JP2010109667A - Camera system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easy-to-use camera system capable of correcting image data in a camera. <P>SOLUTION: The camera system includes an interchangeable lens and a camera body. The interchangeable lens includes a first storage means to store optical data. The camera body includes an imaging means to generate image data by capturing an object image, an acquisition means to acquire optical data from the interchangeable lens, a calculation means to calculate a correction value for correcting the image data generated by the imaging means based on the optical data acquired by the acquisition means, and a second storage means to store the correction value calculated by the calculation means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a camera system, and more particularly to a camera system that can correct captured image data.

  Patent Document 1 discloses a lens-interchangeable digital camera that can perform high-precision distortion and shading correction. The camera body in this interchangeable lens camera system acquires the ID of the interchangeable lens mounted. This lens-interchangeable camera system stores captured image data and a lens ID in a storage medium when capturing image data.

  Patent Document 1 further discloses an image processing apparatus having correction data for correcting distortion and shading for each interchangeable lens. This image processing apparatus can correct distortion and shading of image data stored in a storage medium.

  Here, the image data picked up by the interchangeable lens digital camera is stored in a storage medium together with the ID of the mounted interchangeable lens. Therefore, the image processing apparatus can determine what type of lens is attached to the camera body when the image data stored in the storage medium is generated. As a result, the image processing apparatus can make an appropriate correction according to the image data stored in the storage medium.

As described above, according to the system including the interchangeable lens digital camera and the image processing apparatus, when image data is captured by the interchangeable lens digital camera, the captured image data and the ID of the attached lens are the lowest. Appropriate correction can be performed on the captured image data simply by storing the limited information in the storage medium.
JP 2000-184247 A

  However, according to the interchangeable lens digital camera disclosed in Patent Document 1, it is not possible to correct captured image data without using an image processing apparatus. Therefore, when correcting the captured image data in the camera, the technology for speeding up the camera, the technology for dealing with a lens that exceeds the correction limit, and the control of the image data are well controlled. A technique for improving usability when correcting image data in a camera, such as a technique for performing the above, is not disclosed.

  Accordingly, an object of the present invention is to provide a camera system that can correct image data in a camera and is easy to use.

  In order to solve the above problems, a camera system according to the present invention is a camera system including an interchangeable lens and a camera body, and the interchangeable lens includes first storage means for storing optical data, and the camera body includes: Imaging means for generating image data by capturing a subject image, acquisition means for acquiring optical data from the interchangeable lens, and image data generated by the imaging means based on the optical data acquired by the acquisition means. A calculation unit that calculates a correction value for correction; and a second storage unit that stores the correction value calculated by the calculation unit.

  According to the present invention, it is possible to provide an easy-to-use camera system that can correct image data in a camera.

The first embodiment of the present invention will be described below with reference to the drawings.
[1. Embodiment 1]
[1-1. Overview〕
A camera system 1 according to the present embodiment includes a camera body 100 and an interchangeable lens 200. The camera body 100 can correct image data such as correction of distortion of image data captured by the CCD image sensor 110.

  The present invention is a camera system capable of correcting image data such as correction of distortion aberration, and is an invention made to provide an easy-to-use camera system.

[1-2. Constitution〕
[1-2-1. Configuration of camera body)
The camera body 100 includes a CCD image sensor 110, a liquid crystal monitor 120, a camera controller 140, a body mount 150, a power source 160, and a card slot 170.

  The camera controller 140 controls the entire camera system 1 such as the CCD image sensor 110 in response to an instruction from an operation member such as the release button 130. The camera controller 140 transmits a vertical synchronization signal to the timing generator 112. The camera controller 140 uses the DRAM 141 as a work memory during the control operation and the image processing operation. The flash memory 142 stores programs and parameters used when the camera controller 140 is controlled. Further, the flash memory 142 stores a gain G and a gain TMG for correcting distortion aberration for each interchangeable lens mounted on the camera body 100. The gain G and gain TMG for correcting distortion will be described later. The flash memory 142 stores the gain G and the gain TMG in association with the ID and serial number of the interchangeable lens.

