# US 9,752,875 B2 · Virtual sport system for acquiring good image of ball by controlling camera according to surrounding brightness > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,752,875 B2 - Document ID: US9752875B2 - Status: Granted - Kind: B2 - Application number: 14/346,733 - Filed: 2012-09-24 - Published: 2014-08-21 - Granted: 2017-09-05 - Earliest claimed: 2011-09-23 - Assignees: Creatz Inc. - Applicants: Creatz Inc. - Inventors: Yong Ho Suk - Web page: https://patentgrep.com/patent/US9752875B2 ## CPC - G01C 11/02: Picture taking arrangements specially adapted for photogrammetry or photographic surveying, e.g. controlling overlapping of pictures - A63B 24/0021: {Tracking a path or terminating locations} - A63B 71/022: {Backstops, cages, enclosures or the like, e.g. for spectator protection, for arresting balls} - A63F 13/20: Input arrangements for video game devices - A63F 13/80: Special adaptations for executing a specific game genre or game mode - G06T 7/20: Analysis of motion (motion estimation for coding, decoding, compressing or decompressing digital video signals H04N19/43, H04N19/51) - G06T 7/246: using feature-based methods, e.g. the tracking of corners or segments - A63B 69/3661: {Mats for golf practice, e.g. mats having a simulated turf, a practice tee or a green area} - A63B 2024/0031: {at the starting point} - A63B 2024/0034: {during flight} - G01C 11/36: Videogrammetry, i.e. electronic processing of video signals {from a single source or } from different sources to give parallax or range information - G06T 2207/10016: Video; Image sequence - G06T 2207/10028: Range image; Depth image; 3D point clouds - G06T 2207/10048: Infrared image - G06T 2207/30224: Ball; Puck - G06T 2207/30241: Trajectory - G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S) - A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H) - A63F: CARD, BOARD, OR ROULETTE GAMES; INDOOR GAMES USING SMALL MOVING PLAYING BODIES; VIDEO GAMES; GAMES NOT OTHERWISE PROVIDED FOR - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract The present invention relates to a virtual sport system for acquiring a good image of a ball by controlling a camera according to the surrounding brightness. One embodiment of the present invention provides a virtual sport system which comprises a photographing unit, having a camera for acquiring an image of a ball, and a simulator, for calculating the physical quantity of the ball on the basis of the image of the ball; and which further comprises a control unit that extracts image information from at least one image acquired by the photographing unit by means of the camera, and determining, on the basis of the image information, a control signal for adjusting the image gain or the exposure time of the camera. ## Claims ### Claim 1 A virtual sport system, comprising: a photographing unit comprising a camera to acquire images of a ball; and a simulator to calculate physical quantities of the ball on the basis of the images of the ball, wherein the photographing unit further comprises a control unit to extract visual information from at least one image acquired by the camera and determine a control signal for adjusting an exposure time or video gain of the camera on the basis of the visual information, wherein the control unit extracts visual information from at least one other image acquired by the camera with the adjusted exposure time or video gain, and further adjusts the exposure time or video gain of the camera if the visual information fails to meet a predefined criteria, and wherein the camera further acquires at least one image of a reference subject comprising at least two regions each having a uniform reflectance, the reflectances of the at least two regions being different from each other, and the control unit determines the control signal on the basis of visual information extracted from the at least one image of the reference subject with two or more regions, each region having a reflectance different from each other, such that at least some of the at least two regions in the reference subject are distinguished from a ground surface. ### Claim 2 (depends on 1) A virtual sport system as claimed in claim 1, wherein the camera is an infrared camera. ### Claim 3 (depends on 1) A virtual sport system as claimed in claim 1, wherein the physical quantities of the ball are at least one of a movement trajectory, moving speed and height of the ball. ### Claim 4 (depends on 3) A virtual sport system as claimed in claim 3, wherein the height of the ball is converted on the basis of the distance from the photographing unit to the ball. ### Claim 5 (depends on 1) A virtual sport system as claimed in claim 1, wherein the visual information is at least one of information on the overall brightness of the corresponding image, information on the average brightness of the corresponding image, information on the brightness of the brightest part in the corresponding image, information on the brightness of the darkest part in the corresponding image, and information on the difference between the brightness of the brightest and darkest parts in the corresponding image. ### Claim 6 (depends on 1) A virtual sport system as claimed in claim 1, further comprising an illumination device, wherein the control unit controls the illumination device to be turned on and off. ### Claim 7 (depends on 6) A virtual sport system as claimed in claim 6, wherein the at least one image is two images, and wherein a first of the two images is acquired when the illumination device is turned on and a second of the two images is acquired when the illumination device is turned off. ### Claim 8 (depends on 7) A virtual sport system as claimed in claim 7, wherein the visual information is information on the difference between the visual information corresponding to the first image and that corresponding to the second image.