Calibration techniques using patterned targets and cameras

Abstract

A method can calibrate an autostereoscopic display. The autostereoscopic display includes a display panel and a parallax-generating optic that can direct light from the display panel to a viewer. The method includes receiving, from a camera fixedly attached to a patterned target having a pattern on the patterned target, a captured image of at least the patterned target as reflected from the autostereoscopic display. The method includes determining, based at least in part on the captured image, at least one calibration parameter that quantifies misalignment between the parallax-generating optic and the display panel. The method includes storing, on a storage medium included with or coupled to the autostereoscopic display, data representing the at least one calibration parameter.

Description

CALIBRATION TECHNIQUES USING PATTERNED TARGETS AND CAMERASCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 648,358, filed May 16, 2024, which is hereby incorporated by reference in its entirety.FIELD OF THE DISCLOSURE

[0002] This document relates generally to display systems, and more specifically relates to autostereoscopic or three-dimensional displays.BACKGROUND OF THE DISCLOSURE

[0003] A stereoscopic display can provide two different views of a three- dimensional image to the two eyes of a viewer. An autostereoscopic display can provide the two different views to the two eyes of the viewer without requiring the viewer to wear special glasses or eyewear. There is ongoing effort to improve autostereoscopic displays and techniques for calibrating autostereoscopic displays.SUMMARY

[0004] In an example of a method for calibrating an autostereoscopic display, the autostereoscopic display including a display panel and a parallax-generating optic configured to direct light from the display panel to a viewer, the method includes: receiving, from a camera fixedly attached to a patterned target having a pattern on the patterned target, a captured image of at least the patterned target as reflected from the autostereoscopic display; determining, based at least in part on the captured image, at least one calibration parameter that quantifies misalignment between the parallaxgenerating optic and the display panel; and storing, on a storage medium included with or coupled to the autostereoscopic display, data representing the at least one calibration parameter.

[0005] In an example of a method for calibrating an autostereoscopic display, the autostereoscopic display including a display panel and a parallax-generating optic configured to direct light from the display panel to a viewer, the method includes: determining, using a viewer tracker of the autostereoscopic display, that a camera is located at a first location; while the camera is at the first location, causing the autostereoscopic display to sequentially display a series of specified display images; while the camera is at the first location, causing the camera to capture a respective first series of captured images of the autostereoscopic display as the series of specified images is displayed; generating an alert instructing a user to reposition the camera; determining, using the viewer tracker of the autostereoscopic display, that the camera is located at a second location different from the first location; while the camera is at the second location, causing the autostereoscopic display to sequentially display the series of specified display images; while the camera is at the second location, causing the camera to capture a respective second series of captured images of the autostereoscopic display as the series of specified images is displayed; determining at least one weaving model parameter from the first series of captured images, the second series of captured images, the first location, and the second location, the at least one weaving model parameter pertaining to whether a pixel of the display panel is directed to a left eye of the viewer, a right eye of the viewer, or to both the left eye and the right eye of the viewer; and storing, on a storage medium included with or coupled to the autostereoscopic display, data representing the at least one weaving model parameter.

[0006] In an example of a method for calibrating an autostereoscopic display, the autostereoscopic display including a display panel and a parallax-generating optic configured to direct light from the display panel to a viewer, the method includes: determining, using a viewer tracker of the autostereoscopic display, that a first camera is located at a first location and a second camera is located at a second location different from the first location; causing the autostereoscopic display to sequentially display a series of specified display images; causing the first camera to capture a respective first series of captured images of the autostereoscopic display as the series of specified images is displayed; causing the second camera to capture a respective second series of captured images of the autostereoscopic display as the series of specified images isdisplayed; determining at least one weaving model parameter from the first series of captured images, the second series of captured images, the first location, and the second location, the at least one weaving model parameter pertaining to whether a pixel of the display panel is directed to a left eye of the viewer, a right eye of the viewer, or to both the left eye and the right eye of the viewer; and storing, on a storage medium included with or coupled to the autostereoscopic display, data representing the at least one weaving model parameter.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 shows an exploded, perspective-view schematic drawing of an example of an autostereoscopic display system.

[0008] FIG. 2 shows a front-view drawing of an example of a display panel that includes an array of light-emitting diodes.

[0009] FIG. 3 shows a front-view drawing of an example of a display panel that includes a backlight and a light valve array.

[0010] FIG. 4 shows a front-view drawing of an example of a parallaxgenerating optic that includes a lenticular lens.

[0011] FIG. 5 shows a cross-sectional view of the lenticular lens of FIG. 4.

[0012] FIG. 6 shows a front-view drawing of an example of a parallaxgenerating optic that includes a parallax barrier.

[0013] FIG. 7 shows a cross-sectional view of the parallax barrier of FIG. 6 having transmissive slits.

[0014] FIG. 8 shows an example of the quantities that the processing circuitry can use to generate the phase function when the autostereoscopic display system is operational.

[0015] FIG. 9 shows an exploded, perspective-view schematic drawing of an example of an autostereoscopic display system undergoing calibration.

[0016] FIG. 10 shows a flowchart of an example of a method for calibrating an autostereoscopic display.

[0017] FIG. 11 shows a flowchart of an example of a method for calibrating an autostereoscopic display.

[0018] FIG. 12 shows a flowchart of an example of a method for calibrating an autostereoscopic display.DETAILED DESCRIPTION

[0019] During use of an autostereoscopic display system, an autostereoscopic display can track a position of a viewer and can direct different images to the two eyes of the viewer. Compared to a two-dimensional display system that simply maps the pixels of an image to corresponding time-invariant locations in an area of a two-dimensional display without rearranging the pixels, an autostereoscopic display system may use eye tracking to dynamically determine a position of a user, and may dynamically rearrange the content of an image on a display panel to direct light that is perceptible as the image toward the left and right eyes of the viewer as the viewer moves. To achieve the autostereoscopic effects, the autostereoscopic display system may include more complex hardware than the comparable two-dimensional display system.

[0020] For example, the autostereoscopic display system may include a display panel, such as an array of light-emitting diodes that directly generates light in response to electrical signals, or a backlight and a liquid crystal panel that selectively attenuates light from the backlight in response to electrical signals. The display panel may include pixels or subpixels having a size of a few microns on a side. The autostereoscopic display system may also include a parallax-inducing element, such as a lenticular lens array or a parallax barrier. The parallax-inducing element may have feature sizes and spacings comparable to the size of the pixels or subpixels of the display panel. Manufacturing the parallax-inducing element with relatively tight tolerances can be difficult. Further, during the device assembly process, it can be challenging to position the parallaxinducing element precisely with respect to the display panel, to tolerances within a fraction of the pixel or subpixel size.

[0021] Rather than devote effort and expense to precisely manufacture and position the parallax-inducing element with respect to the display panel, the assembly process can use one or more calibration techniques to allow the autostereoscopic display system to function with relatively loose manufacturing and placement tolerances for the parallax-inducing element. As a result, relatively expensive manufacturing andalignment processes may be replaced by a relatively inexpensive calibration process. The calibration techniques can be performed at a factory or a reconditioning center before the autostereoscopic display system is put into general use.

[0022] The autostereoscopic display system may include a viewer tracker. The viewer tracker can dynamically measure a location in three dimensions of a user as the user moves around in the surroundings. A controller or processing circuitry can receive an image (such as a stereo image or a mono image that the controller can dynamically convert to stereo) along with the measured location of the user and can use the measured location to dynamically rearrange the content of the image on the display panel such that the user perceives the (stereo) image components in the left and right eyes, respectively, of the user.

[0023] Prior to use of the autostereoscopic display system, after the autostereoscopic display system has been assembled but before the autostereoscopic display system is shipped, the autostereoscopic display system can undergo calibration. The calibration can determine a set of parameters for the autostereoscopic display system, which are unique to the particular device under calibration (or are representative of a batch of devices). The autostereoscopic display system can store the parameters locally and can recall and use the parameters during subsequent use of the autostereoscopic display system. The parameters effectively describe how the viewer tracker performs, how the display panel performs, and how the viewer tracker relates to the display panel. For example, the viewer tracker may be rotated about a particular axis when it was attached to a housing of the autostereoscopic display system. The parameters include information that corresponds to the rotation. As another example, the display panel can include a lateral offset between the display panel and the parallaxinducing element. The parameters include information that corresponds to the lateral offset. As another example, the viewer tracker may be laterally offset from a center of the display panel and may be angularly offset from a surface normal of the display panel. The parameters include information that corresponds to the lateral offset and angular offset. These are but examples of some quantities that can have relaxed tolerances during manufacturing and assembly; other examples are also possible. During use of the autostereoscopic display system, the controller can use the stored parameters to interpretdata from the viewer tracker and control the display panel in a manner that allows the autostereoscopic display system to function with these relaxed manufacturing and alignment tolerances.

[0024] The calibration techniques described below do not physically alter an assembled autostereoscopic display system (such as by adjusting a position or a rotational orientation of a component). Instead, the calibration techniques take measurements that can characterize how a specific unit of an autostereoscopic display system was manufactured and assembled, or how a representative unit of a particular batch of multiple display systems, or parts of such display systems, was manufactured and assembled. During use, the autostereoscopic display system can recall and use data corresponding to the calibration measurements to dynamically affect how the images are arranged on the display panel. It is this dynamic arrangement of the image content that ensures that a left eye of the user receives light that is perceptible as a left image of the stereo image and ensures that a right eye of the user receives light that is perceptible as a right image of the stereo image. In other words, the calibration can allow a particular unit to function as it was built, rather than using physical adjustment of any components of the unit to affect performance of the unit.

[0025] In a specific example of an autostereoscopic display system calibration technique, processing circuitry can receive, from a camera fixedly attached to a patterned target having a pattern on the patterned target, a captured image of at least the patterned target as reflected from the autostereoscopic display. The processing circuitry can determine, based at least in part on the captured image, at least one calibration parameter that quantifies misalignment between the parallax-generating optic and the display panel. The processing circuitry can store, on a storage medium included with or coupled to the autostereoscopic display, data representing the at least one calibration parameter. This is but one example of a calibration technique. Other techniques are described in detail below.

