# US 9,750,402 B2 · Ophthalmologic apparatus, image processing method, and medium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,750,402 B2 - Document ID: US9750402B2 - Status: Granted - Kind: B2 - Application number: 15/011,278 - Filed: 2016-01-29 - Published: 2016-08-04 - Granted: 2017-09-05 - Earliest claimed: 2015-01-30 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Mitsuhiro Ono - Web page: https://patentgrep.com/patent/US9750402B2 ## CPC - A61B 3/0025: {characterised by electronic signal processing, e.g. eye models} - A61B 3/1241: {specially adapted for observation of ocular blood flow, e.g. by fluorescein angiography} - A61B 3/14: Arrangements specially adapted for eye photography - G06T 5/90: Dynamic range modification of images or parts thereof - G06T 2207/30041: Eye; Retina; Ophthalmic - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract A disclosed ophthalmologic apparatus includes an image acquisition unit configured to acquire a fundus image of an eye to be examined on the basis of returning light from a fundus that is obtained by irradiating the fundus of the eye with light; and a correction unit configured to correct the fundus image in accordance with a degree of clouding of a clouded portion of the eye such that, among color components contained in the fundus image, a ratio of a color component, in the fundus image, that is scattered by a clouded portion of the eye at a higher rate increases against a ratio of another color component. ## Claims ### Claim 1 An ophthalmologic apparatus, comprising: an image acquisition unit configured to acquire a fundus image of an eye to be examined; and a correction unit configured to correct the fundus image in accordance with a degree of clouding of the eye such that, among color components contained in the fundus image, a ratio of a blue component in the fundus image increases against a red component and a green component. ### Claim 2 (depends on 1) The ophthalmologic apparatus according to claim 1, further comprising: a detection unit configured to detect a highlight point and a shadow point from a luminance distribution of the fundus image, wherein the correction unit causes, among the color components contained in the fundus image, the ratio of the blue component in the fundus image to increase against the red component and the green component, so that an angle formed by a straight line connecting the highlight point and the shadow point in the color space and a predetermined coordinate axis defining the color space approaches a predetermined angle. ### Claim 3 (depends on 2) The ophthalmologic apparatus according to claim 2, wherein the predetermined angle is an angle formed by a straight line connecting a highlight point and a shadow point obtained from a luminance distribution of a fundus image of an eye with clouding that is less than a threshold and the predetermined coordinate axis. ### Claim 4 (depends on 3) The ophthalmologic apparatus according to claim 3, wherein the detection unit detects a luminance difference between the highlight point and the shadow point, and wherein the correction unit enhances a contrast in the fundus image in accordance with the luminance difference. ### Claim 5 (depends on 4) The ophthalmologic apparatus according to claim 4, wherein the correction unit reduces an enhancement degree of the contrast as the luminance difference is greater. ### Claim 6 (depends on 2) The ophthalmologic apparatus according to claim 2, wherein the detection unit detects the highlight point and the shadow point from the luminance distribution of a region excluding an optic disc in the fundus image. ### Claim 7 (depends on 6) The ophthalmologic apparatus according to claim 6, wherein the detection unit detects a luminance difference between the highlight point and the shadow point, and wherein the correction unit enhances a contrast in the fundus image in accordance with the luminance difference. ### Claim 8 (depends on 7) The ophthalmologic apparatus according to claim 7, wherein the correction unit reduces an enhancement degree of the contrast as the luminance difference is greater. ### Claim 9 (depends on 2) The ophthalmologic apparatus according to claim 2, wherein the detection unit detects a luminance difference between the highlight point and the shadow point, and wherein the correction unit enhances a contrast in the fundus image in accordance with the luminance difference. ### Claim 10 (depends on 9) The ophthalmologic apparatus according to claim 9, wherein the correction unit reduces an enhancement degree of the contrast as the luminance difference is greater. ### Claim 11 (depends on 2) The ophthalmologic apparatus according to claim 2, wherein the shadow point includes a blood vessel portion included in the fundus image. ### Claim 12 (depends on 1) The ophthalmologic apparatus according to claim 1, wherein the detection unit carries out an edge detection on the fundus image, and wherein the correction unit enhances a contrast in the fundus image in accordance with the detected edge amount. ### Claim 13 (depends on 12) The ophthalmologic apparatus according to claim 12, wherein the correction unit reduces an enhancement degree of the contrast as the edge amount is greater. ### Claim 14 An image processing method, comprising: acquiring a fundus image of an eye to be examined; and correcting the fundus image in accordance with a degree of clouding of the eye such that, among color components contained in the fundus image, a ratio of a blue component in the fundus image increases against a red component and a green component. ### Claim 15 (depends on 14) A non-transitory storage medium storing a program that causes a computer to execute each step of the image processing method according to claim 14.