Abstract: Embodiments provide image display systems and methods for a camera calibration using a two-sided diffractive optical element (DOE). More specifically, embodiments are directed to determining intrinsic parameters of a camera using a single image obtained using a two-sided DOE. The two-sided DOE has a first pattern on a first surface and a second pattern on a second surface. Each of the first and second patterns may be formed by repeating sub-patterns that are lined when tiled on each surface. The patterns on the two-sided DOE are formed such that the brightness of the central intensity peak on the image of the image pattern formed by the DOE is reduced to a predetermined amount.

Abstract: The systems and methods described can include approaches to calibrate head-mounted displays for improved viewing experiences. Some methods include receiving data of a first target image associated with an undeformed state of a first eyepiece of a head-mounted display device; receiving data of a first captured image associated with deformed state of the first eyepiece of the head-mounted display device; determining a first transformation that maps the first captured image to the image; and applying the first transformation to a subsequent image for viewing on the first eyepiece of the head-mounted display device.

Abstract: Embodiments provide image display systems and methods for one or more camera calibration using a two-sided diffractive optical element (DOE). More specifically, embodiments are directed to determining intrinsic parameters of one or more cameras using a single image obtained using a two-sided DOE. The two-sided DOE has a first pattern on a first surface and a second pattern on a second surface. Each of the first and second patterns may be formed by repeating sub-patterns that are lined when tiled on each surface. The patterns on the two-sided DOE are formed such that the brightness of the central intensity peak on the image of the image pattern formed by the DOE is reduced to a predetermined amount.

Abstract: The systems and methods described can include approaches to calibrate head-mounted displays for improved viewing experiences. Some methods include receiving data of a first target image associated with an undeformed state of a first eyepiece of a head-mounted display device; receiving data of a first captured image associated with deformed state of the first eyepiece of the head-mounted display device; determining a first transformation that maps the first captured image to the image; and applying the first transformation to a subsequent image for viewing on the first eyepiece of the head-mounted display device.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for calibrating an augmented reality device using camera and inertial measurement unit data. In some implementations, a bundle adjustment process jointly optimizes or estimates states of the augmented reality device. The process can use, as input, visual and inertial measurements as well as factory-calibrated sensor extrinsic parameters. The process performs bundle adjustment and uses non-linear optimization of estimated states constrained by the measurements and the factory calibrated extrinsic parameters. The process can jointly optimize inertial constraints, IMU calibration, and camera calibrations. Output of the process can include most likely estimated states, such as data for a 3D map of an environment, a trajectory of the device, and/or updated extrinsic parameters of the visual and inertial sensors (e.g., cameras and IMUs).

Abstract: Multiple cameras are coupled to a camera rig. Multiple diffractive optical elements (DOEs) are coupled to a DOE prop. Each camera is positioned in an eye box of a DOE and takes an image when the cameras are positioned at a first position, a second position and a third position relative to the DOEs. Three images taken by a each camera at each one of the first position, the second position and third position. The images are transmitted to a processor coupled to the camera rig. For each image, the processor identifies data pairs, each data pair including pixel coordinates of an intensity peak in the image and virtual light source produced by the diffractive optical element that corresponds to the intensity peak, and determines extrinsic parameters of the cameras using the identified data pairs for each image.

Abstract: A method for calibrating a wearable device includes displaying an image with a plurality of pixels for each of three primary colors using the wearable device, and determining RGB and XYZ values for each of the plurality of pixels. The method includes selecting a subset of the plurality of pixels to form a group of grid points, and dividing the image into a group of tile regions, with each tile region including a grid point. Grid XYZ values are determined for each grid point, based on averaging XYZ values of all pixels in a corresponding tile region, and a grid RGB-to-XYZ conversion matrix is determined for each grid point. The method also includes determining a correction matrix for each grid point by multiplying an inverse of the grid RGB-to-XYZ conversion matrix for the grid with an sRGB-to-XYZ conversion matrix.

Abstract: The systems and methods described can include approaches to calibrate head-mounted displays for improved viewing experiences. Some methods include receiving data of a first target image associated with an undeformed state of a first eyepiece of a head-mounted display device; receiving data of a first captured image associated with deformed state of the first eyepiece of the head-mounted display device; determining a first transformation that maps the first captured image to the image; and applying the first transformation to a subsequent image for viewing on the first eyepiece of the head-mounted display device.

Abstract: Techniques are described for calibrating a device having a first sensor and a second sensor. Techniques include capturing sensor data using the first sensor and the second sensor. The device maintains a calibration profile including a translation parameter and a rotation parameter to model a spatial relationship between the first sensor and the second sensor. Techniques include determining a calibration level associated with the calibration profile at a first time. Techniques include determining, based on the calibration level, to perform a calibration process. Techniques include performing the calibration process at the first time by generating one or both of a calibrated translation parameter and a calibrated rotation parameter and replacing one or both of the translation parameter and the rotation parameter with one or both of the calibrated translation parameter and the calibrated rotation parameter.

Abstract: Embodiments provide image display systems and methods for one or more camera calibration using a two-sided diffractive optical element (DOE). More specifically, embodiments are directed to determining intrinsic parameters of one or more cameras using a single image obtained using a two-sided DOE. The two-sided DOE has a first pattern on a first surface and a second pattern on a second surface. Each of the first and second patterns may be formed by repeating sub-patterns that are lined when tiled on each surface. The patterns on the two-sided DOE are formed such that the brightness of the central intensity peak on the image of the image pattern formed by the DOE is reduced to a predetermined amount.