[0026] In an example, the calibration can be considered to be completed when the data representing the plurality of physical parameter values is stored. The autostereoscopic display can then be packaged, sold, and delivered to an end-user for routine use.

[0027] During routine operation of the autostereoscopic display, the processing circuitry can determine in real time what intensity to display on a particular pixel or subpixel of the autostereoscopic display panel. The processing circuitry can use the stored physical parameter values, in addition to other static and / or dynamic data, to determine what intensity to display on a particular pixel or subpixel of the autostereoscopic display panel.

[0028] In general, the intensity displayed on the particular pixel or subpixel of the display panel can correspond to either the corresponding pixel or subpixel of a left image of a stereoscopic image pair or the corresponding pixel or subpixel of a right image of the stereoscopic image pair (or, in some cases, a combination of the two). In other words, determining what intensity to display for a pixel or subpixel can involve determining whether light from the pixel or subpixel is directed to the left eye of the viewer or the right eye of the viewer (or, in some cases, both eyes). If the light from the pixel or subpixel is directed to the left eye, then the display panel can use the intensity value of the (corresponding pixel or subpixel of the) left image. If the light from the pixel or subpixel is directed to the right eye, then the display panel can use the intensity value of the (corresponding pixel or subpixel of the) right image. Details are provided below regarding how the processing circuitry can determine whether to use the left image or the right image for a particular pixel or subpixel.

[0029] The preceding paragraphs are merely a summary of some technical details regarding the autostereoscopic display and calibration of the autostereoscopic display. FIGS. 1-7 provide a more complete description of the hardware of the autostereoscopic display. FIGS. 8-12 provide a more complete description of various aspects of calibration techniques for the autostereoscopic display.

[0030] FIG. 1 shows an exploded, perspective-view schematic drawing of an example of an autostereoscopic display system 100 that includes an autostereoscopic display 110. The configuration of FIG. 1 is but one example of an autostereoscopic display system 100; other configurations can be used.

[0031] The sign conventions shown in FIG. 1 and used below assume that the autostereoscopic display 110 extends in an (x, y) plane, and that a z-axis extends away from the autostereoscopic display 110 and generally toward a viewer 42, along adirection that is orthogonal to a plane of the autostereoscopic display 110. Other sign conventions can be used.

[0032] The autostereoscopic display system 100 can include an autostereoscopic display 110. The autostereoscopic display 110 can provide different views of a stereoscopic image pair to the viewer 42. For example, as the viewer 42 moves in space, the autostereoscopic display 110 can direct different views of the stereoscopic image pair to the left and right eyes of the viewer 42, so that the viewer 42 can observe the different views of the stereoscopic image pair from different locations or orientations. In some configurations, the autostereoscopic display 110 can provide the multiple views at respective fixed location regions in space, so that the autostereoscopic display 110 can operate without using eye tracking. In other configurations, such as the autostereoscopic configurations described in detail below, the autostereoscopic display system 100 can use eye tracking to dynamically and continuously (or at relatively frequent discrete times) determine a location of the viewer 42, and in response, can dynamically and continuously control how the autostereoscopic display 110 displays the stereoscopic image pair so that the multiple views follow the viewer 42 or follow the tracked eye location(s) of the viewer 42 as the viewer 42 moves in space relative to a position of the autostereoscopic display 110.

[0033] The autostereoscopic display can provide a left image to a left eye of the viewer 42 and a right image to a right eye of the viewer 42. The left image and the right image can correspond to different views of an object or a scene, and can allow the viewer 42 to perceive the object or scene in 3D with just the viewer’s naked eyes, without the use of additional glasses or headgear.

[0034] The autostereoscopic display system 100 can include a viewer tracker 120 that can dynamically determine the location of the viewer 42. The autostereoscopic display system 100 can use the determined location of the viewer 42 to direct the left image to the left eye of the viewer 42 and the right image to the right eye of the viewer 42. Because the viewer’s location can vary as the viewer 42 moves in space, using eye tracking can allow the autostereoscopic display system 100 to follow the viewer 42, so that the autostereoscopic display can automatically direct the left image to the left eye at the viewer 42’ s (dynamically varying) location and automatically direct the right imageto the right eye at the viewer 42’ s (dynamically varying) location. The viewer tracker 120 can provide a tracked position of the viewer 42, such as a tracked position of a head of the viewer 42, of one or both eyes of the viewer 42, or of another anatomical feature of the viewer 42. The viewer tracker 120 can be coupled to the processing circuitry 130 (described below) or controller, such as by providing viewer 42 location data (shown in FIG. 1 as coordinates x, y, and z) that represents a measured position or location of the viewer 42. The viewer tracker 120 can provide the viewer 42 location data at regular or irregular intervals to the processing circuitry 130. In a specific example of a viewer tracker 120, the viewer tracker 120 can include a camera that can capture an image of the viewer 42. The viewer tracker 120 can further include an image processor (or general- purpose computer programmed as an image processor) that can determine a position of the viewer 42 within the captured image to provide the tracked position. In some examples, the processing circuitry 130 can include the image processor of the viewer tracker 120. In other examples, the processing circuitry 130 can be separate from the image processor of the viewer 42 tracker. Other suitable viewer trackers can be used, including viewer trackers based on lidar (e.g., using time-of-flight of reflected light over a scene to determine distances to one or more objects in the scene, such as a viewer’s head or a viewer’s eyes) or other technologies. The processing circuitry 130 can use an output of the viewer tracker 120, among other data, to perform one or more downstream calculations involved with providing the left view or left image to the left eye of the viewer 42 and the right view or right image to the right eye of the viewer 42.

[0035] The autostereoscopic display can be a lenticular autostereoscopic display. In a lenticular autostereoscopic display, a display panel 112 can display the stereoscopic image pair, and a parallax-generating optic 118 can direct light from the display panel 112 to the viewer 42 such that a left image can be visible from the left eye of the viewer 42 and a right image can be visible from the right eye of the viewer 42. During use of the lenticular autostereoscopic display, the processing circuitry 130 can track the location of the viewer 42, and can use the tracked location to dynamically determine how to distribute content of the stereoscopic image pair over a surface area of the display panel 112 (e.g., using pixels distributed over the display panel 112) such that a left image remains visible from the left eye of the viewer 42 and a right image remains visible fromthe right eye of the viewer 42, even as the viewer 42 changes location. In this manner, the location tracking and the image content distribution can be performed in software, such that following the location of the viewer 42 may not involve physically moving any components of the lenticular autostereoscopic display with respect to one another. Examples of suitable display panels and examples of suitable parallax-generating optics are described below.

[0036] In an example, a display panel 112 can display the stereoscopic image pair. The display panel 112 can have an array of subpixels 114 that can display an image according to stereo mapping coordinates associated with the viewer 42. The subpixels 114 can be located at subpixel locations in a grid having grid axes (for example, the x- axis and -axis). Each subpixel 114 can generate light having a specified color. For example, the subpixels 114 can include red subpixels, green subpixels, and blue subpixels, which generate red light, green light, and blue light, respectively. Other color / wavelength schemes can be used. The subpixels 114 can be grouped into pixels, with each pixel including at least two subpixels 114 that produce light of different colors. The display panel 112 can receive, from the processing circuitry 130 (described below), a display panel driving electrical signal 136 that can specify how the content of the stereoscopic image pair is distributed over the pixels and / or subpixels 114 of the display panel 112. Two possible configurations for the display panel 112 are described below and shown in FIGS. 2 and 3. Other configurations can be used.

[0037] FIG. 2 shows a front-view drawing of an example of a display panel 112A that includes an array 202 of light-emitting diodes 204, such as an array 202 of organic light-emitting diodes. Each light-emitting diode 204 can correspond to a subpixel. The array 202 of light-emitting diodes 204 can include red light-emitting diodes 204R, green light-emitting diodes 204G, and blue light-emitting diodes 204B, which correspond to the red subpixels, green subpixels, and blue subpixels, respectively. Each light-emitting diode 204 can controllably generate light in response to an electrical signal provided by the processing circuitry 130, such as display panel-driving electrical signal 136, or by suitable light-emitting diode-driving circuitry in communication with the processing circuitry 130. The processing circuitry 130 can cause a specified lightemitting diode 204 to be directly powered with a power that varies as a function of anintensity in a corresponding location in the image. The power delivered to a lightemitting diode 204 can optionally be pulse-width modulated at a modulation frequency that is greater than can be perceived by a human eye. Using pulse-width modulation can simplify a design of a light-emitting diode array controller, because it can generate an arbitrary average power level from a relatively small number of instantaneous power levels by varying a duty cycle of the power. In some examples, the array 202 of lightemitting diodes 204 can be arranged in a rectangular or square repeating pattern over a surface area 206 of the array 202. For example, the array 202 can have grid axes 208 that are orthogonal to each other. In some examples, the grid axes 208 can be parallel to edges 210 of the array 202 of light-emitting diodes 204.

