Aligning images
First Claim
1. A method of aligning a pair of original images, the method comprising:
- defining a plurality of different pairs of images at a plurality of different resolutions, wherein the plurality of different pairs of images is associated with a plurality of different pairs of bitmaps, and each particular bitmap is a bitmap of a particular original image at a particular resolution; and
hierarchically aligning the pair of original images by first aligning the pair of images at the lowest resolution and then aligning each pair of images at each higher resolution based on the alignments of the pair of images at the lower resolutions,the hierarchical aligning comprising, for each particular resolution in a subset of resolutions;
for at least one particular image at the particular resolution, dividing the particular image into a plurality of tiles for use in identifying corresponding portions in the other image in the pair at the particular resolution; and
comparing the pair of images by using tiles that are suitable for the comparison while discarding tiles that are unsuitable from the comparison;
wherein identifying suitable and unsuitable tiles in a particular image at a particular resolution comprises identifying tiles that have more than a threshold level of black pixels or tiles that have more than a threshold level of white pixels as unsuitable.
1 Assignment
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Accused Products
Abstract
Some embodiments provide a method of aligning a pair of images. The method defines multiple different pairs of images at multiple different resolutions. The method hierarchically aligns the original pair of images by first aligning the pair of images at the lowest resolution and then aligning each pair of images at each higher resolution based on the alignments of the pair of images at the lower resolutions. For some of the resolutions, to perform the hierarchically alignment, the method identifies, for at least one image at each resolution, portions that are suitable for performing the alignment and portions that are not suitable for performing the alignment. The method compares each pair of images at a particular resolution by using the suitable portions while excluding the unsuitable portions from the comparison.
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Citations
27 Claims
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1. A method of aligning a pair of original images, the method comprising:
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defining a plurality of different pairs of images at a plurality of different resolutions, wherein the plurality of different pairs of images is associated with a plurality of different pairs of bitmaps, and each particular bitmap is a bitmap of a particular original image at a particular resolution; and hierarchically aligning the pair of original images by first aligning the pair of images at the lowest resolution and then aligning each pair of images at each higher resolution based on the alignments of the pair of images at the lower resolutions, the hierarchical aligning comprising, for each particular resolution in a subset of resolutions; for at least one particular image at the particular resolution, dividing the particular image into a plurality of tiles for use in identifying corresponding portions in the other image in the pair at the particular resolution; and comparing the pair of images by using tiles that are suitable for the comparison while discarding tiles that are unsuitable from the comparison; wherein identifying suitable and unsuitable tiles in a particular image at a particular resolution comprises identifying tiles that have more than a threshold level of black pixels or tiles that have more than a threshold level of white pixels as unsuitable. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A non-transitory machine readable medium of a mobile device, the machine readable medium storing a program that when executed by at least one processing unit aligns and composites a plurality of images, the program comprising sets of instructions for:
at each particular resolution of a plurality of resolutions; generating a bitmap at the particular resolution for each image in the pair of images; tiling one of the pair of bitmaps if when the particular resolution is one of a subset of the resolutions; discarding any tile that is not suitable for comparison with portions of the other bitmap, wherein identifying tiles that are not suitable at the particular resolution comprises identifying tiles that have more than a threshold level of black pixels or tiles that have more than a threshold level of white pixels as unsuitable; and finding an offset that aligns the pair of images at that the particular resolution (i) by using any non-discarded tiles, and (ii) when the particular resolution is not the lowest resolution, by using an offset that aligns the images at a lower resolution. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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18. A mobile device, comprising:
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a) a camera for capturing a plurality of images; b) at least one processing unit; c) a machine readable medium storing an alignment module that when executed by the at least one processing unit aligns the plurality of images, the alignment module comprising sets of instructions for; defining a plurality of different pairs of images at a plurality of different resolutions, wherein the plurality of different pairs of images is associated with a plurality of different pairs of bitmaps, and each particular bitmap is a bitmap of a particular original image at a particular resolution; and hierarchically aligning the pair of original images by first aligning the pair of images at the lowest resolution and then aligning each pair of images at each higher resolution based on the alignments at the pair of images at the lower resolutions, the hierarchically aligning comprising, for each particular resolution in a subset of resolutions; for at least one particular image at the particular resolution, dividing the particular image into a plurality of tiles for use in identifying corresponding portions in the other image in the pair at the particular resolution; and comparing the pair of images by using tiles that are suitable for the comparison while discarding tiles that are unsuitable from the comparison; wherein identifying suitable and unsuitable tiles in a particular image at a particular resolution comprises identifying tiles that have more than a threshold level of black pixels or tiles that have more than a threshold level of white pixels as unsuitable; and compositing the aligned pair of original images to produce a high dynamic range image. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27)
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Specification