One of the challenges in digital watermarking is to develop a
statistically powerful blind detector and decoder for multi-bit watermarks. In this paper, we propose a general statistical procedure for blind multi-bit watermark detection and decoding based on the total efficient scores vector and obtain the asymptotic distribution of the proposed detectors. The main idea and mathematics of the general method are illustrated by two widely-used parametric distributions: the generalized Gaussian distribution and the Weibull distribution. Some optimality properties of the procedure are discussed and probability plots are proposed to graphically assess the finite sample performance. The robustness and survivability of the proposed watermarking method for digital images are evaluated and tested by embedding the watermarks in a band of arcs from low to middle frequencies in the DFT domain.