Editing Group theory (section)

===Harmonic analysis===
{{Main|Harmonic analysis}}
Analysis on Lie groups and certain other groups is called [[harmonic analysis]]. [[Haar measure]]s, that is, integrals invariant under the translation in a Lie group, are used for [[pattern recognition]] and other [[image processing]] techniques.<ref>{{Citation | last1=Lenz | first1=Reiner | title=Group theoretical methods in image processing | publisher=[[Springer-Verlag]] | location=Berlin, New York | series=Lecture Notes in Computer Science | isbn=978-0-387-52290-6 | year=1990 | volume=413 | url=https://archive.org/details/grouptheoretical0000lenz | doi=10.1007/3-540-52290-5 | s2cid=2738874 | url-access=registration }}</ref>