# US 10,122,911 B2 · Image pickup apparatus, control method, and non-transitory computer-readable storage medium with aberration and object information acquisition for correcting automatic focus detection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,122,911 B2 - Document ID: US10122911B2 - Status: Granted - Kind: B2 - Application number: 15/413,487 - Filed: 2017-01-24 - Published: 2017-08-10 - Granted: 2018-11-06 - Earliest claimed: 2016-02-09 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Yumi Takao - Web page: https://patentgrep.com/patent/US10122911B2 ## CPC - H04N 23/672: {based on the phase difference signals} - G02B 7/346: {using horizontal and vertical areas in the pupil plane, i.e. wide area autofocusing} - G02B 7/36: using image sharpness techniques {, e.g. image processing techniques for generating autofocus signals (image data processing per se G06T; in cameras having a solid state image sensor H04N23/67)} - G02B 7/365: {by analysis of the spatial frequency components of the image} - G06T 5/73: Deblurring; Sharpening - G06T 7/90: Determination of colour characteristics - H04N 23/673: {based on contrast or high frequency components of image signals, e.g. hill climbing method} - H04N 23/81: for suppressing or minimising disturbance in the image signal generation - H04N 25/134: {based on three different wavelength filter elements} - H04N 25/445: by skipping some contiguous pixels within the read portion of the array - H04N 25/704: Pixels specially adapted for focusing, e.g. phase difference pixel sets - G06T 5/80: Geometric correction - H04N 23/667: Camera operation mode switching, e.g. between still and video, sport and normal or high- and low-resolution modes - H04N 25/61: the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4" - H04N 2209/041: using solid-state devices - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract An image pickup apparatus is capable of executing automatic focus detection of an imaging optical system, and includes a first acquisition unit configured to acquire aberration information of the imaging optical system, a second acquisition unit configured to acquire object information of an object in a focus detecting area, a calculation unit configured to calculate, based on the aberration information of the imaging optical system and the object information, a correction value used to correct a difference between a focus state of a captured image and a result of the automatic focus detection, caused by the aberration of the imaging optical system, and a correction unit configured to correct the result of the automatic focus detection using the correction value. ## Claims ### Claim 1 An image pickup apparatus capable of executing automatic focus detection of an imaging optical system, the image pickup apparatus comprising: a first acquisition unit configured to acquire aberration information of the imaging optical system; a second acquisition unit configured to acquire object information of an object in a focus detecting area; a determination unit configured to determine, based on the aberration information, whether it is necessary to obtain color information, angular information, and spatial frequency information of the object; a calculation unit configured to calculate, based on the aberration information of the imaging optical system and the object information, a correction value used to correct a difference between a focus state of a captured image and a result of the automatic focus detection, caused by the aberration of the imaging optical system; and a correction unit configured to correct the result of the automatic focus detection using the correction value. ### Claim 2 (depends on 1) The image pickup apparatus according to claim 1, wherein the object information contains at least one of color information, angular information, and spatial frequency information of the object in the focus detecting area. ### Claim 3 (depends on 1) The image pickup apparatus according to claim 1, wherein the aberration information of the imaging optical system contains information on at least one of an astigmatism, a chromatic aberration, and a spherical aberration. ### Claim 4 (depends on 1) The image pickup apparatus according to claim 1, wherein the aberration information of the imaging optical system contains information on a plurality of imaging positions each of which corresponds to a maximum value of a modulation transfer function corresponding to one of a plurality of different spatial frequencies. ### Claim 5 (depends on 4) The image pickup apparatus according to claim 4, wherein the calculation unit calculates the correction value based on a result of calculating an imaging position corresponding to a spatial frequency for a focus detection using information of an imaging position of the imaging optical system for each spatial frequency of the object, and a result of calculating an imaging position corresponding to a spatial frequency for the captured image using the information of the imaging position of the imaging optical system for each spatial frequency of the object. ### Claim 6 (depends on 5) The image pickup apparatus according to claim 5, further comprising a setting unit configured to set a first weighting coefficient that depends on a first color, a second color, and a third color in color information of the object, a second weighting coefficient that depends on a first direction and a second direction orthogonal to the first direction in angular information the object, and a third weighting coefficient that depends on spatial frequency information of the object, wherein the correction unit calculates the correction signal by weighting information of the imaging position of the imaging optical system for each spatial frequency of the object as set by the setting unit. ### Claim 7 (depends on 6) The image pickup apparatus according to claim 6, wherein the correction unit performs a calculation using the aberration information, the first weighting coefficient, and the second weighting coefficient prior to a calculation using the aberration information and the third weighting coefficient. ### Claim 8 (depends on 1) The image pickup apparatus according to claim 1, wherein the determination unit determines that it is unnecessary to obtain the color information