Image processing apparatus, image pickup apparatus, lens apparatus, image processing method, and storage medium

Abstract

The invention relates to an image processing apparatus, an image pickup apparatus, a lens apparatus, an image processing method, and a storage medium. The image processing apparatus includes: an acquisition unit configured to acquire image data; and a corrector configured to correct color shading in the image data using color shading information according to characteristics of the optical system. The image data corresponds to an optical image that has passed through an optical filter that separates light that has passed through the optical system into a first color component, a second color component, and a third color component. The color shading information includes information on a value of the first color component, a value of the second color component, and a value of the third color component, and differs according to a focal length of the optical system.

Description

Technical Field

[0001] One of aspects of the embodiments relates to an image processing device, an image pickup device, a lens device, an image processing method, and a storage medium. Background Art

[0002] An image captured by an optical system may include significant color shading due to a transmittance difference caused by a thickness difference between the central portion and the peripheral portion of a lens in the optical system and a thickness difference of an anti-reflection film between the central portion and the peripheral portion of the lens caused by a manufacturing error of the anti-reflection film coated on the lens surface. Here, color shading (color unevenness) refers to a phenomenon in which the hue of an image captured by an image pickup device of a uniform luminance surface is different between the central portion and the peripheral portion of the image.

[0003] Japanese Patent Laid-Open No. 2012-244239 discloses a method of storing correction items for correcting luminance shading and color shading of a captured image according to imaging conditions, and correcting the luminance shading and color shading using the correction items after acquiring the captured image.

[0004] The method disclosed in Japanese Patent Laid-Open No. 2012-244239 can correct both color shading and luminance shading, and thus the luminance around the captured image is affected. Summary of the invention

[0005] An image processing device according to one aspect of the present disclosure includes: an acquisition unit configured to acquire image data; and a corrector configured to correct color shading in the image data using color shading information according to the characteristics of an optical system. The image data corresponds to an optical image that has passed through an optical filter, and the optical filter separates the light that has passed through the optical system into a first color component, a second color component, and a third color component. The color shading information includes information about the value of the first color component, the value of the second color component, and the value of the third color component, and is different depending on the focal length of the optical system. An image pickup device and a lens device each having the above image processing device also constitute another aspect of the present disclosure. An image processing method corresponding to the above image processing device also constitutes another aspect of the present disclosure. A storage medium storing a program that causes a computer to execute the above image processing method also constitutes another aspect of the present disclosure.

[0006] Further features of various embodiments of the present disclosure will become apparent from the following description of the embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a configuration diagram of an imaging system according to each embodiment.

[0008] Figure 2 is a flowchart illustrating a color shading correction method according to each embodiment.

[0009] Figure 3 Color shading information in each embodiment is illustrated.

[0010] Figure 4 The image circle in each embodiment is explained.

[0011] Figure 5 The model of the antireflection film of the lens according to each embodiment is explained.

[0012] Figure 6 The image information in the third embodiment is explained. DETAILED DESCRIPTION

[0013] In the following, the term "unit" may refer to a software context, a hardware context, or a combination of software and hardware contexts. In the software context, the term "unit" refers to functionality, application, software module, function, routine, instruction set, or program, which can be executed by a programmable processor (such as a microprocessor), a central processing unit (CPU), or a specially designed programmable device or controller. The memory contains instructions or programs, which, when executed by the CPU, cause the CPU to perform operations corresponding to the unit or function. In the hardware context, the term "unit" refers to a hardware element, circuit, component, physical structure, system, module, or subsystem. Depending on the specific embodiment, the term "unit" may include mechanical, optical or electrical components, or any combination thereof. The term "unit" may include active (e.g., transistors) or passive (e.g., capacitors) components. The term "unit" may include a semiconductor device having a substrate and other material layers having various conductive concentrations. It may include a CPU or a programmable processor that can execute a program stored in a memory to perform a specified function. The term "unit" may include a logic element (e.g., AND, OR) implemented by a transistor circuit or any other switching circuit. In the combination of software and hardware contexts, the term "unit" or "circuit" refers to any combination of software and hardware contexts as described above. In addition, the term "element", "component", "part", or "device" may also refer to a "circuit" with or without integration with packaging materials.

