Reconverging stereoscopic image pair based on saliency

Abstract

An autostereoscopic display system can reconverge a stereoscopic image pair. Processing circuitry can determine saliency information that indicates a region of interest of an initial stereoscopic image pair, determine a convergence plane based on disparity characteristics of the region of interest of the initial stereoscopic image pair, and generate a final stereoscopic image pair using the initial stereoscopic image pair and the convergence plane. The processing circuitry can introduce a horizontal offset between left and right images of the initial stereoscopic image pair to form left and right images of the final stereoscopic image pair. The horizontal offset can have an offset value selected such that a difference between the left and right images of the final stereoscopic image pair in the region of interest is less than a difference between the left and right images of the initial stereoscopic image pair in the region of interest.

Description

RECONVERGING STEREOSCOPIC IMAGE PAIR BASED ON SALIENCYCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 623,748, filed January 22, 2024, which is incorporated by reference herein in its entirety.FIELD OF THE DISCLOSURE

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

[0003] A multiview display can provide different views of a multiview image to a viewer. 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.SUMMARY

[0004] In an example, an autostereoscopic display system can comprise processing circuitry that can perform operations. The operations can comprise: receiving data specifying an initial stereoscopic image pair; determining, from the initial stereoscopic image pair, saliency information that indicates a region of interest of the initial stereoscopic image pair; determining a convergence plane based on disparity characteristics of the region of interest of the initial stereoscopic image pair; and generating a final stereoscopic image pair using the initial stereoscopic image pair and the convergence plane.

[0005] In an example, a method can include reconverging a stereoscopic image pair, and the image pair can optionally be displayed using an autostereoscopic system. The method can comprise: receiving, with processing circuitry, data specifying an initial stereoscopic image pair; determining, with the processing circuitry, from the initialstereoscopic image pair, saliency information that indicates a region of interest of the initial stereoscopic image pair; determining, with the processing circuitry, a convergence plane based on disparity characteristics of the region of interest of the initial stereoscopic image pair; and generating, with the processing circuitry, a final stereoscopic image pair using the initial stereoscopic image pair and the convergence plane.

[0006] This Summary is intended to provide an overview of subject matter of the present document. It is not intended to provide an exclusive or exhaustive explanation of the invention. The detailed description is included to provide further information about the present subject matter.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 shows an exploded, perspective-view schematic drawing of an example of a multi view 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 a flowchart of an example of a method for reconverging a stereoscopic image pair.

[0015] FIG. 9 shows a front view drawing of examples of a left image and a right image of an initial stereoscopic image pair.

[0016] FIG. 10 shows a front view drawing of examples of saliency information that indicates a region of interest of the initial stereoscopic image pair.

[0017] FIG. 11 shows a schematic drawing of an example of determining the convergence plane based on disparity characteristics of the region of interest of the initial stereoscopic image pair.

[0018] FIG. 12 shows a front view drawing of examples of a left image and a right image of a final stereoscopic image pair.DETAILED DESCRIPTION

[0019] An autostereoscopic display system can receive a stereoscopic image pair for display on an autostereoscopic display. The received stereoscopic image pair may require additional processing, before being displayed, to improve the autostereoscopic viewing experience. For example, to improve the comfort of the viewer, the autostereoscopic display system can select a different convergence plane for the stereoscopic image pair, in a process referred to as “reconverging” the image pair. More specifically, the autostereoscopic display system can receive an initial stereoscopic image pair, can reconverge the initial stereoscopic image pair to form a final stereoscopic image pair having a convergence plane selected in a particular manner, and can display the final stereoscopic image pair on the autostereoscopic display.

[0020] In the reconverging technique described in detail below, the autostereoscopic display system can use saliency information from the initial stereoscopic image pair to identify a region of interest in the stereoscopic image. The autostereoscopic display system can reconverge the initial stereoscopic image pair based on disparity information in the region of interest. When the autostereoscopic display system displays the final stereoscopic image pair on the autostereoscopic display, a viewer can perceive the region of interest as being located roughly at or near the plane of autostereoscopic display, rather than too close to the viewer (e.g., in front of the autostereoscopic display) or too far from the viewer (e.g., behind the autostereoscopic display). As used herein, the term disparity is intended to mean a difference in location of a given location in a scene between left and right images of a stereoscopic image pair representing the scene.

[0021] As a specific example, the initial stereoscopic image pair may include a flower on a background. The autostereoscopic display system can determine that the flower forms the region of interest, such that a perimeter of the flower defines a perimeter of the region of interest. The autostereoscopic display system can reconverge the initial stereoscopic image pair, based on disparity information in the region of the flower (such as without using information from the background), to form the final stereoscopic image pair. When the autostereoscopic display system displays the finalstereoscopic image pair on the autostereoscopic display, the flower can be perceived as being at or near the plane of the autostereoscopic display, rather than far above or far behind the plane of the autostereoscopic display.

