# US 5,706,368 A · Image processing apparatus and method having detection of background color and encoding of color image data > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,706,368 A - Document ID: US5706368A - Status: Granted - Kind: A - Application number: 08/306,536 - Filed: 1994-09-15 - Granted: 1998-01-06 - Earliest claimed: 1990-12-26 - Assignees: Canon Kabushiki Kaisha - Inventors: Yoshinobu Mita - Web page: https://patentgrep.com/patent/US5706368A ## CPC - H04N 1/56: Processing of colour picture signals (H04N1/52 takes precedence) - H04N 1/41: Bandwidth or redundancy reduction (by scanning H04N1/17 {; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00}) - H04N 1/642: {Adapting to different types of images, e.g. characters, graphs, black and white image portions} - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A color image processing apparatus, including an input unit for inputting color image data having a plurality of color components, a detecting unit for detecting background color of a color image represented by the color image data input by the input unit, a removing unit for removing the background color from the color image data having the plurality of color components, an encoding unit for encoding the color image data with the background color removed, a transmission unit for transmitting the color image data with the background color removed encoded by the encoding unit, and a selecting unit for manually selecting between a first mode, in which the removing unit is operated, and a second mode, in which the removing unit is not operated. ## Claims ### Claim 1 A color image processing apparatus comprising: input means for inputting first color image data representing a first color image of a picture; judging means for judging a background color in the first color image on the basis of the first color image data input by said input means; removing means for removing the background color judged by said judging means from at least a part of the first color image and thereby generating second color image data representing a second color image of the picture, the second color image not including the background color; and encoding means for encoding the second color image of the picture and outputting encoded data. ### Claim 2 (depends on 1) The color image processing apparatus according to claim 1, further comprising combining means for combining data representing the background color with the encoded data output by the encoding means and outputting the combined data. ### Claim 3 (depends on 1) The color image processing apparatus according to claim 1, wherein the background color judged by said judging means varies in accordance with the first color image data input by said input means. ### Claim 4 A method of color image processing comprising the steps of: inputting first color image data representing a first color image of a picture; judging a background color in the first color image on the basis of the first color image data input in said inputting step; removing the background color judged in said judging step from at least a part of the first color image and thereby generating second color image data representing a second color image of the picture, the second color image not including the background color; encoding the second color image data; and outputting the encoded data. ### Claim 5 (depends on 4) The method of color image processing according to claim 4, further comprising the steps of: combining data representing the background color with the encoded data output in said outputting step; and outputting the combined data. ### Claim 6 (depends on 4) The method of color image processing according to claim 4, wherein the background color judged in said judging step varies in accordance with the first color image data input in said inputting step. ### Claim 7 A method of image processing comprising the steps of: inputting image data; determining whether the input image data input in said inputting step represents a color image or a black-and-white image; detecting a background color of an image represented by the input image data; and removing the background color from the image data when it is determined in said determining step that the input image data represents the black-and-white image. ### Claim 8 (depends on 7) The method according to claim 7, wherein said detecting step comprises the step of detecting the background color according to a distribution of a histogram of the input image data. ### Claim 9 (depends on 7) The method according to claim 7, further comprising an encoding step for encoding the image data from which the background color has been removed in said removing step. ### Claim 10 A method of image processing comprising the steps of: inputting image data; detecting a background color of an image represented by the input image data input in said inputting step; determining whether the image other than its background-color portion is a color image or a black-and-white image; and removing the background color from the image when it is determined in said determining step that the image other than the background-color portion is the black-and-white image. ### Claim 11 (depends on 10) The method according to claim 10 wherein said detecting step comprises the step of detecting the background color according to a distribution of a histogram of the input image data. ### Claim 12 (depends on 10) The method according to claim 10, further comprising the step of encoding the image data from which the background color has been removed in said removing step. ### Claim 13 A color image processing apparatus comprising: input means for inputting color image data having a plurality of color components; detecting means for detecting backgroud color of a color image represented by the input color image data input by said input means; removing means for removing the background color from the color image data having the plurality of color components; encoding means for encoding the color image data with the background color removed; transmission means for transmitting the color image data with the background color removed encoded by said encoding means; and selecting means for manually selecting between a first mode, in which said removing means is operated, and a second mode, in which said removing means is not operated. ### Claim 14 (depends on 13) An apparatus according to claim 13, wherein said detecting means detects the background color