[0038] FIG. 3 shows a front-view drawing of an example of a display panel 112B that includes a backlight 302 and a light valve array 304. Although FIG. 3 shows the backlight 302 and the light valve array 304 as being separated, in practice, the backlight 302 and the light valve array 304 may be in contact or may be located as close together as is practical. The backlight 302 can provide illumination having a uniform or substantially uniform intensity over a surface area of the backlight 302. The backlight 302 can provide illumination having a relatively broad spectrum, such as including most or all of the visible portion of the electromagnetic spectrum. The backlight 302 can provide the illumination into a continuum of propagation angles toward the light valve array 304. The backlight 302 can provide unmodulated illumination to the light valve array 304. The light valve array 304 can include light valves 306 that are individually controllable or controllable in one or more groups by the processing circuitry 130 (described below). Each light valve 306 can controllably attenuate the illumination from the backlight 302, such as in response to an electrical signal provided by the processing circuitry 130, such as display panel-driving electrical signal 136, or by suitable light valve driving circuitry in communication with the processing circuitry 130. Each light valve 306 can have a corresponding color filter that allows only a portion of the electromagnetic spectrum to pass through the light valve. For example, the light valves 306 can include red light valves 306R that have a red filter that allows only red light to pass through the red light valves 306R, green light valves 306G that have a green filter that allows only green light to pass through the green light valves 306G, and blue lightvalves 306B that have a blue filter that allows only blue light to pass through the blue light valves 306B. Other color schemes and numbers of colors can be used. Suitable light valves can include liquid crystal light valves, electrophoretic light valves, light valves based on electrowetting, and others. In some examples, the light valves 306 of the light valve array 304 can be arranged in a rectangular or square repeating pattern over a surface area 308 of the light valve array 304. For example, the light valve array 304 can have grid axes 208 that are orthogonal to each other. In some examples, the grid axes 208 can be parallel to edges 312 of the light valve array 304.

[0039] Referring again to FIG. 1, the autostereoscopic display can include a parallax-generating optic 118 that can direct light from the display panel 112 to the viewer 42, such that a left view or a left image can be visible from a left eye of the viewer 42 and a right view or a right image can be visible from a right eye of the viewer 42. Two possible configurations for the parallax-generating optic 118 are described below and shown in FIGS. 4 and 5 and in FIGS. 6 and 7. Other configurations can be used. Each of the configurations of FIGS. 4 and 5 and in FIGS. 6 and 7 can be used in combination with any of the configurations of the display panel 112 shown in FIGS. 2 and 3 (e.g., the array of light-emitting diodes 204 in FIG. 2 or the backlight 302 and light valve array 304 in FIG. 3).

[0040] FIG. 4 shows a front-view drawing of an example of a parallaxgenerating optic 118A that includes a lenticular lens 402. FIG. 5 shows a cross-sectional view of the lenticular lens 402 of FIG. 4. The lenticular lens 402 can include a plurality of cylindrical lenses 504 that are equally spaced apart. The lenticular lens 402 can have a focal plane coincident with the display panel 112. The lenticular lens 402 can be positioned to receive light from the display panel 112 and at least partially focus the received light to direct the light to specified regions proximate the viewer’s eyes.

[0041] FIG. 6 shows a front-view drawing of an example of a parallaxgenerating optic 118B that includes a parallax barrier 602. The parallax barrier can include a plurality of transmissive slits 704 that are equally spaced apart. FIG. 7 shows a cross-sectional view of the parallax barrier 602 (FIG. 6) having transmissive slits 704. The parallax barrier 602 can include an array of opaque strips 706 and thin transmissive slits 704 arranged to occlude portions of a displayed image in left and right viewingregions. The transmissive slits 704 can be spatially arranged to ensure that the left / right image portions are only visible in the corresponding left / right viewing regions for which they are intended. The parallax barrier 602 can be provided by a static physical layer in which the slits are precisely positioned, or electronically generated on an adaptive intermediate liquid crystal display layer.

[0042] The parallax-generating optic 118 can be invariant along an optical axis (OA) that is angled with respect to the grid axes (e.g., the x-axis and the -axis), such as at a rotational orientation (a) of 45 degrees or about 45 degrees with respect to the grid axes 208 or the x-axis. For example, the parallax-generating optic 118 can have transmissive features, such as the cylindrical lenses or the transmissive slits, that are invariant along the optical axis (OA) and are periodic along an axis that is orthogonal to the optical axis (OA).

[0043] Referring again to FIG. 1, the autostereoscopic display can include a material 116 disposed between the display panel 112 and the parallax-generating optic 118. In some examples, the material 116 may extend fully between the display panel 112 and the parallax-generating optic 118, such that a light ray originating at the display panel 112 passes only through the material 116 (and does not pass through any air or unfilled volume) before arriving at the parallax-generating optic 118. In other examples, the material 116 may occupy only a portion of the volume between the display panel 112 and the parallax-generating optic 118, such that a light ray originating at the display panel 112 passes through at least some of the material 116 and passes through a volume of air before arriving at the parallax-generating optic 118. The material 116 may have a refractive index denoted by quantity n. The value of the refractive index n may be between about 1.3 and about 2, although other suitable values may be used. Suitable materials 116 can include glass, plastic, a transparent optical adhesive, and others. In some examples, the material 116 can be dispensed in a liquid form, then cured in place, such as by exposure to ultraviolet light or heat. In other examples, the material 116 can be manufactured as a solid unit and placed in its location in the autostereoscopic display. For example, the material 116 can function as a cover glass for the display panel 112. In some examples, the material 116 can function as a relatively precise spacing element. For example, the material 116 can be manufactured to have a specified thickness towithin a specified thickness tolerance, and can set the spacing between the display panel 112 and parallax-generating optic 118 to have a value equal to the specified thickness when the autostereoscopic display is assembled.

[0044] As an alternative configuration, the autostereoscopic display can include, in order along the Z-axis, a backlight, the parallax-generating optic, and a display panel that can selectively modulate light that passes through the pixels or subpixels of the display panel. In other words, the parallax-generating optic may be disposed in an optical path between the backlight and the display panel. The material of refractive index n may be disposed between the parallax-generating optic and the display panel.

[0045] As illustrated in FIG. 1, the autostereoscopic display system 100 can include processing circuitry 130. The processing circuitry 130 can include a processor 132 and memory 134 storing instructions executable by the processor 132. The instructions can be executable by the processor 132 to perform data processing activities. The data processing activities can include, among other activities: receiving an image, captured within a field of view of the autostereoscopic display, of at least some of a calibration pattern as displayed on the autostereoscopic display; determining, from the image, a plurality of physical parameter values that quantify a characteristic of the parallax-generating optic and an alignment between the parallax-generating optic and the display panel; and storing, on a storage medium included with or coupled to the autostereoscopic display, data representing the plurality of physical parameter values. By executing these data processing activities, the processing circuitry can calibrate the autostereoscopic display system 100. These data processing activities are described in detail below.

[0046] During use of the autostereoscopic display system 100, after calibration has been completed, the processing circuitry 130 can determine, in real time, whether a particular pixel or subpixel displays a corresponding pixel from the left image or a corresponding pixel from the right image. There are many ways to make this determination; one specific example is described presently.

[0047] One technique for determining whether the left image is used or the right image is used involves calculating a phase function for each pixel or subpixel. The phase function can be a closed-form algebraic expression based on raytracing from theviewer, through the parallax-generating optic, to the display panel. The phase function can be a function of the pixel or subpixel location (e.g., within an operational area of the display panel), a location of the viewer (e.g., dynamically measured in real-time for systems that use a viewer tracker), and the stored physical parameter values. The phase function can generate a scalar value as output. If the value of the phase function is within a specified range (such as between 0 and 0.5 after taking a modulus of 1), then the light from the pixel or subpixel is directed to the left eye, and the processing circuitry uses the intensity value of the left image on the pixel or subpixel or the display panel. If the value of the phase function is within another specified range (such as between 0.5 and 1 after taking a modulus of 1), then the light from the pixel or subpixel is directed to the right eye, and the processing circuitry uses the intensity value of the right image on the pixel or subpixel or the display panel. The term “stereo mapping coordinates” can include the data that represents whether a particular pixel or subpixel displays the intensity of the corresponding pixel or subpixel from the left image or the right image. The stereo mapping coordinates can be a function of a viewer location and a pixel or subpixel location.

[0048] Using such a phase function is well-suited to calibrating an autostereoscopic display system 100 from one or more images. For example, when the display panel 112 displays a calibration pattern, and a camera captures an image of the calibration pattern (optionally with one or more constraints on where the camera is located and how the camera is focused), the intensity (or brightness) levels in the image can correspond to the phase function. For example, the brightness distribution can vary within an envelope, and the envelope can be mapped to a corresponding phase value. The envelope may optionally include one or more offsets or shifts, such that the mapping may not be strictly linear.

[0049] As an example of a phase function, the processing circuitry 130 can calculate the predicted phase function (5) according to Eqs. (l)-(3):d (x-x0)

[0052] U = - ■ (2)

[0055] FIG. 8 shows an example of the quantities 800 that the processing circuitry 130 can use to generate the phase function (5) when the autostereoscopic display system 100 is operational (e.g., after calibration has been completed).

[0056] In an example, the phase function fS) is a function of a viewer location (x, y, z) 802. After calibration has been completed, during typical use of the autostereoscopic display 110, a viewer tracker can dynamically measure the viewer location in real time or nearly in real time. For some applications in which the viewer does not move significantly, such as in a driver’s seat of a vehicle, the viewer location may be fixed (e.g., not measured in real time or nearly in real time).

[0057] In an example, the phase function (5) is a function of a pixel location or subpixel location (xo, yo) 804 in the operational area of the autostereoscopic display 110. Each pixel or subpixel of the display panel 112 has its own location, which is known to the processing circuitry 130 and need not be measured.

[0058] In an example, the phase function (5) is a function of the separation (d) 806 between the display panel 112 and the parallax-generating optic 118. For configurations in which the parallax-generating optic 118 is disposed between the display panel 112 and the viewer 42, such as in FIG. 1, the separation (d) is positive. For alternate configurations in which the display panel 112 is disposed between the parallax-generating optic 118 and the viewer 42, the separation (d) is negative.

[0059] In an example, the phase function (5) is a function of the refractive index (n) 808 of the material 116 disposed between the display panel 112 and the parallaxgenerating optic 118. Typical values of refractive index (ri) are between about 1.3 and about 2, although other values can be used.

