The problem of optimal approximation of members

of a vector space by a linear combination of members

of a large overcomplete library of vectors is of importance

in many areas including image and video coding,

image analysis, control theory, and statistics. Finding

the optimal solution in the general case is mathematically

intractable. Matching pursuit, and its orthogonal

version, provide greedy solutions to this problem.

Orthogonal matching pursuit typically provides significantly

better solution compared to the nonorthogonal

version, but requires much more computation. This

paper presents a fast algorithm for implementation of

orthogonal matching pursuit which for many coding

applications has computational complexity very close

to that of the nonorthogonal version.