[0022] FIG. 1 shows an exploded, perspective-view schematic drawing of an example of a multiview display system 100 that includes a multiview display 110. The configuration of FIG. 1 is but one example of a multiview display system 100; other configurations can be used.

[0023] The sign conventions shown in FIG. 1 and used below assume that the multiview display 110 extends in an (x, y) plane, and that a z-axis extends away from the multiview display 110 and generally toward a viewer 42, along a direction that is orthogonal to a plane of the multiview display 110. Other sign conventions can be used.

[0024] The multiview display system 100 can include a multiview display 110. The multiview display 110 can provide different views of a multiview image to the viewer 42. For example, as the viewer 42 moves in space, the multiview display 110 can direct different views of the multiview image to the left and right eyes of the viewer 42, so that the viewer 42 can observe the different views of the multiview image from different locations or orientations. In some configurations, the multiview display 110 can provide the multiple views at respective fixed location regions in space, so that the multiview display 110 can operate without using eye tracking. In other configurations, such as the autostereoscopic configurations described in detail below, the multiview 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 multiview display 110 displays the multiview image 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 multi view display 110.

[0025] For configurations in which the multiview display 110 provides just two different views of the multiview image, the multiview display 110 can be an autostereoscopic display or three-dimensional (3D) display. 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 scenein 3D with just the viewer’s naked eyes, without the use of additional glasses or headgear.

[0026] The multiview display system 100 can include a viewer tracker 120 that can dynamically determine the location of the viewer 42. The multiview 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 multiview 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 image to 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 xv, yv, and zv) 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, a camera 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.

[0027] The autostereoscopic display can be a lenticular autostereoscopic display. In a lenticular autostereoscopic display, a display panel 112 can display the multiviewimage, 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 multiview image 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 from the 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.

[0028] In an example, a display panel 112 can display the multiview image. 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 y- 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 138 that can specify how the content of the multiview image 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.

[0029] 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 138, 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 an intensity 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.

[0030] 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 138, 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 theelectromagnetic 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 light valves 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.

[0031] 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).

[0032] 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.

[0033] 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 viewing regions. 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.

[0034] 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 slant angle (a) of 45 degrees or about 45 degrees with respect to the grid axes 208. 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).

[0035] 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 to within a specified thickness tolerance and can set the spacing between the display panel112 and parallax-generating optic 118 to have a value equal to the specified thickness when the autostereoscopic display is assembled.

[0036] As illustrated in FIG. 1, the multiview display system 100 can include processing circuitry 130. The processing circuitry 130 can include a non-transitory computer-readable storage medium 132, such as a hard disk, a solid-state hard drive, memory, optical media, magnetic media, semiconductor media, punch cards, or others. The non-transitory computer-readable storage medium 132 can be included locally with the processing circuitry 130 or can be located remotely from the processing circuitry 130 and be accessible through a wired or wireless connection. The non-transitory computer- readable storage medium 132 can store instructions 134 for performing a particular task or series of tasks or executing some or all steps of a method.

[0037] The instructions 134, when executed by the processing circuitry 130, can cause the processing circuitry 130 to perform operations 136. For example, the instructions 134 may be for reconverging a stereoscopic image pair. Suitable operations 136 for reconverging a stereoscopic image pair can include, among other operations: receiving, with the processing circuitry 130, data specifying an initial stereoscopic image pair; determining, with the processing circuitry 130, from the initial stereoscopic image pair, saliency information that indicates a region of interest of the initial stereoscopic image pair; determining, with the processing circuitry 130, a convergence plane based on disparity characteristics of the region of interest of the initial stereoscopic image pair; and generating, with the processing circuitry 130, a final stereoscopic image pair using the initial stereoscopic image pair and the convergence plane. By executing these operations 136, the processing circuitry 130 can cause the multiview display system 100 to perform reconverging a stereoscopic image pair. The operations 136 can further include using the multiview display system 100 to display the stereoscopic image pair. These operations 136 are described in detail below.

[0038] FIG. 8 shows a flowchart of an example of a method 800 for reconverging a stereoscopic image pair. The method 800 can be executed on, apply to, or can be used by or used with, an autostereoscopic display system, such as the multiview display system 100 of FIG. 1. The method 800 can be stored as instructions 134 on a non-transitory computer-readable storage medium 132. The instructions 134, when executed by the processing circuitry 130, can cause the processing circuitry 130 to perform the operations 136. The operations 136 can include the operations detailedbelow for the method 800. The method 800 is but one method for reconverging a stereoscopic image pair; other suitable methods may be used. FIGS. 9-11 provide additional detail regarding the operations 802-808 of method 800.

[0039] At operation 802, the processing circuitry 130 can receive data specifying an initial stereoscopic image pair. The data can be received from memory, a local storage device, or a remote storage device. The data can be included as one or more frames of a video signal, which can specify the initial stereoscopic image pair as one of a series of sequential stereoscopic image pairs. FIG. 9 shows a front view drawing of examples of a left image 912L and a right image 912R of an initial stereoscopic image pair 910. As an example, the initial stereoscopic image pair 910 shows two views of a scene that includes a “+” sign. Other scenes can be used.

