# US 10,771,771 B2 · Method of determining calibration parameter for three-dimensional (3D) display device and 3D display device using the method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,771,771 B2 - Document ID: US10771771B2 - Status: Granted - Kind: B2 - Application number: 14/709,148 - Filed: 2015-05-11 - Published: 2016-05-26 - Granted: 2020-09-08 - Earliest claimed: 2014-11-24 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Hyoseok Hwang; Juyong Park; Hyun Sung Chang; Dong Kyung Nam - Web page: https://patentgrep.com/patent/US10771771B2 ## CPC - H04N 13/327: Calibration thereof - H04N 13/106: Processing image signals (for multi-view video sequence encoding H04N19/597) - H04N 13/302: for viewing without the aid of special glasses, i.e. using autostereoscopic displays - H04N 13/324: Colour aspects - H04N 13/398: Synchronisation thereof; Control thereof - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A method of determining a calibration parameter for a three-dimensional (3D) display device includes determining a calibration parameter for a 3D display device based on an image of a second pattern three-dimensionally converted from an image of a first pattern. ## Claims ### Claim 1 A method of determining a calibration parameter for a three-dimensional (3D) display device, the method comprising: acquiring an image of a first pattern output through a panel and an optical layer as an image of a second pattern; and determining the calibration parameter for the 3D display device based on a parameter corresponding to a period of the first pattern, a parameter corresponding to a gradient of the second pattern, and a parameter corresponding to a period of the second pattern, wherein the parameter corresponding to the period of the first pattern is an interval between lines included in the first pattern, and wherein the determining comprises calculating a rotation angle θ between the optical layer and the panel and a pitch p of the optical layer based on relations between the rotation angle θ and the pitch p, the relations comprising: a first relation between the rotation angle θ and the pitch p being based on the parameter corresponding to the period of the first pattern and the parameter corresponding to the gradient of the second pattern; and a second relation between the rotation angle θ and the pitch p being based on the parameter corresponding to the period of the second pattern. ### Claim 2 (depends on 1) The method of claim 1, wherein the first pattern is displayed using subpixels aligned in the panel. ### Claim 3 (depends on 1) The method of claim 1, wherein the first pattern is a pattern in which continuous lines of an identical brightness are at desired intervals. ### Claim 4 (depends on 1) The method of claim 1, wherein the second pattern is a pattern in which lines comprising a plurality of points are at desired intervals. ### Claim 5 (depends on 1) The method of claim 1, wherein the optical layer comprises at least one of a lens array, a parallax barrier, and a directional backlight. ### Claim 6 (depends on 1) The method of claim 1, wherein the calibration parameter comprises at least one of: a parameter associated with a size of the optical layer; and a parameter associated with a position of the optical layer. ### Claim 7 (depends on 6) The method of claim 6, wherein the parameter associated with the size of the optical layer comprises a pitch of the optical layer. ### Claim 8 (depends on 6) The method of claim 6, wherein the parameter associated with the position of the optical layer comprises the rotation angle between the optical layer and the panel. ### Claim 9 (depends on 1) The method of claim 1, wherein the determining comprises obtaining a parameter corresponding to the period of the first pattern based on a subpixel structure of the panel. ### Claim 10 (depends on 9) The method of claim 9, wherein the subpixel structure of the panel comprises an interval between subpixels of a color used for the first pattern. ### Claim 11 (depends on 1) The method of claim 1, wherein the determining comprises at least one of: measuring a parameter corresponding to the gradient of the second pattern; and measuring a parameter corresponding to the period of the second pattern. ### Claim 12 (depends on 11) The method of claim 11, wherein the parameter corresponding to the gradient of the second pattern comprises a slope of a line included in the second pattern. ### Claim 13 (depends on 11) The method of claim 11, wherein the parameter corresponding to the period of the second pattern comprises an interval between lines included in the second pattern. ### Claim 14 (depends on 1) The method of claim 1, wherein the determining comprises: performing a Fourier transform on the image of the second pattern; measuring a parameter corresponding to the gradient of the second pattern based on the Fourier-transformed image; and measuring a parameter corresponding to the period of the second pattern based on the Fourier-transformed image. ### Claim 15 (depends on 14) The method of claim 14, wherein the measuring of the parameter corresponding to the period of the second pattern comprises: calculating a height difference between pixels having highest intensities in the Fourier-transformed image; and calculating an interval between lines included in the second pattern based on the calculated height difference and a height of the Fourier-transformed image. ### Claim 16 (depends on 14) The