Registration of low contrast images

摘要

The registration of images captured at multiple locations, for purposes such as location mapping, can be improved by utilizing multiple image capture elements pointing in at least two different directions or having different viewable ranges. At least one primary image is captured at each location. If the primary image is not able to be correlated with at least one other image based on one or more matching features, image information captured by at least one other camera at substantially the same times as those images can be analyzed to attempt to determine a change in position and/or orientation of the device between those times, which can assist in correlating the primary images. In some embodiments, motion or orientation determining elements can assist in the determination of device movement, and in at least some embodiments can reduce the amount of image information to be processed for a match.

主权项

1. A computer-implemented method for mapping an area using a portable computing device, comprising:
capturing a plurality of primary images at each of a plurality of positions using a primary image capture element of the portable computing device, each primary image being captured to include at least a portion of the area to be mapped and having associated position information; capturing at least one secondary image for each primary image, each secondary image being captured with a secondary image capture element of the portable computing device at substantially a time of image capture for a corresponding primary image, the second image capture element having a different image capture direction from the first image capture element; for each selected primary image in the plurality of primary images captured using the primary image capture element:
determining at least one other primary image, different from the selected primary image, having at least one common image feature with the selected primary image, the selected primary image and the other primary image being captured at different times using the primary image capture element of the portable computing device;determining a change in relative positions between the at least one common image feature in the selected primary image and the at least one common image feature in the at least one other primary image captured at different times by the primary image capture element, the change in relative positions indicating an offset between the selected primary image and the at least one other primary image, the offset comprising a lateral translation between the relative positions of the at least one common image feature in the selected primary image and the at least one other primary image;determining a second offset to apply to a first secondary image for the selected primary image and to a second secondary image for the at least one other primary image based at least in part on the offset; anddetermining registration information between the selected primary image and at least one other primary image determined to be at least partially overlapping; and storing image information corresponding to at least the selected primary image and the at least one other primary image, the registration information, and the associated position information of the selected primary image and the at least one other primary image for use in generating a three-dimensional representation of the area.