# US 2013/0154985 A1 · Interactive whiteboards and programs > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0154985 A1 - Document ID: US20130154985A1 - Status: Published application - Kind: A1 - Application number: 13/818,397 - Filed: 2011-08-12 - Published: 2013-06-20 - Earliest claimed: 2010-08-25 - Assignees: Hitachi Solutions, Ltd. - Inventors: Hiroshi Miyazaki - Web page: https://patentgrep.com/patent/US20130154985A1 ## CPC - G06F 3/0418: {for error correction or compensation, e.g. based on parallax, calibration or alignment} - G06F 3/0412: {Digitisers structurally integrated in a display} - G06F 3/0421: {by interrupting or reflecting a light beam, e.g. optical touch-screen} - G06F 3/0488: using a touch-screen or digitiser, e.g. input of commands through traced gestures - H04N 7/183: {for receiving images from a single remote source} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Provided is a technique of correcting influences of optical environment to correctly recognize the color of an input object used for inputting of coordinates, and enabling automatic designation of a color to be used for drawing. A coordinate detection unit detects coordinates of an input object. Next, display light on the display plane in the vicinity of the coordinates is estimated from display data, and a correction value to remove influences of the display light is calculated. A captured image of an input object used for input operations on the display plane is extracted, and the color of the captured image is corrected with a display light correction value. Thereby, influences of the display light added to the input object are removed, enabling the original color of the input object to be identified. ## Claims ### Claim 1 An interactive whiteboard, comprising: a coordinate detection unit configured to detect, as two-dimensional coordinates on a display plane, a contact position of an input object with reference to the display plane or an operating position of the input object with reference to a detection plane set in front side of the display plane; an image-capturing unit configured to capture, as a color image, an image of a vicinity of at least a region where two-dimensional coordinates are detected, wherein a range where the coordinate detector can detect the two-dimensional coordinates is set as an imageable range; a display light correction value calculation unit configured to calculate a display light correction value to correct a variation in image color that is caused by light addition to an image of the input object, the light being from the display plane in a vicinity of the coordinates of the input object detected by the coordinate detection unit, the calculation being performed on a basis of a display color of the display plane in the vicinity of the detected coordinates; a background removal unit configured to extract an image of the input object only from the color image captured by the image-capturing unit; a color correction unit configured to correct color information of the image of the input object extracted by the background removal unit with the display light correction value; a color identification unit configured to identify a color of the image of the input object subjected to color correction by the color correction unit; and a display control unit configured to draw an object having a color identified by the color identification unit and a predetermined size at the detected coordinates of the display plane. ### Claim 2 (depends on 1) The interactive whiteboard according to claim 1, further comprising: an environment light correction value measurement screen display control unit configured to make the display plane display an environment light correction value measurement screen; and environment light correction value calculation unit configured to calculate, when the coordinate detection unit detects the input object during displaying of the environment light correction value measurement screen by the environment light correction value measurement screen display control unit, an environment light correction value to correct a variation in image color that is generated by addition of environment light on a basis of an image of an achromatic-colored input image having an achromatic range for reference, the image being extracted by the background removal unit; wherein the color correction unit corrects the image of the input object on the basis of the environment light correction value and the display light correction value. ### Claim 3 (depends on 1) The interactive whiteboard according to claim 1, wherein the color identification unit identifies the color of the input object as any predetermined achromatic color when the background removal unit fails in background removal or when both or any one of saturation and brightness of the image of the input object after the color correction is in a predetermined determination range. ### Claim 4 (depends on 1) The interactive whiteboard according to claim 1, further comprising: a background plate to be imaged as a background of the input object when the image-capturing unit captures an image of the input object, wherein the background plate protrudes by a predetermined length in a direction perpendicular to the display plane toward a front direction from a position surrounding a range where the coordinate detection unit can detect two-dimensional coordinates. ### Claim 5 (depends on 4) The interactive whiteboard according to claim 4, wherein the background plate is in a predetermined achromatic color. ### Claim 6 A program that makes a computer configuring an interactive whiteboard function as the following units, comprising: a coordinate detection unit configured to detect, as two-dimensional coordinates on a display plane, a contact position of an input object with reference to the display plane or an operating position of the input object with reference to a detection plane set in front side of the display plane; a display light correction value calculation unit configured to calculate a display light correction value to correct a variation in image color that is generated by light addition to an image of the input object, the light being from the display plane in a vicinity of the coordinates of the input object detected by the coordinate detection unit, the calculation being performed on a basis of a display color of the display plane in the vicinity of the detected coordinates; a background removal unit configured to extract an image of the input object only from the color image captured at at least a vicinity of