We propose a method called the base-oriented algorithm for image hiding. The method classifies each block of the host image H according to the base value (BV) that represents the block's variation. The classified blocks then either uses BV embedding or module substitution to hide data. The hiding capability of the proposed method is high, whereas the visual performance is also good. The lossless extraction of the confidential image from the mixed image is simple and uses no look-up table. The method can be used as an economic tool to hide and store confidential data in images.