I changed my background desktop image today but I cannot find any options to change it to fill or span the screen like this:

Any ideas?
I changed my background desktop image today but I cannot find any options to change it to fill or span the screen like this:

Any ideas?
For 17.04 the default picture options for wallpapers can be set via the command line:
gsettings set org.gnome.desktop.background picture-options 'none'
gsettings set org.gnome.desktop.background picture-options 'wallpaper'
gsettings set org.gnome.desktop.background picture-options 'centered'
gsettings set org.gnome.desktop.background picture-options 'scaled'
gsettings set org.gnome.desktop.background picture-options 'stretched'
gsettings set org.gnome.desktop.background picture-options 'zoom'
gsettings set org.gnome.desktop.background picture-options 'spanned'
To reset back to the default:
gsettings reset org.gnome.desktop.background picture-options
Late to answer on this one, but for anyone who is interested.
You can also install the gnome-tweak-tool, which is now called gnome-tweaks as of 18.04. You to the tab Appearance you will then find the setting under Adjustment.
sudo apt-get install gnome-tweak-tool
or if you are version 18.04 or later.
sudo apt install gnome-tweaks