  The CCD image sensor 110 captures a subject image incident through the interchangeable lens 200 and generates image data. The generated image data is digitized by the AD converter 111. The image data digitized by the AD converter 111 is subjected to various image processing by the camera controller 140. Examples of various image processing include gamma correction processing, white balance correction processing, scratch correction processing, YC conversion processing, electronic zoom processing, JPEG compression processing, and other image compression processing, distortion aberration correction processing, and chromatic aberration correction processing. Etc. Thus, the camera system 1 according to the present embodiment has a distortion correction function. Details of the distortion correction function will be described later.

  The CCD image sensor 110 operates at a timing controlled by the timing generator 112. The operation of the CCD image sensor 110 includes a still image capturing operation, a moving image capturing operation, a through image capturing operation, and the like. Here, the through image is an image that is not recorded on the memory card 171 after image capturing. The through image is mainly a moving image, and is displayed on the liquid crystal monitor 120 in order to determine a composition for capturing a still image.

  The liquid crystal monitor 120 displays an image indicated by the display image data image-processed by the camera controller 140. The liquid crystal monitor 120 can selectively display both moving images and still images.

  The card slot 170 can be loaded with a memory card 171. The card slot 170 controls the memory card 171 based on the control from the camera controller 140. The memory card 171 can store image data generated by image processing of the camera controller 140. For example, the memory card 171 can store a JPEG image file. The memory card 171 can output image data or an image file stored therein. The image data or image file output from the memory card 171 is subjected to image processing by the camera controller 140. For example, the camera controller 140 expands the image data or image file acquired from the memory card 171 and generates display image data.

  The power supply 160 supplies power for consumption by the camera system 1. The power source 160 may be, for example, a dry battery or a rechargeable battery. Moreover, the power supplied from the outside by the power cord may be supplied to the camera system 1.

  The body mount 150 can be mechanically and electrically connected to the lens mount 250 of the interchangeable lens 200. The body mount 150 can send and receive commands and data to and from the interchangeable lens 200 via the lens mount 250. The body mount 150 transmits various control signals received from the camera controller 140 to the lens controller 240 via the lens mount 250. The body mount 150 supplies the power received from the power supply 160 to the entire interchangeable lens 200 via the lens mount 250.

[1-2-2. Interchangeable lens configuration)
The interchangeable lens 200 includes an optical system, a lens controller 240, and a lens mount 250. The optical system of the interchangeable lens 200 includes a zoom lens 210, an OIS lens 220, a diaphragm 260, and a focus lens 230.

  The zoom lens 210 is a lens for changing the magnification of a subject image formed by the optical system of the interchangeable lens 200. The zoom lens 210 is composed of one or a plurality of lenses. The drive mechanism 211 includes a zoom ring or the like that can be operated by the user, transmits the operation by the user to the zoom lens 210, and moves the zoom lens 210 along the optical axis direction of the optical system. The detector 212 detects the drive amount in the drive mechanism 211. The lens controller 240 can grasp the zoom magnification in the optical system by acquiring the detection result in the detector 212.

  The OIS lens 220 is a lens for correcting blurring of a subject image formed by the optical system of the interchangeable lens 200. The OIS lens 220 moves in a direction that cancels out the blur of the camera system 1, thereby reducing the blur of the subject image on the CCD image sensor 110. The OIS lens 220 is composed of one or a plurality of lenses. The actuator 221 drives the OIS lens 220 in a plane perpendicular to the optical axis of the optical system under the control of the OIS IC 223. The actuator 221 can be realized by a magnet and a flat coil, for example. The position detection sensor 222 is a sensor that detects the position of the OIS lens 220 in a plane perpendicular to the optical axis of the optical system. The position detection sensor 222 can be realized by a magnet and a Hall element, for example. The OIS IC 223 controls the actuator 221 based on the detection result of the position detection sensor 222 and the detection result of a shake detector such as a gyro sensor. The OIS IC 223 obtains the detection result of the shake detector from the lens controller 240. Further, the OIS IC 223 transmits a signal indicating the state of the optical image blur correction process to the lens controller 240.

  The diaphragm 260 is a member for adjusting the amount of light passing through the optical system. The diaphragm 260 includes, for example, a plurality of diaphragm blades, and the amount of light can be adjusted by opening and closing an opening formed by the blades. The diaphragm motor 261 is a driving unit for opening and closing the opening of the diaphragm 260.

