Patent AU-2019202426-B2 (AU)
Title: OCT Image Processing
Inventor: FLEMING ALAN DUNCAN
IPC: A61B3/10
Filed: 2019-04-08
Granted: 2020-02-13
Abstract: Abstract There is provided an apparatus (100-1) for rendering optical coherence tomography, OCT, 5 retinal image data, which has been acquired by an OCT scanner scanning a retina of an eye over a range of scan locations, wherein each of the scan locations is associated with a respective coordinate in a first coordinate system, and each pixel of the rendered OCT retinal image data is associated with a respective coordinate in a second coordinate system that is different from the first coordinate system. The apparatus comprises a 10 communication module (110) arranged to receive the OCT retinal image data acquired by the OCT scanner, and a coordinate-determining module (120-1) arranged to determine values of coordinates in the second coordinate system of pixels in the received OCT retinal image using a transformation from coordinates in the first coordinate system to coordinates in the second coordinate system. The apparatus further comprises an 15 interpolation module (130-1) arranged to interpolate between values of the pixels at the determined values of coordinates in the second coordinate system to calculate values of the pixels of the rendered OCT retinal image data. Fig. 1. Input OCT Rendered OCT retinal image data retinal image data -110 Communication module Coordinate 130-1 120-1 determining module Interpolation module 100-1 Fig. 1 Working 230 Memory Processor I/F Instruction Store 2 j Fig. 2 Start Receive the OCT retinal image data acquired S10 by the OCT scanner Determine coordinates in the second coordinate system of pixels in the received OCT retinal image using a transformation S20 between coordinates in the first coordinate system and coordinates in the second coordinate system Interpolate between values of the pixels at the determined coordinates in the second S30 coordinate system to calculate values of the pixels of the rendered OCT retinal image data Stop Fig. 3 Determine coordinates in the second coordinate system of pixels in the received OCT retinal image using a transformation S20 between coordinates in the first coordinate system and coordinates in the second coordinate system Select first pixel Determine H, V and D values of pixel Convert the determined H, V and D values S23 associated with the pixel to coordinates in a first coordinate system Convert coordinates of pixel in the first S24 coordinate system into corresponding coordinates in a second coordinate system Seec nxtpiel No Have all pixels Select next pixel been processed? Yes Return Fig. 4 Input OCT Rendered OCT retinal image data retinal image data Communication module Coordinate 130-2 120 determining module Interpolation module 100-2 Fig. 5 ::Sta rtD Receive the OCT retinal image data acquired 510 by the OCT scanner Determine coordinates in the second coordinate system of pixels in the received S20 OCT retinal image using a transformation between coordinates in the first coordinate system and coordinates in the second coordinate system Interpolate between the determined S40 coordinates in the second coordinate system to calculate coordinates of the pixels in the pixel array in the first coordinate system Use the calculated coordinates of the pixels of the pixel array in the first S50 coordinate system to interpolate between values of the pixels of the received OCT retinal image data to calculate values of the pixels in the pixel array Stop Fig. 6 Input OCT Rendered OCT retinal image data retinal image data J, 110 Communication module Coordinate 130-1 120-3 determining module Interpolation module 100-3 Fig. 7 Determine coordinates in the second coordinate system of pixels in the received 520' OCT retinal image using a transformation between coordinates in the first coordinate system and coordinates in the second coordinate system Select a subset of pixels in the received OCT S21' retinal image data that are distributed substantially uniformly in the received OCT retinal image data Determine, for each pixel of the subset pixels, a respective coordinate in the second S22' coordinate system using the transformation between the coordinates in the first coordinate system and the coordinates in the second coordinate system Use the determined coordinates of pixels of the subset of pixels in the second coordinate 523' system to determine parameters of a parameterised mapping between coordinates in the first coordinate system and coordinates in the second coordinate system Use the parameterised mapping with the determined parameters to determine S24' coordinates in the second coordinate system of pixels in the received OCT retinal image data Return Fig. 8 InputOCT Rendered OCT retinal image data retinal image data Communication module Coordinate 130-4 120-4 determining module Interpolation module 100-4 Fig. 9 Start Receive the OCT retinal image data acquired S10 by the OCT scanner Determine, for each pixel of the pixel array, a respective coordinate in the first coordinate S60 system using a transformation between coordinates in the first coordinate system and coordinates in the second coordinate system Calculate values of the pixels of the pixel array by using the determined coordinates in S70 the first coordinate system to interpolate between values of pixels of the received OCT retinal image data Stop Fig. 10