# US 2013/0278798 A1 · Image processing apparatus and image processing method for performing image synthesis > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0278798 A1 - Document ID: US20130278798A1 - Status: Published application - Kind: A1 - Application number: 13/834,121 - Filed: 2013-03-15 - Published: 2013-10-24 - Earliest claimed: 2012-04-20 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Mitsuaki HATTORI - Web page: https://patentgrep.com/patent/US20130278798A1 ## CPC - H04N 23/71: Circuitry for evaluating the brightness variation - H04N 23/73: by influencing the exposure time - H04N 23/6812: {based on additional sensors, e.g. acceleration sensors} - H04N 23/683: {performed by a processor, e.g. controlling the readout of an image memory} - H04N 23/951: by using two or more images to influence resolution, frame rate or aspect ratio - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An image processing apparatus capable of properly synthesizing a strobe-illuminated image and non-strobe-illuminated images, irrespective of a condition for illuminating a photographic subject. A sensitivity of strobe emission photographing is set to be lower than a sensitivity of non-strobe emission photographing, and a strobe-illuminated image and plural sheets of non-strobe-illuminated images are continuously photographed with the set sensitivities. The strobe-illuminated image is gain-processed with a gain amount, and positional deviations of the plural sheets of non-strobe-illuminated images relative to the strobe-illuminated image are corrected. An averaged image obtained by synthesizing the gain-processed image and the images after the positional deviation correction is synthesized with the strobe-illuminated image, while taking account of amounts of strobe illumination in the strobe-illuminated image, thereby obtaining a synthesized image. ## Claims ### Claim 1 An image processing apparatus comprising: a photographing unit configured to continuously photograph a first image by first photographing with an emission by an emission unit and plural sheets of second images by second photographing without the emission; a sensitivity setting unit configured to set a sensitivity of the first photographing to be lower than a sensitivity of the second photographing; a gain processing unit configured to perform gain processing in which image data of the first image is multiplied by a gain amount; an averaging unit configured to create an averaged image based on the first image gain processed by said gain processing unit and the plural sheets of the second images; and a synthesis unit configured to create a synthesized image by synthesizing the first image photographed by said photographing unit and the averaged image created by said averaging unit. ### Claim 2 (depends on 1) The image processing apparatus according to claim 1, wherein said gain processing unit multiplies the first image by a gain amount that compensates for a sensitivity difference between the sensitivity of the first photographing and the sensitivity of the second photographing that are set by said sensitivity setting unit. ### Claim 3 (depends on 1) The image processing apparatus according to claim 1, wherein said sensitivity setting unit sets the sensitivity of the first photographing to be lower with increase of a number of photographed sheets of the second images. ### Claim 4 (depends on 1) The image processing apparatus according to claim 1, further including: a positional deviation correcting unit configured to detect positional deviation amounts of the plural sheets of the second images relative to the first image, and correct positional deviations of the plural sheets of the second images based on the detected positional deviation amounts. ### Claim 5 (depends on 4) The image processing apparatus according to claim 4, wherein when detecting the positional deviation amounts of the plural sheets of the second images relative to the first image, said positional deviation correcting unit uses, as the first image, the first image gain-processed by said gain processing unit. ### Claim 6 (depends on 1) The image processing apparatus according to claim 1, further including: an illumination amount calculating unit configured to determine amounts of illumination in the first image, wherein said photographing unit photographs the plural sheets of the second images after photographing the first image, and said illumination amount calculating unit compares the first image with the second image firstly photographed among the plural sheets of the second images, determines differences between brightness values on a per pixel basis, and determines the amounts of illumination on a per pixel basis by referring to a brightness difference vs. illumination amount table prepared in advance. ### Claim 7 (depends on 1) The image processing apparatus according to claim 1, wherein said averaging unit calculates, on a per pixel basis, average values of pixel values of the first image gain-processed by said gain processing unit and pixel values of the plural sheets of second images, and create the averaged image based on calculated average values of the pixel values. ### Claim 8 An image processing apparatus comprising: a photographing unit configured to continuously photograph a first image by first photographing with an emission by an emission unit and plural sheets of second images by second photographing without the emission; a sensitivity setting unit configured to set a sensitivity of the first photographing to be lower than a sensitivity of the second photographing; a gain processing unit configured to perform gain processing in which image data of the first image is multiplied by a gain amount; an averaging unit configured to create an averaged image based on the first image gain processed by said gain processing unit and the plural sheets of the second images; and a synthesis unit configured to compare pixel values of the first image photographed by said photographing unit with pixel values of the averaged image created by said averaging unit and select pixel values, whichever are brighter, and create a synthesized image based on the selected pixel values. ### Claim 9 An image processing method executed by an image processing apparatus, comprising: a sensitivity setting step of setting a sensitivity of a first photographing with an emission by an emission unit to be lower than a sensitivity of a second photographing without the emission; a photographing step of continuously photographing a first image by the first photographing and plural sheets of the second images by the second photographing with the sensitivities set in said sensitivity setting step; a gain processing step of performing gain processing in which respective pixel values of the first image are each multiplied by a gain amount; an averaging step of creating an averaged image based on the first image gain processed in said gain processing step and the plural sheets of the second images; and a synthesis step of creating a synthesized image by synthesizing, on a per pixel basis, the first image photographed in said photographing step and the averaged image created in said averaging step. ### Claim 10 An image processing method executed by an image processing apparatus, comprising: a sensitivity setting step of setting a sensitivity of a first photographing with an emission by an emission unit to be lower than a sensitivity of a second photographing without the emission; a photographing step of continuously photographing a first image by the first photographing and plural sheets of second images by the second photographing with the sensitivities set in said sensitivity setting step; a gain processing step of performing gain processing in which respective pixel values of the first image are each multiplied by a gain amount; an averaging step of creating an averaged image based on the first image gain processed in said gain processing step and the plural sheets of the second images; and a synthesis step of comparing pixel values of the first image photographed in said photographing step with pixel values of the averaged image created in said averaging step and selecting pixel values, whichever are brighter, and creating a synthesized image based on the selected pixel values.