  The focus lens 230 is a lens for changing the focus state of the subject image formed on the CCD image sensor 110 in the optical system. The focus lens 230 is composed of one or a plurality of lenses.

  The focus motor 233 drives the focus lens 230 to advance and retract along the optical axis of the optical system based on the control of the lens controller 240. Thereby, the focus state of the subject image formed on the CCD image sensor 110 by the optical system can be changed. As the focus motor 233, a stepping motor is used in the first embodiment. However, the present invention is not limited to this. For example, it can be realized by a servo motor, an ultrasonic motor, or the like.

  The lens controller 240 controls the entire interchangeable lens 200 such as the OIS IC 223 and the focus motor 233 based on the control signal from the camera controller 140. The lens controller 240 receives signals from the detector 212, the OIS IC 223, and the like and transmits them to the camera controller 140. The lens controller 240 performs the transmission / reception with the camera controller 140 via the lens mount 250 and the body mount 150.

  The lens controller 240 uses the SRAM 241 as a work memory at the time of control. The flash memory 242 stores a program and parameters used when the lens controller 240 is controlled. The flash memory 242 stores distortion aberration correction information described later.

  The lens mount 250 can be mechanically and electrically connected to the body mount 150 of the camera body 100. The lens mount 250 can send and receive commands and data to and from the camera body 100 via the body mount 150. The lens mount 250 transmits various control signals received from the lens controller 240 to the camera controller 140 via the body mount 150. For example, the lens mount 250 transmits the distortion correction information received from the lens controller 240 to the camera controller 140 via the body mount 150.

[1-2-3. Correspondence with the present invention]
The interchangeable lens 200 is an example of the interchangeable lens of the present invention. The camera body 100 is an example of the camera body of the present invention. The flash memory 242 is an example of the first storage unit of the present invention. The CCD image sensor 110 is an example of an imaging unit of the present invention. The body mount 150 is an example of an acquisition unit of the present invention. The camera controller 140 is an example of a calculation unit of the present invention. The flash memory 142 is an example of a second storage unit of the present invention.

  The camera controller 140 is an example of the identification unit of the present invention. The camera controller 140 is an example of a determination unit of the present invention.

[1-3. (Distortion correction)
As described above, the camera system 1 has a function of electrically correcting distortion. Hereinafter, the distortion correction will be described.

[1-3-1. (Basic concept of distortion correction)
The basic concept of distortion correction will be described with reference to FIGS. As shown in FIGS. 2 and 3, there are two types of distortion aberration, barrel type and pincushion type. In the case of barrel distortion, when an image A1 without distortion is used as a reference, the four corners of the image A1 are distorted inward toward the optical center O, and a rounded image A2 is formed on the CCD image sensor 110 as a whole. It is formed. The optical center O is the center of the CCD image sensor 110 and substantially coincides with the optical axis of the optical system 201.

  On the other hand, in the case of pincushion distortion, when an image A3 in which distortion is not generated is used as a reference, the image A4 is distorted so that the four corners of the image A3 spread outward from the optical center O, and the image A4 with sharp corners sharply sharpened is an CCD. It is formed on the image sensor 110.

  Thus, when distortion occurs, the subject image is distorted at the outer periphery of the image acquired by the CCD image sensor 110.

  Here, the amount of distortion aberration is DY, the actual image height at which distortion has occurred (distance from the optical center O in images A2 and A4) is Y, and the ideal image height at which distortion does not occur (optical center O in images A1 and A3). If the distance from the lens is Y ′, the distortion amount DY is expressed by the following equation (1).

  In the present embodiment, the distortion aberration amount DY is defined by the following equation (2).

  The correction coefficients C3, C5, and C7 have different optimum values depending on the specifications of the optical system mounted on the interchangeable lens. That is, it can be said that these correction coefficients C3, C5, and C7 are values specific to the interchangeable lens 200. Using these coefficients, distortion aberration is corrected. In addition, this formula (2) is an example of a formula used when correcting the distortion, and another formula may be used. When using other formulas, the type of correction coefficient may be different from formula (2).

  In order to correct distortion, it is necessary to convert the real image height Y to the ideal image height Y ′. In order to convert the real image height Y to the ideal image height Y ′, the gain G is defined by the following equation (3).