[0040] Returning to FIG. 8, at operation 804, the processing circuitry 130 can determine, from the initial stereoscopic image pair, saliency information that indicates a region of interest of the initial stereoscopic image pair 910. The region of interest can include less than all of a left image of the initial stereoscopic image pair 910 and less than all of a right image of the initial stereoscopic image pair 910. The region of interest can include one or more regions of deemed importance to the human visual system.

[0041] The processing circuitry 130 can determine saliency information using one or more techniques. For example, the processing circuitry 130 can use a fully convolutional neural network model. The neural network model can include an encoder based on a residual neural network (ResNet). The neural network model can include a decoder configuration having skip connection that are similar to those in a U-Net. The architecture of a U-Net can include an encoder path, also known as the contracting path, and a decoder path, also known as the expanding path. The encoder can extract features from an input image. The decoder can project those features onto pixel space to produce a dense classification. The encoder and decoder may be symmetrical and connected by paths, which can give the model a “U” shape. The convolutional neural network model can include millions (or more) of trainable parameters, such as can be trained on multiple (e.g., thousands, millions) of images that have known saliency characteristics.

[0042] FIG. 10 shows a front view drawing of examples of saliency information that indicates a region of interest of the initial stereoscopic image pair 910. The processing circuitry 130 can analyze a specified image and can generate the saliency information from the image.

[0043] In the example of FIG. 10, the processing circuitry 130 has determined that the region of interest in the initial stereoscopic image pair 910 is the “+” sign. One way to represent the saliency information is via a saliency map, which can have saliency values (S) in an array that corresponds to a left image and / or a right image of the initial stereoscopic image pair 910. A relatively large value of S, for a pixel of the saliency map, can indicate a relatively high saliency for the corresponding pixel in the image. A relatively small value of S (such as zero), for a pixel of the saliency map, can indicate a relatively low saliency for the corresponding pixel in the image. In some examples, the values of S can take on a finite or infinite number of values. The saliency map can be binary, such with a positive value in the region of interest and a zero value outside the region of interest. In the specific example of FIG. 10, the values of S can have one or more positive values in the region of interest, and a value of zero outside the region of interest.

[0044] The processing circuitry 130 can determine, for the left image 912L of the initial stereoscopic image pair 910, a left saliency map 1022L that indicates the region of interest of the left image 912L of the initial stereoscopic image pair 910. The left saliency map 1022L can have a positive value of S within the region of interest 1024L of the left image 912L. The processing circuitry 130 can determine, from a right image 912R of the initial stereoscopic image pair 910, a right saliency map 1022R that indicates the region of interest of the right image 912R of the initial stereoscopic image pair 910. The right saliency map 1022R can have a positive value of S within the region of interest 1024R of the right image 912R.

[0045] Returning to FIG. 8, at operation 806, the processing circuitry 130 can determine a convergence plane based on disparity characteristics of the region of interest of the initial stereoscopic image pair 910. FIG. 11 shows a schematic drawing of an example of determining the convergence plane based on disparity characteristics of the region of interest of the initial stereoscopic image pair 910.

[0046] Operation 806 can include introducing a horizontal offset between the left image 912L and the right image 912R of the initial stereoscopic image pair 910 to form the left image and the right image of the final stereoscopic image pair. (In this document, the term horizonal is intended to correspond to the axis between the left eye and the right eye of a viewer.) The processing circuitry 130 can select an amount of horizontal offset to reduce or eliminate differences between the left and right images ofthe final stereoscopic image pair in the region of interest. Specifically, the processing circuitry 130 can select the horizontal offset to have an offset value such that a difference between the left and right images of the final stereoscopic image pair in the region of interest is less than a difference between the left image 912L and the right image 912R of the initial stereoscopic image pair 910 in the region of interest. The processing circuitry 130 can effectively ignore portions of the left and right images outside the region of interest. For example, the processing circuitry 130 can use only image information within the region of interest when determining how much horizontal offset to introduce.

[0047] In the example of FIG. 11, the right image 912R is offset from the left image 912L by a variable offset amount. Alternatively, the left image 912L may be offset from the right image 912R by a variable offset amount. As a further alternative, the left image 912L and the right image 912R may be offset from each other by a variable offset amount.

[0048] To determine how much horizontal offset to introduce, the processing circuitry 130 can specify a plurality of horizontal offset values. The plurality of horizontal offset values can include sequential values that are separated by a spacing value that corresponds to a pixel spacing of the initial stereoscopic image pair. For example, the horizontal offset values may include sequential values that are separated by 1 pixel, 2 pixels, or an integer multiple of a pixel size. Other horizontal offsets can be used.

[0049] The processing circuitry 130 can then generate a plurality of provisional stereoscopic image pairs based on the initial stereoscopic image pair and the respective plurality of horizontal offset values. Each provisional stereoscopic image pair can be formed from the left image 912L and the right image 912R of the initial stereoscopic image pair 910 being horizontally offset with respect to each other by an amount corresponding to the respective horizontal offset value.

