Generation of dewarped OCT B-scan images

A non-transitory storage medium storing computer-readable instructions which, when executed by a processor, cause the processor to perform a method of generating a look-up table for constructing a dewarped B-scan image from A-scans of a cropped part of a sequence of A-scans acquired by an optical coherence tomography, OCT, imaging apparatus, wherein the look-up table associates each of a plurality of pixel arrays that are to form the dewarped B-scan image with a respective one of the A-scans in the cropped part of the sequence of A-scans, the method comprising:

• receiving an indication of a spatial distribution of scan locations of the A-scans acquired by the OCT imaging apparatus;
• receiving cropping information in accordance with which the cropped part of the sequence of A-scans is cropped from the sequence of A-scans acquired by the OCT imaging apparatus;
• using the received indication to determine a dewarp function for selecting, from among the A-scans acquired by the OCT imaging apparatus, A-scans that have been acquired at substantially uniformly spaced scan locations;
• and
• generating the look-up table by:
• using the determined dewarp function and the received cropping information to select, for each of the pixel arrays, a respective A-scan from the A-scans in the sequence of A-scans, such that the selected A-scans are selected from the cropped part of the sequence of A-scans and have scan locations that are substantially uniformly spaced;
• and
• storing, for each of the pixel arrays, a respective pixel array identifier of the pixel array in association with a respective A-scan identifier of the selected A-scan.

An apparatus configured to generate a look-up table for constructing a dewarped B-scan image from A-scans of a cropped part of a sequence of A-scans acquired by an optical coherence tomography, OCT, imaging apparatus, wherein the look-up table associates each of a plurality of pixel arrays that are to form the dewarped B-scan image with a respective one of the A-scans in the cropped part of the sequence of A-scans, the apparatus comprising:

• a receiver module configured to receive:
• an indication of a spatial distribution of scan locations of the A-scans acquired by the OCT imaging apparatus;
• and
• cropping information in accordance with which the cropped part of the sequence of A-scans is cropped from the sequence of A-scans acquired by the OCT imaging apparatus;
• a dewarp function generator module configured to use the received indication to determine a dewarp function for selecting, from among the A-scans acquired by the OCT imaging apparatus, A-scans that have been acquired at substantially uniformly spaced scan locations;
• and
• a look-up table generator module configured to generate the look-up table by:
• using the determined dewarp function and the received cropping information to select, for each of the pixel arrays, a respective A-scan from the A-scans in the sequence of A-scans, such that the selected A-scans are selected from the cropped part of the sequence of A-scans and have scan locations that are substantially uniformly spaced;
• and
• storing in a memory, for each pixel array of the pixel arrays, a respective pixel array identifier of the pixel array in association with a respective A-scan identifier of the selected A-scan.