  The gain G in Expression (3) represents a gain function for converting the real image height Y to the ideal image height Y ′. When the maximum value of the real image height Y is 1, the gain shape can be expressed as shown in FIGS. 4 and 5, the vertical axis represents the gain G and the horizontal axis represents the real image height Y.

  In the case of the gain shapes shown in FIGS. 4 and 5, the absolute value of the gain G gradually increases as the real image height Y increases (that is, as the distance from the optical center O increases). This means that the amount of distortion at the outer periphery of the image is larger than the amount of distortion at the center.

  As shown in FIG. 4, when the gain G is larger than 1, the image is enlarged outward when the real image height Y is converted into the ideal image height Y ′. That is, the gain shape shown in FIG. 4 means that the distortion is a barrel shape as shown in FIG.

  On the other hand, when the gain G is smaller than 1 as shown in FIG. 5, the image is reduced inward when the real image height Y is converted to the ideal image height Y ′. That is, the gain shape shown in FIG. 5 means that the distortion shape is a pincushion type as shown in FIG.

  Thus, by defining the gain G as described above, distortion can be visually grasped.

[1-3-2. Correction rate
Next, a correction rate for correcting distortion will be described with reference to FIGS.

  When the above gain G is used, it is theoretically possible to completely correct distortion.

  However, it may be preferable not to completely correct the distortion. For example, humans are less sensitive to barrel distortion, but people tend to react more sensitively to pincushion distortion. Furthermore, since an image with barrel distortion is slightly rounded, it feels warm.

  For example, for barrel distortion, by reducing the distortion correction ratio, barrel distortion remains in the corrected image, and a warm image can be obtained. Also, for pincushion distortion, increasing the distortion correction ratio completely removes pincushion distortion from the corrected image, making it slightly rounded like barrel distortion. A warm and tasteful image is obtained.

  Therefore, the camera system 1 according to the present embodiment is provided with a function of adjusting the distortion correction ratio.

  Specifically, a gain TG obtained by multiplying the gain G by the correction factor T is defined as the following equation (4).

  By using the gain TG instead of the aforementioned gain G, the degree of distortion correction can be adjusted. For example, when G> 1, the gain TG is smaller than the gain G when the correction factor is T <1. That is, in the case of barrel distortion, by setting the correction rate T <1, the degree of distortion correction becomes smaller than that with the gain G.

  When G <1, the gain TG is smaller than the gain G when the correction factor is T <1. That is, in the case of the pincushion type distortion aberration, the degree of distortion correction is smaller than the correction with the gain G.

  The gain shape of the gain TG in the above case can be expressed as shown in FIGS. 6 and 7, for example. Here, the correction rate T can be expressed by the following equation (5).

[1-3-3. (Magnification correction value)
Next, magnification correction values for correcting distortion will be described with reference to FIGS.

  The camera system 1 according to the present embodiment uses the information regarding the correction coefficients C3, C5, and C7 unique to the interchangeable lens 200 stored in the flash memory 242, and according to the characteristics of the optical system by the method described above. It is possible to correct distortion.

  However, when correcting the pincushion type distortion aberration, since G <1, the corrected image becomes smaller than the real image. For this reason, the image after correction becomes smaller than the CCD image sensor 110 depending on conditions. As a result, there may be a region where information is lost in the image output from the CCD image sensor 110. Such a phenomenon is called a pixel defect.

  In order to prevent the occurrence of pixel defects, the camera system 1 according to the present embodiment uses a magnification correction value M that corrects the magnification of the entire image when correcting distortion. For example, using the magnification correction value M, the gain G is corrected so that the gain G becomes G ≧ 1 within the range of 0 ≦ real image height Y ≦ 1, as shown in FIG.

  Specifically, the gain MG considering the magnification correction value M is defined as the following formula (6).

  The minimum value in the range of 0 ≦ Y ≦ 1 is obtained, and the gain shape is multiplied by M such that the minimum value is 1 or more. The minimum value can be obtained from the equation (7) obtained by differentiating the gain G with the real image height Y.

  Specifically, a solution (for example, a, b) when Expression (7) is 0 is obtained, and gains G at four points Y = 0, a, b, and 1 are compared. As a result, the real image height Y when the gain G is minimum can be obtained. From this real image height Y and the equation (7), the minimum value of the gain G can be obtained. When the minimum value of the gain G is G = GMIN, MG ≧ 1 can be satisfied by setting the magnification correction value to M = 1 / GMIN.

