# US 10,373,298 B2 · Image distortion correction method and apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,373,298 B2 - Document ID: US10373298B2 - Status: Granted - Kind: B2 - Application number: 15/571,674 - Filed: 2015-09-15 - Published: 2018-05-03 - Granted: 2019-08-06 - Earliest claimed: 2015-09-15 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Congchao Zhu; Wei Luo - Web page: https://patentgrep.com/patent/US10373298B2 ## CPC - G06T 5/80: Geometric correction - G06T 3/4038: Image mosaicing, e.g. composing plane images from plane sub-images - G06T 5/50: using two or more images, e.g. averaging or subtraction - H04N 23/698: for achieving an enlarged field of view, e.g. panoramic image capture - G06T 2200/32: involving image mosaicing - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A method includes shooting an nth frame of image at a first angle, where a projection of a distance value of a first pixel point of the nth frame of image to an optical center onto an optical axis direction is a first distance value, and a projection of a distance value of an ith pixel point of the nth frame of image to the optical center onto the optical axis direction is a second distance value, obtaining a third and a fourth distance value, obtaining a correction coefficient of the ith pixel point of the nth frame of image according to the first, the second, the third, and the fourth distance value, and correcting a location of the ith pixel point of the nth frame of image according to the correction coefficient using a location of an ith pixel point of the first frame of image as a reference. ## Claims ### Claim 1 An image distortion correction method, comprising: shooting an nth frame of an image at a first angle deviating from a vertical direction, wherein a projection of a distance value of a first pixel point of the nth frame of the image to an optical center onto an optical axis direction is a first distance value, wherein a projection of a distance value of an ith pixel point of the nth frame of the image to the optical center onto the optical axis direction is a second distance value, and wherein the first pixel point is a pixel point at a lowest end of the nth frame of the image; obtaining a third distance value and a fourth distance value, wherein the third distance value is a projection of a pixel point at an uppermost end of a first frame of the image to the optical center onto the optical axis direction when the first frame of the image is shot at a second angle deviating from the vertical direction, wherein the fourth distance value is a projection of a pixel point at a lowest end of the first frame of the image to the optical center onto the optical axis direction when the first frame of image is shot at the second angle deviating from the vertical direction, wherein the second angle is less than the first angle, and wherein the first angle and the second angle are angles when images are shot at a same side in the vertical direction; obtaining a correction coefficient of the ith pixel point of the nth frame of the image according to a first ratio and a second ratio, the first ratio being obtained according to the first distance value the second distance value, the second ratio being obtained according to the third distance value and the fourth distance value; and correcting a location of the ith pixel point of the nth frame of the image according to the correction coefficient using a location of an ith pixel point of the first frame of the image as a reference, wherein a value of n is 2 to N, and wherein a value of N is a positive integer greater than or equal to 2. ### Claim 2 (depends on 1) The method according to claim 1, wherein the method further comprises calculating a proportion of image deformation when the nth frame of the image deviates from the vertical direction by the first angle. ### Claim 3 (depends on 1) The method according to claim 1, wherein the second ratio is 1. ### Claim 4 (depends on 1) The method according to claim 1, wherein a formula for obtaining the correction coefficient is T i ′ = T i T 1 , wherein Ti′ is the correction coefficient of the ith pixel point of the nth frame of the image, wherein Ti is the first ratio, and wherein T1 is the second ratio. ### Claim 5 (depends on 1) The method according to claim 1, wherein the location of the ith pixel point of the nth frame of the image comprises a column coordinate of the location of the ith pixel point of the nth frame of the image, and wherein correcting the location of the ith pixel point of the nth frame of the image comprises obtaining, according to the column coordinate and the correction coefficient, a column coordinate of the ith pixel point after correction. ### Claim 6 (depends on 5) The method according to claim 5, wherein a formula for obtaining the column coordinate of the ith pixel point after correction is J ′ = ( J - width 2 ) × T i ′ + width 2 , wherein J′ is the column coordinate of the ith pixel point after correction, wherein J is the column coordinate of the location of the ith pixel point of the nth frame of the image, wherein width is a width of an image using a pixel as a unit, and wherein Ti′ is the correction coefficient. ### Claim 7 An image distortion correction apparatus, comprising: a camera configured to: shoot an nth frame of an image at a first angle deviating from a vertical direction; and shoot a first frame of the image at a second angle deviating from the vertical direction, wherein the second angle is less than the first angle, and wherein the first angle and the second angle are angles when images are shot at a same side in the vertical direction; and a processor coupled to the camera and configured to: measure a first distance value, a second distance value, a third distance value, and a fourth distance value, wherein the first distance value is a projection of a distance value of a first pixel point of the nth frame of the image to an optical center onto an optical axis direction when the camera shoots the nth frame of the image at the first angle deviating from the vertical direction, wherein the second distance value is a projection of a distance value of an ith pixel point of the nth frame of the image to the optical center onto the optical axis direction when the camera shoots the nth frame of the image at the first angle deviating from the vertical direction, wherein the first pixel point is a pixel point at a lowest end of the nth frame of the image, wherein