[0050] The processing circuitry 130 can then determine a plurality of difference values. Each difference value can represent a difference between left and right images of the respective provisional stereoscopic image pair, of the plurality of provisional stereoscopic image pairs, in the region of interest.

[0051] A specific example of a difference value can include an LI distance value. To calculate the LI distance value between the left and right images of a provisionalstereoscopic image pair, the processing circuitry 130 can, for each pixel of the left and right images, perform the following calculations. The processing circuitry 130 can calculate a first quantity as a product of the left image intensity value (such as having larger values with increasing brightness) and the left image saliency value (S, such as a non-zero value in the region of interest and zero outside the region of interest). The processing circuitry 130 can calculate a second quantity as a product of the right image intensity value (such as having larger values with increasing brightness) and the right image saliency value (S, such as a non-zero value in the region of interest and zero outside the region of interest). The processing circuitry 130 can calculate a third quantity as an absolute value of a difference between the first quantity and the second quantity. To produce an image-wide difference value, the processing circuitry 130 can sum the respective third quantities of all the pixels in the left and right images of the provisional stereoscopic image pair. The image-wide difference value represents the difference between the left and right images, only taking into account the region of interest of the left and right images (or weighting the various regions in the images according to values in the respective saliency maps).

[0052] The processing circuitry 130 can repeat the above calculations for different values of horizontal offset to produce a plot 1120 of difference value (along the vertical axis of the plot 1120 of FIG. 11) as a function of horizontal offset (along the horizontal axis of the plot 1120). The processing circuitry 130 can select a convergence plane from the data in the plot 1120. Two examples follow of techniques for selecting the convergence plane.

[0053] In a first example, the processing circuitry 130 can select, as a selected difference value, a least difference value 1132 of the plurality of difference values. The processing circuitry 130 can then select, as the final stereoscopic image pair, a provisional stereoscopic image pair of the plurality of provisional stereoscopic image pairs that corresponds to the selected difference value.

[0054] In a second example, the processing circuitry 130 can fit a difference value curve via interpolation to the plurality of difference values. The processing circuitry 130 can determine a minimum value 1130 of the difference value curve. The processing circuitry 130 can set the convergence plane to be disposed at a location that corresponds to the minimum value of the difference value curve. In many cases, the minimum value of the difference value curve can be located between two adjacentdifference values of the plurality of difference values, and the final stereoscopic image pair can be located between two adjacent provisional stereoscopic image pairs of the plurality of provisional stereoscopic image pairs. These two examples are but mere example for selecting the convergence plane. Other techniques for selecting the convergence plane can be used.

[0055] Returning to FIG. 8, at operation 808, the processing circuitry 130 can generate a final stereoscopic image pair using the initial stereoscopic image pair and the convergence plane. FIG. 12 shows a front view drawing of examples of a left image 1242L and a right image 1242R of a final stereoscopic image pair 1240. As an example, the final stereoscopic image pair 1240 shows two views of the scene that includes the “+” sign as the region of interest. Other scenes can be used.

[0056] The autostereoscopic display, such as the multiview display 110, can display the final stereoscopic image pair 1240 such that when the final stereoscopic image pair 1240 is displayed on the autostereoscopic display: the convergence plane coincides with a plane of the autostereoscopic display (and the region of interest), a first portion of the final stereoscopic image pair appears to be located above the plane of the autostereoscopic display, and a second portion of the final stereoscopic image pair appears to be located below the plane of the autostereoscopic display. A viewer tracker, such as the viewer tracker 120, can determine a location of a viewer, such as the viewer 42

[0057] The autostereoscopic display can include a display panel, such as the display panel 112. The display panel can have an array of subpixels, such as the array of subpixels 114, that can display the final stereoscopic image pair 1240. The autostereoscopic display can include a parallax-generating optic, such as the parallaxgenerating optic 118, that can direct light from the display panel to the viewer. The parallax-generating optic can include one of a lenticular lens, such as the lenticular lens 402, or a parallax barrier having transmissive slits, such as the parallax barrier 602 having transmissive slits 704. The parallax-generating optic can be invariant along an optical axis, such as the optical axis (OA), that has a slant angle relative to the display panel. The slant angle can be within a specified angular tolerance of forty -five degrees, such as within one degree, two degrees, five degrees, ten degrees, or another suitable angular tolerance. The parallax-generating optic can be periodic along an axis orthogonal to the optical axis. The processing circuitry 130 can arrange the left image1242L and the right image 1242R of the final stereoscopic image pair 1240 on the array of subpixels such that the parallax-generating optic directs the left image 1242L and the right image 1242R to respective eyes of the viewer at the location of the viewer.

[0058] 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.

