5 results about "Maximum a posteriori estimation" patented technology

The application provides a cross-view splicing detection method based on coarse-to-fine matching, which comprises the following steps: performing feature extraction on a to-be-detected image to obtain feature points; setting a coarse matching threshold, matching the feature points to obtain a coarse matching set, wherein the coarse matching set comprises correct matching pairs and incorrect matching pairs; modeling the coarse matching set to obtain a mixed model, performing maximum a posteriori estimation on the mixed model, distinguishing the correct matching pairs from the incorrect matching pairs, and obtaining an output correct matching pair set; and positioning a splicing tampering region of the to-be-detected image according to the correct matching pair set to obtain a detection result.

The application discloses an infrared small target adaptive mask generation method and product based on physical priori, and the method comprises the following steps: acquiring an infrared image to be processed and a single-point label located at any position in a small target effective response area; taking the single-point label as a seed point, performing polarity unification processing on the infrared image according to local background statistical information of the seed point neighborhood; establishing a candidate small target area with the seed point, constructing a priority queue of pixels to be expanded, and initializing the candidate area and a statistical quantity; modeling a target mask generation problem as a maximum posterior estimation problem, and constructing a posterior energy function; gradually expanding the candidate area based on the priority queue and a greedy search strategy, and recording the posterior energy in the expansion process to obtain an energy record sequence; selecting an energy peak value from the energy record sequence, and generating a target pixel-level mask according to a corresponding optimal state backtracking; and extracting geometric supervision information according to the target pixel-level mask.

The invention provides a high-latitude transfer alignment algorithm based on a factor graph, and belongs to the technical field of high-precision navigation. The invention aims to solve the problem that the traditional Kalman filtering method is difficult to deal with the strong nonlinearity and parameter coupling problem of high-dimensional regional navigation, so that the precision and robustness of transfer alignment are reduced. The method comprises the following steps: S1, modeling a high-latitude transfer alignment problem into a time sequence factor graph model; s2, calculating the posterior distribution probability of the system according to the time sequence factor graph model; s3, according to the posterior distribution probability, obtaining an error state estimation value of the sub inertial navigation relative to the main inertial navigation through maximum posterior estimation; and S4, correcting the navigation parameters of the sub inertial navigation according to the error state estimated value, and completing transfer alignment in the high-latitude environment.

This invention belongs to the field of aerospace and space situational awareness technology, specifically relating to a method and apparatus for associating short-arc data of space debris based on factor graphs. The method includes: acquiring and preprocessing optical angle measurement short-arc data from observation stations; obtaining initial orbital state values ​​using an angle observation initial orbit determination algorithm; constructing a cost matrix to initially screen the initial orbital state values ​​corresponding to different short-arc observation data, and generating a limited number of multiple association hypotheses through perturbation sampling expansion; constructing a nonlinear factor graph under each association hypothesis; solving for the maximum a posteriori estimate, and selecting the optimal association hypothesis based on residual and information criteria; outputting the association cluster, orbital state, and its uncertainty, and performing a consistency check. This invention enables efficient and robust multi-arc association and preliminary orbit estimation of optical angle measurement short-arc data in both ground-based and space-based observation scenarios, achieving scene adaptability, real-time performance, and high accuracy.