a region where two-dimensional coordinates are detected; a color correction unit configured to correct color information of the image of the input object extracted by the background removal unit with the display light correction value; a color identification unit configured to identify a color of the image of the input object subjected to color correction by the color correction unit; and a display control unit configured to draw an object having a color identified by the color identification unit and a predetermined size at the detected coordinates of the display plane. ### Claim 7 (depends on 6) The program according to claim 6, further making the computer function as the following units, comprising: an environment light correction value measurement screen display control unit configured to make the display plane display an environment light correction value measurement screen; and an environment light correction value calculation unit configured to calculate, when the coordinate detection unit detects the input object during displaying of the environment light correction value measurement screen by the environment light correction value measurement screen display control unit, an environment light correction value to correct a variation in image color that is generated by addition of environment light on a basis of an image of an achromatic-colored input image having an achromatic range for reference, the image being extracted by the background removal unit; wherein the color correction unit corrects the image of the input object on the basis of the environment light correction value and the display light correction value. ### Claim 8 (depends on 6) The program according to claim 6, wherein when the program makes the computer function as the color identification unit, the color identification unit identifies the color of the input object as any predetermined achromatic color when the background removal unit fails in background removal or when both or any one of saturation and brightness of the image of the input object after the color correction is in a predetermined determination range. ### Claim 9 (depends on 1) The interactive whiteboard according to claim 1, further comprising: a brightness correction unit configured to reduce a brightness difference without changing hue of pixels in the color image captured by the image-capturing unit; and an in-shadow determination unit configured to determine whether or not the input object enters a shadow in the color image captured by the image-capturing unit, wherein the background removal unit extracts an image of the input object only from the color image subjected to brightness correction by the brightness correction unit, and the color correction unit performs predetermined color correction only when the in-shadow determination unit determines that the input object does not enter a shadow. ### Claim 10 (depends on 6) The program according to claim 6, wherein the program makes the computer further function as: a brightness correction unit configured to reduce a brightness difference without changing hue of pixels in the color image captured by the image-capturing unit; and an in-shadow determination unit configured to determine whether or not the input object enters a shadow in the color image captured by the image-capturing unit, wherein the background removal unit extracts an image of the input object only from the color image subjected to brightness correction by the brightness correction unit, and the color correction unit performs predetermined color correction only when the in-shadow determination unit determines that the input object does not enter a shadow. ### Claim 11 (depends on 2) The interactive whiteboard according to claim 2, wherein the color identification unit identifies the color of the input object as any predetermined achromatic color when the background removal unit fails in background removal or when both or any one of saturation and brightness of the image of the input object after the color correction is in a predetermined determination range. ### Claim 12 (depends on 2) The interactive whiteboard according to claim 2, further comprising: a background plate to be imaged as a background of the input object when the image-capturing unit captures an image of the input object, wherein the background plate protrudes by a predetermined length in a direction perpendicular to the display plane toward a front direction from a position surrounding a range where the coordinate detection unit can detect two-dimensional coordinates. ### Claim 13 (depends on 7) The program according to claim 7, wherein when the program makes the computer function as the color identification unit, the color identification unit identifies the color of the input object as any predetermined achromatic color when the background removal unit fails in background removal or when both or any one of saturation and brightness of the image of the input object after the color correction is in a predetermined determination range. ### Claim 14 (depends on 2) The interactive whiteboard according to claim 2, further comprising: a brightness correction unit configured to reduce a brightness difference without changing hue of pixels in the color image captured by the image-capturing unit; and an in-shadow determination unit configured to determine whether or not the input object enters a shadow in the color image captured by the image-capturing unit, wherein the background removal unit extracts an image of the input object only from the color image subjected to brightness correction by the brightness correction unit, and the color correction unit performs predetermined color correction only when the in-shadow determination unit determines that the input object does not enter a shadow. ### Claim 15 (depends on 7) The program according to claim 7, wherein the program makes the computer further function as: a brightness correction unit configured to reduce a brightness difference without changing hue of pixels in the color image captured by the image-capturing unit; and an in-shadow determination unit configured to determine whether or not the input object enters a shadow in the color image captured by the image-capturing unit, wherein the background removal unit extracts an image of the input object only from the color image subjected to brightness correction by the brightness correction unit, and the color correction unit performs predetermined color correction only when the in-shadow determination unit determines that the input object does not enter a shadow.