method of claim 14, wherein the measuring of the parameter corresponding to the gradient of the second pattern comprises: calculating a slope of a first line connecting pixels having highest intensities in the Fourier-transformed image; and calculating a slope of a second line included in the second pattern based on the calculated slope of the first line. ### Claim 17 (depends on 16) The method of claim 16, wherein the measuring of the parameter corresponding to the gradient of the second pattern further comprises: detecting a point that is horizontally closest to an origin of the Fourier-transformed image; and calculating a slope of a third line connecting the origin and the detected point, wherein the slope of the second line is calibrated based on the calculated slope of the third line. ### Claim 18 (depends on 1) The method of claim 1, wherein the first relation corresponds to Equation 1 and the second relation corresponds to Equation 2, g ⁢ ⁢ tan ⁢ ⁢ αsinθ + g ⁢ ⁢ cos ⁢ ⁢ θ - np = 0 [ Equation ⁢ ⁢ 1 ] c = p sin ⁢ ⁢ θ , [ Equation ⁢ ⁢ 2 ] wherein g denotes a parameter corresponding to the period of the first pattern, a denotes a parameter corresponding to the gradient of the second pattern, c denotes a parameter corresponding to the period of the second pattern, n denotes a number of elements of the optical layer corresponding to a single period of the first pattern, θ denotes the rotation angle between the optical layer and the panel, and p denotes the pitch of the optical layer. ### Claim 19 (depends on 18) The method of claim 18, wherein the calculating of the rotation angle between the optical layer and the panel and the pitch of the optical layer comprises: calculating (n, θ) candidates having n being a positive integer, and θ being an angle within a desired range; selecting one of the (n, θ) candidates based on an initial parameter; and calculating p corresponding to the selected (n, θ) candidate. ### Claim 20 (depends on 1) The method of claim 1, wherein, if a subpixel structure of the panel corresponds to a red, green, and blue (RGB) stripe structure, the first pattern corresponds to a stripe pattern having one of red, green, and blue colors, and a direction in which subpixels of an identical color are aligned in the panel. ### Claim 21 (depends on 1) The method of claim 1, wherein the image of the second pattern is a single image. ### Claim 22 (depends on 1) A non-transitory computer-readable medium comprising program code that, when executed by a processor, performs operations according to the method of claim 1. ### Claim 23 A three-dimensional (3D) display device comprising: memory storing computer-executable instructions; and one or more processors configured to execute the computer-executable instructions such that the one or more processors are configured to, calibrate mapping information of a subpixel included in a panel based on a calibration parameter for the 3D display device, and perform rendering for a 3D image based on the calibrated mapping information, wherein the one or more processors are further configured to execute the computer-executable instructions such that the one or more processors are configured to determine the calibration parameter based on, an image of a second pattern output through a combination of the panel and an optical layer, the second pattern being based on an image of a first pattern applied to the panel, a parameter corresponding to a period of the first pattern, a parameter corresponding to a gradient of the second pattern, and a parameter corresponding to a period of the second pattern, wherein the parameter corresponding to the period of the first pattern is an interval between lines included in the first pattern, and wherein the one or more processors are further configured to calculate a rotation angle θ between the optical layer and the panel and a pitch p of the optical layer based on relations between the rotation angle 9 and the pitch p, the relations comprising: a first relation between the rotation angle 9 and the pitch p being based on the parameter corresponding to the period of the first pattern and the parameter corresponding to the gradient of the second pattern; and a second relation between the rotation angle 9 and the pitch p being based on the parameter corresponding to the period of the second pattern. ### Claim 24 (depends on 23) The 3D display device of claim 23, wherein the first pattern is displayed using subpixels aligned in the panel. ### Claim 25 (depends on 23) The 3D display device of claim 23, wherein the first pattern is a pattern in which continuous lines of an identical brightness are at desired intervals, and the second pattern is a pattern in which lines comprising a plurality of points are at desired intervals. ### Claim 26 (depends on 23) The 3D display device of claim 23, wherein the optical layer comprises at least one of a lens array, a parallax barrier, and a directional backlight unit. ### Claim 27 (depends on 23) The 3D display device of claim 23, wherein the parameter corresponding to the gradient of the second pattern comprises a slope of a line included in the second pattern, and the parameter corresponding to the period of the second pattern comprises an interval between lines included in the second pattern. ### Claim 28 (depends on 23) The 3D display device of claim 23, wherein the parameter corresponding to the period of the first pattern is obtained based on a subpixel structure of the panel. ### Claim 