[0060] In an example, the phase function (5) is a function of the rotational orientation (a) 810 of the parallax-generating optic 118 with respect to the x-axis. Therotational orientation (a) corresponds to an angle, in the x-y plane, between the optical axis (OA; FIG. 1) and the x-axis. The rotational orientation (a) is 0 degrees when the parallax-generating optic 118 has its periodic features oriented horizontally along the x-axis. The rotational orientation (a) is 90 degrees when the parallax-generating optic 118 has its periodic features oriented vertically along the -axis. In some examples, the rotational orientation (a) can nominally be 45 degrees or about 45 degrees, optionally to within relatively loose angular placement tolerances. The rotational orientation (a) can vary from part-to-part or from unit-to-unit, such that the calibration technique can measure the rotational orientation (a) of a particular unit. In some examples, the measurement can subtract the nominal value or design value from the rotational orientation, such that the resulting quantity (such as rotational orientation error Aa) may be zero if the unit is perfectly aligned to the design value.

[0061] In an example, the phase function (S) is a function of the pitch (p) 812 of the parallax-generating optic 118. In some examples, the parallax-generating optic 118 may have relatively loose fabrication tolerances. In contrast, the display panel 112 may have relatively tight tolerances of the pixel spacing or subpixel spacing, which can result from fabrication using a relatively precise lithographic mask. In some expressions for the phase function (S), the pitch ( / ?) of the parallax-generating optic 118 may be replaced by an x-projected pitch (px), the value of which is given by the pitch (p) divided by the sine of the rotational orientation (a) of the parallax-generating optic 118 with respect to the x-axis. The x-projected pitch (px) may be greater than or equal to the pitch (p). In some alternate expressions for the phase function (5), the pitch (p) can be expressed indirectly as a function of the pixel -to-pixel or subpixel-to-subpixel spacing of the display panel 112. For example, the pixel -to-pixel or subpixel-to-subpixel spacing of the display panel 112 may be represented as a quantity equal to the x-projected pitch (px) divided by the quantity (1+s), where quantity (.s) is a dimensionless quantity. For configurations in which the parallax-generating optic 118 is disposed between the display panel 112 and the viewer 42, such as in FIG. 1, the quantity (5) is positive. For alternate configurations in which the display panel 112 is disposed between the parallaxgenerating optic 118 and the viewer 42, the quantity (5) is negative.

[0062] In an example, the phase function (5) is a function of a center phase (0C) 814 or phase offset of the parallax-generating optic 118. The center phase (0C) can correspond to a lateral offset (e.g., in the x-y plane) between the parallax-generating optic 118 and the display panel 112. In general, one or the most demanding steps of the device fabrication process is laterally aligning the parallax-generating optic 118 and the display panel 112. Rather than expend the time and effort performing such a mechanical placement to relatively tight tolerances, the placement tolerances are loosened, and any residual misalignment is fully accounted for by calibration process. Specifically, the quantity of center phase (0C) or phase offset accounts for the lateral offset between the parallax-generating optic 118 and the display panel 112. The calibration process measures a value for the center phase (0C) or phase offset for a particular unit and stores the measured value. During routine use of the unit, the processing circuitry 130 uses the stored value of center phase (0C) or phase offset (and other physical parameters) to dynamically generate the phase function (5). As an example, if the lateral offset of the parallax-generating optic 118 is sufficient to translate one cylindrical lens or transmissive slit so that it lies upon an adjacent cylindrical lens or transmissive slit, then the center phase (0C) associated with such a lateral offset can equal 1 or -1, so that the phase function (5) is unaffected by the lateral offset. If the lateral offset translates one cylindrical lens or transmissive slit exactly halfway toward an adjacent cylindrical lens or transmissive slit, then the center phase (0C) associated with such a lateral offset is 0.5 or -0.5. In the specific example of Eqs. (l)-(3), the phase function (5) includes taking a modulus with a divisor of 1, such that the phase function (5) remains between 0 and 1. Other divisors can be used, such as 2K.

[0063] A calibration process for the autostereoscopic display 110 can measure some or all of the device-specific physical quantities 816 (the device-specific physical quantities 816 excluding the viewer location (x, , z) 802 and the pixel or subpixel location (xo, yo) 804). For example, a calibration process can measure one or more of the separation (d) 806 between the display panel 112 and the parallax-generating optic 118, the refractive index (n) 808 of the material 116 disposed between the display panel 112 and the parallax-generating optic 118, the rotational orientation (a) 810 of the parallaxgenerating optic 118, the pitch (p) 812 of the parallax-generating optic 118, and thecenter phase (0C) 814 or phase offset of the parallax-generating optic 118. The devicespecific physical quantities 816 that are not measured can be estimated, with the understanding that using an estimate may reduce the time involved with the calibration process, but may reduce the overall accuracy of the phase function (S), and may lead to increased crosstalk (e.g., the presence of an image of the stereo image pair being directed to the incorrect eye of the viewer). For example, to calibrate a relatively large batch of devices, one device could be measured to generate good estimates for the separation (d) and refractive index (n), and the good estimates for the separation (d) and refractive index (ri) can be used for calibrating the other devices in the batch.

[0064] In some examples, the physical parameter values can be expressed as different numerical quantities. For example, the rotational orientation (a) can be expressed as a rotational orientation error (Aa) with respect to a nominal value or a design value. As another example, the rotational orientation (a) can be expressed in terms of a slope value or a slant angle. As another example, the pitch ( / ?) of the parallaxgenerating optic 118 can be expressed in terms of the pixel -to-pixel spacing or sub pixel - to-subpixel spacing of the display panel 112. For example, the calibration technique may represent the pitch ( / ?) of the parallax-generating optic 118 by the dimensionless quantity s, where the pixel -to-pixel spacing or subpixel-to-subpixel spacing of the display panel 112 equals the x-projected pitch ( / ),) divided by the quantity (1+s).

[0065] The phase function (5) according to Eqs. ( 1 )-(3) above is but one example of how an autostereoscopic display system can, for a given pixel on the autostereoscopic display, determine whether to display a corresponding pixel from a left image, a corresponding pixel from a right image, or a combination of the pixels of the left and right images. The parameters shown in FIG. 8 and discussed above correspond to the specific phase function (5). The calibration techniques discussed in detail below also correspond to the specific phase function (5), in that the calibration techniques determine one or more parameters shown in FIG. 8. Alternatively, there may be other techniques, based on different mathematical expressions, that can determine whether to display information from the left image, the right image, or a combination of the two. These other techniques may use different parameters than those shown in FIG. 8, such as by adding one or more parameters and / or deleting one or more parameters from thoseshown in FIG. 8. Those other techniques may have corresponding calibration techniques to determine the suitable parameters. Those other techniques may differ from the calibration techniques discussed in detail below, such as by determining different physical properties than those shown in FIG. 8.

[0066] FIG. 9 shows an exploded, perspective-view schematic drawing of an example of an autostereoscopic display system 900 undergoing calibration. Calibration can involve performing measurements on a particular device, forming estimates to some or all of the physical parameter values 816 shown in FIG. 8 for the particular device in response to the measurements, and storing the estimates of the physical parameter values 816 locally on the particular device. After the calibration is completed, and the estimated physical parameter values 816 have been stored, the particular device can be shipped for routine use. During routine use, the device can access the stored physical parameter values 816, along with a viewer location and a location of a pixel or subpixel, to dynamically determine whether the pixel or subpixel directs light to a left eye of the viewer or a right eye of the viewer. The pixel or subpixel can display an intensity value from a left image if the pixel or subpixel directs light to the left eye, or an intensity value from a right image if the pixel or subpixel directs light to the right eye.

[0067] The autostereoscopic display system 900 can include an autostereoscopic display 110. The autostereoscopic display 110 can include a display panel 112 and a parallax-generating optic 118 configured to direct light from the display panel 112 to a viewer. The autostereoscopic display 110, display panel 112, the material 116, and the parallax-generating optic 118 may be similar in structure and function to the corresponding elements in FIG. 1. The material 116 may extend fully between the display panel 112 and the parallax-generating optic 118.

[0068] To perform the calibration, the autostereoscopic display system 900 can use a camera 902. The camera 902 may not be part of the autostereoscopic display system 900. For example, the camera 902 can be part of a test equipment station at a factory or reconditioning center. The camera 902 can be integrated into a user device, such as a cellular phone, a smart phone, a computing tablet, or a laptop computer, or may be a stand-alone camera. In some examples, the camera 902 can be mounted or held in a known location, with respect to the autostereoscopic display system 900. The camera902 can optionally be mounted on a movable stand or mount that can reposition the camera 902 between capturing images. The optional movable stand can optionally be calibrated to record or report absolute or relative positions or locations, such as the positions or locations at which the camera 902 captures images.

[0069] The camera 902 can be fixedly attached to a patterned target 908, such as a planar target (e.g., a board or a plate) that has a pattern of indicia, such as a grid, a pattern of alternating bright and dark squares or rectangles, such as a chessboard or checkerboard, pattern lines, or others. The indicia can include at least one identifier that can identify a specified orientation for the indicia, such as a specifically-identified square in the chessboard or checkerboard pattern. The specifically-identified square can include a marker (for example, a dot or hole) in the square. In some examples, the patterned target 908 can have a hole therethrough, and the camera 902 can be disposed at or near the hole, such as on a side of the patterned target 908 that faces away from the autostereoscopic display 110. The camera 902 can have a field of view that extends through the hole toward the autostereoscopic display 110. The hole is readily visible when the patterned target 908 is viewed by a user or imaged (in reflection) by the camera 902. The camera 902 and patterned target 908 can be positioned and repositioned, together, such that the camera 902 can have a fixed location with respect to the patterned target 908 throughout the calibration process. The camera 902 and patterned target 908, together, may be referred to as a cartridge 906.

[0070] The camera 902 can include a lens and a sensor. The lens and the sensor are separated by a distance such that the lens brings light from a specified object in a scene to a focus at the sensor. Objects that are closer to the camera 902 than the specified object or farther away from the camera 902 than the specified object can appear blurry or out of focus at the sensor. In many cameras, the distance between the lens and the sensor can be adjustable, such as by a focus actuator that can dynamically adjust the distance between the lens and the sensor in response to an input signal or a mechanical movement. The size of the field of view of the camera 902 and the size of the patterned target 908 can be selected such that the pattern of the patterned target 908 can fill the field of view (e.g., in one dimension, such as in the horizontal dimension) of the camera 902 when the camera 902 captures images of the patterned target 908.