[0014] Now, with reference to the accompanying drawings, a detailed description of embodiments according to the present disclosure will be given. Corresponding elements in the various drawings will be marked with the same reference numerals, and their repeated description will be omitted. First embodiment

[0015] Configuration of the imaging system

[0016] Reference now Figure 1 , a description will be given of an imaging system 10 according to a first embodiment of the present disclosure. Figure 1 is a configuration diagram of an imaging system 10. The imaging system 10 includes a camera (image pickup device) 200 and an interchangeable lens (lens device) 100 that is attachable to and detachable from the camera 200. However, the present embodiment is not limited to this example, and may be applied to an imaging system in which an image pickup device and a lens device are integrated.

[0017] The interchangeable lens 100 includes an optical system (imaging optical system) 101, a lens microcomputer 102, a lens memory (storage unit) 103, an optical system control unit 104, and an operation unit 105. The camera 200 includes an imaging unit 201, a camera microcomputer 202, a camera memory (storage unit) 203, a signal processing unit 204, an image processing unit (image processing device) 205, a recorder 206, and a display unit 207. In addition, the lens microcomputer 102 and the camera microcomputer 202 may be configured as control units separate from the interchangeable lens 100 and the camera 200, respectively. Figure 1 Components not relevant to this embodiment are omitted.

[0018] The optical system 101 has a variable power optical system 1011, an aperture stop (diaphragm) 1012, and a focusing optical system 1013. The optical system 101 forms an object image on an image sensor 2012 of an imaging unit 201 using light from an object at a focused position. The variable power optical system 1011 changes the focal length. The aperture stop 1012 adjusts the amount of light taken in from the object. The focusing optical system 1013 is an optical system for focusing on an object.

[0019] The lens microcomputer 102 is a communication unit for communicating with the camera microcomputer 202 that controls the camera 200. The lens microcomputer 102 reads out necessary information from the lens memory 103 according to a command received from the camera microcomputer 202, and transmits data requested by the camera microcomputer 202 to the camera microcomputer 202.

[0020] The optical system control unit 104 drives the aperture blades of the aperture stop 1012 and drives the focusing optical system 1013 to perform focusing according to a command from the lens microcomputer 102 .

[0021] The lens memory 103 stores color shading information about the optical system 101. As described later, the color shading information in this embodiment is information about the ratio (B / G) of the first color component (B) to the second color component (G) and the ratio (R / G) of the third color component (R) to the second color component (G). The color shading information is stored in association with the state (imaging condition) of the optical system 101 such as the focal length, the focus object distance, and the aperture diameter (aperture value, F number) of the optical system 101 for each position (such as image height) in the image data. In other words, the color shading information differs depending on the state of the optical system 101 such as the focal length, the focus object distance, and the aperture diameter of the optical system 101.

[0022] Using such color shading information can satisfactorily correct color shading in a captured image according to the characteristics of the optical system 101. Here, color shading refers to a color difference in an image in the case of imaging a uniform luminance surface, particularly a difference in hue between a central portion and a peripheral portion of an image. The characteristics of the optical system 101 are, for example, the transmittance of a lens in the optical system 101, or characteristics related to an anti-reflection film provided on the lens. Instead of the lens memory 103, the camera memory 203 may store color shading information about the optical system 101. Alternatively, both the lens memory 103 and the camera memory 203 may store color shading information about the optical system 101.

[0023] The operation unit 105 is provided so that the user can manually operate the optical system 101. For example, the user can change the focal length by manually operating the position of the variable power optical system 1011 of the optical system 101, and can change the in-focus position by manually adjusting the position of the focus optical system.

[0024] The imaging unit 201 includes a color filter (optical filter) 2011 and an image sensor 2012. The color filter 2011 has a filter that transmits blue light to separate the object image into a first color component (B), a filter that transmits green light to separate the object image into a second color component (G), and a filter that transmits red light to separate the object image into a third color component (R). For example, a Bayer array is used as an arrangement pattern for each color. The object image separated into three color components by the color filter 2011 is formed on the image sensor 2012. The image sensor 2012 is a photoelectric conversion element such as a CCD (charge coupled device) image sensor or a CMOS (complementary metal oxide semiconductor) image sensor. The image sensor 2012 performs photoelectric conversion on the object image (optical image) formed by the optical system 101 and outputs an analog signal.

[0025] The camera microcomputer 202 controls each part of the camera 200, and communicates with the lens microcomputer 102 to control the interchangeable lens 100. The camera microcomputer 202 corrects color shading in an image. Figure 2 , a description will be given of a method of correcting color shading in an image using the camera microcomputer 202. Figure 2 is a flow chart illustrating a method of color shading correction.

