# US 2017/0257583 A1 · Image processing device and control method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0257583 A1 - Document ID: US20170257583A1 - Status: Published application - Kind: A1 - Application number: 15/445,244 - Filed: 2017-02-28 - Published: 2017-09-07 - Earliest claimed: 2016-03-01 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Yuki Yoshimura; Akihiko Kanda - Web page: https://patentgrep.com/patent/US20170257583A1 ## CPC - H04N 13/218: using spatial multiplexing - H04N 23/10: for generating image signals from different wavelengths - H04N 25/50: Control of the SSIS exposure - H04N 25/61: the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4" - H04N 25/68: applied to defects - H04N 25/704: Pixels specially adapted for focusing, e.g. phase difference pixel sets - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An imaging element of an imaging apparatus includes a plurality of microlenses and a plurality of photoelectric conversion units corresponding to the microlenses. A parallax picture having a parallax is generated by acquiring signals from the plurality of photoelectric conversion units. A CPU performs defective pixel detection by calculating an evaluation value from a first output value which is an output value of a detection pixel and a second output value determined from a pixel adjacent to the pixel and comparing the evaluation value with a predetermined threshold value. The CPU calculates a second evaluation value using the second output value and a first evaluation value derived from the first output value and the second output value and detects the pixel as a defective pixel if the second evaluation value is greater than the threshold value. ## Claims ### Claim 1 An image processing device for acquiring output values of a plurality of pixels and processing image signals, the image processing device comprising: an acquisition unit configured to acquire a first output value from a pixel and acquire a second output value determined from a pixel adjacent to the pixel; and a detection unit configured to perform defective pixel detection by calculating an evaluation value of the pixel from the first output value and the second output value and comparing the evaluation value with a threshold value, wherein the detection unit calculates a second evaluation value using the second output value and a first evaluation value derived from the first output value and the second output value and detects the pixel as a defective pixel if the second evaluation value is greater than the threshold value. ### Claim 2 (depends on 1) The image processing device according to claim 1, wherein the detection unit calculates the second evaluation value by correcting the first evaluation value in a function including a standard output value of the defective pixel detection. ### Claim 3 (depends on 1) The image processing device according to claim 1, wherein the second output value is a median value or a mean value determined from an output value of a pixel adjacent to a target pixel. ### Claim 4 (depends on 1) The image processing device according to claim 1, wherein the detection unit determines the second output value using one or more of the first output value, a color filter of the pixel, a pupil area through which a received light beam passes, and the number of added pixels as the same condition. ### Claim 5 (depends on 1) The image processing device according to claim 1, wherein the pixel is a pixel of an imaging element including a plurality of microlenses and a plurality of photoelectric conversion units corresponding to the microlenses. ### Claim 6 (depends on 2) The image processing device according to claim 2, wherein the first evaluation value is calculated by dividing a difference between the first output value and the second output value by the second output value, and wherein the second evaluation value is calculated by multiplying a term which increases when the second value increases with respect to the standard output value by the first evaluation value. ### Claim 7 (depends on 6) The image processing device according to claim 6, wherein, when the first evaluation value is denoted by E(i,j,t) which is a function of a pixel position (i,j) and a photographing time (t), the standard output value is denoted by Sstd(i,j) which is a function of the pixel position (i,j), the second output value is denoted by Styp, and the threshold value is denoted by Eerror0, and an allowed variation is denoted by α0, the detection unit detects the pixel as the defective pixel if the pixel satisfies the following formula. S typ  ( i , j ) S std · E  ( i , j , t ) > Eerror 0 + ( S typ  ( i , j ) S std - 1 ) · α 0 ### Claim 8 (depends on 1) The image processing device according to claim 1, comprising: a pixel correction unit configured to correct a pixel signal of the defective pixel detected by the detection unit. ### Claim 9 (depends on 8) The image processing device according to claim 8, comprising: a shading correction unit configured to perform shading correction using the pixel signal corrected by the pixel correction unit. ### Claim 10 (depends on 9) The image processing device according to claim 9, wherein the shading correction unit performs shading correction of a parallax picture. ### Claim 11 (depends on 1) The image processing device according to claim 1, wherein the first evaluation value is a luminance evaluation value normalized in luminance. ### Claim 12 An image processing device for acquiring output values of a plurality of pixels and processing image signals, the image processing device comprising: an acquisition unit configured to acquire a first output value from a pixel and acquire a second output value determined from a pixel adjacent to the pixel; a detection unit configured to perform defective pixel detection by calculating a first evaluation value of the pixel from the first output value and the second output value and comparing a second evaluation value calculated from the first evaluation value and the second output value with a threshold value; a pixel correction unit configured to correct a pixel signal of a defective pixel detected by the detection unit; and a shading correction unit configured to perform shading correction using the pixel signal corrected by the pixel correction unit. ### Claim 13 (depends on 12) The image processing device according to claim 12, wherein the shading correction unit acquires a correction value corresponding to an image height or a correction value corresponding to an aperture value or an exit pupil distance of a lens unit from a storage unit and performs shading correction during picture reproduction. ### Claim 14 (depends on 12) The image processing device according to claim 12, wherein the first evaluation value is a luminance evaluation value normalized in luminance. ### Claim 15 A control method to be executed by an image processing device for acquiring output values of a plurality of pixels and processing image signals, the control method comprising: acquiring a first output value from a pixel and acquiring a second output value determined from a pixel adjacent to the pixel; and performing, by a detection unit, defective pixel detection by calculating an evaluation value of the pixel from the first output value and the second output value and comparing the evaluation value with a threshold value, wherein the detection includes calculating, by the detection unit, a second evaluation value using the second output value and a first evaluation value derived from the first output value and the second output value and detecting the pixel as a defective pixel if the second evaluation value is greater than the threshold value. ### Claim 16 A control method to be executed by an image processing device for acquiring output values of a plurality of pixels and processing image signals, the control method comprising: acquiring a first output value from a pixel and acquiring a second output value determined from a pixel adjacent to the pixel; performing, by a detection unit, defective pixel detection by calculating a first evaluation value of the pixel from the first output value and the second output value and comparing a second evaluation value calculated from the first evaluation value and the second output value with a threshold value; correcting, by a pixel correction unit, a pixel signal of the detected defective pixel; and performing, by a shading correction unit, shading correction using the pixel signal corrected by the pixel correction unit.