[0071] In the calibration technique described in detail below, the camera 902 is configured to capture one or more images 904 of the autostereoscopic display 110. For use of the camera 902, the distance between the lens and the sensor can optionally be set so that the autostereoscopic display 110 is in focus, or is approximately in focus, at the sensor.

[0072] The calibration technique can include calculations performed by processing circuitry 930, which may be included with the autostereoscopic display system 900, external to (e.g., separate from) the autostereoscopic display system 900, or both internal and external to the autostereoscopic display system 900.

[0073] During the calibration procedure, the processing circuitry 930 can receive, from the camera 902 fixedly attached to the patterned target 908 having the pattern on the patterned target 908, an image of at least the patterned target 908 as reflected from the autostereoscopic display. For example, a user can position the patterned target 908 and the camera 902 to face the autostereoscopic display 110 such that a reflection of the patterned target 908 from the autostereoscopic display 110 is within a field of view of the camera 902. The processing circuitry 930 can cause the autostereoscopic display 110 to display the pattern (e.g., the same pattern that is present on the patterned target 908, such as a grid or a checkerboard pattern). As a result, capturing the image can include capturing, with the camera 902, a real-time captured image of the autostereoscopic display 110. The real-time captured image can include a superposition of the pattern as displayed on the autostereoscopic display 110 and the reflection of the patterned target 908. The pattern, as displayed, can be from stored data or can be from a real-time image captured by a camera of the autostereoscopic display (such as a camera of the viewer tracker 120) viewing the patterned target 908. The real-time captured image can include a superposition offset between the pattern as displayed on the autostereoscopic display 110 and the reflection of the patterned target 908. The superposition offset can have an initial superposition offset value.

[0074] The calibration technique can cause at least one of the camera 902 or the autostereoscopic display 110 to reduce the superposition offset from the initial superposition offset value to a reduced superposition offset value.

[0075] As a first example of reducing the superposition offset, the processing circuitry 930 can prompt a user to manually adjust at least one of a position of the camera 902 or a position of the autostereoscopic display 110 to manually reduce the superposition offset, such as by alternating between adjusting the position of the camera 902 and adjusting the position of the autostereoscopic display 110 to manually reduce the superposition offset.

[0076] As a second example of reducing the superposition offset, the processing circuitry 930 can automatically cause the autostereoscopic display 110 to adjust a position of the pattern displayed on the autostereoscopic display 110. For example, the processing circuitry 930 can determine a display offset value. The processing circuitry 930 can repeatedly: display, on the autostereoscopic display 110, an offset pattern that comprises the pattern as offset by the display offset value; capture, with the camera 902, a real-time captured image of the autostereoscopic display 110, the real-time captured image including a superposition of the offset pattern as displayed on the autostereoscopic display 110 and the reflection of the patterned target 908, the real-time captured image including a superposition offset between the pattern as displayed on the autostereoscopic display 110 and the reflection of the patterned target 908, the superposition offset having a superposition offset value; and automatically revise, based on the real-time captured image, the display offset value to reduce the superposition offset value. The processing circuitry 930 can use steepest descent to automatically revise the display offset value.

[0077] The calibration technique described above is but one calibration technique. Other suitable calibration techniques are described below. Some techniques may use additional hardware, such as an additional camera, and may therefore be executed more quickly than comparable techniques that use less hardware, such as a single camera.

[0078] During the calibration procedure, the processing circuitry 930 can determine, from the image 904, a plurality of physical parameter values 910 that quantify a characteristic (such as part-to-part variations, or part-to-part variations of a pitch) of the parallax-generating optic 118 and an alignment (such as part-to-part misalignments, or part-to-part variations in rotational alignment or azimuthal alignment in the x-y plane) between the parallax-generating optic 118 and the display panel 112. The plurality ofphysical parameter values 910 can include a pitch of the parallax-generating optic 118 and a rotational misalignment between the display panel 112 and the parallax-generating optic 118.

[0079] The processing circuitry 930 can store, on a storage medium 912 included with or coupled to the autostereoscopic display 110, data representing the plurality of physical parameter values.

[0080] FIG. 10 shows a flowchart of an example of a method 1000 for calibrating an autostereoscopic display. The autostereoscopic display can include a display panel, such as display panel 112, and a parallax-generating optic, such as parallax-generating optic 118, that can direct light from the display panel to a viewer, such as viewer 42. The method 1000 can be executed by processing circuitry, such as processing circuitry 930. The method 1000 is but one example of a method for calibrating an autostereoscopic display. Other suitable methods can be used.

[0081] At operation 1002, the method 1000 can receive, from a camera fixedly attached to a patterned target having a pattern on the patterned target, such as camera 902 being fixedly attached to the patterned target 908, a captured image of at least the patterned target as reflected from the autostereoscopic display. The patterned target can include indicia that extend in a plane. For example, the indicia can include a grid, a pattern of alternating bright and dark squares, or other features that can allow image processing software to identify specific locations on the patterned target (e.g., a center, an upper-left corner, or an intersection of a specified horizontal line and a specified vertical line) based on an image of the patterned target.

[0082] At operation 1004, the method 1000 can determine, based at least in part on the captured image, at least one calibration parameter that quantifies misalignment between the parallax-generating optic and the display panel. The at least one calibration parameter can include one or more of the physical parameter values 816 shown in FIG.8.

[0083] For example, operation 1004 can include causing at least one of the camera or the autostereoscopic display to reduce the superposition offset from the initial superposition offset value to a reduced superposition offset value. Operation 1004 can include determining the at least one calibration parameter from conditions of theautostereoscopic display and the camera when the superposition offset has the reduced superposition offset value. The at least one calibration parameter can quantify a misalignment between the parallax-generating optic and the display panel.

[0084] In a first example of operation 1004, the method 1000 can optionally include prompting a user to manually adjust at least one of a position of the camera or a position of the autostereoscopic display to manually reduce the superposition offset. Prompting the user can include prompting the user to alternate between adjusting the position of the camera and adjusting the position of the autostereoscopic display to manually reduce the superposition offset.

[0085] In a second example of operation 1004, the method 1000 can optionally include automatically causing the autostereoscopic display to adjust a position of the pattern displayed on the autostereoscopic display. For example, operation 1004 can include determining a display offset value. Operation 1004 can include repeatedly executing the following three suboperations. The first suboperation can include displaying, on the autostereoscopic display, an offset pattern that comprises the pattern as offset by the display offset value. The second suboperation can include capturing, with the camera, a real-time captured image of the autostereoscopic display. The realtime captured image can include a superposition of the offset pattern as displayed on the autostereoscopic display and the reflection of the patterned target. The real-time captured image can include a superposition offset between the pattern as displayed on the autostereoscopic display and the reflection of the patterned target. The superposition offset can have a superposition offset value. The third suboperation can include automatically revising, based on the real-time captured image, the display offset value to reduce the superposition offset value. The third suboperation can use steepest descent to automatically revise the display offset value, or can use another suitable technique.

[0086] At operation 1006, the method 1000 can store, on a storage medium included with or coupled to the autostereoscopic display, such as storage medium 912, data representing the at least one calibration parameter.

[0087] The method 1000 can optionally further include generating instructions to position the patterned target and the camera to face the autostereoscopic display such thata reflection of the patterned target from the autostereoscopic display is within a field of view of the camera.

[0088] The method 1000 can optionally further include causing the autostereoscopic display to display the pattern. For example, displaying the pattern comprises can include displaying the captured image. As another example, displaying the pattern can include displaying a generated image or a previously saved image of the patterned target.

[0089] The method 1000 can optionally further include causing the camera to capture the captured image of the autostereoscopic display. The captured image can include a superposition of the pattern as displayed on the autostereoscopic display and the reflection of the patterned target. The captured image can include a superposition offset between the pattern as displayed on the autostereoscopic display and the reflection of the patterned target. The superposition offset can having an initial superposition offset value.

[0090] The method 1000 can optionally further include determining, with a viewer tracker of the autostereoscopic display, such as viewer tracker 120, a position of the camera when the superposition offset has the reduced superposition offset value. When the superposition offset is zero, the camera can have a longitudinal axis that is orthogonal to a plane of the autostereoscopic display.

[0091] FIG. 11 shows a flowchart of an example of a method 1100 for calibrating an autostereoscopic display. The autostereoscopic display can include a display panel, such as display panel 112, and a parallax-generating optic, such as parallax-generating optic 118, that can direct light from the display panel to a viewer, such as viewer 42. The method 1100 can be executed by processing circuitry, such as processing circuitry 930. The method 1100 is but one example of a method for calibrating an autostereoscopic display. Other suitable methods can be used.

[0092] At operation 1102, the method 1100 can determine, using a viewer tracker of the autostereoscopic display, such as viewer tracker 120, that a camera is located at a first location. The camera at the first location can be referred to as a cartridge camera, which is a different camera than a camera of the viewer tracker.

[0093] At operation 1104, while the camera is at the first location, the method 1100 can cause the autostereoscopic display to sequentially display a series of specified display images. In a specific example, the series of specified display images can include 28 specified display images. Other numbers of images can be used.

[0094] At operation 1106, while the camera is at the first location, the method 1100 can cause the camera to capture a respective first series of captured images of the autostereoscopic display as the series of specified images is displayed.

[0095] At operation 1108, the method 1100 can generate an alert instructing a user to reposition the camera.

[0096] At operation 1110, the method 1100 can determine, using the viewer tracker of the autostereoscopic display, that the camera is located at a second location different from the first location;

[0097] At operation 1112, while the camera is at the second location, the method 1100 can cause the autostereoscopic display to sequentially display the series of specified display images. The camera at the second location can also be referred to as the cartridge camera.

[0098] At operation 1114, while the camera is at the second location, the method 1100 can cause the camera to capture a respective second series of captured images of the autostereoscopic display as the series of specified images is displayed.

