# US 8,570,605 B2 · Image correction method and image correction system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,570,605 B2 - Document ID: US8570605B2 - Status: Granted - Kind: B2 - Application number: 12/697,792 - Filed: 2010-02-01 - Published: 2010-08-19 - Granted: 2013-10-29 - Earliest claimed: 2009-02-13 - Assignees: Canon Kabushiki Kaisha - Applicants: Takeshi Murase - Inventors: Takeshi Murase - Web page: https://patentgrep.com/patent/US8570605B2 ## CPC - H04N 1/6097: {depending on the characteristics of the output medium, e.g. glossy paper, matt paper, transparency or fabrics} - G06T 7/90: Determination of colour characteristics - G06T 11/10: Texturing; Colouring; Generation of textures or colours (retouching, inpainting or scratch removal G06T5/77) - H04N 1/60: Colour correction or control {(H04N1/54 takes precedence)} - G06T 2207/30144: Printing quality - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract A patch is printed on a printing medium, and ink discharge amount information is acquired from a colorimetric value that is acquired by measuring a printed patch. According to the information, color correction is performed on image data to be processed for printing, using a correction table that corresponds to a designated type of printing media. ## Claims ### Claim 1 An image processing method for printing by a print head which discharges an ink droplet, the method comprising the steps of: acquiring amount information on an amount of ink droplet discharged by the print head, based on a measurement value by measuring a test pattern printed by the print head and information corresponding to a print medium on which the test pattern is printed among a plurality of kinds of information corresponding to a plurality of kinds of print media, wherein each of the plurality of kinds of information associates the amount information with a predetermined measurement value; and determining a correction table corresponding to a print medium on which an image is to be printed, based on the acquired amount information. ### Claim 2 (depends on 1) The method according to claim 1, wherein ink droplet absorption characteristics of the plurality of kinds of print media differ from each other. ### Claim 3 (depends on 1) The method according to claim 1, wherein predetermined measurement values of the plurality of kinds of print media differ from each other, wherein each of the predetermined measurement values is a color-measured value by discharging a predetermined amount of ink into a unit area of an image in each of the plurality of kinds of print media. ### Claim 4 (depends on 1) The method according to claim 1, wherein the print head is able to discharge ink droplets corresponding to a plurality of ink colors, wherein the measurement value corresponds to each of the plurality of ink colors, wherein the correction table is determined on each of the plurality of ink colors, and wherein print data includes a plurality of pieces of data, corrected by the correction table, corresponding to the plurality of ink colors. ### Claim 5 (depends on 1) The method according to claim 1, further comprising a step of printing the test pattern on the printing medium by the print head. ### Claim 6 (depends on 1) The method according to claim 1, further comprising a step of measuring the test pattern by using a measurement unit and acquiring the measurement value. ### Claim 7 (depends on 6) The method according to claim 6, wherein the measurement unit is a spectro-colorimeter. ### Claim 8 (depends on 1) The method according to claim 1, wherein the test pattern includes a plurality of patches which correspond to a plurality of printing densities, and the correction table is a 1D-LUT for correcting density of the print data. ### Claim 9 (depends on 1) The method according to claim 1, further comprising a step of determining whether or not the amount of the ink droplet is adequate, in the case where it is determined that the amount of the ink droplet is adequate, the correction table is determined based on the amount information on the amount of the ink droplet, in the case where it is determined that the amount of the ink droplet is not adequate, the correction table is determined based on the amount information on an amount of the ink droplet which had been previously acquired. ### Claim 10 (depends on 1) The method according to claim 1, wherein the plurality of kinds of print media include a first print medium and a second print medium, and wherein the correction table corresponding to the first print medium is determined in a case where an image is to be printed on the first print medium, and the correction table corresponding to the second medium different from the first print medium is determined in a case where the image is to be printed on the second medium. ### Claim 11 (depends on 1) The method according to claim 1, further comprising a step of correcting image data of the image by using the determined correction table. ### Claim 12 (depends on 1) The method according to claim 1, wherein the measurement value is a L* value of a CIE-L*a*b* color coordinate system. ### Claim 13 (depends on 1) The method according to claim 1, wherein the plurality of kinds of print media includes a glossy paper and an art paper. ### Claim 14 An image processing apparatus for printing by a print head which discharges an ink droplet, the apparatus comprising: a storage unit configured to store a plurality of kinds of information, wherein the plurality of kinds of information correspond to a plurality of types of printing media, and wherein each of the plurality of kinds of information associates amount information on an amount of ink droplet discharged by the print head with a predetermined measurement value by measuring a test pattern printed by the print head; a acquisition unit configured to acquire amount information on an amount of ink droplet discharged by the print head, based on a measurement value by measuring a test pattern printed by the print head and information corresponding to a print medium on which the test pattern is printed among a plurality of kinds of information corresponding to a plurality of kinds of print media, wherein each of the plurality of kinds of information associates the amount information with the predetermined measurement value; and a determination unit configured to determine a correction table corresponding to a print medium on which an image is to be printed, based on the acquired amount information. ### Claim 15 (depends on 14) The apparatus according to claim 14, wherein the print head is able to discharge ink droplets corresponding to a plurality of ink colors, wherein the measurement value corresponds to each of the plurality of ink colors, wherein the determination unit determines the correction table on each of the plurality of ink colors, wherein print data includes a plurality of pieces of data, corrected by the correction table, corresponding to the plurality of ink colors. ### Claim 16 (depends on 14) The apparatus according to claim 14, further comprising a measuring unit configured to measure the test pattern and acquire the measurement value. ### Claim 17 (depends on 14) The apparatus according to claim 14, wherein ink droplet absorption characteristics of the plurality of kinds of print media differ from each other. ### Claim 18 (depends on 14) The apparatus according to claim 14, wherein redetermined measurement values of the plurality of kinds of print media differ from each other, wherein each of the predetermined measurement values is a color-measured value by discharging a predetermined amount of ink into a unit area of an image in each of the plurality of kinds of print media. ### Claim 19 (depends on 14) The apparatus according to claim 14, wherein the test pattern includes a plurality of patches which correspond to a plurality of printing densities, and the correction table is a 1D-LUT for correcting density of the print data. ### Claim 20 (depends on 14) The apparatus according to claim 14, wherein the determining unit further determines whether or not an amount of the ink droplet is adequate, in the case where it is determined that the amount of the ink droplet is adequate, the correction table is determined based on the amount information on the amount of the ink droplet, in the case where it is determined that the amount of the ink droplet is not adequate, the correction table is determined based on the amount information on an amount of the ink droplet which had been previously acquired. ### Claim 21 (depends on 14) The apparatus according to claim 14, wherein the plurality of kinds of print media include a first print medium and a second print medium, and wherein the correction table corresponding to the first print medium is determined in a case where an image is to be printed on the first print medium, and the correction table corresponding to the second medium different from the first print medium is determined in a case where the image is to be printed on the second medium. ### Claim 22 A computer-readable storage medium storing a program which causes a computer to execute an image processing method for printing by a print head which discharges an ink droplet, the method comprising the steps of: acquiring amount information on an amount of ink droplet discharged by the print head, based on a measurement value by measuring a test pattern printed by the print head and information corresponding to a print medium on which the test pattern is printed among a plurality of kinds of information corresponding to a plurality of kinds of print media, wherein each of the plurality of kinds of information associates the amount information with a predetermined measurement value; and determining a correction table corresponding to a print medium on which an image is to be printed, based on the acquired amount information.