according to a distribution of a histogram of the input color image data. ### Claim 15 A color image processing method comprising the steps of: inputting color image data having a plurality of color components; detecting background color of a color image represented by the input color image data input in said inputting step; removing the background color from the color image data having the plurality of color components; encoding the color image data after removal of the background color in said removing step; transmitting the encoded color image; and manually selecting between a first mode, in which said removinq step is performed, and a second mode, in which said removing step is not performed. ### Claim 16 A color image processing apparatus comprising: input means for inputing color imaaqe data having a plurality of color components; detectinq means for detecting background color of a color image represented by the input color image data input by said input means; removing means for removing the background color from the color image having the plurality of color components; encoding means for encoding the color image data with the background color removed; transmitting means for transmitting the color image data with the background color removed encoded by said encoding means; and control means for controlling said removing means so as to operate or so as not to operate in accordance with an apparatus at the reception side of transmission by said transmission means. ### Claim 17 A color image processing apparatus comprising: receiving means for receiving encded color image data having a plurality of color components; decoding means for decoding the encoded color image data to output reproducing color image data having a plurality of color components; removing means for removing background color of a color image represented by the reproducing color image data; and selecting means for manually selecting between a first mode, in which said removing means is operated, and a second mode, in which said removing means is not operated. ### Claim 18 (depends on 17) An apparatus according to claim 17, further comprising detecting means for detecting the background color removed by said removing means. ### Claim 19 (depends on 18) An apparatus according to claim 18, wherein said detecting means detects the background color by analyzing the received encoded color image data removed by said removing means. ### Claim 20 A color image processing method comprising the steps of: receiving encoded color image data having a plurality of color components; decoding the encoded color image data and outputting reproducing-color image data having a plurality of color components; removing background color of a color image represented by the reproducing-color image data; and manually selecting between a first mode, in which said removing step is performed, and a second mode, in which said removing step is not performed. ### Claim 21 An image processing apparatus comprising: input means for inputting image data; determining means for determining whether the input image data input by said input means represents a color image or a black-and-white image; detecting means for detecting a background color of an image represented by the input image data; and removing means for removing the background color from the image data when said determining means determines that the input image data represents the black-and-white image. ### Claim 22 (depends on 21) An apparatus according to claim 21, wherein said detecting means detects the background color according to a distribution of a histogram of the input image data. ### Claim 23 (depends on 21) An apparatus according to claim 21, wherein said input means comprises a scanner further comprising a CCD (charge-coupled device) sensor, and wherein said determining means and detecting means are operated during a prescanning operation of said scanner. ### Claim 24 (depends on 21) An apparatus according to claim 21, further comprising selecting means for manually selecting between a first mode, in which said removing means is operated, and a second mode, in which said removing means is not operated. ### Claim 25 (depends on 21) An apparatus according to claim 21, further comprising encoding means for encoding the image data from which the background color has been removed by said removing means. ### Claim 26 An image processing apparatus comprising: input means for inputting image data; detecting means for detecting a background color of an image represented by the input image data input by said input means; determining means for determining whether the image other than its background-color portion is a color image or a black-and-white image; and removing means for removing the background color from the image when said determining means determines that the image other than the background-color portion is the black-and-white image. ### Claim 27 (depends on 26) An apparatus according to claim 26, wherein said detecting means detects the background color according to a distribution of a histogram of the input image data. ### Claim 28 (depends on 26) An apparatus according to claim 26, wherein said input means comprises a scanner further comprising a CCD (charge-coupled device) sensor, and wherein said determining means and detecting means are operated during a prescanning operation of said scanner. ### Claim 29 (depends on 26) An apparatus according to claim 26, further comprising selecting means for manually selecting between a first mode, in which said removing means is operated, and a second mode, in which said removing means is not operated. ### Claim 30 (depends on 26) An apparatus according to claim 26, further comprising encoding means for encoding the image data from which the background color has been removed by said removing means. ### Claim 31 A color image processing method comprising the steps of: inputting color image data having a plurality of color components; detecting background color of a color image represented by the input color image data input in said inputting step; removing the background color from the color image data having the plurality of color components; encoding the color image data after removal of the background color in said removing step; transmitting the encoded color image; and controlling so as to perform or so as not to perform said removing step in accordance with an apparatus at the reception side of transmission of said transmitting step.