[0059] In Example 1, an autostereoscopic display system can comprise: processing circuitry configured to perform operations, the operations comprising: receiving data specifying an initial stereoscopic image pair; determining, from the initial stereoscopic image pair, saliency information that indicates a region of interest of the initial stereoscopic image pair; determining a convergence plane based on disparity characteristics of the region of interest of the initial stereoscopic image pair; and generating a final stereoscopic image pair using the initial stereoscopic image pair and the convergence plane.

[0060] In Example 2, the autostereoscopic display system of Example 1 can optionally be configured such that the operations further comprise: introducing a horizontal offset between left and right images of the initial stereoscopic image pair to form left and right images of the final stereoscopic image pair, the horizontal offset having an offset value selected such that a difference between the left and right images of the final stereoscopic image pair in the region of interest is less than a difference between the left and right images of the initial stereoscopic image pair in the region of interest.

[0061] In Example 3, the autostereoscopic display system of any one of Examples 1-2 can optionally be configured such that the operations further comprise: specifying a plurality of horizontal offset values; generating a plurality of provisional stereoscopic image pairs based on the initial stereoscopic image pair and the respective plurality of horizontal offset values, each provisional stereoscopic image pair being formed from left and right images of the initial stereoscopic image pair being horizontally offset with respect to each other by an amount corresponding to the respective horizontal offset value; and determining a plurality of difference values, each difference value representing a difference between left and right images of the respective provisional stereoscopic image pair, of the plurality of provisional stereoscopic image pairs, in the region of interest.

[0062] In Example 4, the autostereoscopic display system of any one of Examples 1-3 can optionally be configured such that the operations further comprise: selecting, as a selected difference value, a least difference value of the plurality of difference values; and selecting, as the final stereoscopic image pair, a provisional stereoscopic image pair of the plurality of provisional stereoscopic image pairs that corresponds to the selected difference value.

[0063] In Example 5, the autostereoscopic display system of any one of Examples 1-4 can optionally be configured such that the operations further comprise: fitting a difference value curve via interpolation to the plurality of difference values; determining a minimum value of the difference value curve; and setting the convergence plane to be disposed at a location that corresponds to the minimum value of the difference value curve, wherein: the minimum value of the difference value curve is between two adjacent difference values of the plurality of difference values; and the final stereoscopic image pair is located between two adjacent provisional stereoscopic image pairs of the plurality of provisional stereoscopic image pairs.

[0064] In Example 6, the autostereoscopic display system of any one of Examples 1-5 can optionally be configured such that the plurality of horizontal offset values comprises sequential values that are separated by a spacing value that corresponds to a pixel spacing of the initial stereoscopic image pair.

[0065] In Example 7, the autostereoscopic display system of any one of Examples 1-6 can optionally be configured such that the operations further comprise: determining, from a left image of the initial stereoscopic image pair, a left saliency map that indicates the region of interest of the left image of the initial stereoscopic image pair; and determining, from a right image of the initial stereoscopic image pair, a right saliency map that indicates the region of interest of the right image of the initial stereoscopic image pair.

[0066] In Example 8, the autostereoscopic display system of any one of Examples 1-7 can optionally be configured such that: the region of interest includes less than all of a left image of the initial stereoscopic image pair and less than all of a right image of the initial stereoscopic image pair; and the region of interest includes one or more regions of deemed importance.

[0067] In Example 9, the autostereoscopic display system of any one of Examples 1-8 can optionally further comprise: an autostereoscopic display configured todisplay the final stereoscopic image pair such that when the final stereoscopic image pair is displayed on the autostereoscopic display: the convergence plane coincides with a plane of the autostereoscopic display; a first portion of the final stereoscopic image pair appears to be located above the plane of the autostereoscopic display; and a second portion of the final stereoscopic image pair appears to be located below the plane of the autostereoscopic display; and a viewer tracker configured to determine a location of a viewer.

[0068] In Example 10, the autostereoscopic display system of any one of Examples 1-9 can optionally be configured such that the autostereoscopic display comprises: a display panel having an array of subpixels configured to display the final stereoscopic image pair; and a parallax-generating optic configured to direct light from the display panel to the viewer, the parallax-generating optic including one of a lenticular lens or a parallax barrier having transmissive slits, the parallax-generating optic being invariant along a optical axis having a slant angle relative to the display panel, the slant angle being within a specified angular tolerance of forty -five degrees, the parallaxgenerating optic being periodic along an axis orthogonal to the optical axis; and wherein the operations further comprise: arranging left and right images of the final stereoscopic image pair on the array of subpixels such that the parallax-generating optic directs the left and right images to respective eyes of the viewer at the location of the viewer.

[0069] In Example 11, a method for reconverging a stereoscopic image pair can comprise: receiving, with processing circuitry, data specifying an initial stereoscopic image pair; determining, with the processing circuitry, from the initial stereoscopic image pair, saliency information that indicates a region of interest of the initial stereoscopic image pair; determining, with the processing circuitry, a convergence plane based on disparity characteristics of the region of interest of the initial stereoscopic image pair; and generating, with the processing circuitry, a final stereoscopic image pair using the initial stereoscopic image pair and the convergence plane.