[0026] First, in step S1, the camera microcomputer 202 acquires the state of the optical system 101 (information such as focal length, focusing or in-focus object distance, and aperture diameter) from the lens microcomputer 102 and the optical system control unit 104. Next, in step S2, the camera microcomputer 202 acquires color shading information (information according to the characteristics of the optical system 101) due to the characteristics of the optical system 101 in the state of the optical system 101 acquired in step S1 from the lens memory 103. Next, in step S3, the camera microcomputer 202 generates a correction value based on the color shading information acquired in step S2. Next, in step S4, the camera microcomputer 202 corrects the color shading caused by the characteristics of the optical system 101.

[0027] The camera memory 203 stores various information necessary for the operations of the camera microcomputer 202 and the lens microcomputer 102. The signal processing unit 204 converts an analog signal output from the imaging unit 201 into a digital signal and outputs it to the image processing unit 205.

[0028] The image processing unit 205 performs color shading correction processing on the digital signal according to the control of the camera microcomputer 202, and generates image information (image data). The image data corresponds to the optical image that has passed through the color filter 2011 that separates the light that has passed through the optical system 101 into the first color component (B), the second color component (G), and the third color component (R). The image information generated by the image processing unit 205 is output to the recorder 206, or is displayed on the display unit 207. In this embodiment, the image processing unit 205 includes an acquisition unit 205a and a correction unit 205b. The acquisition unit 205a acquires image information about the image captured by the imaging unit 201. The corrector 205b corrects the color shading in the image data acquired by the acquisition unit 205a using the color shading information according to the characteristics of the optical system 101.

[0029] Color shading information and color shading correction according to characteristics of optical system 101

[0030] Figure 3 The diagram shows color shading information. Figure 3, the horizontal axis represents the image height h, and the vertical axis represents the color shading information. For each image height (distance from the center of the captured image) obtained by dividing the ratio B / G of the first color component (B) to the second color component (G) and the ratio R / G of the third color component (R) to the second color component (G) by an arbitrary number, the color shading information is acquired (calculated).

[0031] In order to correct the color component relative to the center of the captured image (the center position in the image data), this embodiment stores the color shading information about each image height divided by the value of the color shading information at the center of the captured image in the lens memory 103 in advance. In other words, the color shading information is based on the value of the center position in the image data (the value divided by the ratio of the center position). Then, color shading correction is performed using the color shading information. Here, the color shading correction includes multiplying the first color component (B) by the reciprocal of B / G for each image height, and multiplying the third color component (R) by the reciprocal of R / G for each image height. The correction ratio can be adjusted by multiplying the reciprocal of B / G or the reciprocal of R / G by a coefficient. For B / G or R / G between image heights divided by an arbitrary number, the B / G or R / G of the closest image height can be used, or the B / G or R / G obtained by an arbitrary interpolation method can be used.

[0032] Derivation of color shading information based on characteristics of optical system 101

[0033] In this embodiment, the color shading information based on the characteristics of the optical system 101 can be calculated by numerical simulation. In the numerical simulation, the color shading information is calculated using the value (numerical simulation value) of the spectral transmittance T1 of the optical system 101 calculated for each image height, the spectral distribution S of the light source assumed during imaging, and the spectral transmittance of the color filter 2011.

[0034] A description will now be given of a method of calculating the spectral transmittance of the optical system 101 . Figure 4 The image circle formed by the optical system 101 on the image sensor 2012 is explained. The optical system 101 is a rotationally symmetric optical system, and in a polar coordinate system with the center O of the image circle as the origin, the spectral transmittance can be calculated for each image height in an arbitrary radial direction (for example, θ=0).

[0035] Figure 5 A model used in numerical simulation of an antireflection film on a lens surface included in the optical system 101 is explained. This model assumes that the position of the deposition source of the antireflection film is sufficiently far from the center of curvature of the lens, and that the antireflection film is attached to the lens in a direction parallel to the optical axis. Therefore, the film thickness d in the direction parallel to the optical axis is the same (constant) at the center and periphery of the lens. This embodiment uses Figure 5The model of the antireflection film shown in calculates the spectral transmittance of the optical system 101 for each image height.

[0036] Next, a general imaging environment is assumed as a light source during imaging, and, for example, a spectral distribution S of daylight white having a color temperature of approximately 5000K is used.