  In this way, by setting the magnification correction value M, it is possible to keep the corrected image at a predetermined size or larger, and to prevent the corrected image from becoming smaller than the size of the CCD image sensor 110. it can. That is, occurrence of pixel defects can be prevented.

  As described above, when the correction rate T and the magnification correction value M are taken into consideration, the final gain TMG is expressed by the following equation (8).

  From Expression (8) and Expression (3), Expression (9) for converting the real image height Y to the ideal image height Y ′ is as follows.

  Here, a calculation example in the case of C3 = 0.2, C5 = −0.2, C7 = −0.1, and T = 0.9 will be described. Under this condition, the distortion amount DY and the gain G are expressed by the following equations (10) and (11) from the equations (3) and (4).

  The expressions (10) and (11) are represented by the graphs of FIGS. 9 (A) and (B). When the equation (11) is differentiated to obtain the minimum value of the gain G, the following equation (12) is obtained.

The minimum value of the gain G is a point where the gradient of the gain G is 0 or a point where Y = 0 and 1. Assuming Z = Y ^2, the following quadratic equation is derived.

  The solution of equation (13) is Z = 0.387426, -1.72076.

  Here, as a condition that no pixel defect occurs, when the aspect ratio is 16: 9, the minimum value of the gain G at 0.49 <Y <1 is the solution. Therefore, from 0.2401 <Z <1 and 0.49 <Y <1, Z = 0.387426, that is, Y = 0.622435.

  The minimum value of the gain G at Y = 0.49, 0.622435, 1 is Y = 0.622435, and GMIN = 0.95835.

  Therefore, the gain function MG is as follows.

  Finally, in consideration of T = 0.9, the following gain function TMG can be derived from the equations (14) and (4).

  This equation (15) can be expressed as shown in FIG. In FIG. 9C, since the gain TMG is 1 or more in the range of 0 ≦ Y ≦ 1, even when correcting the pincushion type distortion aberration, the image is corrected to be enlarged. Thereby, it is possible to prevent pixel defects from occurring.

  By performing such calculation, the camera controller 140 can calculate the gain G and the gain TMG for correcting distortion aberration of image data captured by the CCD image sensor 110. The camera controller 140 corrects distortion aberration of image data captured by the CCD image sensor 110 using the gain G and gain TMG calculated in this way.

[1-3-4. (Distortion correction information)
Next, distortion correction information will be described with reference to FIG. In the distortion aberration correction described above, the correction coefficients C3, C5, and C7 correspond to only one distortion characteristic.

  However, in an interchangeable lens type digital camera, since the specifications of the optical system differ depending on the type of interchangeable lens, it is necessary to select a correction coefficient suitable for the optical system of the interchangeable lens to be mounted.

  Even with the same optical system, the distortion aberration characteristics change according to the focal length and focus lens position, so correction coefficient errors according to the focal length and focus lens position! Link is not correct. It is necessary to select.

  Therefore, a correction coefficient table E (an example of first correction information) is stored in the flash memory 242 of the interchangeable lens 200. Specifically, as shown in FIG. 10, the correction coefficient table E of the lens controller 240 has zoom information ZENC, focus information FENC, a plurality of correction coefficients C3, C5, and C7, and a plurality of correction factors T. . The correction coefficient table E, zoom information ZENC, focus information FENC, correction coefficients C3, C5, and C7, and the correction factor T are examples of information for correcting distortion.

  In the correction coefficient table E, correction coefficients C3, C5, C7 and a correction rate T corresponding to the zoom information ZENC and the focus information FENC are arranged. The number of data of the zoom information ZENC is, for example, Nz + 1. The number of data of the focus information FENC is, for example, Nf + 1.

  Correction coefficients C3, C5, C7 and a correction factor T can be selected from the correction coefficient table E according to zoom information and focus information. By performing the above-described distortion correction using the selected correction coefficients C3, C5, and C7 and the correction factor T, it becomes possible to perform distortion correction suitable for the state of the interchangeable lens 200 at that time.

