Abstract: A displacement field relating positions of pixels between at least two images having an initial displacement field is adjusted. Each pixel of the first image and the second image is associated with a label. A first pixel in the first image maps to a second pixel in the second image based on a vector of the initial displacement field. A set of third pixels includes the second pixel and a plurality of adjacent pixels to the second pixel, the third pixels being associated with labels and a candidate shift vector with respect to the second pixel. A covariance score is determined for each of the third pixels, the covariance score defining a statistical dependence between the first label of the first pixel and each of the third labels. An adjustment shift vector is then determined based on the covariance scores and the candidate shift vectors of the third pixels.

Abstract: A method determining a retinal pigment epithelium identifies a plurality of regions using captured image data of the eye and fits a curve into at least some of the regions. A curve score is determined associated with the fitted curve using at least a distance between the fitted curve and at least some of the regions in which a contribution of the regions to the curve score is biased towards (asymmetric) regions below the fitted curve. These steps are repeated whereupon one of the fitted curves is selected, using the corresponding associated curve score, for classifying some of the regions as forming at least a part of a retinal pigment epithelium.

Abstract: A method of compensating for distortion, in a plurality of retinal image frames, arising from eye movement receives at least one reference image frame and plural other image frames of the eye. For each frame, the method determines a plurality of shifts relative to the reference image frame, and an initial eye movement trajectory based on at least an initial reference frame distortion, and the shifts within each of said other image frames. The method estimates a current reference frame distortion using the initial trajectory and the shifts within each of the other image frames, and a current eye movement trajectory based on the estimated current reference frame distortion, and the shifts within each of said other image frames to provide a smooth transition between the other image frames in the eye movement. With this the method compensates for distortion in said frames using the current eye movement trajectory.

Abstract: A displacement field relating positions of pixels between at least two images having an initial displacement field is adjusted. Each pixel of the first image and the second image is associated with a label. A first pixel in the first image maps to a second pixel in the second image based on a vector of the initial displacement field. A set of third pixels includes the second pixel and a plurality of adjacent pixels to the second pixel, the third pixels being associated with labels and a candidate shift vector with respect to the second pixel. A covariance score is determined for each of the third pixels, the covariance score defining a statistical dependence between the first label of the first pixel and each of the third labels. An adjustment shift vector is then determined based on the covariance scores and the candidate shift vectors of the third pixels.

Abstract: A computer-implementable method of analyzing tissues of a retina. A polarization-sensitive (PS-OCT) image data set of the retina is received from a polarization-sensitive device, each element in the polarization-sensitive image data set being associated with an intensity value ({I1, . . . , IL}) and a polarization direction ({P1, . . . , PL}). A likelihood score is determined for each element of the polarization-sensitive image data set based on the intensity value of the element and a degree of divergence (?*TP or D2) of the polarization direction associated with the element from a reference polarization direction (?*) associated with the polarization sensitive image data set, wherein the likelihood score indicates whether said element is drawn from a directionally polarized distribution or a depolarizing distribution, Elements of the polarization-sensitive image data set are classified using the determined likelihood scores to analyze tissues of the retina.

Abstract: A method of determining a coordinate transform between a first image and a second image, said method comprising the steps of: determining a rate of change of pixel values for locations on the first image to identify candidate alignment patches in the first image; specifying subsets of patches from the set of candidate alignment patches based on an error metric, selecting a subset of candidate alignment patches from said plurality of subsets of candidate alignment patches based upon a predetermined criterion; estimating, for each patch in the selected subset, a shift between the patch and a corresponding patch in the second image, the location of the corresponding patch in the second image being determined from the location of the patch in the first image; and determining the coordinate transform between the first image and second image based on the estimated shifts.

Abstract: A method calibrates a microscope using a test pattern by capturing a plurality of images of the test pattern with the microscope. The test pattern has a plurality of uniquely identifiable positions across a plurality of repeating and overlapping 2D sub-patterns. The method determines an image contrast metric from the captured image in a selected patch of the test pattern and a reference contrast metric in the corresponding region; and (iii) determines a normalised contrast metric using the reference contrast metric and the image contrast metric. The method estimates depths of the two captured images at the plurality of positions using the normalised contrast metrics and a set of predetermined calibration data for a stack of images captured using the test pattern at a range of depths, and calibrates the microscope using a comparison of the determined depth estimates for the at least two images.

Abstract: A method of compensating for distortion, in a plurality of retinal image frames, arising from eye movement receives at least one reference image frame and plural other image frames of the eye. For each frame, the method determines a plurality of shifts relative to the reference image frame, and an initial eye movement trajectory based on at least an initial reference frame distortion, and the shifts within each of said other image frames. The method estimates a current reference frame distortion using the initial trajectory and the shifts within each of the other image frames, and a current eye movement trajectory based on the estimated current reference frame distortion, and the shifts within each of said other image frames to provide a smooth transition between the other image frames in the eye movement. With this the method compensates for distortion in said frames using the current eye movement trajectory.

Abstract: A method of demodulating an image captured from an imaging system having at least one two-dimensional grating. The captured image comprises a phase modulated fringe pattern comprising cross-term phase components resulting from presence of the at least one two-dimensional grating. The method determines parameters of at least a first non-linear transformation for attenuating the cross-term phase components. The parameters of the first non-linear transformation are determined for the imaging system to reduce artefacts in a demodulated image introduced by the cross-term phase components. The method demodulates the captured image by applying at least the first non-linear transformation with the determined parameters to the captured image to attenuate the cross-term phase components.

Abstract: A method determining a retinal pigment epithelium identifies a plurality of regions using captured image data of the eye and fits a curve into at least some of the regions. A curve score is determined associated with the fitted curve using at least a distance between the fitted curve and at least some of the regions in which a contribution of the regions to the curve score is biased towards (asymmetric) regions below the fitted curve. These steps are repeated whereupon one of the fitted curves is selected, using the corresponding associated curve score, for classifying some of the regions as forming at least a part of a retinal pigment epithelium.

Abstract: A method of determining a coordinate transform between a first image and a second image, said method comprising the steps of: determining a rate of change of pixel values for locations on the first image to identify candidate alignment patches in the first image; specifying subsets of patches from the set of candidate alignment patches based on an error metric, selecting a subset of candidate alignment patches from said plurality of subsets of candidate alignment patches based upon a predetermined criterion; estimating, for each patch in the selected subset, a shift between the patch and a corresponding patch in the second image, the location of the corresponding patch in the second image being determined from the location of the patch in the first image; and determining the coordinate transform between the first image and second image based on the estimated shifts.