[0037] Finally, the spectral transmittance of each color component is used as the spectral transmittance of the color filter 2011. The color filter 2011 includes a filter (first filter) that transmits blue light to separate the light into a first color component, a filter (second filter) that transmits green light to separate the light into a second color component, and a filter (third filter) that transmits red light to separate the light into a third color component. That is, the spectral transmittance Tb of the first filter, the spectral transmittance Tg of the second filter, and the spectral transmittance Tr of the third filter are used. The peak wavelength of the spectral transmittance Tb is in the range of 400 nm to 500 nm, the peak wavelength of the spectral transmittance Tg is in the range of 500 nm to 570 nm, and the peak wavelength of the spectral transmittance Tr is in the range of 570 nm to 700 nm.

[0038] The above values ​​and the following equations (1) and (2) can be used to calculate the color shading information for each image height.

[0039]

[0040] In equations (1) and (2), λ is the wavelength, the integration interval is from 400 nm to 700 nm, and h is the image height.

[0041] In this embodiment, in order to correct the color component relative to the center (h = 0) of the captured image, this embodiment uses a value (3) obtained by dividing equation (1) by B (0) / G (0) and a value (4) obtained by dividing equation (2) by R (0) / G (0). The values ​​obtained by equations (3) and (4) are stored in the lens memory 103 as color shading information.

[0042]

[0043] The color shading information obtained by equations (3) and (4) changes according to the state of the optical system 101, such as the focal length, the focus object distance, and the aperture diameter. In this embodiment, the lens memory 103 divides the state of the optical system 101 into an arbitrary number, and stores a plurality of pieces of color shading information that are different according to the state of the optical system 101. Thus, even when the magnification of the optical system 101 changes, the focus object distance changes, or the aperture diameter changes, the color shading can be satisfactorily corrected. In the case where the state of the optical system 101 is divided into an arbitrary number of states, the color shading information between the states can use a value obtained by an arbitrary interpolation method, or can use the color shading information about the closest state. The number of divisions of the state of the optical system 101 can be set to one without dividing the state of the optical system 101, so as to save the storage capacity of the lens memory 103.

[0044] Color shading correction can be performed using the color shading information thus calculated. More specifically, the first color component is multiplied by the inverse of the value obtained by equation (3), and the third color component is multiplied by the inverse of the value obtained by equation (4).

[0045] In this embodiment, the optical system 101 is a rotationally symmetric optical system, but this embodiment can also be applied to a rotationally asymmetric optical system that is not rotationally symmetric. In a rotationally asymmetric optical system that defines a polar coordinate system with the center of a captured image as the origin, color shading information in the circumferential direction can be added to color shading information in the radial direction.

[0046] In this embodiment, the light source during imaging has a daylight spectral distribution of about 5000 K, but is not limited to this example. For example, the spectral distribution of any light source may be changed according to the environment during which imaging is performed.

[0047] In this embodiment, the interchangeable lens 100 is interchangeable with respect to the camera 200, so that appropriate color shading information can be used for each interchangeable lens. Thus, even when a different interchangeable lens is attached to the camera 200, color shading can be satisfactorily corrected. Second embodiment

[0048] A description will now be given of a second embodiment of the present disclosure. This embodiment calculates color shading information that depends on the characteristics of the optical system 101 using the spectral transmittance measurement values ​​of the optical system 101, and stores it in advance in the lens memory 103. In other words, this embodiment calculates the color shading information using the spectral transmittance measurement values ​​of the optical system 101, the spectral transmittance of the color filter 2011, and the spectral distribution of the light source assumed during imaging. The configuration of the imaging system, the color shading information, and the color shading correction processing in this embodiment are the same as those of the first embodiment, so a detailed description thereof will be omitted.

[0049] In the first embodiment, the optical system 101 is a rotationally symmetric optical system and has the same optical characteristics in the circumferential direction at any image height. Therefore, when calculating the spectral transmittance by numerical simulation, the spectral transmittance can be calculated for each image height in any radial direction from the optical axis. However, the actual optical system is rotationally asymmetric due to eccentricity caused by manufacturing errors. Therefore, the optical characteristics in the circumferential direction are different even at the same image height. In addition, although Figure 5 The model of the anti-reflection film (anti-reflection coating) shown in is a rotationally symmetric system, but the anti-reflection film of an actual lens is rotationally asymmetric due to manufacturing errors. This embodiment corrects color shading using color shading information based on manufacturing errors.

[0050] In Figure 3 This embodiment measures the spectral transmittance in the radial direction and the circumferential direction in a polar coordinate system with the center O of the image circle shown in as the origin. The spectral transmittance can be measured in eight radial directions (image heights) at intervals of θ=45 degrees in the circumferential direction, and the average value of the results of these eight measurements can be set as the spectral transmittance of the optical system 101. In this case, the color shading information is a value obtained by averaging the information in multiple radial directions from the center position in the image data (a common value is obtained at the same image height). The color shading information is calculated from this spectral transmittance in the same manner as in the first embodiment, and is stored in the lens memory 103.

