Speckle reduction in optical coherence tomography images
AssigneesAgency for Science, Technology and Research, Topcon Corporation
InventorsJun Cheng, Jiang Liu, Wing Kee Damon Wong, Masahiro Akiba
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Abstract
An optical coherence tomography (OCT) image composed of a plurality of A-scans of a structure is analyzed by defining, for each A-scan, a set of neighboring A-scans surrounding the A-slices scan. Following an optional de-noising step, the neighboring A-scans are aligned in the imaging direction, then a matrix X is formed from the aligned A-scans, and matrix completion is performed to obtain a reduced speckle noise image.
Claims11
A computer-implemented method of enhancing an optical coherence tomography (OCT) image composed of a plurality of A-scans, each A-scan being indicative of a structure imaged in a predefined direction, the A-scans being grouped as one or more B-scans, the method comprising, for each A-scan:
- (a) defining a respective neighborhood comprising a set of A-scans surrounding said each A-scan, the set of A-scans forming a two-dimensional as viewed in the predefined direction;
- (b) aligning the set of A-scans in the respective neighborhood to said each A-scan of the respective neighborhood;
- (c) using the aligned A-scans to form a first matrix X, respective columns of the first matrix X being the aligned A-scans;
- and
- (d) seeking a second matrix which minimizes a cost function indicative of the difference between the first matrix X and the second matrix, the second matrix being constrained to obey a complexity constraint.
A computer system comprising a processor and a memory device configured to store program instructions operative, when performed by the processor, to cause the processor to perform a method of enhancing an optical coherence tomography (OCT) image composed of a plurality of A-scans, each A-scan being indicative of a structure imaged in a predefined direction, the A-scans being grouped as one or more B-scans, the method comprising, for each A-scan:
- (a) defining a respective neighborhood comprising a set of A-scans surrounding said each A-scan, the set of A-scans forming a two-dimensional array as viewed in the predefined direction;
- (b) aligning the set of A-scans the respective neighborhood to said each A-scan of the respective neighborhood;
- (c) using the aligned A-scans to form a first matrix X, respective columns of the first matrix X being the aligned A-scans;
- and
- (d) seeking a second matrix which minimizes a cost function indicative of the difference between the first matrix X and the second matrix, the second matrix being constrained to obey a complexity constraint.
A non-transitory computer program product, storing program instructions operative, when performed by a processor, to cause the processor to perform a method of enhancing an optical coherence tomography (OCT) image composed of a plurality of A-scans, each A-scan being indicative of a structure imaged in a predefined direction, the A-scans being grouped as one or more B-scans, the method comprising, for each A-scan:
- (a) defining a respective neighborhood comprising of a set of A-scans surrounding said each A-scan, the set of A-scans forming a two-dimensional array as viewed in the predefined direction;
- (b) aligning the set of A-scans in the respective neighborhood to said each A-scan of the respective neighborhood;
- (c) using the aligned A-scans to form a first matrix X, respective columns of the first matrix X being the aligned A-scans;
- and
- (d) seeking a second matrix which minimizes a cost function indicative of the difference between the first matrix X and the second matrix, the second matrix being constrained to obey a complexity constraint.
Dependencies are inferred from the claim text.