Let Sg be a general prime K3 surface in IP g of genus g ≥ 3 or a general double cover of IP 2 ramified along a sextic curve for g = 2 and Si,g its ith Veronese embedding. In this article we compute the corank of the Gaussian map ΦOSi,g (1) : ∧2 H(Si,g,OSi,g(1)) → H (Si,g,Ω 1 Si,g (2)) for i ≥ 2, g ≥ 2 and i = 1, g ≥ 17. The main idea is to reduce the surjectivity of ΦOSi,g (1) to an application...