# US 2019/0170585 A1 · Color calibration device, color calibration system, color calibration hologram, color calibration method, and program > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170585 A1 - Document ID: US20190170585A1 - Status: Published application - Kind: A1 - Application number: 16/258,569 - Filed: 2019-01-26 - Published: 2019-06-06 - Earliest claimed: 2016-07-27 - Assignees: Toppan Printing Co., Ltd. - Applicants: Toppan Printing Co., Ltd. - Inventors: Takashi OKADA; Tomohito MASUDA; Tetsuro MORIMOTO - Web page: https://patentgrep.com/patent/US20190170585A1 ## CPC - G01J 3/524: {Calibration of colorimeters} - B42D 25/328: Diffraction gratings; Holograms - G01J 3/02: Details - G01J 3/50: using electric radiation detectors - G01J 3/52: using colour charts - G02B 5/32: Holograms used as optical elements - G03H 1/26: Processes or apparatus specially adapted to produce multiple {sub-} holograms or to obtain images from them, e.g. multicolour technique - G06T 7/90: Determination of colour characteristics - H04N 23/10: for generating image signals from different wavelengths - G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N) - B42D: BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G03H: HOLOGRAPHIC PROCESSES OR APPARATUS (holograms, e.g. point holograms, used as ordinary optical elements G02B5/32; producing stereoscopic or other three-dimensional effects G02B30/00; diffraction-grating systems G02B27/44; systems using moiré fringes G02B27/60; optical logic elements G02F3/00; stereo-photography G03B35/00; photosensitive materials or processes for photographic purposes G03C; {stereo-photographic or similar processes G03C9/00}; apparatus for processing exposed photographic materials G03D; analogue computers performing mathematical operations with the aid of optical elements G06E3/00; authentication by radiation, of concealed information carried by holograms or diffraction gratings G06K19/16; holographic storage G11B7/0065, G11C13/04; {stereoscopic or other three dimensional effects in television systems H04N13/00}) - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract This color calibration device is a color calibration device, calibrating colors in a captured image of a first imaging device between different imaging devices using a hologram emitting diffracted light at different frequencies corresponding to an observation angle, the color calibration device includes: a diffracted light spectral distribution calculation unit that obtains respective diffracted light spectral distribution of the diffracted light from the hologram; a camera sensitivity function estimation unit that estimates spectral sensitivity of the imaging device from the respective diffracted light spectral distribution of the diffracted light and each captured image of the diffracted light; and a color calibration unit that calibrates difference in color of the first imaging device relative to a second imaging device different from the first imaging device using the estimated spectral sensitivity. ## Claims ### Claim 1 A color calibration device, calibrating colors in a captured image of a first imaging device between different imaging devices using a hologram emitting diffracted light at different frequencies corresponding to an observation angle, comprising: a diffracted light spectral distribution calculation unit that obtains a respective diffracted light spectral distribution of the diffracted light from the hologram; a camera sensitivity function estimation unit that estimates spectral sensitivity of the imaging device from the respective diffracted light spectral distribution of the diffracted light and each captured image of the diffracted light; and a color calibration unit that calibrates difference in color of the first imaging device relative to a second imaging device different from the first imaging device using the estimated spectral sensitivity. ### Claim 2 (depends on 1) The color calibration device of claim 1, wherein the imaging device further comprises an observation angle estimation unit that estimates an observation angle and an observation position for imaging of the hologram from the captured image imaged by the imaging device, and the diffracted light spectral distribution calculation unit calculates the respective diffracted light spectral distribution of the diffracted light using the observation angle and the observation position estimated from each captured image of the diffracted light. ### Claim 3 (depends on 1) The color calibration device of claim 1, wherein the camera sensitivity function estimation unit estimates the spectral sensitivity of the imaging device from the respective diffracted light spectral distribution of the diffracted light and respective light intensity of the captured image of the diffracted light at a corresponding frequency. ### Claim 4 (depends on 1) The color calibration device of claim 1, further comprising an imaging operation instruction unit that outputs information instructing an operation to capture all captured images having diffracted light spectral distribution respectively corresponding to a plurality of items of required diffracted light spectral distribution set in advance. ### Claim 5 (depends on 4) The color calibration device of claim 4, wherein the imaging operation instruction unit determines whether a captured image having diffracted light spectral distribution corresponding to the required diffracted light spectral distribution has been imaged, and if the captured image having the diffracted light spectral distribution has not been imaged, outputs a notification to prompt imaging of the captured image having the diffracted light spectral distribution on a display unit of the