[0051] Even if the optical system 101 is eccentric due to manufacturing errors, the color shading information calculated in this way enables satisfactory correction of color shading. When measuring the spectral transmittance in the radial direction and the circumferential direction, this embodiment sets the number of divisions in the circumferential direction to eight, but is not limited to this example, and an arbitrary number of divisions can be used. This embodiment calculates the color shading information using a value obtained by averaging the spectral transmittance in a plurality of radial directions, but is not limited to this example, and color shading information that is different in the radial direction can be used without averaging the spectral transmittance. Third embodiment

[0052] A description will now be given of a third embodiment of the present disclosure. This embodiment calculates color shading information dependent on the characteristics of the optical system 101 obtained in advance from image information (image data) obtained using the camera 200, and stores it in the lens memory 103. That is, in this embodiment, the color shading information is calculated using the image data obtained by imaging. The configuration of the imaging system, the color shading information, and the color shading correction processing according to this embodiment are the same as those of the first embodiment, so a detailed description thereof will be omitted.

[0053] This embodiment measures spectral transmittance at a plurality of positions within the image circle and takes a long measurement time. This embodiment uses image information obtained by the camera 200 to simply obtain color shading information about the optical system 101 .

[0054] A description will now be given of a method of calculating color shading information about the optical system 101 using the camera 200. First, the camera 200 images a uniform luminance surface having a daylight light source having a color temperature of about 5000 K. At this time, image information is acquired without performing a color shading correction process performed by the image processing unit 205. No color shading correction process provides image information to which the color shading information about the optical system 101 is added.

[0055] When the position of the color filter 2011 is deviated from a pixel (light receiving element) in the image sensor 2012 due to a manufacturing error, or light from the optical system 101 obliquely enters an adjacent pixel and the adjacent pixels have different color components, color shading occurs in the camera 200. In the case where the camera 200 has an infrared cut filter, the reflection characteristics change due to the obliquely incident light, and color shading occurs.

[0056] Therefore, the image information contains not only color shading information generated by the characteristics of the optical system 101 but also color shading information generated by the characteristics of the camera 200. Therefore, in order to obtain color shading information about the optical system 101 from the image information, the color shading information generated by the characteristics of the camera 200 is removed.

[0057] In order to remove color shading due to the characteristics of the camera 200 from the image information, color shading information generated by the characteristics of the camera 200 when a light beam equivalent to the light beam of the optical system 101 is incident is checked in advance. Removing the color shading information generated by the camera 200 that has been checked in advance from the image information can use the color shading information provided by the camera 200 on the optical system 101.

[0058] Using the above method Figure 6The color shading information about the optical system 101 in the entire image information shown in makes it possible to satisfactorily correct the color shading in the entire image information. This embodiment can reduce the amount of information stored in the lens memory 103. Figure 6 The color shading information in eight directions of the center O of the image information shown in , including the horizontal image points H1 and H2, the vertical image points V1 and V2, and the diagonal image points D1, D2, D3, and D4 can be averaged and stored, and the color shading correction values ​​in the circumferential direction can be equalized. In this embodiment, the camera 200 has imaged a uniform daylight white light source having a color temperature of about 5000K, but this is only an assumption of a light source in a general imaging environment, and this embodiment is not limited to this example. For example, the light source can be changed to an arbitrary light source according to the imaging environment. Other embodiments

[0059] The embodiments of the present disclosure may also be implemented by reading out and executing computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be more completely referred to as a 'non-transitory computer-readable storage medium') to perform one or more functions of the above-mentioned embodiments and / or a computer of a system or device including one or more circuits (e.g., an application-specific integrated circuit (ASIC)) for performing one or more functions of the above-mentioned embodiments, and by a method performed by a computer of the system or device by, for example, reading out and executing computer executable instructions from a storage medium to perform one or more functions of the above-mentioned embodiments and / or controlling one or more circuits to perform one or more functions of the above-mentioned embodiments. The computer may include one or more processors (e.g., a central processing unit (CPU), a microprocessing unit (MPU)), and may include a network of separate computers or separate processors to read out and execute computer executable instructions. Computer executable instructions may be provided to the computer, for example, from a network or a storage medium. The storage medium may include, for example, a hard disk, a random access memory (RAM), a read-only memory (ROM), a storage device of a distributed computing system, an optical disk (such as a compact disk (CD), a digital versatile disk (DVD), or a Blu-ray disk (BD) TM ), one or more of flash memory devices, memory cards, etc.

