert image:

cwebp in.png -o out.webp

# adjust quality (default 75)
cwebp -q 80 in.png -o out.webp

Batch conversion:

for file in $( ls *.png); do cwebp "${file}" -o "${file%*.png}.webp"; done

Manipulate image with ImageMagick​

Install in Ubuntu/Debian:

apt update && apt install imagemagick

Resize an image:

convert input.jpg -resize 800x output.jpg
convert input.jpg -resize 800x -quality 80 output.jpg
convert input.jpg -resize 800x -quality 80 -filter Lanczos -sharpen 0x0.8 output.jpg

Resize using alternative magick command:

magick input.jpg -filter Lanczos -resize 800x -unsharp 0x0.8+0.8+0.02 -quality 80 output.jpg

Crop image:

# crop (WxH+x_offset+y_offset)
magick in.jpg -crop 800x1200+100+200 +repage out.jpg
magick in.jpg -crop 60%x40%+100+200 +repage out.jpg

We can use magick command to convert to webp alongside resize:

magick in.jpg -auto-orient -filter Lanczos -resize 800x \
    -unsharp 0x0.8+0.8+0.02 -strip \
    -define webp:method=6 -quality 80 out.webp