imaging device. ### Claim 6 (depends on 5) The color calibration device of claim 5, wherein the imaging operation instruction unit displays on the display unit an imaging direction for imaging a captured image having diffracted light spectral distribution corresponding to the required diffracted light spectral distribution and not yet obtained. ### Claim 7 (depends on 6) The color calibration device of claim 6, wherein the imaging operation instruction unit displays an imaging frame of the hologram to define an imaging position of the captured image on a display screen of the display unit for imaging of a captured image having diffracted light spectral distribution corresponding to the required diffracted light spectral distribution. ### Claim 8 A color calibration system, comprising: a color calibration hologram that emits diffracted light at different frequencies corresponding to an observation angle; a spectral distribution calculation unit that obtains respective spectral distribution of the diffracted light from the color calibration hologram; a camera sensitivity function estimation unit that estimates spectral sensitivity of an imaging device from the respective spectral distribution of the diffracted light and each captured image of the diffracted light; and a color calibration unit that calibrates difference in color of a first imaging device relative to a second imaging device different from the first imaging device using the estimated spectral sensitivity. ### Claim 9 (depends on 8) The color calibration system of claim 8, wherein the color calibration hologram is provided adjacent to an imaging object imaged as a captured image for calibration of the difference in color. ### Claim 10 (depends on 9) The color calibration system of claim 9, wherein the imaging object is an anti-counterfeiting medium used for authentication determination of an article and having an observed light pattern changing with change in a light property as a property of irradiated light. ### Claim 11 (depends on 8) The color calibration system of claim 8, further comprising an imaging operation instruction unit that outputs information instructing an operation to capture all captured images having diffracted light spectral distribution respectively corresponding to a plurality of items of required diffracted light spectral distribution set in advance. ### Claim 12 A color calibration hologram, emitting diffracted light at different frequencies corresponding to an observation angle, wherein the hologram is used to obtain spectral sensitivity for calibrating colors in a captured image of a first imaging device between different imaging devices. ### Claim 13 (depends on 12) The color calibration hologram of claim 12, wherein the hologram is provided adjacent to an imaging object imaged as a captured image for calibration of the difference in color. ### Claim 14 (depends on 13) The color calibration hologram of claim 13, wherein the imaging object is an anti-counterfeiting medium used for authentication determination of an article and having an observed light pattern changing with change in a light property as a property of irradiated light. ### Claim 15 A color calibration method, calibrating colors in a captured image of a first imaging device between different imaging devices using a hologram emitting diffracted light at different frequencies corresponding to an observation angle, the color calibration method comprising: a step of calculating diffracted light spectral distribution to obtain respective diffracted light spectral distribution of the diffracted light from the hologram; a step of estimating a spectral sensitivity to estimate spectral sensitivity of the imaging device from the respective diffracted light spectral distribution of the diffracted light and each captured image of the diffracted light; and a step of calibrating colors to calibrate difference in color of the first imaging device relative to a second imaging device different from the first imaging device using the estimated spectral sensitivity. ### Claim 16 (depends on 15) The color calibration method of claim 15, further comprising a step of instructing an imaging operation to output information instructing an operation to capture all captured images having diffracted light spectral distribution respectively corresponding to a plurality of items of required diffracted light spectral distribution set in advance. ### Claim 17 A program causing a computer to execute an operation to calibrate colors in a captured image of a first imaging device between different imaging devices using a hologram emitting diffracted light at different frequencies corresponding to an observation angle, the program causing the computer to operate as: a diffracted light spectral distribution calculation means to obtain respective diffracted light spectral distribution of the diffracted light from the hologram; a spectral sensitivity estimation means to estimate spectral sensitivity of the imaging device from the respective diffracted light spectral distribution of the diffracted light and each captured image of the diffracted light; and a color calibration means to calibrate difference in color of the first imaging device relative to a second imaging device different from the first imaging device using the estimated spectral sensitivity. ### Claim 18 (depends on 17) The program of claim 17, wherein the program causes the computer to further operate as an imaging operation instruction means to output information instructing an operation to capture all captured images having diffracted light spectral distribution respectively corresponding to a plurality of items of required diffracted light spectral distribution set in advance.