[0099] At operation 1116, the method 1100 can determine at least one weaving model parameter from the first series of captured images, the second series of captured images, the first location, and the second location. The at least one weaving model parameter can pertain to whether a pixel of the display panel is directed to a left eye of the viewer, a right eye of the viewer, or to both the left eye and the right eye of the viewer.

[0100] At operation 1118, the method 1100 can store, on a storage medium included with or coupled to the autostereoscopic display, data representing the at least one weaving model parameter.

[0101] The method 1100 can optionally further include determining, from the first series of captured images, the second series of captured images, the first location,and the second location, a value of a slant angle, such as a rotational orientation (a), between the parallax-generating optic and the display panel.

[0102] The method 1100 can optionally further include determining, from the first series of captured images, the second series of captured images, the first location, and the second location, a relationship between a pitch of the parallax-generating optic and a pitch of the display panel.

[0103] The method 1100 can optionally further include determining, from the first series of captured images, the second series of captured images, the first location, and the second location, a phase function central value, such as a center phase (0C), that corresponds to a lateral misalignment between the parallax-generating optic and the display panel.

[0104] FIG. 12 shows a flowchart of an example of a method 1200 for calibrating an autostereoscopic display. The autostereoscopic display can include a display panel, such as display panel 112, and a parallax-generating optic, such as parallax-generating optic 118, that can direct light from the display panel to a viewer, such as viewer 42. Compared with the method 1100 of FIG. 11, the method 1200 can use additional hardware, such as by using two cameras rather than a single camera, and can be executed more quickly because the images need only be displayed a single time, rather than twice. The method 1200 can be executed by processing circuitry, such as processing circuitry 930. The method 1200 is but one example of a method for calibrating an autostereoscopic display. Other suitable methods can be used.

[0105] At operation 1202, the method 1200 can determine, using a viewer tracker of the autostereoscopic display, such as viewer tracker 120, that a first camera is located at a first location and a second camera is located at a second location different from the first location. The first and second cameras can be referred to as first and second cartridge cameras, which are different than a camera of the viewer tracker.

[0106] At operation 1204, the method 1200 can cause the autostereoscopic display to sequentially display a series of specified display images.

[0107] At operation 1206, the method 1200 can cause the first camera to capture a respective first series of captured images of the autostereoscopic display as the series of specified images is displayed.

[0108] At operation 1208, the method 1200 can cause the second camera to capture a respective second series of captured images of the autostereoscopic display as the series of specified images is displayed.

[0109] At operation 1210, the method 1200 can determine at least one weaving model parameter from the first series of captured images, the second series of captured images, the first location, and the second location. The at least one weaving model parameter can pertain to whether a pixel of the display panel is directed to a left eye of the viewer, a right eye of the viewer, or to both the left eye and the right eye of the viewer.

[0110] At operation 1212, the method 1200 can store, on a storage medium included with or coupled to the autostereoscopic display, data representing the at least one weaving model parameter.

[0111] The method 1200 can optionally further include determining, from the first series of captured images, the second series of captured images, the first location, and the second location, a value of a slant angle, such as a rotational orientation (a), between the parallax-generating optic and the display panel.

[0112] The method 1200 can optionally further include determining, from the first series of captured images, the second series of captured images, the first location, and the second location, a relationship between a pitch of the parallax-generating optic and a pitch of the display panel.

[0113] The method 1200 can optionally further include determining, from the first series of captured images, the second series of captured images, the first location, and the second location, a phase function central value, such as a center phase (0C), that corresponds to a lateral misalignment between the parallax-generating optic and the display panel.

[0114] Six specific examples of techniques for calibrating an autostereoscopic display are described presently.

[0115] In a first example, a user can position the at least one patterned target to face the autostereoscopic display of the autostereoscopic display system. The user can position the patterned target and camera such that the camera points at the autostereoscopic display. The autostereoscopic display system can cause the camera tocapture an image of the patterned target, as reflected from the autostereoscopic display. The camera can have a specified location at the target, such as located in a square of the chessboard or checkerboard pattern. The camera can be visible in the image of the patterned target. The camera can be attached to the patterned target so that the patterned target and the camera can be moved together by positioning the patterned target. The autostereoscopic display system can display the captured image on the autostereoscopic display such that the camera can capture an image of the displayed patterned target as displayed on the autostereoscopic display, superimposed with (but misaligned with) a reflection of the patterned target formed from a surface of the autostereoscopic display. The user can manually adjust at least one of the position of the camera or the position of the autostereoscopic display to align the displayed patterned target and the reflection of the patterned target. The user can perform the manual adjustment iteratively, such as by alternating between adjusting the position of the camera and adjusting the position of the autostereoscopic display. Performing alignment involves reducing an offset between the displayed patterned target and the reflection of the patterned target. As the offset is reduced, an angular misalignment of the autostereoscopic display (e.g., an angular error between where the autostereoscopic display intends to direct light and where the autostereoscopic display actually directs the light) is reduced. When the displayed patterned target and the reflection of the patterned target are aligned, the angular misalignment between the camera and the autostereoscopic display is reduced or minimized.

[0116] In a second example, the hardware can be the same as in the first example, but the autostereoscopic display system can perform the alignment automatically (rather than having the user perform the alignment manually). For example, the autostereoscopic display system can cause the autostereoscopic display to adjust the position of the displayed patterned target on the autostereoscopic display to move toward the position of the reflection of the patterned target (which may not change during the automatic alignment), to reduce the offset between the displayed patterned target and the reflection of the patterned target. The autostereoscopic display system can perform the automatic adjustment iteratively, such as by steepest descent, using a series of captured images from the camera. As the offset is reduced, an angular misalignmentof the autostereoscopic display is reduced. When the displayed patterned target and the reflection of the patterned target are aligned, the angular misalignment of the autostereoscopic display is reduced or minimized.

[0117] In a third example, the hardware can be the same as in the first and second examples, and the autostereoscopic display system can perform the alignment automatically, but the autostereoscopic display system can cause the autostereoscopic display to display a generated or previously-saved image of the patterned target, rather than displaying a live (or nearly live) image obtained in real time (or nearly real time) from the camera. The autostereoscopic display system can perform calculations that simulate the iterations, without requiring the camera to obtain multiple captured images. For example, the autostereoscopic display system can adjust the location on the autostereoscopic display at which the generated or previously saved image is displayed, to reduce the offset between the displayed generated or previously-saved image and the reflection of the patterned target. As the offset is reduced, an angular misalignment of the autostereoscopic display is reduced. When the displayed patterned target and the reflection of the patterned target are aligned, the angular misalignment of the autostereoscopic display is reduced or minimized.

[0118] In the first, second, and third examples described above, the autostereoscopic display system can use one camera and one patterned target to calibrate the autostereoscopic display. In the following fourth, fifth, and sixth examples, the calibration techniques can calibrate weaving model parameters (e.g., three-dimensional or 3D parameters) for the autostereoscopic display. The weaving model parameters describe how pixels of an image are distributed over the surface area of a display panel of the autostereoscopic display, such that a parallax-inducing element (e.g., a lenticular lens array or a parallax-inducing barrier) can direct the pixels to the eyes of a viewer to simulate 3D perception.

[0119] A fourth example can be performed using a single patterned target and a single camera. In the fourth example, a user can position the patterned target and camera at a first location such that the camera points at the autostereoscopic display. The autostereoscopic display system can cause the autostereoscopic display to display a series of specified images (such as 28 woven images). The autostereoscopic displaysystem can cause the camera to capture a respective first series of captured images of the autostereoscopic display as the series of specified images is displayed. The user can then reposition the patterned target and camera at a second location, different from the first location, such that the camera points at the autostereoscopic display. The autostereoscopic display system can cause the autostereoscopic display to again display the series of specified images (such as the 28 images). The autostereoscopic display system can cause the camera to capture a respective second series of captured images of the autostereoscopic display as the series of specified images is displayed. The autostereoscopic display system can determine a beneficial set of weaving model parameters from the first and second series of captured images.

[0120] A fifth example can be performed using a single patterned target and two cameras attached to the patterned target. The fifth example may be executed more quickly than the fourth example but may require additional hardware. In the fifth example, a user can position the patterned target and camera at a location such that both cameras point at the autostereoscopic display. The autostereoscopic display system can cause the autostereoscopic display to display a series of specified images (such as 28 images). The autostereoscopic display system can cause the cameras to capture respective first and second series of captured images of the autostereoscopic display as the series of specified images is displayed. The autostereoscopic display system can determine a beneficial set of weaving model parameters from the first and second series of captured images.

[0121] A sixth example can be performed using either a single patterned target and a single camera, capturing series of images at two different locations, or a single patterned target and two cameras at different locations on the patterned target, each camera capturing a respective series of images. The sixth example can use Fourier analysis to determine a slant / pitch center view and can fit the weaving model parameters.

[0122] For the six examples discussed above, the patterned target and associated one or more cameras may be referred to as a “cartridge”. The six examples discussed above can provide calibration of the lateral alignment of the parallax-inducing element to the display panel. This calibration may be referred to as calibration of the 3D lens. This calibration may determine values for some or all of the quantities shown in FIG. 8,which can allow the autostereoscopic display system to operate with a specified lateral misalignment and / or longitudinal misalignment between the components. There are other types of calibrations, which can optionally use different hardware configurations and can measure and optionally correct for different quantities.

[0123] Seven specific examples of techniques for calibrating properties of the cameras are described presently.

[0124] As a first example, a calibration technique can measure and / or correct for quantities related to intrinsics, such as specific properties of each camera independent of any other cameras. For example, intrinsic properties of a camera can include specifying a field of view of the camera, ensuring that the lens is properly aligned to the sensor, and others. The intrinsic properties relate to cameras that are part of the autostereoscopic display system, such as cameras that are part of a smart phone, tablet, monitor, or laptop computer. The calibration technique may utilize one or two of these cameras. The calibration technique can use a single, relatively large patterned target, which may be positioned to cover a field of view (or at least a horizontal extent of the field of view) of the camera or cameras. This example may not require any cameras in the cartridge. Using only a single patterned target can allow the user to calibrate distortion parameters, but not a focal length of the lens in the camera. If the distance from an effective lens pinhole to the calibration target is known, then the focal length of the lens in the camera can be determined.