29 (depends on 28) The 3D display device of claim 28, wherein the subpixel structure of the panel comprises an interval between subpixels of a color used for the first pattern in the panel. ### Claim 30 (depends on 23) The 3D display device of claim 23, wherein at least one of the parameter corresponding to the gradient of the second pattern and the parameter corresponding to the period of the second pattern is measured based on an image acquired by performing a Fourier transform on the image of the second pattern. ### Claim 31 (depends on 30) The 3D display device of claim 30, wherein the one or more processors are further configured to execute the computer-executable instructions such that, to measure the parameter corresponding to the period of the second pattern, the one or more processors determine an interval between lines included in the second pattern based on a height difference between pixels having highest intensities in the Fourier-transformed image and a height of the Fourier-transformed image. ### Claim 32 (depends on 30) The 3D display device of claim 30, wherein the one or more processors are further configured to execute the computer-executable instructions such that, to measure the parameter corresponding to the gradient of the second pattern, the one or more processors determine a slope of a first line included in the second pattern based on a slope of a second line connecting pixels having highest intensities in the Fourier-transformed image. ### Claim 33 (depends on 23) The 3D display device of claim 23, wherein the calibration parameter comprises at least one of: a parameter associated with a size of the optical layer; and a parameter associated with a position of the optical layer. ### Claim 34 (depends on 33) The 3D display device of claim 33, wherein the parameter associated with the size of the optical layer comprises a pitch of the optical layer, and the parameter associated with a pose of the optical layer comprises the rotation angle between the optical layer and the panel. ### Claim 35 (depends on 23) The 3D display device of claim 23, wherein the first relation corresponds to Equation 1 and the second relation corresponds to Equation 2, g ⁢ ⁢ tan ⁢ ⁢ αsinθ + g ⁢ ⁢ cos ⁢ ⁢ θ - np = 0 [ Equation ⁢ ⁢ 1 ] c = p sin ⁢ ⁢ θ , [ Equation ⁢ ⁢ 2 ] wherein g denotes a parameter corresponding to the period of the first pattern, a denotes a parameter corresponding to the gradient of the second pattern, c denotes a parameter corresponding to the period of the second pattern, n denotes a number of elements of the optical layer corresponding to a single period of the first pattern, θ denotes the rotation angle between the optical layer and the panel, and p denotes the pitch of the optical layer. ### Claim 36 (depends on 23) The 3D display device of claim 23, wherein the image of the second pattern is a single image. ### Claim 37 A device comprising: memory storing computer-executable instructions; and one or more processors configured to execute the computer-executable instructions such that the one or more processors are configured to, determine a calibration parameter for a three-dimensional (3D) display device based on, a first image having a first pattern and a second image having a second pattern, the second image being a version of the first image that is displayed with a panel and an optical layer of the 3D display device, a parameter corresponding to a period of the first pattern, a parameter corresponding to a gradient of the second pattern, and a parameter corresponding to a period of the second pattern, and calibrate subpixels of the panel based on the calibration parameter to indicate a propagation direction of light from each subpixel, wherein the parameter corresponding to the period of the first pattern is an interval between lines included in the first pattern, and wherein the one or more processors are further configured to calculate a rotation angle θ between the optical layer and the panel and a pitch p of the optical layer based on relations between the rotation angle θ and the pitch p, the relations comprising: a first relation between the rotation angle θ and the pitch p being based on the parameter corresponding to the period of the first pattern and the parameter corresponding to the gradient of the second pattern; and a second relation between the rotation angle θ and the pitch p being based on the parameter corresponding to the period of the second pattern. ### Claim 38 (depends on 37) The device of claim 37, wherein the first pattern is a pattern in which continuous lines of an identical brightness are at desired intervals. ### Claim 39 (depends on 37) The device of claim 37, wherein the second pattern is a pattern in which lines comprising a plurality of points are at desired intervals. ### Claim 40 (depends on 37) The device of claim 37, wherein the optical layer comprises at least one of a lens array, a parallax barrier, and a directional backlight. ### Claim 41 (depends on 37) The device of claim 37, wherein the calibration parameter comprises at least one of: a parameter associated with a size of the optical layer; and a parameter associated with a position of the optical layer. ### Claim 42 (depends on 37) The device of claim 37, wherein the one or more processors are further configured to execute the computer-executable instructions such that the one or more processors are configured to render a calibrated image based on the calibrated subpixels.