The purpose of geometric matching is to extract the geometric transformation parameters between the corresponding images. It is widely used in photogrammetric mapping, deformation detection, and flying platform's posture analysis, etc. In this paper, a new image matching method which is different from the traditional features based image matching algorithm is proposed, it takes all the pixels of the corresponding images to participate the matching procedure and calculate the geometric parameters by least square criterion. The principle of the algorithm, including the gray corresponding equation, the information quantity inequation and procedure of least square solution are expressed. Particularly, the wavelet analysis for gray signal and calculating the information quantity by signal to noise ratio are discussed in detail. For verifying the theory and algorithm, a series of sequential images taking from a video camera mounted on a helicopter are selected for experiment. The results of two typical models according to the relative orientation elements model and parallax grid model are given, and the experimental results show that the proposed algorithm is feasible and effective. The comparison of APM with ordinary features based method by the information quantity inequation is given in the conclusion.