Dictionary

*learning*(DL) is a representation*learning*method which aims to find a sparse representation of the input data (also known as sparse coding) in the form of a linear combination of basic elements as well as those basic elements themselves. As above, matching pursuit is mapping a vector or measurement onto a basis which yields a sparse approximation. However, it is necessary to know what the basis is which can allow matching pursuit in order to have a sparse representation. Some basis construction algorithms are proposed, one of which is dictionary*learning*. Dictionary*learning*makes it possible to build an overcomplete basis and allow a sparse representation.