US 12,333,753 B2
Matching local image feature descriptors in image analysis
Ruan Lakemond, Cheltenham (AU); and Timothy Smith, London (GB)
Assigned to Imagination Technologies Limited, Kings Langley (GB)
Filed by Imagination Technologies Limited, Kings Langley (GB)
Filed on Sep. 11, 2023, as Appl. No. 18/244,516.
Application 18/244,516 is a continuation of application No. 17/108,145, filed on Dec. 1, 2020, granted, now 11,756,222, issued on Sep. 12, 2023.
Application 17/108,145 is a continuation of application No. 16/376,003, filed on Apr. 5, 2019, granted, now 10,885,376, issued on Jan. 5, 2021.
Claims priority of application No. 1805688 (GB), filed on Apr. 5, 2018.
Prior Publication US 2024/0029287 A1, Jan. 25, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. G06T 7/593 (2017.01); G06F 18/22 (2023.01); G06T 7/73 (2017.01); G06V 10/44 (2022.01); G06V 10/46 (2022.01); G06V 10/74 (2022.01); G06V 20/10 (2022.01)
CPC G06T 7/593 (2017.01) [G06F 18/22 (2023.01); G06T 7/73 (2017.01); G06V 10/467 (2022.01); G06V 20/10 (2022.01); G06T 2207/20164 (2013.01); G06V 10/443 (2022.01); G06V 10/462 (2022.01); G06V 10/761 (2022.01)] 17 Claims
OG exemplary drawing
 
1. A computer-implemented method of matching features identified in first and second images captured from respective camera viewpoints related by an epipolar geometry, each identified feature being described by a local descriptor, the method comprising:
using the epipolar geometry to derive an epipolar line in the second image corresponding to a first feature in the first image represented by a first local descriptor;
transforming the coordinate system of the second image so as to map the epipolar line to be parallel to one of the coordinate axes of the coordinate system;
using the epipolar line to define a geometrically-constrained region in the second image in the transformed coordinate system corresponding to the first feature in the first image;
comparing the first local descriptor with local descriptors of features in the second image, thereby determining respective measures of similarity between the first feature in the first image and the respective features in the second image; and
identifying, from the measures of similarity between the first feature in the first image and the respective features in the second image, a best match feature to the first feature.