, Volume 14, Issue 3, pp 186-227,
Open Access This content is freely available online to anyone, anywhere at any time.

Compression of Samplable Sources


We study the compression of polynomially samplable sources. In particular, we give efficient prefix-free compression and decompression algorithms for three classes of such sources (whose support is a subset of {0, 1} n ).

  1. 1.

    We show how to compress sources X samplable by logspace machines to expected length H(X) + O(1).

Our next results concern flat sources whose support is in P.
  1. 2.

    If H(X) ≤ k =  n − O(log n), we show how to compress to expected length k + polylog(nk).

  2. 3.

    If the support of X is the witness set for a self-reducible NP relation, then we show how to compress to expected length H(X) + 5.