  The lens controller 240 transmits the correction coefficient table E stored in the flash memory 242 to the camera controller 140. The camera controller 140 calculates a gain G for correcting distortion aberration using the received correction coefficient table E. The camera controller 140 corrects distortion aberration of image data captured by the CCD image sensor 110 by using the calculated gain G. Hereinafter, various operations in the camera system 1 according to the present embodiment will be described.

[1-4. Operation)
[1-4-1. Initialization operation (first installation))
An initialization operation in the camera system 1 according to the present embodiment will be described with reference to FIG. It is assumed that this initialization operation is an initialization operation that is performed when the interchangeable lens 200 is first attached to the camera body 100.

  FIG. 11 is a diagram for explaining the exchange of information between the camera body 100 and the interchangeable lens 200 in the initialization operation. The user can turn on the power of the camera system 1 by operating a power button (not shown) (S10). When the power is turned on, the initialization operation of the camera system 1 is started.

  When the initialization operation is started, first, the camera body 100 notifies the interchangeable lens 200 of a request signal for requesting information such as the ID of the interchangeable lens 200 (S11). When a request signal for requesting information such as ID is acquired, the interchangeable lens 200 notifies the camera body 100 of information such as ID, serial number, and version information (S12).

  When information such as ID is acquired, the camera controller 140 determines whether or not the gain G and gain TMG corresponding to the acquired ID are stored in the flash memory 142. Here, since it is assumed that the interchangeable lens 200 is attached for the first time, the camera controller 140 determines that the gain G and the gain TMG corresponding to the acquired ID are not stored in the flash memory 142 (S13).

  If it is determined that the gain G or gain TMG corresponding to the acquired ID is not stored in the flash memory 142, the camera body 100 requests the interchangeable lens 200 to transmit optical data such as a correction coefficient table. Is notified (S14). When the request signal is acquired, the interchangeable lens 200 transmits optical data such as a correction coefficient table to the camera body 100 (S15).

  When the optical data such as the correction coefficient table is acquired, the camera controller 140 calculates a correction value for correcting distortion aberration such as the gain G and the gain TMG by the above-described method based on the acquired correction coefficient table ( S16).

  When the correction value is calculated, the camera controller 140 determines whether the calculated correction value is a correction value that exceeds the limit of distortion correction of the camera body 100. If it is determined that the distortion correction limit is exceeded, the camera controller 140 multiplies the calculated correction value by the correction rate (by suppressing the calculated correction value), thereby converting the correction value into the distortion aberration. (S16). Specifically, the correction value is within the limit of distortion correction by the camera controller 140 by a method as shown in FIG. In the camera system 1 according to the present embodiment, the camera controller 140 can correct distortion up to 10%. In this case, it is assumed that the gain G (correction value) calculated by the camera controller 140 is 1.2. In this case, if the image data picked up by the CCD image sensor 110 is corrected with the gain G indicated by the curve A shown in FIG. 12, the distortion aberration can theoretically be perfectly corrected. However, since the camera system 1 according to the present embodiment can only correct distortion aberration of image data up to 10%, the gain G at each distance from the center position is multiplied by 10/12 as a correction factor. Thus, a correction value that can be expressed by the curve B can be obtained. The gain G that can be represented by the curve B is a gain (correction value) within the limit of distortion aberration correction by the camera controller 140 because correction is performed within 10% at all distances from the center. Thereby, the camera system 1 according to the present embodiment can perform maximum distortion correction even for an interchangeable lens that cannot perform distortion correction completely. The rate of 10% at which the camera system 1 according to the present embodiment can correct distortion is determined by the specification. Therefore, it is not necessarily 10%, and may be 15% if it is defined as 15% as a specification, or 20% if it is defined as 20% as a specification.

  On the other hand, when it is determined that the calculated correction value is within the limit of distortion correction by the camera controller 140, the camera controller 140 associates the calculated gain G (correction value) with the ID of the interchangeable lens 200. Then, it is stored in the flash memory 142 (S18). Further, even when the calculated gain G (correction value) exceeds the limit range of distortion aberration correction by the camera controller 140, the gain G that is within the limit range of distortion aberration correction multiplied by the correction factor. (Correction value) is stored in the flash memory 142 in association with the ID of the interchangeable lens 200 (S18).