[0070] In Example 12, the method of Example 11 can optionally further comprise: introducing, with the processing circuitry, a horizontal offset between left and right images of the initial stereoscopic image pair to form left and right images of the final stereoscopic image pair, the horizontal offset having an offset value selected such that a difference between the left and right images of the final stereoscopic image pair inthe region of interest is less than a difference between the left and right images of the initial stereoscopic image pair in the region of interest.

[0071] In Example 13, the method of any one of Examples 11-12 can optionally further comprise: specifying, with the processing circuitry, a plurality of horizontal offset values; generating, with the processing circuitry, a plurality of provisional stereoscopic image pairs based on the initial stereoscopic image pair and the respective plurality of horizontal offset values, each provisional stereoscopic image pair being formed from left and right images of the initial stereoscopic image pair being horizontally offset with respect to each other by an amount corresponding to the respective horizontal offset value; and determining, with the processing circuitry, a plurality of difference values, each difference value representing a difference between left and right images of the respective provisional stereoscopic image pair, of the plurality of provisional stereoscopic image pairs, in the region of interest.

[0072] In Example 14, the method of any one of Examples 11-13 can optionally further comprise: selecting, with the processing circuitry, as a selected difference value, a least difference value of the plurality of difference values; and selecting, with the processing circuitry, as the final stereoscopic image pair, a provisional stereoscopic image pair of the plurality of provisional stereoscopic image pairs that corresponds to the selected difference value.

[0073] In Example 15, the method of any one of Examples 11-14 can optionally further comprise: fitting, with the processing circuitry, a difference value curve via interpolation to the plurality of difference values; determining, with the processing circuitry, a minimum value of the difference value curve; and setting, with the processing circuitry, the convergence plane to be disposed at a location that corresponds to the minimum value of the difference value curve, wherein: the minimum value of the difference value curve is between two adjacent difference values of the plurality of difference values; and the final stereoscopic image pair is located between two adjacent provisional stereoscopic image pairs of the plurality of provisional stereoscopic image pairs.

[0074] In Example 16, a non-transitory computer-readable storage medium can store instructions for reconverging a stereoscopic image pair. The instructions, when executed by processing circuitry, can cause the processing circuitry to perform operations. The operations can comprise: receiving, with the processing circuitry, dataspecifying an initial stereoscopic image pair; determining, with the processing circuitry, from the initial stereoscopic image pair, saliency information that indicates a region of interest of the initial stereoscopic image pair; determining, with the processing circuitry, a convergence plane based on disparity characteristics of the region of interest of the initial stereoscopic image pair; and generating, with the processing circuitry, a final stereoscopic image pair using the initial stereoscopic image pair and the convergence plane.

[0075] In Example 17, the non-transitory computer-readable storage medium of Example 16 can optionally be configured such that the operations further comprise: introducing, with the processing circuitry, a horizontal offset between left and right images of the initial stereoscopic image pair to form left and right images of the final stereoscopic image pair, the horizontal offset having an offset value selected such that a difference between the left and right images of the final stereoscopic image pair in the region of interest is less than a difference between the left and right images of the initial stereoscopic image pair in the region of interest.

[0076] In Example 18, the non-transitory computer-readable storage medium of any one of Examples 16-17 can optionally be configured such that the operations further comprise: specifying, with the processing circuitry, a plurality of horizontal offset values; generating, with the processing circuitry, a plurality of provisional stereoscopic image pairs based on the initial stereoscopic image pair and the respective plurality of horizontal offset values, each provisional stereoscopic image pair being formed from left and right images of the initial stereoscopic image pair being horizontally offset with respect to each other by an amount corresponding to the respective horizontal offset value; and determining, with the processing circuitry, a plurality of difference values, each difference value representing a difference between left and right images of the respective provisional stereoscopic image pair, of the plurality of provisional stereoscopic image pairs, in the region of interest.

[0077] In Example 19, the non-transitory computer-readable storage medium of any one of Examples 16-18 can optionally be configured such that the operations further comprise: selecting, with the processing circuitry, as a selected difference value, a least difference value of the plurality of difference values; and selecting, with the processing circuitry, as the final stereoscopic image pair, a provisional stereoscopic image pair ofthe plurality of provisional stereoscopic image pairs that corresponds to the selected difference value.

[0078] In Example 20, the non-transitory computer-readable storage medium of any one of Examples 16-19 can optionally be configured such that the operations further comprise: fitting, with the processing circuitry, a difference value curve via interpolation to the plurality of difference values; determining, with the processing circuitry, a minimum value of the difference value curve; and setting, with the processing circuitry, the convergence plane to be disposed at a location that corresponds to the minimum value of the difference value curve, wherein: the minimum value of the difference value curve is between two adjacent difference values of the plurality of difference values; and the final stereoscopic image pair is located between two adjacent provisional stereoscopic image pairs of the plurality of provisional stereoscopic image pairs.