the third distance value is a projection of a pixel point at an uppermost end of the first frame of the image to the optical center onto the optical axis direction when the camera shoots the first frame of the image at the second angle deviating from the vertical direction, and wherein the fourth distance value is a projection of a pixel point at a lowest end of the first frame of the image to the optical center onto the optical axis direction when the camera shoots the first frame of image at the second angle deviating from the vertical direction; obtain a correction coefficient of the ith pixel point of the nth frame of the image according to a first ratio and a second ratio, the first ratio being obtained according to the first distance value the second distance value, the second ratio being obtained according to the third distance value and the fourth distance value; and correct a location of the ith pixel point of the nth frame of the image according to the correction coefficient obtained using a location of an ith pixel point of the first frame of image as a reference, wherein a value of n is 2 to N, and wherein a value of N is a positive integer greater than or equal to 2. ### Claim 8 (depends on 7) The apparatus according to claim 7, wherein the processor is further configured to calculate a proportion of image deformation when the nth frame of the image deviates from the vertical direction by the first angle, relative to an ideal status. ### Claim 9 (depends on 8) The apparatus according to claim 8, wherein the ideal status is based on an optical axis of the camera being perpendicular to an imaging plane of the image. ### Claim 10 (depends on 7) The apparatus according to claim 7, wherein the second ratio is 1. ### Claim 11 (depends on 7) The apparatus according to claim 7, wherein a formula for obtaining the correction coefficient is T i ′ = T i T 1 , wherein Ti′ is the correction coefficient of the ith pixel point of the nth frame of the image, wherein Ti is the first ratio, and wherein T1 is the second ratio. ### Claim 12 (depends on 7) The apparatus according to claim 7, wherein the location of the ith pixel point of the nth frame of the image comprises a column coordinate of the location of the ith pixel point of the nth frame of the image, and wherein the processor is further configured to obtain, according to the column coordinate of the location of the ith pixel point of the nth frame of the image and the correction coefficient, a column coordinate of the ith pixel point after correction. ### Claim 13 (depends on 12) The apparatus according to claim 12, wherein a formula for obtaining the column coordinate of the ith pixel point after correction is J ′ = ( J - width 2 ) × T i ′ + width 2 , wherein J′ is the column coordinate of the ith pixel point after correction, wherein J is the column coordinate of the location of the ith pixel point of the nth frame of image, wherein width is a width of an image using a pixel as a unit, and wherein Ti′ is the correction coefficient. ### Claim 14 A non-transitory computer readable storage medium storing one or more programs, wherein the one or more programs comprise an instruction, wherein when a portable electronic device comprising a display and a plurality of application programs executes the instruction, the portable electronic device performs a method that comprises: shooting an nth frame of an image at a first angle deviating from a vertical direction, wherein a projection of a distance value of a first pixel point of the nth frame of the image to an optical center onto an optical axis direction is a first distance value, wherein a projection of a distance value of an ith pixel point of the nth frame of the image to the optical center onto the optical axis direction is a second distance value, and wherein the first pixel point is a pixel point at a lowest end of the nth frame of the image; obtaining a third distance value and a fourth distance value, wherein the third distance value is a projection of a pixel point at an uppermost end of a first frame of the image to the optical center onto the optical axis direction when the first frame of the image is shot at a second angle deviating from the vertical direction, wherein the fourth distance value is a projection of a pixel point at a lowest end of the first frame of the image to the optical center onto the optical axis direction when the first frame of image is shot at the second angle deviating from the vertical direction, wherein the second angle is less than the first angle, and wherein the first angle and the second angle are angles when images are shot at a same side in the vertical direction; obtaining a correction coefficient of the ith pixel point of the nth frame of the image according to a first ratio and a second ratio, the first ratio being obtained according to the first distance value and the second distance value, the second ratio being obtained according to the third distance value and the fourth distance value; and correcting a location of the ith pixel point of the nth frame of the image according to the correction coefficient using a location of an ith pixel point of the first frame of the image as a reference, wherein a value of n is 2 to N, wherein a value of N is a positive integer greater than or equal to 2, and wherein the display comprises a touch-sensitive surface and a display screen. ### Claim 15 (depends on 14) The non-transitory computer readable storage medium according to claim 14, wherein correcting the location of the ith pixel point of the nth frame of the image comprises obtaining a column coordinate of the ith pixel point after correction. ### Claim 16 (depends on 14) The non-transitory computer readable storage medium according to claim 14, wherein the location of the ith pixel point of the nth frame of the image comprises a column coordinate of the location of the ith pixel point of the nth frame of the image. ### Claim 17 (depends on 14) The non-transitory computer readable storage medium according to claim 14, wherein the method further comprises calculating a proportion of image deformation when the nth frame of the image deviates from the vertical direction by the first angle. ### Claim 18 (depends on 14) The non-transitory computer readable storage medium according to claim 14, wherein the method further comprises calculating a proportion of image deformation when the first frame of the image deviates from the vertical direction by the second angle.