  Thereafter, the camera controller 140 uses the gain G stored in the flash memory 142 to correct distortion of image data captured by the CCD image sensor 110. When the distortion correction process is completed and image data after distortion correction is generated, the liquid crystal monitor 120 starts displaying an image indicated by the image data after distortion correction (S19). Note that the liquid crystal monitor 120 does not display the image indicated by the image data captured by the CCD image sensor 110 before the correction of the distortion of the image data captured by the CCD image sensor 110 is completed.

  As described above, in the camera system 1 according to the present embodiment, the camera controller 140 is such that the distortion aberration correction gain G calculated based on the optical data acquired from the interchangeable lens 200 exceeds the distortion aberration correction limit. In some cases, by multiplying the calculated gain G by the correction factor (by suppressing the gain G), the gain G falls within the limit of distortion correction. As a result, the camera system 1 according to the present embodiment has a CCD image even when the distortion due to the optical characteristics of the interchangeable lens attached exceeds the limit of distortion correction by the camera controller 140. A relatively suitable correction of distortion can be performed on the image data captured by the sensor 110.

  In the camera system 1 according to the present embodiment, the liquid crystal monitor 120 receives the image data captured by the CCD image sensor 110 before the correction of distortion aberration of the image data captured by the CCD image sensor 110 is completed. The image shown is not displayed. As a result, the camera system 1 according to the present embodiment can prevent the user from seeing a relatively unappealing image that has not been subjected to distortion correction.

[1-4-2. Initialization operation (installing the same interchangeable lens for the second time and later)
An initialization operation in the camera system 1 according to the present embodiment will be described with reference to FIG. This initialization operation is an initialization operation that is performed for the second and subsequent times after mounting the same interchangeable lens.

  FIG. 13 is a diagram for explaining the exchange of information between the camera body 100 and the interchangeable lens 200 in the initialization operation. The user can turn on the power of the camera system 1 by operating a power button (not shown) (S20). When the power is turned on, the initialization operation of the camera system 1 is started.

  When the initialization operation is started, first, the camera body 100 notifies the interchangeable lens 200 of a request signal for requesting information such as the ID of the interchangeable lens 200 (S21). When a request signal for requesting information such as ID is acquired, the interchangeable lens 200 notifies the camera body 100 of information such as ID, serial number, and version information (S22).

  When information such as ID is acquired, the camera controller 140 determines whether or not the gain G and gain TMG corresponding to the acquired ID are stored in the flash memory 142. Here, since the initialization operation is performed for the second and subsequent times after the interchangeable lens 200 is mounted, the camera controller 140 determines that the gain G and the gain TMG corresponding to the acquired ID are stored in the flash memory 142 ( S23).

  If it is determined that the gain G or gain TMG corresponding to the acquired ID is stored in the flash memory 142, the camera controller 140 is based on the gain G or gain TMG stored in the flash memory 142. The distortion aberration of the image data picked up by the above is corrected (S24).

  When the correction of the distortion aberration of the image data captured by the CCD image sensor 110 is completed, the liquid crystal monitor 120 displays an image indicated by the image data after the correction of the distortion aberration is completed (S25).

  Thus, in the camera system 1 according to the present embodiment, the flash memory 142 is associated with the ID of the interchangeable lens on which the gain G for correcting distortion G and the gain TMG calculated by the camera controller 140 are attached. Remember. Further, in the camera system 1 according to the present embodiment, the camera controller 140 is such that the distortion G correction gain G and gain TMG corresponding to the attached interchangeable lens are already stored in the flash memory 142. In this case, the gain G and the gain TMG are not calculated again. In such a case, the camera controller 140 corrects the distortion aberration of the image data captured by the CCD image sensor 110 using the gain G or gain TMG already stored in the flash memory 142. Thus, the camera controller 140 does not need to calculate the distortion aberration correction gain G and gain TMG based on the optical data of the interchangeable lens 200 every time the initialization operation is performed. As a result, the camera system 1 according to the present embodiment can finish the second and subsequent initialization operations in a relatively short time with the same interchangeable lens attached. In addition, the camera system 1 according to the present embodiment can display an image indicated by the image data after distortion correction on the liquid crystal monitor 120 at a relatively early stage after the second time with the same interchangeable lens attached. it can.

