# US 2001/0024518 A1 · Image processing apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2001/0024518 A1 - Document ID: US20010024518A1 - Status: Published application - Kind: A1 - Application number: 09/795,122 - Filed: 2001-03-01 - Published: 2001-09-27 - Earliest claimed: 2000-03-03 - Assignees: Canon Kabushiki Kaisha - Inventors: Hiroyuki Yaguchi - Web page: https://patentgrep.com/patent/US20010024518A1 ## CPC - H04N 1/4074: {using histograms} - H04N 1/6027: {Correction or control of colour gradation or colour contrast (H04N1/6058 takes precedence)} - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A scanner with an automatic density adjustment function executes image processing in which prescanning is performed and the background level is made white before the next scan starts. However, if an automatic density adjustment is applied when the same document is read as a color image and as a monochrome image, it is necessary to perform prescanning before the color image is read and prescanning before the monochrome image is read. Reading the image therefore takes time. Accordingly, if an automatic density adjustment based upon prescanning has been designated, prescanning is carried out and then a histogram is obtained for each of the components R, G and B and the background levels are calculated for color scanning and monochrome scanning. A table in a scanner image processor is set in accordance with a background peak value PeakBW for monochrome scanning. For color scanning, on the other hand, the table in the scanner image processor is set in accordance with a background peak value PeakCL for the color scan. ## Claims ### Claim 1 An image processing apparatus for obtaining a color and/or monochrome image by scanning an original image, comprising: a prescanner for extracting background information for a color image and for a monochrome image from the original image using a scanner before the original image is scanned by the scanner; and a controller for setting image processing conditions of the scanner based upon the background information extracted. ### Claim 2 (depends on 1) The apparatus according to claim 1, wherein prescanning by said prescanner is performed once for one original. ### Claim 3 An image processing apparatus comprising: a scanner for obtaining a color and/or monochrome image by scanning an original image; a prescanner for prescanning an original image, which is to be scanned, using said scanner; a generator for generating a histogram corresponding to an image signal level of the image that has been prescanned; an extractor for extracting background information for a color image and/or background information for a monochrome image from the histogram; and a controller for setting image processing conditions of said scanner based upon the background information extracted. ### Claim 4 (depends on 3) The apparatus according to claim 3, wherein prescanning by said prescanner is performed once for one original. ### Claim 5 (depends on 3) The apparatus according to claim 3, wherein if acquisition of a color image has been designated, said controller sets image processing conditions, which are based upon the background information for the color image, in said scanner. ### Claim 6 (depends on 3) The apparatus according to claim 3, wherein if acquisition of a monochrome image has been designated, said controller sets image processing conditions, which are based upon the background information for the monochrome image, in said scanner. ### Claim 7 (depends on 3) The apparatus according to claim 3, wherein said extractor divides the histogram into a plurality of areas of prescribed width, discriminates an area, for which the sum of frequencies is indicative of a peak value, with regard to each color component of the image signal, and extracts, from the obtained areas of each of the color components, an area corresponding to a lower image-signal level, this area serving as the background information for the color image. ### Claim 8 (depends on 7) The apparatus according to claim 7, wherein said extractor extracts an area of a predetermined color component, which has been obtained by said discrimination, as the background information for the monochrome image. ### Claim 9 An image processing method of obtaining a color and/or monochrome image by scanning an original image, comprising the steps of: extracting background information for a color image and for a monochrome image from the original image using a scanner before the original image is scanned by the scanner; and setting image processing conditions of the scanner based upon the background information extracted. ### Claim 10 (depends on 9) The method according to claim 9, wherein prescanning for extracting the background information is performed once for one original. ### Claim 11 An image processing method comprising the steps of: prescanning an original image, which is to be scanned, using a scanner that is for scanning the original image to obtain a color and/or monochrome image; generating a histogram corresponding to an image signal level of the image that has been prescanned; extracting background information for a color image and/or background information for a monochrome image from the histogram; and setting image processing conditions of said scanner based upon the background information extracted. ### Claim 12 (depends on 11) The method according to claim 11, wherein prescanning for extracting the background information is performed once for one original. ### Claim 13 A computer program product comprising a computer-readable medium having computer program code for an image processing method of obtaining a color and/or monochrome image by scanning an original image, comprising process procedure code for: extracting background information for a color image and for a monochrome image from the original image using a scanner before the original image is scanned by the scanner; and setting image processing conditions of the scanner based upon the background information extracted. ### Claim 14 (depends on 13) The product according to claim 13, wherein prescanning for extracting the background information is performed once for one original. ### Claim 15 A computer program product comprising a computer-readable medium having computer program code for an image processing method, comprising process procedure code for: prescanning an original image, which is to be scanned, using a scanner that is for scanning the original image to obtain a color and/or monochrome image; generating a histogram corresponding to an image signal level of the image that has been prescanned; extracting background information for a color image and/or background information for a monochrome image from the histogram; and setting image processing conditions of said scanner based upon the background information extracted. ### Claim 16 (depends on 15) The product according to claim 15, wherein prescanning for extracting the background information is performed once for one original.