[0079] The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention can be practiced. These embodiments are also referred to herein as "examples." Such examples can include elements in addition to those shown or described. However, examples are contemplated in which only those elements shown or described are provided. Moreover, other examples can any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.

[0080] In this document, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of "at least one" or "one or more." In this document, the term "or" is used to refer to a nonexclusive or, such that "A or B" can include "A but not B," "B but not A," and "A and B," unless otherwise indicated. In the appended claims, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein". Also, in the following claims, the terms "including" and "comprising" are open-ended, that is, a system, device, article, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms "first," "second," and"third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

[0081] The above description is intended to be illustrative, and not restrictive.For example, the above-described examples (or one or more aspects thereof) can be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features can be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter can lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

CLAIMSWHAT IS CLAIMED IS:

1. An autostereoscopic display system, comprising: processing circuitry configured to perform operations, the operations comprising: receiving data specifying an initial stereoscopic image pair; determining, from the initial stereoscopic image pair, saliency information that indicates a region of interest of the initial stereoscopic image pair; determining a convergence plane based on disparity characteristics of the region of interest of the initial stereoscopic image pair; and generating a final stereoscopic image pair using the initial stereoscopic image pair and the convergence plane.

2. The autostereoscopic display system of claim 1, wherein the operations further comprise: introducing a horizontal offset between left and right images of the initial stereoscopic image pair to form left and right images of the final stereoscopic image pair, the horizontal offset having an offset value selected such that a difference between the left and right images of the final stereoscopic image pair in the region of interest is less than a difference between the left and right images of the initial stereoscopic image pair in the region of interest.

3. The autostereoscopic display system of claim 1, wherein the operations further comprise: specifying a plurality of horizontal offset values; generating a plurality of provisional stereoscopic image pairs based on the initial stereoscopic image pair and the respective plurality of horizontal offset values, each provisional stereoscopic image pair being formed from left and right images of the initial stereoscopic image pair being horizontally offset with respect to each other by an amount corresponding to the respective horizontal offset value; and determining a plurality of difference values, each difference value representing a difference between left and right images of the respective provisional stereoscopic image pair, of the plurality of provisional stereoscopic image pairs, in the region of interest.

4. The autostereoscopic display system of claim 3, wherein the operations further comprise: selecting, as a selected difference value, a least difference value of the plurality of difference values; and selecting, as the final stereoscopic image pair, a provisional stereoscopic image pair of the plurality of provisional stereoscopic image pairs that corresponds to the selected difference value.

5. The autostereoscopic display system of claim 3, wherein the operations further comprise: fitting a difference value curve via interpolation to the plurality of difference values; determining a minimum value of the difference value curve; and setting the convergence plane to be disposed at a location that corresponds to the minimum value of the difference value curve, wherein: the minimum value of the difference value curve is between two adjacent difference values of the plurality of difference values; and the final stereoscopic image pair is located between two adjacent provisional stereoscopic image pairs of the plurality of provisional stereoscopic image pairs.

6. The autostereoscopic display system of claim 3, wherein the plurality of horizontal offset values comprises sequential values that are separated by a spacing value that corresponds to a pixel spacing of the initial stereoscopic image pair.

7. The autostereoscopic display system of claim 1, wherein the operations further comprise: determining, from a left image of the initial stereoscopic image pair, a left saliency map that indicates the region of interest of the left image of the initial stereoscopic image pair; and determining, from a right image of the initial stereoscopic image pair, a right saliency map that indicates the region of interest of the right image of the initial stereoscopic image pair.

8. The autostereoscopic display system of claim 1, wherein: the region of interest includes less than all of a left image of the initial stereoscopic image pair and less than all of a right image of the initial stereoscopic image pair; and the region of interest includes one or more regions of deemed importance.

9. The autostereoscopic display system of claim 1, further comprising: an autostereoscopic display configured to display the final stereoscopic image pair such that when the final stereoscopic image pair is displayed on the autostereoscopic display: the convergence plane coincides with a plane of the autostereoscopic display; a first portion of the final stereoscopic image pair appears to be located above the plane of the autostereoscopic display; and a second portion of the final stereoscopic image pair appears to be located below the plane of the autostereoscopic display; and a viewer tracker configured to determine a location of a viewer.

10. The autostereoscopic display system of claim 9, wherein the autostereoscopic display comprises: a display panel having an array of subpixels configured to display the final stereoscopic image pair; and a parallax-generating optic configured to direct light from the display panel to the viewer, the parallax-generating optic including one of a lenticular lens or a parallax barrier having transmissive slits, the parallax-generating optic being invariant along a optical axis having a slant angle relative to the display panel, the slant angle being within a specified angular tolerance of forty -five degrees, the parallax-generating optic being periodic along an axis orthogonal to the optical axis; and wherein the operations further comprise: arranging left and right images of the final stereoscopic image pair on the array of subpixels such that the parallax-generating optic directs the left and right images to respective eyes of the viewer at the location of the viewer.

