Abstract: The present disclosure is directed to a system for calibrating cameras with a fixed focal point. In particular, a camera calibration system comprising one or more computing devices can project a plurality of fiducial markers on a target surface using the plurality of collimators. The camera calibration system can capture, using the camera, a plurality of images of the target surface with the camera, wherein the camera is rotated between each captured image in the plurality of images. The camera calibration system can compare the plurality of images with a ground truth projection. The camera calibration system can generate calibration data based on the comparison of the plurality of images with the ground truth projection. The camera calibration system can store the calibration data for use in rectifying the camera.

Abstract: The present disclosure is directed to a system for calibrating cameras with a fixed focal point. In particular, a camera calibration system comprising one or more computing devices can project a plurality of fiducial markers on a target surface using the plurality of collimators. The camera calibration system can capture, using the camera, a plurality of images of the target surface with the camera, wherein the camera is rotated between each captured image in the plurality of images. The camera calibration system can compare the plurality of images with a ground truth projection. The camera calibration system can generate calibration data based on the comparison of the plurality of images with the ground truth projection. The camera calibration system can store the calibration data for use in rectifying the camera.

Abstract: A method of detecting sensor obstructions in a computing device includes: at an emitter, emitting a beam of light through a scan window toward a treaded surface; at an image sensor, for a sequence of positions of the computing device along the treaded surface: capturing a sequence of images corresponding to the sequence of positions, each image in the sequence having a first region and a second region; wherein the first regions depict a first subset of reflections of the beam of light originating from a first depth range; and wherein the second regions depict a second subset of the reflections originating from a second depth range; at a controller: receiving the sequence of images; determining, based on the second regions, whether an intensity of the second subset of the reflections exceeds a occlusion threshold; and when the determination is affirmative, generating an alert indicating obstruction of the scan window.

Abstract: A device for measuring tread depth includes: an image sensor; first and second depth sensing modules spaced apart along a separation axis, each including (i) an emitter configured to emit a beam of light, and (ii) an optical assembly configured to direct reflections of the beam of light onto a respective region of the image sensor; a controller connected to the image sensor and configured, responsive to the device traversing a treaded surface, to: receive, from the image sensor, a sequence of images corresponding to sequential positions of the device traversing the treaded surface in a travel direction substantially perpendicular to the separation axis, the sequence of images depicting successive reflections of the beams from the treaded surface; determine, for each image in the sequence of images, a first depth measurement and a second depth measurement; and store, in a memory, the first and second depth measurements.

Abstract: A method of detecting sensor obstructions in a computing device includes: at an emitter, emitting a beam of light through a scan window toward a treaded surface; at an image sensor, for a sequence of positions of the computing device along the treaded surface: capturing a sequence of images corresponding to the sequence of positions, each image in the sequence having a first region and a second region; wherein the first regions depict a first subset of reflections of the beam of light originating from a first depth range; and wherein the second regions depict a second subset of the reflections originating from a second depth range; at a controller: receiving the sequence of images; determining, based on the second regions, whether an intensity of the second subset of the reflections exceeds a occlusion threshold; and when the determination is affirmative, generating an alert indicating obstruction of the scan window.

Abstract: A device for measuring tread depth includes: an image sensor; first and second depth sensing modules spaced apart along a separation axis, each including (i) an emitter configured to emit a beam of light, and (ii) an optical assembly configured to direct reflections of the beam of light onto a respective region of the image sensor; a controller connected to the image sensor and configured, responsive to the device traversing a treaded surface, to: receive, from the image sensor, a sequence of images corresponding to sequential positions of the device traversing the treaded surface in a travel direction substantially perpendicular to the separation axis, the sequence of images depicting successive reflections of the beams from the treaded surface; determine, for each image in the sequence of images, a first depth measurement and a second depth measurement; and store, in a memory, the first and second depth measurements.

Abstract: An interferometric imaging apparatus utilizes a split spectrum and/or frequency filtering process for generating fundus images. According to the split spectrum process, a bandwidth of a light source is divided into sub-spectrums of light, each used to generate pixel data for the fundus image. Data capture can thus be increased by a factor corresponding to the number of sub-spectrums. According to the frequency filtering process, a frequency filter associated with a depth of interest selectively retains data corresponding to that depth.

Abstract: Optical coherence tomography light sources can be non-linear and attempts to linearize them can lead to asynchrony between the light source and A-line scans and missampling in the scans causing signal noise. Accordingly, a system and methods are provided herein to detect missampling by obtaining a plurality of interferograms; providing at least two wavenumber reference signals at different wavenumbers, wherein the wavenumber reference signals comprise attenuated or enhanced portions of each of the plurality of interferograms; aligning each of the plurality of interferograms according to one of the at least two wavenumber reference signals; and for each of the plurality of interferograms, identifying an interferogram as missampled if another of the at least two reference signals does not align with a corresponding reference signal in a statistically significant number of the plurality of interferograms. An optical element, for example, an optical notch, may be used to generate the reference signals.

