# US 2014/0153055 A1 · Image processing apparatus, image processing method, and storage medium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0153055 A1 - Document ID: US20140153055A1 - Status: Published application - Kind: A1 - Application number: 14/091,136 - Filed: 2013-11-26 - Published: 2014-06-05 - Earliest claimed: 2012-12-04 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Shuji Ozawa - Web page: https://patentgrep.com/patent/US20140153055A1 ## CPC - G06K 15/1881: {Halftoning (halftoning of still images in general H04N1/405, H04N1/52)} - G06T 11/60: Creating or editing images; Combining images with text - H04N 1/4051: {producing a dispersed dots halftone pattern, the dots having substantially the same size (different sizes H04N1/4057)} - H04N 1/644: {using a reduced set of representative colours, e.g. each representing a particular range in a colour space} - G06K 15/1807: {relating to the print image preparation} - G06K 2215/0094: Colour printing - G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An image processing method includes receiving image data including a color lookup table, and rendering the image data without referring to the color lookup table for each pixel when a combination of color values defined in the color lookup table is a predetermined combination. ## Claims ### Claim 1 An image processing apparatus comprising: a receiving unit configured to receive image data including a color lookup table; and a rendering unit configured to render the image data without referring to the color lookup table for each pixel if a combination of color values defined in the color lookup table is a predetermined combination. ### Claim 2 (depends on 1) The image processing apparatus according to claim 1, wherein the rendering unit is configured to refer to the color lookup table for each pixel in rendering the image data if the combination of color values defined in the color lookup table is not the predetermined combination. ### Claim 3 (depends on 1) The image processing apparatus according to claim 1 further comprising: a half-toning unit configured to perform halftone processing, wherein the halftone processing includes obtaining each pixel included in the received image data and performing threshold processing on each obtained pixel based on a dither matrix, wherein the rendering unit is configured to cause the half-toning unit to perform the halftone processing to render image data including a predetermined number of bits per pixel if the combination of color values defined in the color lookup table is not the predetermined combination, and wherein the rendering unit is configured to render image data including a predetermined number of bits per pixel without causing the half-toning unit to perform the halftone processing if the combination of color values defined in the color lookup table is the predetermined combination. ### Claim 4 (depends on 3) The image processing apparatus according to claim 3, wherein the rendering unit is configured to render the image data including the predetermined number of bits per pixel using a halftone pattern obtained by performing threshold processing on the color values defined in the color lookup table based on the dither matrix, without causing the half-toning unit to perform the halftone processing, if the combination of color values defined in the color lookup table is the predetermined combination. ### Claim 5 (depends on 1) The image processing apparatus according to claim 1, wherein the rendering unit comprises: a conversion unit configured to convert the received image data into image data having a format that does not include any color lookup table based on the combination of color values if the combination of color values defined in the color lookup table is the predetermined combination; and a converted image rendering unit configured to render the converted image data. ### Claim 6 (depends on 5) The image processing apparatus according to claim 5, wherein the conversion unit is configured to convert the received image data into the image data the format of which does not include any color lookup table and includes a color value determined based on the combination of color values, in which the determined color value is a filling color of the converted image data. ### Claim 7 (depends on 6) The image processing apparatus according to claim 6, wherein the converted image rendering unit is configured to render the converted image data using a color value of the filling color included in the converted image data. ### Claim 8 (depends on 6) The image processing apparatus according to claim 6, wherein the predetermined combination includes, at least, (i) a combination of minimum color values and (ii) a combination of maximum color values. ### Claim 9 (depends on 5) The image processing apparatus according to claim 5, wherein the conversion unit is configured to convert the received image data into the image data the format of which does not include any color lookup table and includes a source image included in the received image data together with raster operation (ROP) information determined based on the combination of color values, in which the determined ROP information is ROP information about the source image included in the converted image data. ### Claim 10 (depends on 9) The image processing apparatus according to claim 9, wherein the predetermined combination is a combination of color values usable to obtain a rendered image equivalent to the source image included in the received image data or a combination of color values usable to obtain a rendered image equivalent to a reverse image of the source image included in the received image data. ### Claim 11 (depends on 10) The image processing apparatus according to claim 10, wherein the predetermined combination is a combination of a minimum color value and a maximum color value. ### Claim 12 (depends on 11) The image processing apparatus according to claim 11, wherein the conversion unit is configured to convert the received image data into the image data the format of which does not include any color lookup and includes the source image together with ROP information that overwrites the source image, if the combination of color values defined in the color lookup table includes the minimum color value as a color value corresponding to an OFF pixel of the source image and the maximum color value as a color value corresponding to an ON pixel of the source image. ### Claim 13 (depends on 11) The image processing apparatus according to claim 11, wherein the conversion unit is configured to convert the received image data into the image data having the format that does not include any color lookup table and includes the source image together with ROP information that inversely overwrites the source image, if the combination of color values defined in the color lookup table includes the maximum color value as a color value corresponding to an OFF pixel of the source image and the minimum color value as a color value corresponding to an ON pixel of the source image. ### Claim 14 (depends on 5) The image processing apparatus according to claim 5, wherein, if the combination of color values defined in the color lookup table includes a color value of an intermediate color, the conversion unit is configured to convert the received image data into the image data the format of which does not include any color lookup table and includes a halftone pattern obtained by performing threshold processing on the color value of the intermediate color based on a dither matrix together with a source image included in the received image data. ### Claim 15 (depends on 14) The image processing apparatus according to claim 14, wherein the converted image rendering unit is configured to apply the halftone pattern included in the converted image data to the source image included in the converted image data when the converted image rendering unit renders the converted image data. ### Claim 16 (depends on 1) The image processing apparatus according to claim 1, wherein the source image included in the received image data is constituted by one bit per pixel, and wherein the color lookup table defines two color values. ### Claim 17 (depends on 1) The image processing apparatus according to claim 1, wherein the rendering unit is configured to perform processing for rendering a plurality of pixels at a time. ### Claim 18 (depends on 1) The image processing apparatus according to claim 1, further comprising a printing unit configured to print an image on a sheet based on the rendered image data. ### Claim 19 An image processing method comprising: receiving image data including a color lookup table; and rendering the image data without referring to the color lookup table for each pixel if a combination of color values defined in the color lookup table is a predetermined combination. ### Claim 20 A non-transitory computer-readable storage medium storing a program that causes a computer to perform an image processing method, the image processing method comprising: receiving image data including a color lookup table; and rendering the image data without referring to the color lookup table for each pixel if a combination of color values defined in the color lookup table is a predetermined combination.