Abstract:
A method of processing a sequence of images of a retina acquired by an ophthalmic device to generate retinal position tracking information indicative of retina movement during acquisition. The method includes (i) receiving one or more images of the retina; (ii) calculating a cross-correlation between a reference image and an image based on the received image(s) to acquire an offset between the image and reference image; and repeating processes (i) and (ii) to acquire, as the tracking information, respective offsets for images that are based on the respective received image(s). Another step includes modifying the reference image during the repeating, by determining a measure of similarity between correspondingly located regions of pixels in two or more received images and accentuating features in the reference image representing structures of the imaged retina in relation to other features in the reference image based on the determined measure of similarity.
Abstract:
A method, apparatus, and computer-readable medium, for assessing image quality of an image produced by a scanning imaging system. The method comprises acquiring (S10) image data of an image produced by the scanning imaging system and calculating (S20 to S40), for each section of the image: a respective first value measuring at least one of sharpness or contrast of at least a part of the section, the measuring depending on noise, a respective second value measuring noise in at least a part of the section, and a respective third value indicating image quality, by combining the first and second values. The combining is such that calculated third values have a weaker dependency on the noise than the first values. The method further comprises determining (S50) a quality score that is indicative of image quality of the image based on a variation of the calculated third values among the sections.
Abstract:
A laser scanning ophthalmoscope obtains images of a retina. An image is processed by (i) mapping an image along a one dimensional slice; (ii) computing a wavelet scalogram of the slice; (iii) mapping ridge features from the wavelet scalogram; repeating steps (i), (ii) and (iii) for one or more mapped image slices. The mapped ridge features from the slices are superimposed. Textural information is derived from the superimposed mapped ridge features. The analysis can be tuned to detect various textural features, for example to detect image artefacts, or for retinal pathology classification.
Abstract:
Aspects of the present invention relate to a method of suppressing a banding artefact in an ophthalmic image of a patient's eye. The method comprises: partitioning the ophthalmic image into a plurality of segments that partially overlap each other, applying an image correction algorithm, which computes a discrete cosine transform of each segment of the plurality of segments to suppress the banding artefact in the plurality of segments removing at least part of the one or more overlapping regions from each segment to remove an artefact introduced by the image correction algorithm to generate a respective corrected segment; and combining the corrected segments to generate a corrected ophthalmic image that comprises less of the banding artefact than the ophthalmic image.
Abstract:
A method, system, and computer-readable medium, for detecting whether an eye blink or non-blink is captured in the image. The method includes filtering, from the image, one or more objects that are predicted to be unsuitable for determining whether an eye blink or no-blink is captured in the image, to provide a filtered image. The method also includes correlating the filtered image with a reference image, and determining, based on the correlating, whether the eye blink or non-blink is captured in the image. The eye blink is a full eye blink or a partial eye blink, and the images may be sequentially captured IR SLO images, in one example embodiment herein. Images determined to include an eye blink can be omitted from inclusion in a final (e.g., OCT) image.
Abstract:
A method, apparatus, and computer-readable medium, for assessing image quality of an image produced by a scanning imaging system. The method comprises acquiring (S10) image data of an image produced by the scanning imaging system and calculating (S20 to S40), for each section of the image: a respective first value measuring at least one of sharpness or contrast of at least a part of the section, the measuring depending on noise, a respective second value measuring noise in at least a part of the section, and a respective third value indicating image quality, by combining the first and second values. The combining is such that calculated third values have a weaker dependency on the noise than the first values. The method further comprises determining (S50) a quality score that is indicative of image quality of the image based on a variation of the calculated third values among the sections.
Abstract:
A method, system, and computer-readable medium, for detecting whether an eye blink or non-blink is captured in the image. The method includes filtering, from the image, one or more objects that are predicted to be unsuitable for determining whether an eye blink or no-blink is captured in the image, to provide a filtered image. The method also includes correlating the filtered image with a reference image, and determining, based on the correlating, whether the eye blink or non-blink is captured in the image. The eye blink is a full eye blink or a partial eye blink, and the images may be sequentially captured IR SLO images, in one example embodiment herein. Images determined to include an eye blink can be omitted from inclusion in a final (e.g., OCT) image.
Abstract:
A method of processing a sequence of images of a retina acquired by an ophthalmic device to generate retinal position tracking information indicative of retina movement during acquisition. The method includes (i) receiving one or more images of the retina; (ii) calculating a cross-correlation between a reference image and an image based on the received image(s) to acquire an offset between the image and reference image; and repeating processes (i) and (ii) to acquire, as the tracking information, respective offsets for images that are based on the respective received image(s). Another step includes modifying the reference image during the repeating, by determining a measure of similarity between correspondingly located regions of pixels in two or more received images and accentuating features in the reference image representing structures of the imaged retina in relation to other features in the reference image based on the determined measure of similarity.
Abstract:
A laser scanning ophthalmoscope obtains images of a retina. An image is processed by (i) mapping an image along a one dimensional slice; (ii) computing a wavelet scalogram of the slice; (iii) mapping ridge features from the wavelet scalogram; repeating steps (i), (ii) and (iii) for one or more mapped image slices. The mapped ridge features from the slices are superimposed. Textural information is derived from the superimposed mapped ridge features. The analysis can be tuned to detect various textural features, for example to detect image artifacts, or for retinal pathology classification.
Abstract:
The present disclosure provides a method of processing an image comprising receiving a measured image, producing a sharpened image by filtering the measured image to increase its sharpness, and transforming the sharpened image using at least one selected geometric transformation. The present disclosure further provides a computer readable media storing program instructions which, when executed, perform the method of processing an image and a system for processing an image comprising a receiving module which receives a measured image, a sharpening module which produces a sharpened image by filtering the measured image to increase its sharpness, and a transformation module which transforms the sharpened image using at least one selected geometric transformation.