# US 11,445,158 B2 · Image processing apparatus, image capturing apparatus, image processing method, and storage medium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,445,158 B2 - Document ID: US11445158B2 - Status: Granted - Kind: B2 - Application number: 16/830,677 - Filed: 2020-03-26 - Published: 2020-10-01 - Granted: 2022-09-13 - Earliest claimed: 2019-03-27 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Toshihisa Miyake - Web page: https://patentgrep.com/patent/US11445158B2 ## CPC - H04N 9/646: {for image enhancement, e.g. vertical detail restoration, cross-colour elimination, contour correction, chrominance trapping filters} - H04N 9/7908: {Suppression of interfering signals at the reproducing side, e.g. noise} - H04N 23/88: for colour balance, e.g. white-balance circuits or colour temperature control - H04N 25/134: {based on three different wavelength filter elements} - H04N 25/61: the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4" - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract There is provided an image processing apparatus. An estimation unit estimates a color difference component of noise included in a captured image that has undergone white balance correction. A determination unit determines a strength of color suppression processing based on a size of the color difference component of the noise. A processing unit applies the color suppression processing to the captured image at the determined strength. ## Claims ### Claim 1 An image processing apparatus comprising: at least one processor; a memory coupled to the at least one processor storing instructions that, when executed by the at least one processor, cause the at least one processor to function as: an estimation unit configured to estimate a color difference component of noise included in a captured image that has undergone white balance correction, based on a white balance gain determined for each color; a determination unit configured to determine a strength of color suppression processing based on a size of the color difference component of the noise; and a processing unit configured to apply the color suppression processing to the captured image at the determined strength. ### Claim 2 (depends on 1) The image processing apparatus according to claim 1, wherein the estimation unit is configured to estimate a luminance component of the noise, the determination unit is configured to determine a luminance range for applying the color suppression processing, based on a size of the luminance component of the noise, and the processing unit is configured to apply the color suppression processing to pixels having a luminance within the luminance range, out of pixels of the captured image. ### Claim 3 (depends on 2) The image processing apparatus according to claim 2, wherein the luminance range is a range of luminance less than or equal to the size of the luminance component of the noise or a range of luminance less than the size of the luminance component of the noise. ### Claim 4 (depends on 1) The image processing apparatus according to claim 1, wherein the determination unit is configured to determine a color difference range for applying the color suppression processing, based on a color difference component of the noise, and the processing unit is configured to apply the color suppression processing to pixels having a color difference within the color difference range, out of pixels of the captured image. ### Claim 5 (depends on 4) The image processing apparatus according to claim 4, wherein the color difference range is a range of color difference near the color difference component of the noise. ### Claim 6 (depends on 1) The image processing apparatus according to claim 1, wherein the captured image is obtained by applying a gain common to all colors and the white balance gain, to an image signal generated through photoelectric conversion by an image capturing unit, and the estimation unit is configured to estimate the color difference component of the noise, based on the gain and the white balance gain. ### Claim 7 (depends on 1) The image processing apparatus according to claim 1, wherein the captured image is obtained by applying a gain common to all colors and the white balance gain, to an image signal generated through photoelectric conversion by an image capturing unit that includes a shaded region and an unshaded region, and the estimation unit is configured to estimate the color difference component of the noise, based on pixel values of a region of the captured image that corresponds to the shaded region. ### Claim 8 (depends on 1) The image processing apparatus according to claim 1, wherein the instructions, when executed by the at least one processor, cause the at least one processor to further function as a selection unit configured to select a partial region of the captured image in accordance with a user instruction, wherein the captured image is obtained by applying a gain common to all colors and the white balance gain, to an image signal generated through photoelectric conversion by an image capturing unit, and the estimation unit is configured to estimate the color difference component of the noise, based on pixel values of the partial region of the captured image. ### Claim 9 (depends on 6) An image capturing apparatus comprising: the image processing apparatus according to claim 6; and the image capturing unit. ### Claim 10 An image processing method executed by an image processing apparatus, comprising: estimating a color difference component of noise included in a captured image that has undergone white balance correction based on a white balance gain determined for each color; determining a strength of color suppression processing based on a size of the color difference component of the noise; and applying the color suppression processing to the captured image at the determined strength. ### Claim 11 A non-transitory computer-readable storage medium which stores a program for causing a computer to execute an image processing method comprising: estimating a color difference component of noise included in a captured image that has undergone white balance correction based on a white balance gain determined for each color; determining a strength of color suppression processing based on a size of the color difference component of the noise; and applying the color suppression processing to the captured image at the determined strength.