Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for graphical overlay object translation. One of the methods includes receiving a first plurality of first feature points, each first feature point being associated with a plurality of feature descriptors and a respective location on the first digital image. The method includes receiving a second plurality of second feature points, each second feature point being associated with a plurality of feature descriptors and a respective location on the second digital image. The method includes determining the translation offset for the second digital image from the first digital image by matching locations of the first feature points with locations of the second feature points without regard to the feature descriptors.

Abstract: This specification relates to locating objects using indicia. In general, one innovative aspect of the subject matter described in this specification can be embodied in methods that include the actions of obtaining an image captured from a camera in proximity of an object located in an indoor facility, the image being of a portion of a surface of the indoor facility comprising a plurality of visible indicia, the camera having an orientation generally pointed at the surface. A plurality of local indicia are identified within the image. The locations of the local indicia within the image and an index of the visible indicia of the surface are used to determine the location of the object relative to the surface.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for graphical overlay object translation. One of the methods includes receiving a first plurality of first feature points, each first feature point being associated with a plurality of feature descriptors and a respective location on the first digital image. The method includes receiving a second plurality of second feature points, each second feature point being associated with a plurality of feature descriptors and a respective location on the second digital image. The method includes determining the translation offset for the second digital image from the first digital image by matching locations of the first feature points with locations of the second feature points without regard to the feature descriptors.

Abstract: A three-dimensional model of a scene is constructed from images of the scene. The three-dimensional model comprises parameters including point parameters describing points of the scene and camera parameters describing cameras that captured the images of the scene. The parameters are iteratively modified by correcting the parameters in each iteration. The corrections to the parameters are determined by solving a sparse equation based on Jacobian of residuals of the parameters. A linear system of equations is formulated by determining row blocks of the Jacobian for each point, processing each row block independent of other row blocks and combining the results. The linear system of equation is solved to determine the corrections to the parameters. The corrections to the parameters are determined without storing the entire Jacobian matrix in memory at the same time. As a result, the construction of the three-dimensional model is performed with fewer memory resources.