As an extension of Gabor signal processing, the covariant Weyl-Heisenberg integral quantization is implemented to transform  functions on the eight-dimensional  phase space (x,k) into Hilbertian operators. The x=(x^{\mu}) are space-time variables and the k=(k^{\mu}) are their conjugate wave vector-frequency variables. The procedure is first applied to the variables (x,k) and produces canonically conjugate essentially  self-adjoint operators. It is next applied to the metric field g_{\mu\nu}(x) of general relativity and yields regularised  semi-classical phase space portraits of it. The latter give rise to modified tensor energy density.  Examples are given with the uniformly accelerated reference system  and  the Schwarzschild metric. Interesting probabilistic aspects are discussed.