Abstract: The systems and methods described can include approaches to calibrate head-mounted displays for improved viewing experiences. Some methods include receiving data of a first target image associated with an undeformed state of a first eyepiece of a head-mounted display device; receiving data of a first captured image associated with deformed state of the first eyepiece of the head-mounted display device; determining a first transformation that maps the first captured image to the image; and applying the first transformation to a subsequent image for viewing on the first eyepiece of the head-mounted display device.

Abstract: The systems and methods described can include approaches to calibrate head-mounted displays for improved viewing experiences. Some methods include receiving data of a first target image associated with an undeformed state of a first eyepiece of a head-mounted display device; receiving data of a first captured image associated with deformed state of the first eyepiece of the head-mounted display device; determining a first transformation that maps the first captured image to the image; and applying the first transformation to a subsequent image for viewing on the first eyepiece of the head-mounted display device.

Abstract: A method for characterizing a digital color camera includes, for each of three primary colors used in a field sequential color virtual image, determining a conversion model for each color using RGB values and the color-measurement values. For each primary color, the method includes illuminating a display device using an input light beam of a primary color having spectral properties representative of a light beam in a virtual image in a wearable device. The method includes capturing, with the digital color camera, an image of the display device, and determining, from the image, RGB values for each primary color. The method includes capturing, with a color-measurement device, a color-measurement value associated with each corresponding primary color at the display device, thereby acquiring a color-measurement value in an absolute color space. A conversion model for each color is determined using RGB values and the color-measurement values.

Abstract: Multiple cameras are coupled to a camera rig. Multiple diffractive optical elements (DOEs) are coupled to a DOE prop. Each camera is positioned in an eye box of a DOE and takes an image when the cameras are positioned at a first position, a second position and a third position relative to the DOEs. Three images taken by a each camera at each one of the first position, the second position and third position. The images are transmitted to a processor coupled to the camera rig. For each image, the processor identifies data pairs, each data pair including pixel coordinates of an intensity peak in the image and virtual light source produced by the diffractive optical element that corresponds to the intensity peak, and determines extrinsic parameters of the cameras using the identified data pairs for each image.

Abstract: Techniques are described for calibrating a device having a first sensor and a second sensor. Techniques include capturing sensor data using the first sensor and the second sensor. The device maintains a calibration profile including a translation parameter and a rotation parameter to model a spatial relationship between the first sensor and the second sensor. Techniques include determining a calibration level associated with the calibration profile at a first time. Techniques include determining, based on the calibration level, to perform a calibration process. Techniques include performing the calibration process at the first time by generating one or both of a calibrated translation parameter and a calibrated rotation parameter and replacing one or both of the translation parameter and the rotation parameter with one or both of the calibrated translation parameter and the calibrated rotation parameter.

Abstract: Multiple cameras are coupled to a camera rig. Multiple diffractive optical elements (DOEs) are coupled to a DOE prop. Each camera is positioned in an eye box of a DOE and takes an image when the cameras are positioned at a first position, a second position and a third position relative to the DOEs. Three images taken by a each camera at each one of the first position, the second position and third position. The images are transmitted to a processor coupled to the camera rig. For each image, the processor identifies data pairs, each data pair including pixel coordinates of an intensity peak in the image and virtual light source produced by the diffractive optical element that corresponds to the intensity peak, and determines extrinsic parameters of the cameras using the identified data pairs for each image.

Abstract: A method for calibrating a device having a first sensor and a second sensor. The method includes capturing sensor data using the first sensor and the second sensor. The device maintains a calibration profile including a translation parameter and a rotation parameter to model a spatial relationship between the first sensor and the second sensor. The method also includes determining a calibration level associated with the calibration profile at a first time. The method further includes determining, based on the calibration level, to perform a calibration process. The method further includes performing the calibration process at the first time by generating one or both of a calibrated translation parameter and a calibrated rotation parameter and replacing one or both of the translation parameter and the rotation parameter with one or both of the calibrated translation parameter and the calibrated rotation parameter.

Abstract: A method for calibrating a wearable device includes displaying an image with a plurality of pixels for each of three primary colors using the wearable device, and determining RGB and XYZ values for each of the plurality of pixels. The method includes selecting a subset of the plurality of pixels to form a group of grid points, and dividing the image into a group of tile regions, with each tile region including a grid point. Grid XYZ values are determined for each grid point, based on averaging XYZ values of all pixels in a corresponding tile region, and a grid RGB-to-XYZ conversion matrix is determined for each grid point. The method also includes determining a correction matrix for each grid point by multiplying an inverse of the grid RGB-to-XYZ conversion matrix for the grid with an sRGB-to-XYZ conversion matrix.

Abstract: A method for calibrating a device having a first sensor and a second sensor. The method includes capturing sensor data using the first sensor and the second sensor. The device maintains a calibration profile including a translation parameter and a rotation parameter to model a spatial relationship between the first sensor and the second sensor. The method also includes determining a calibration level associated with the calibration profile at a first time. The method further includes determining, based on the calibration level, to perform a calibration process. The method further includes performing the calibration process at the first time by generating one or both of a calibrated translation parameter and a calibrated rotation parameter and replacing one or both of the translation parameter and the rotation parameter with one or both of the calibrated translation parameter and the calibrated rotation parameter.

Abstract: Multiple cameras are coupled to a camera rig. Multiple diffractive optical elements (DOEs) are coupled to a DOE prop. Each camera is positioned in an eye box of a DOE and takes an image when the cameras are positioned at a first position, a second position and a third position relative to the DOEs. Three images taken by a each camera at each one of the first position, the second position and third position. The images are transmitted to a processor coupled to the camera rig. For each image, the processor identifies data pairs, each data pair including pixel coordinates of an intensity peak in the image and virtual light source produced by the diffractive optical element that corresponds to the intensity peak, and determines extrinsic parameters of the cameras using the identified data pairs for each image.