Abstract: An embodiment provides a method for setting the characteristics of the light to be output from a light source unit for optical coherence tomography, using a computer. This method is performed by using relation information in which a representative wavelength, a wavelength range including said representative wavelength, and the light loss amount due to absorption by a medium are related to each other. This method includes the following steps: setting each value of a first parameter and a second parameter among the representative wavelength, the wavelength range, and the light loss amount; acquiring a value of a third parameter among the representative wavelength, the wavelength range, and the light loss amount other than said first parameter and said second parameter based on the set two values and said relation information; and outputting a value of said acquired third parameter.

Abstract: An image measuring method according to an embodiment comprises a clock generating step, a noise reducing step, a data acquisition step, a digital data generating step and an image data generating step. In the clock generating step, clock signals are generated. In the noise reducing step, the noise of the generated clock signals is reduced to a predetermined threshold or lower. In the data acquisition step, analog data indicating the inner morphology of an object is acquired. In the digital data generating step, digital data is generated by sampling the analog data based on the clock signals with reduced noise. In the image data generating step, image data of the object is generated by performing data processing including Fourier transform on the generated digital data.

Abstract: Optical coherence tomography light sources can be non-linear and attempts to linearize them can lead to asynchrony between the light source and A-line scans and missampling in the scans causing signal noise. Accordingly, a system and methods are provided herein to detect missampling by obtaining a plurality of interferograms; providing at least two wavenumber reference signals at different wavenumbers, wherein the wavenumber reference signals comprise attenuated or enhanced portions of each of the plurality of interferograms; aligning each of the plurality of interferograms according to one of the at least two wavenumber reference signals; and for each of the plurality of interferograms, identifying an interferogram as missampled if another of the at least two reference signals does not align with a corresponding reference signal in a statistically significant number of the plurality of interferograms. An optical element, for example, an optical notch, may be used to generate the reference signals.

Abstract: An optical imaging method in an embodiment includes: a scanning step to scan each of a plurality of A-lines of an object with a signal light while alternately changing the phase difference between the signal light and a reference light to two preset phase differences; a detection step to detect the interference light of the signal light passing through the A-line and the reference light; and an imaging step to generate a complex interference spectrum based on the detection results of the interference lights corresponding to the plurality of A-lines sequentially obtained in the detection step according to the scanning, and form, based on the complex interference spectrum, the tomographic image along the arrangement of the plurality of A-lines in which a complex conjugate artifact is substantially removed.

Abstract: [Problem] Image artifacts caused by noises in clock signals are suppressed. [Solution] An image measuring method according to an embodiment comprises a clock generating step, a noise reducing step, a data acquisition step, a digital data generating step and an image data generating step. In the clock generating step, clock signals are generated. In the noise reducing step, the noise of the generated clock signals is reduced to a predetermined threshold or lower. In the data acquisition step, analog data indicating the inner morphology of an object is acquired. In the digital data generating step, digital data is generated by sampling the analog data based on the clock signals with reduced noise. In the image data generating step, image data of the object is generated by performing data processing including Fourier transform on the generated digital data.

Abstract: An embodiment provides a method for setting the characteristics of the light to be output from a light source unit for optical coherence tomography, using a computer. This method is performed by using relation information in which a representative wavelength, a wavelength range including said representative wavelength, and the light loss amount due to absorption by a medium are related to each other. This method includes the following steps: setting each value of a first parameter and a second parameter among the representative wavelength, the wavelength range, and the light loss amount; acquiring a value of a third parameter among the representative wavelength, the wavelength range, and the light loss amount other than said first parameter and said second parameter based on the set two values and said relation information; and outputting a value of said acquired third parameter.

Abstract: An optical imaging method is provided that can realize, at low cost, the extension of the imaging depth range. An optical imaging apparatus 400 is an apparatus that forms a tomographic image of an object using FD-OCT, and performs a scanning step, detection step and imaging step. In the scanning step, the object is scanned with a signal light while alternately changing the phase difference between the signal light and a reference light to two preset phase differences. In the detection step, interference light of the signal light passing through the object and the reference light is detected. In the imaging step, a tomographic image of the object is formed based on the detection results of a plurality of the interference lights sequentially obtained in the detection step according to the scanning.

Abstract: An optical imaging method in an embodiment includes: a scanning step to scan each of a plurality of A-lines of an object with a signal light while alternately changing the phase difference between the signal light and a reference light to two preset phase differences; a detection step to detect the interference light of the signal light passing through the A-line and the reference light; and an imaging step to generate a complex interference spectrum based on the detection results of the interference lights corresponding to the plurality of A-lines sequentially obtained in the detection step according to the scanning, and form, based on the complex interference spectrum, the tomographic image along the arrangement of the plurality of A-lines in which a complex conjugate artifact is substantially removed.

Abstract: An optical imaging method is provided that can realize, at low cost, the extension of the imaging depth range. An optical imaging apparatus 400 is an apparatus that forms a tomographic image of an object using FD-OCT, and performs a scanning step, detection step and imaging step. In the scanning step, the object is scanned with a signal light while alternately changing the phase difference between the signal light and a reference light to two preset phase differences. In the detection step, interference light of the signal light passing through the object and the reference light is detected. In the imaging step, a tomographic image of the object is formed based on the detection results of a plurality of the interference lights sequentially obtained in the detection step according to the scanning.