A much faster and more universal search is with locate command:
$ locate '*image*desktop'
/usr/share/app-install/desktop/gimagereader:gimagereader-gtk.desktop
/usr/share/app-install/desktop/gnome-disk-utility:gnome-disk-image-mounter.desktop
/usr/share/app-install/desktop/gnome-disk-utility:gnome-disk-image-writer.desktop
/usr/share/app-install/desktop/imagej:imagej.desktop
/usr/share/app-install/desktop/imagemagick-6.q16:display-im6.q16.desktop
/usr/share/app-install/desktop/imagemagick:display-im6.desktop
/usr/share/app-install/desktop/imagevis3d:imagevis3d.desktop
/usr/share/app-install/desktop/kimagemapeditor:kde4__kimagemapeditor.desktop
/usr/share/app-install/desktop/simple-image-reducer:simple-image-reducer.desktop
/usr/share/app-install/desktop/trimage:trimage.desktop
/usr/share/applications/gnome-disk-image-mounter.desktop
/usr/share/applications/gnome-disk-image-writer.desktop
/usr/share/applications/screensavers/tessellimage.desktop
locate can search millions of files in a few seconds where it would take find many many minutes:
$ time find / -name '*image*.desktop'
real 0m52.563s
user 0m6.271s
sys 0m9.002s
$ time locate '*image*desktop'
real 0m0.705s
user 0m0.693s
sys 0m0.012s
Notice how grep was eliminated from original method and find command was ammended.
The disadvantage of locate is the database is updated daily. If you just installed the application you are searching for today, you will first need to run:
sudo updatedb
Installation
In newer versions of Ubuntu, you can install locate by installing the package plocate:
sudo apt install plocate