[0125] As a second example, a calibration technique can measure and / or correct for quantities related to intrinsics, such as specific properties of each camera independent of any other cameras. The calibration technique can use two relatively small patterned targets, which may be positioned to be non-parallel (e.g., angled with respect to each other, such as one being rotated about a vertical axis compared to the other). The two relatively small patterned targets can cover a field of view (or at least a horizontal extent of the field of view) of the camera or cameras. This example may not require any cameras in the cartridge. Using two angled targets can allow the user to determine most or all of the intrinsic properties of the camera. The two targets can be angled by 30 degrees, an angle between 25 and 35 degrees, or any suitable angle. The second examplemay not be able to calculate a skew parameter for the camera, but the skew parameter may be estimated to be zero for most cameras.

[0126] As a third example, a calibration technique can measure and / or correct for quantities related to extrinsics, such as properties of one camera as it relates to another camera or to the autostereoscopic display. For example, extrinsic properties of the camera can include a position of the camera in space, a rotation of the camera in space, and a translation of the camera in space, and others. The extrinsic properties relate to cameras that are part of the autostereoscopic display system, such as cameras that are part of a smart phone, tablet, or laptop computer. The calibration technique may utilize two or more of these cameras. The calibration technique can use a single, relatively small patterned target, which may optionally be positioned to cover a field of view (or at least a horizontal extent of the field of view) of the camera or cameras. The calibration technique may not require any cameras in the cartridge, and therefore may not require that the cartridge be calibrated.

[0127] As a fourth example, a calibration technique can measure and / or correct for quantities related to extrinsics, such as properties of one camera as it relates to another camera. Such properties can include a center screen of the camera. The extrinsic properties relate a camera that is part of the autostereoscopic display system to an external camera, such as a camera included with a patterned target. The calibration technique can use a single, relatively small patterned target, which may optionally be positioned to cover a field of view (or at least a horizontal extent of the field of view) of the camera or cameras. The calibration technique may use one camera in the cartridge. The calibration technique may not require that the cartridge be calibrated, although such calibration of the cartridge can improve an accuracy of the calibration technique.

[0128] As a fifth example, a calibration technique (such as the six examples described above) can measure and / or correct for quantities related to the 3D lens, which is included in the autostereoscopic display. The calibration technique can use a single, relatively small patterned target, which may optionally be positioned to cover a field of view (or at least a horizontal extent of the field of view) of the camera or cameras. The calibration technique may use two cameras in the cartridge to capture one series of measurements, or one camera in the cartridge to capture two subsequent series ofmeasurements. The calibration technique may not require that the cartridge be calibrated, although such calibration of the cartridge can improve an accuracy of the calibration technique.

[0129] Due to tolerances in the manufacturing process, the 3D lens parameters can vary over the surface of the autostereoscopic display. The calibration technique can account for such variation by using correction maps. A first correction map (“correction map A”) can account for nonuniformities or variations in a lateral direction. A second correction map (“correction map B”) can account for nonuniformities or variations in a perpendicular (or longitudinal) direction.

[0130] As a sixth example, a calibration technique can measure and / or correct for quantities related to correction map A. The calibration technique can use a single, relatively small patterned target, which may optionally be positioned to cover a field of view (or at least a horizontal extent of the field of view) of the camera or cameras. The calibration technique may use one camera in the cartridge, which can be positioned to capture the complete operational surface area of the autostereoscopic display. The calibration technique may not require that the cartridge be calibrated, although such calibration of the cartridge can improve an accuracy of the calibration technique.

[0131] As a seventh example, a calibration technique can measure and / or correct for quantities related to correction map B. The calibration technique can use a single, relatively small patterned target, which may optionally be positioned to cover a field of view (or at least a horizontal extent of the field of view) of the camera or cameras. The calibration technique may use two or more cameras in the cartridge, which can be positioned to each capture the complete operational surface area of the autostereoscopic display. The calibration technique may not require that the cartridge be calibrated, although such calibration of the cartridge can improve an accuracy of the calibration technique.

[0132] For an autostereoscopic screen with an eye-tracking camera, it can be beneficial to perform calibration while the cameras in the system are in reciprocal tracking mode, for example, the eye-tracking camera can track the cartridge patterned board, while at the same time the camera in the cartridge can track the autostereoscopic screen. One benefit is that a misinterpretation of the tracking camera can becompensated with a misinterpretation of the cartridge camera trying to estimate the position of the autostereoscopic screen. This can lead to good 3D performance of the autostereoscopic display.

[0133] In general, a single camera directed toward the autostereoscopic display allows the calibration system to determine optimal values for slant, distance-to-pitch ratio, and center view parameters for that specific camera position, along with lateral correction parameters. The lateral correction parameters incorporate corrections that belong to perpendicular correction parameters, because the system may lack additional viewing angles to distinguish their respective contributions.

[0134] The calibration system can achieve precise calibration with minimal phase error when using two cameras, as the optimization process per pixel combines both lateral and perpendicular corrections with two measurements for two unknown values. The correction parameters can absorb any measurement noise.

[0135] The system can reject more noise when using three to five cameras by fitting the lateral and perpendicular correction values across multiple measurement points.

[0136] Multiple viewing angles for each pixel determine the perpendicular correction parameters and the distance parameter. Positioning cameras with substantial separation distances from each other improves parameter estimates, with horizontal separation providing sufficient results. For example, positioning cameras with 20 centimeters of baseline separation at a distance of 70 centimeters away from the autostereoscopic display, plus adding a camera position between the separated cameras, can produce robust estimates of the parameters and robust rejection of noise in the estimates.

[0137] Optionally positioning the multiple cameras in a non-linear arrangement, rather than along a purely horizontal line, can improve accuracy in the estimated parameters with reduced noise in the estimates of the parameters.

[0138] To further illustrate the system and method disclosed herein, a nonlimiting list of examples is provided below. Each of the following non-limiting examples can stand on its own or can be combined in any permutation or combination with any one or more of the other examples.

[0139] In Example 1, a method for calibrating an autostereoscopic display, the autostereoscopic display comprising a display panel and a parallax-generating optic configured to direct light from the display panel to a viewer, the method can comprise: receiving, from a camera fixedly attached to a patterned target having a pattern on the patterned target, a captured image of at least the patterned target as reflected from the autostereoscopic display; determining, based at least in part on the captured image, at least one calibration parameter that quantifies misalignment between the parallaxgenerating optic and the display panel; and storing, on a storage medium included with or coupled to the autostereoscopic display, data representing the at least one calibration parameter.

[0140] In Example 2, the method of Example 1 can optionally further comprise: generating instructions to position the patterned target and the camera to face the autostereoscopic display such that a reflection of the patterned target from the autostereoscopic display is within a field of view of the camera.

[0141] In Example 3, the method of any one of Examples 1-2 can optionally further comprise: causing the autostereoscopic display to display the pattern; and causing the camera to capture the captured image of the autostereoscopic display, the captured image including a superposition of the pattern as displayed on the autostereoscopic display and the reflection of the patterned target, the captured image including a superposition offset between the pattern as displayed on the autostereoscopic display and the reflection of the patterned target, the superposition offset having an initial superposition offset value.

[0142] In Example 4, the method of any one of Examples 1-3 can optionally be configured such that determining the at least one calibration parameter comprises: causing at least one of the camera or the autostereoscopic display to reduce the superposition offset from the initial superposition offset value to a reduced superposition offset value; and determining the at least one calibration parameter from conditions of the autostereoscopic display and the camera when the superposition offset has the reduced superposition offset value, the at least one calibration parameter quantifying a misalignment between the parallax-generating optic and the display panel.

[0143] In Example 5, the method of any one of Examples 1-4 can optionally further comprise: determining, with a viewer tracker of the autostereoscopic display, a position of the camera when the superposition offset has the reduced superposition offset value.

[0144] In Example 6, the method of any one of Examples 1-5 can optionally be configured such that when the superposition offset is zero, the camera has a longitudinal axis that is orthogonal to a plane of the autostereoscopic display.

[0145] In Example 7, the method of any one of Examples 1-6 can optionally be configured such that displaying the pattern comprises displaying the captured image.

[0146] In Example 8, the method of any one of Examples 1-7 can optionally be configured such that displaying the pattern comprises displaying a generated image or a previously saved image of the patterned target.

[0147] In Example 9, the method of any one of Examples 1-8 can optionally be configured such that causing at least one of the camera or the autostereoscopic display to reduce the superposition offset comprises prompting a user to manually adjust at least one of a position of the camera or a position of the autostereoscopic display to manually reduce the superposition offset.

[0148] In Example 10, the method of any one of Examples 1-9 can optionally be configured such that prompting the user comprises prompting the user to alternate between adjusting the position of the camera and adjusting the position of the autostereoscopic display to manually reduce the superposition offset.

[0149] In Example 11, the method of any one of Examples 1-10 can optionally be configured such that causing at least one of the camera or the autostereoscopic display to reduce the superposition offset comprises automatically causing the autostereoscopic display to adjust a position of the pattern displayed on the autostereoscopic display.

[0150] In Example 12, the method of any one of Examples 1-11 can optionally further comprise: determining a display offset value; and repeatedly: displaying, on the autostereoscopic display, an offset pattern that comprises the pattern as offset by the display offset value; capturing, with the camera, a real-time captured image of the autostereoscopic display, the real-time captured image including a superposition of the offset pattern as displayed on the autostereoscopic display and the reflection of thepatterned target, the real-time captured image including a superposition offset between the pattern as displayed on the autostereoscopic display and the reflection of the patterned target, the superposition offset having a superposition offset value; and automatically revising, based on the real-time captured image, the display offset value to reduce the superposition offset value.

