Collaborative alignment of images

An apparatus comprising:

• a processor configured to:
• access a plurality of frames of images, the frames having pixels;
• select pairs of the frames;
• for each of the selected pairs, find a correspondence between the pixels or regions in the frames in the pair and associate a confidence with the correspondence between the pixels or regions in the frames in the pair;
• and
• assign a coordinate system to each of the plurality of frames that is consistent with the correspondence and associated confidence for each of the selected pairs of frames.

A computer-readable storage device having computer-readable instructions embodied thereon for use by a processor, the computer-readable instructions cause the processor to:

• access a plurality of frames of images, the frames having pixels;
• select pairs of the frames;
• for each of the selected pairs, estimate a set of difference transformation parameters for each of the selected pairs of frames;
• and
• assign a set of transformation parameters to each of the plurality of frames that is consistent with the sets of difference transformation parameters for each of the selected pairs of frames, wherein the computer-readable instructions that cause the processor to assign a set of transformation parameters to each of the plurality of frames further cause the processor to determine a least squares solution to a set of equations in which the set of transformation parameters for each of the plurality of frames are unknown and the set of difference transformation parameters for each of the frames of pairs are known.

An apparatus comprising:

• a processor configured to:
• access a plurality of frames of images, the frames having pixels and having regions;
• select pairs of the plurality of frames;
• for each of the selected pairs, find a correspondence between the pixels or the regions in the frames in the pair;
• assign a coordinate system to each of the plurality of frames that is consistent with the correspondence;
• align the plurality of frames based on the coordinate system assigned to each of the plurality of frames;
• and
• detect a location of a screen in the plurality of frames after the alignment, wherein to detect the location of the screen the processor is configured to:
• a) form an image based on one of more of the plurality of frames;
• b) identify a set of lines in the plurality of frames that are candidates for boundaries of the screen;
• c) integrate the image on each side of each line in the set of lines to form integration results;
• d) form a set of screen hypothesis based on the integration results;
• e) score screens in the screen hypothesis according to a criterion;
• and
• f) select a screen from the screens in set of screen hypothesis based on the scoring.

An apparatus comprising:

• a processor configured to:
• access a plurality of frames of images, the frames having pixels;
• select pairs of the frames;
• for each of the selected pairs, find a correspondence between the pixels or regions in the frames in the pair;
• assign a coordinate system to each of the plurality of frames that is consistent with the correspondence for each of the selected pairs of frames;
• after the coordinate system is assigned to each of the plurality of frames, remove from the plurality of frames a frame that is an outlier;
• select new pairs of frames after the outlying frame has been removed from the plurality of frames;
• for each of the new selected pairs, find a correspondence between the pixels or regions in the frames in the pair;
• and
• assign a coordinate system to each of the plurality of frames that is consistent with the correspondence.