when an amount of the chromatic aberration in the aberration information is smaller than a predetermined value. ### Claim 9 (depends on 1) The image pickup apparatus according to claim 1, wherein the determination unit determines that it is unnecessary to obtain the angular information when an amount of the astigmatism in the aberration information is smaller than a predetermined value. ### Claim 10 (depends on 1) The image pickup apparatus according to claim 1, wherein the determination unit determines that it is unnecessary to obtain the spatial frequency information when an amount of the spatial aberration in the aberration information is smaller than a predetermined value. ### Claim 11 (depends on 1) The image pickup apparatus according to claim 1, wherein the determination unit further determines, based on the object information, whether it is necessary to calculate the correction value. ### Claim 12 (depends on 1) The image pickup apparatus according to claim 1, wherein the determination unit further determines, based on the aberration information and the object information, that the correction value is to be calculated when at least one aberration among chromatic aberration, astigmatism, and spherical aberration of the object is larger than a predetermined value. ### Claim 13 A control method for an image pickup apparatus capable of executing automatic focus detection of an imaging optical system, the control method comprising the steps of: acquiring aberration information of the imaging optical system; acquiring object information of an object in a focus detecting area; determining, based on the aberration information, whether it is necessary to obtain color information, angular information, and spatial frequency information of the object; calculating, based on the aberration information of the imaging optical system and the object information, a correction value used to correct a difference between a focus state of a captured image and a result of the automatic focus detection, caused by the aberration of the imaging optical system; and correcting the result of the automatic focus detection using the correction value. ### Claim 14 A non-transitory computer-readable storage medium storing a program that enables a computer to execute a method that includes the steps of: executing automatic focus detection of an imaging optical system; acquiring aberration information of the imaging optical system; acquiring object information of an object in a focus detecting area; determining, based on the aberration information, whether it is necessary to obtain color information, angular information, and spatial frequency information of the object; calculating, based on the aberration information of the imaging optical system and the object information, a correction value used to correct a difference between a focus state of a captured image and a result of the automatic focus detection, caused by the aberration of the imaging optical system; and correcting the result of the automatic focus detection using the correction value. ### Claim 15 An image pickup apparatus capable of executing automatic focus detection of an imaging optical system, the image pickup apparatus comprising: a first acquisition unit configured to acquire aberration information of the imaging optical system; a second acquisition unit configured to acquire object information of an object in a focus detecting area; a determination unit configured to determine, based on the aberration information, whether it is necessary to obtain color information of the object; a calculation unit configured to calculate, based on the aberration information of the imaging optical system and the object information, a correction value used to correct a difference between a focus state of a captured image and a result of the automatic focus detection, caused by the aberration of the imaging optical system; and a correction unit configured to correct the result of the automatic focus detection using the correction value, wherein the determination unit determines that it is unnecessary to obtain the color information when an amount of the chromatic aberration in the aberration information is smaller than a predetermined value. ### Claim 16 A control method for an image pickup apparatus capable of executing automatic focus detection of an imaging optical system, the control method comprising the steps of: acquiring aberration information of the imaging optical system; acquiring object information of an object in a focus detecting area; determining, based on the aberration information, whether it is necessary to obtain color information of the object; calculating, based on the aberration information of the imaging optical system and the object information, a correction value used to correct a difference between a focus state of a captured image and a result of the automatic focus detection, caused by the aberration of the imaging optical system; and correcting the result of the automatic focus detection using the correction value, wherein the determining step determines that it is unnecessary to obtain the color information when an amount of the chromatic aberration in the aberration information is smaller than a predetermined value. ### Claim 17 A non-transitory computer-readable storage medium storing a program that enables a computer to execute a method that includes the steps of: executing automatic focus detection of an imaging optical system; acquiring aberration information of the imaging optical system; acquiring object information of an object in a focus detecting area; determining, based on the aberration information, whether it is necessary to obtain color information of the object; calculating, based on the aberration information of the imaging optical system and the object information, a correction value used to correct a difference between a focus state of a captured image and a result of the automatic focus detection, caused by the aberration of the imaging optical system; and correcting the result of the automatic focus detection using the correction value, wherein the determining step determines that it is unnecessary to obtain the color information when an amount of the chromatic aberration in the aberration information is smaller than a predetermined value.