[0151] In Example 13, the method of any one of Examples 1-12 can optionally further comprise using steepest descent to automatically revise the display offset value.

[0152] In Example 14, the method of any one of Examples 1-13 can optionally be configured such that the patterned target comprises indicia that extend in a plane.

[0153] In Example 15, the method of any one of Examples 1-14 can optionally be configured such that the indicia comprises a grid or a pattern of alternating bright and dark squares.

[0154] In Example 16, a method for calibrating an autostereoscopic display, the autostereoscopic display comprising a display panel and a parallax-generating optic configured to direct light from the display panel to a viewer, the method can comprise: determining, using a viewer tracker of the autostereoscopic display, that a camera is located at a first location; while the camera is at the first location, causing the autostereoscopic display to sequentially display a series of specified display images; while the camera is at the first location, causing the camera to capture a respective first series of captured images of the autostereoscopic display as the series of specified images is displayed; generating an alert instructing a user to reposition the camera; determining, using the viewer tracker of the autostereoscopic display, that the camera is located at a second location different from the first location; while the camera is at the second location, causing the autostereoscopic display to sequentially display the series of specified display images; while the camera is at the second location, causing the camera to capture a respective second series of captured images of the autostereoscopic display as the series of specified images is displayed; determining at least one weaving model parameter from the first series of captured images, the second series of captured images, the first location, and the second location, the at least one weaving model parameter pertaining to whether a pixel of the display panel is directed to a left eye of the viewer, a right eye of the viewer, or to both the left eye and the right eye of the viewer; andstoring, on a storage medium included with or coupled to the autostereoscopic display, data representing the at least one weaving model parameter.

[0155] In Example 17, the method of Example 16 can optionally further comprise: determining, from the first series of captured images, the second series of captured images, the first location, and the second location: a value of a slant angle between the parallax-generating optic and the display panel; a relationship between a pitch of the parallax-generating optic and a pitch of the display panel; and a phase function central value that corresponds to a lateral misalignment between the parallaxgenerating optic and the display panel.

[0156] In Example 18, method of any one of Examples 16-17 can optionally be configured such that the series of specified display images includes 28 specified display images.

[0157] In Example 19, a method for calibrating an autostereoscopic display, the autostereoscopic display comprising a display panel and a parallax-generating optic configured to direct light from the display panel to a viewer, the method can comprise: determining, using a viewer tracker of the autostereoscopic display, that a first camera is located at a first location and a second camera is located at a second location different from the first location; causing the autostereoscopic display to sequentially display a series of specified display images; causing the first camera to capture a respective first series of captured images of the autostereoscopic display as the series of specified images is displayed; causing the second camera to capture a respective second series of captured images of the autostereoscopic display as the series of specified images is displayed; determining at least one weaving model parameter from the first series of captured images, the second series of captured images, the first location, and the second location, the at least one weaving model parameter pertaining to whether a pixel of the display panel is directed to a left eye of the viewer, a right eye of the viewer, or to both the left eye and the right eye of the viewer; and storing, on a storage medium included with or coupled to the autostereoscopic display, data representing the at least one weaving model parameter.

[0158] In Example 20, the method of Example 19 can optionally further comprise: determining, from the first series of captured images, the second series ofcaptured images, the first location, and the second location: a value of a slant angle between the parallax-generating optic and the display panel; a relationship between a pitch of the parallax-generating optic and a pitch of the display panel; and a phase function central value that corresponds to a lateral misalignment between the parallax- generating optic and the display panel.

[0159] It should be understood that the above-described examples are merely illustrative of some of the many specific examples that represent the principles described herein. Clearly, those skilled in the art can readily devise numerous other arrangements without departing from the scope as defined by the following claims.

Claims

CLAIMSWHAT IS CLAIMED IS:

1. A method for calibrating an autostereoscopic display, the autostereoscopic display comprising a display panel and a parallax-generating optic configured to direct light from the display panel to a viewer, the method comprising: receiving, from a camera fixedly attached to a patterned target having a pattern on the patterned target, a captured image of at least the patterned target as reflected from the autostereoscopic display; determining, based at least in part on the captured image, at least one calibration parameter that quantifies misalignment between the parallax-generating optic and the display panel; and storing, on a storage medium included with or coupled to the autostereoscopic display, data representing the at least one calibration parameter.

2. The method of claim 1, further comprising: generating instructions to position the patterned target and the camera to face the autostereoscopic display such that a reflection of the patterned target from the autostereoscopic display is within a field of view of the camera.

3. The method of claim 2, further comprising: causing the autostereoscopic display to display the pattern; and causing the camera to capture the captured image of the autostereoscopic display, the captured image including a superposition of the pattern as displayed on the autostereoscopic display and the reflection of the patterned target, the captured image including a superposition offset between the pattern as displayed on the autostereoscopic display and the reflection of the patterned target, the superposition offset having an initial superposition offset value.

4. The method of claim 3, wherein determining the at least one calibration parameter comprises: causing at least one of the camera or the autostereoscopic display to reduce the superposition offset from the initial superposition offset value to a reduced superposition offset value; and determining the at least one calibration parameter from conditions of the autostereoscopic display and the camera when the superposition offset has the reduced superposition offset value, the at least one calibration parameter quantifying a misalignment between the parallax-generating optic and the display panel.

5. The method of claim 4, further comprising: determining, with a viewer tracker of the autostereoscopic display, a position of the camera when the superposition offset has the reduced superposition offset value.

6. The method of claim 5, wherein when the superposition offset is zero, the camera has a longitudinal axis that is orthogonal to a plane of the autostereoscopic display.

7. The method of claim 4, wherein displaying the pattern comprises displaying the captured image.

8. The method of claim 4, wherein displaying the pattern comprises displaying a generated image or a previously saved image of the patterned target.

9. The method of claim 4, wherein causing at least one of the camera or the autostereoscopic display to reduce the superposition offset comprises prompting a user to manually adjust at least one of a position of the camera or a position of the autostereoscopic display to manually reduce the superposition offset.

10. The method of claim 9, wherein prompting the user comprises prompting the user to alternate between adjusting the position of the camera and adjusting the position of the autostereoscopic display to manually reduce the superposition offset.

11. The method of claim 4, wherein causing at least one of the camera or the autostereoscopic display to reduce the superposition offset comprises automatically causing the autostereoscopic display to adjust a position of the pattern displayed on the autostereoscopic display.

12. The method of claim 11, further comprising: determining a display offset value; and repeatedly: displaying, on the autostereoscopic display, an offset pattern that comprises the pattern as offset by the display offset value; capturing, with the camera, a real-time captured image of the autostereoscopic display, the real-time captured image including a superposition of the offset pattern as displayed on the autostereoscopic display and the reflection of the patterned target, the real-time captured image including a superposition offset between the pattern as displayed on the autostereoscopic display and the reflection of the patterned target, the superposition offset having a superposition offset value; and automatically revising, based on the real-time captured image, the display offset value to reduce the superposition offset value.

13. The method of claim 12, further comprising using steepest descent to automatically revise the display offset value.

14. The method of claim 4, wherein the patterned target comprises indicia that extend in a plane.

15. The method of claim 14, wherein the indicia comprises a grid or a pattern of alternating bright and dark squares.

16. A method for calibrating an autostereoscopic display, the autostereoscopic display comprising a display panel and a parallax-generating optic configured to direct light from the display panel to a viewer, the method comprising: determining, using a viewer tracker of the autostereoscopic display, that a camera is located at a first location; while the camera is at the first location, causing the autostereoscopic display to sequentially display a series of specified display images; while the camera is at the first location, causing the camera to capture a respective first series of captured images of the autostereoscopic display as the series of specified images is displayed; generating an alert instructing a user to reposition the camera; determining, using the viewer tracker of the autostereoscopic display, that the camera is located at a second location different from the first location; while the camera is at the second location, causing the autostereoscopic display to sequentially display the series of specified display images; while the camera is at the second location, causing the camera to capture a respective second series of captured images of the autostereoscopic display as the series of specified images is displayed;determining at least one weaving model parameter from the first series of captured images, the second series of captured images, the first location, and the second location, the at least one weaving model parameter pertaining to whether a pixel of the display panel is directed to a left eye of the viewer, a right eye of the viewer, or to both the left eye and the right eye of the viewer; and storing, on a storage medium included with or coupled to the autostereoscopic display, data representing the at least one weaving model parameter.

17. The method of claim 16, further comprising: determining, from the first series of captured images, the second series of captured images, the first location, and the second location: a value of a slant angle between the parallax-generating optic and the display panel; a relationship between a pitch of the parallax-generating optic and a pitch of the display panel; and a phase function central value that corresponds to a lateral misalignment between the parallax-generating optic and the display panel.

18. The method of claim 16, wherein the series of specified display images includes 28 specified display images.

19. A method for calibrating an autostereoscopic display, the autostereoscopic display comprising a display panel and a parallax-generating optic configured to direct light from the display panel to a viewer, the method comprising: determining, using a viewer tracker of the autostereoscopic display, that a first camera is located at a first location and a second camera is located at a second location different from the first location; causing the autostereoscopic display to sequentially display a series of specified display images; causing the first camera to capture a respective first series of captured images of the autostereoscopic display as the series of specified images is displayed; causing the second camera to capture a respective second series of captured images of the autostereoscopic display as the series of specified images is displayed; determining at least one weaving model parameter from the first series of captured images, the second series of captured images, the first location, and the second location, the at least one weaving model parameter pertaining to whether a pixel of the display panel is directed to a left eye of the viewer, a right eye of the viewer, or to both the left eye and the right eye of the viewer; and storing, on a storage medium included with or coupled to the autostereoscopic display, data representing the at least one weaving model parameter.

20. The method of claim 19, further comprising: determining, from the first series of captured images, the second series of captured images, the first location, and the second location: a value of a slant angle between the parallax-generating optic and the display panel; a relationship between a pitch of the parallax-generating optic and a pitch of the display panel; and a phase function central value that corresponds to a lateral misalignment between the parallax-generating optic and the display panel.

Images