A random grid is a two-dimensional binary array in which entries, 0 or 1, are determined in 50% to 50%. A generalized random grid is also a 2-D binary array in which entries are determined but not necessarily 50% to 50%. Using generalized random grids for visual secret sharing, friendly meaningful transparencies, also called shares, can be generated, and the size of each share is the same with the secret image size. In the decoding phase, stacking at least two friendly meaningful shares together, the content of the secret image can be revealed without any computation, and the more shares stacked, the clearer the result. The proposed method can also be implemented for gray and color images.