[0060] The embodiments of the present invention may also be implemented by providing software (program) for executing the functions of the above embodiments to a system or device via a network or various storage media, and a computer or a central processing unit (CPU) or a microprocessing unit (MPU) of the system or device reads and executes the program.

[0061] Although the present disclosure has described example embodiments, it is to be understood that some embodiments are not limited to the disclosed embodiments.The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

[0062] Each embodiment corrects color shading according to the characteristics of the optical system using color shading information that is a ratio (B / G) of a first color component to a second color component and a ratio (R / G) of a third color component to a second color component. Therefore, each embodiment can provide an image processing device, an image pickup device, a lens device, and an image processing method, each of which can suppress a change in luminance around a captured image and appropriately correct the hue of the captured image.

Claims

1. An image processing device, comprising: an acquisition unit, wherein the acquisition unit is configured to acquire image data; as well as a corrector configured to correct color shading in the image data using color shading information according to characteristics of the optical system, The image data corresponds to an optical image that has passed through an optical filter, and the optical filter separates the light that has passed through the optical system into a first color component, a second color component, and a third color component. The color shading information includes information on a value of the first color component, a value of the second color component, and a value of the third color component, and differs according to a focal length of the optical system. 2 . The image processing apparatus according to claim 1 , further comprising a memory configured to store the color shading information.

3. The image processing device according to claim 1, characterized in that The color shading information is related to a ratio of the first color component to the second color component and a ratio of the third color component to the second color component.

4. The image processing device according to claim 1, characterized in that: The color shading information varies according to a focusing object distance of the optical system.

5. The image processing device according to claim 1, characterized in that: The color shading information differs according to an aperture diameter of the optical system.

6. The image processing device according to claim 1, characterized in that: The color shading information is a value based on a center position in the image data.

7. The image processing device according to claim 1, characterized in that: The optical filter includes a first filter that separates light into the first color component, a second filter that separates light into the second color component, and a third filter that separates light into the third color component, wherein the spectral transmittance of the first filter has a peak wavelength in the range of 400 nm to 500 nm, wherein the spectral transmittance of the second filter has a peak wavelength in the range of 500 nm to 570 nm, and Wherein the spectral transmittance of the third filter has a peak wavelength in the range of 570 nm to 700 nm.

8. The image processing device according to claim 1, characterized in that: The color shading information has a value obtained by averaging information in a plurality of radial directions from a central position in the image data.

9. The image processing device according to claim 1, characterized in that: The color shading information is calculated using a numerical simulation value of a spectral transmittance of the optical system, a spectral transmittance of the optical filter, and a spectral distribution of a light source.

10. The image processing device according to claim 1, characterized in that: The color shading information is calculated using a measured value of a spectral transmittance of the optical system, a spectral transmittance of the optical filter, and a spectral distribution of a light source.

11. The image processing device according to claim 1, characterized in that: The color shading information is calculated using the image data.

12. An image pickup device, comprising: Image sensor; as well as An image processing apparatus according to any one of claims 1 to 11.

13. A lens device comprising: Optical system; as well as An image processing apparatus according to any one of claims 1 to 11.

14. A lens device attachable to and detachable from an image pickup device, the lens device comprising: Optical system; a memory configured to store color shading information according to characteristics of the optical system for use in correction of color shading in image data acquired by the image pickup device; as well as a communication unit configured to communicate with the image pickup device, The communication unit transmits the color shading information stored in the memory to the image pickup device according to a request from the image pickup device, wherein the image data corresponds to an optical image that has passed through an optical filter, the optical filter separating the light that has passed through the optical system into a first color component, a second color component, and a third color component, and The color shading information includes information on a value of the first color component, a value of the second color component, and a value of the third color component, and differs according to a focal length of the optical system.

15. An image processing method comprising the following steps: Get image data, and correcting color shading in the image data using color shading information according to characteristics of the optical system, The image data corresponds to an optical image that has passed through an optical filter, and the optical filter separates the light that has passed through the optical system into a first color component, a second color component, and a third color component. The color shading information includes information on a value of the first color component, a value of the second color component, and a value of the third color component, and differs according to a focal length of the optical system. 16 . A non-transitory computer-readable storage medium storing a program for causing a computer to execute the image processing method according to claim 15 .

Images