11. A method for reconverging a stereoscopic image pair, the method comprising: receiving, with processing circuitry, data specifying an initial stereoscopic image pair; determining, with the processing circuitry, from the initial stereoscopic image pair, saliency information that indicates a region of interest of the initial stereoscopic image pair; determining, with the processing circuitry, a convergence plane based on disparity characteristics of the region of interest of the initial stereoscopic image pair; and generating, with the processing circuitry, a final stereoscopic image pair using the initial stereoscopic image pair and the convergence plane.

12. The method of claim 11, further comprising: introducing, with the processing circuitry, a horizontal offset between left and right images of the initial stereoscopic image pair to form left and right images of the final stereoscopic image pair, the horizontal offset having an offset value selected such that a difference between the left and right images of the final stereoscopic image pair in the region of interest is less than a difference between the left and right images of the initial stereoscopic image pair in the region of interest.

13. The method of claim 11, further comprising: specifying, with the processing circuitry, a plurality of horizontal offset values; generating, with the processing circuitry, a plurality of provisional stereoscopic image pairs based on the initial stereoscopic image pair and the respective plurality of horizontal offset values, each provisional stereoscopic image pair being formed from left and right images of the initial stereoscopic image pair being horizontally offset with respect to each other by an amount corresponding to the respective horizontal offset value; and determining, with the processing circuitry, a plurality of difference values, each difference value representing a difference between left and right images of the respective provisional stereoscopic image pair, of the plurality of provisional stereoscopic image pairs, in the region of interest.

14. The method of claim 13, further comprising: selecting, with the processing circuitry, as a selected difference value, a least difference value of the plurality of difference values; and selecting, with the processing circuitry, as the final stereoscopic image pair, a provisional stereoscopic image pair of the plurality of provisional stereoscopic image pairs that corresponds to the selected difference value.

15. The method of claim 13, further comprising: fitting, with the processing circuitry, a difference value curve via interpolation to the plurality of difference values; determining, with the processing circuitry, a minimum value of the difference value curve; and setting, with the processing circuitry, the convergence plane to be disposed at a location that corresponds to the minimum value of the difference value curve, wherein: the minimum value of the difference value curve is between two adjacent difference values of the plurality of difference values; and the final stereoscopic image pair is located between two adjacent provisional stereoscopic image pairs of the plurality of provisional stereoscopic image pairs.

16. A non-transitory computer-readable storage medium storing instructions for reconverging a stereoscopic image pair, the instructions, when executed by processing circuitry, cause the processing circuitry to perform operations, the operations comprising: receiving, with the processing circuitry, data specifying an initial stereoscopic image pair; determining, with the processing circuitry, from the initial stereoscopic image pair, saliency information that indicates a region of interest of the initial stereoscopic image pair; determining, with the processing circuitry, a convergence plane based on disparity characteristics of the region of interest of the initial stereoscopic image pair; and generating, with the processing circuitry, a final stereoscopic image pair using the initial stereoscopic image pair and the convergence plane.

17. The non-transitory computer-readable storage medium of claim 16, wherein the operations further comprise: introducing, with the processing circuitry, a horizontal offset between left and right images of the initial stereoscopic image pair to form left and right images of the final stereoscopic image pair, the horizontal offset having an offset value selected such that a difference between the left and right images of the final stereoscopic image pair in the region of interest is less than a difference between the left and right images of the initial stereoscopic image pair in the region of interest.

18. The non-transitory computer-readable storage medium of claim 16, wherein the operations further comprise: specifying, with the processing circuitry, a plurality of horizontal offset values; generating, with the processing circuitry, a plurality of provisional stereoscopic image pairs based on the initial stereoscopic image pair and the respective plurality of horizontal offset values, each provisional stereoscopic image pair being formed from left and right images of the initial stereoscopic image pair being horizontally offset with respect to each other by an amount corresponding to the respective horizontal offset value; and determining, with the processing circuitry, a plurality of difference values, each difference value representing a difference between left and right images of the respective provisional stereoscopic image pair, of the plurality of provisional stereoscopic image pairs, in the region of interest.

19. The non-transitory computer-readable storage medium of claim 18, wherein the operations further comprise: selecting, with the processing circuitry, as a selected difference value, a least difference value of the plurality of difference values; and selecting, with the processing circuitry, as the final stereoscopic image pair, a provisional stereoscopic image pair of the plurality of provisional stereoscopic image pairs that corresponds to the selected difference value.

20. The non-transitory computer-readable storage medium of claim 18, wherein the operations further comprise: fitting, with the processing circuitry, a difference value curve via interpolation to the plurality of difference values; determining, with the processing circuitry, a minimum value of the difference value curve; and setting, with the processing circuitry, the convergence plane to be disposed at a location that corresponds to the minimum value of the difference value curve, wherein: the minimum value of the difference value curve is between two adjacent difference values of the plurality of difference values; and the final stereoscopic image pair is located between two adjacent provisional stereoscopic image pairs of the plurality of provisional stereoscopic image pairs.

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