A Mixture Likelihood Model of the Anisotropic Gaussian and Uniform Distributions for Accurate Oblique Image Point Matching

In this letter, we propose a mixture likelihood model for accurate oblique image point matching. The basic prior assumption is that the noises are anisotropic with zero mean and different covariances in x- and y-directions for inliers, while the outliers have uniform distribution, which is more suitable for tilted scenes or viewpoint changes. Furthermore, the oblique image point matching problem is formulated as an improved maximum a posteriori (IMAP) estimation of a Bayesian model. In this model, based on the vector field interpolation framework, we combined the mixture likelihood model and our previous adaptive image mismatch removal method, where a two-order term of the regularization coefficient is introduced into the regularized risk function, and a parameter self-adaptive Gaussian kernel function is imposed to construct the regularization term. Subsequently, the expectation-maximization algorithm is utilized to solve the IMAP estimation, in which all the latent variances are able to obtain excellent estimation. Experimental results on real data sets verified that our method was superior to some similar methods in terms of precision and also had better self-adaptability characteristic than some hypothesis-and-verify methods. More experiments on viewpoint changes demonstrated our method's effectiveness without loss of precision-recall tradeoffs, besides significant efficiency improvement.