  In the camera system 1 according to the present embodiment, the flash memory 142 stores the correction value for correcting distortion aberration and the ID of the interchangeable lens in association with each other. However, such a configuration is not necessarily required, and the flash memory 142 may store a correction value for distortion and the serial number of the interchangeable lens in association with each other. Thereby, it is possible to perform appropriate correction individually for each of the subtle optical characteristics existing between the interchangeable lenses having the same ID.

  The flash memory 142 may store the correction value for correcting distortion aberration and the version information of the interchangeable lens in association with each other. Thus, it is possible to cope with correction of distortion aberration when an interchangeable lens that upgrades optical characteristic information is installed via the Internet. That is, when the optical characteristic data is changed due to the version of the interchangeable lens being updated after the last correction value of distortion is calculated, the camera controller 140 again sets the correction value for correcting distortion. By calculating and correcting the distortion using the correction value, it is possible to correct the distortion more appropriately.

[1-4-3. (Distortion correction operation when the interchangeable lens is removed)
In the camera system 1 according to the present embodiment, the distortion correction operation when the interchangeable lens 200 is removed from the camera body 100 with the power turned on will be described with reference to FIGS.

  FIG. 14 is a flowchart for explaining an operation of correcting distortion when the interchangeable lens 200 is detached from the camera body 100. FIG. 15 is an explanatory diagram for explaining the operation of correcting distortion when the interchangeable lens 200 is detached from the camera body 100. FIG.

  In the case of the state A shown in FIG. 15A, the camera controller 140 corrects distortion aberration of image data captured by the CCD image sensor 110 (S100). Further, the liquid crystal monitor 120 displays an image indicated by the image data after distortion correction (S100). Here, the state A is a state in which the connection confirmation terminal that electrically recognizes that the camera body 100 and the interchangeable lens 200 are connected is ON, and the camera body 100 and the interchangeable lens 200 are connected. The lock pin that mechanically recognizes that it has been turned off is in an OFF state. That is, the state A is a state in which the camera body 100 and the interchangeable lens 200 are completely connected both electrically and mechanically.

  The camera controller 140 monitors whether the lock pin is turned on in a state where the distortion aberration correction is performed and the image indicated by the image data after the distortion aberration correction is displayed on the liquid crystal monitor 120 (S110). If it is determined that the lock pin is turned on, the camera controller 140 corrects distortion aberration of the image data captured by the CCD image sensor 110 (S120). Further, the liquid crystal monitor 120 displays an image indicated by the image data after the distortion aberration correction (S120). That is, even in the case of the state B shown in FIG. 15B, the camera controller 140 corrects the distortion of the image data captured by the CCD image sensor 110, and the liquid crystal monitor 120 displays the image data after the distortion correction. The image indicated by is displayed. Here, the state B is a state where the lock pin is turned on but the camera body 100 and the interchangeable lens 200 are still electrically and mechanically connected.

  When the camera system 1 enters the state B, the camera controller 140 determines whether or not the connection confirmation terminal is connected (S130). When determining that the connection confirmation terminal is not electrically connected, the camera controller 140 corrects the distortion aberration of the image data captured by the CCD image sensor 110 (S140). Further, the liquid crystal monitor 120 displays an image indicated by the image data after the distortion aberration correction (S140). That is, even in the state C shown in FIG. 15 (3), the camera controller 140 corrects the distortion of the image data captured by the CCD image sensor 110, and the liquid crystal monitor 120 displays the image data after the distortion correction. The image indicated by is displayed. Here, the state C is a state in which the lock pin is ON and the connection confirmation terminal is not electrically connected.

  When the camera system 1 is in the state C, the camera controller 140 determines whether the lock pin is turned off (S150). If it is determined that the lock pin is OFF, the camera controller 140 stops correcting the distortion of the image data captured by the CCD image sensor 110 (S160). In addition, the liquid crystal monitor 120 displays image data that is not corrected for distortion, which is captured by the CCD image sensor 110 (S160). That is, in the case of the state D shown in FIG. 15 (4), the camera controller 140 stops correcting the distortion of the image data captured by the CCD image sensor 110, and the liquid crystal monitor 120 is not corrected for distortion. The image indicated by the image data is displayed. Here, the state D is a state in which the lock pin is turned off and the connection confirmation terminal is electrically turned off. That is, in the state D, the camera body 100 and the interchangeable lens 200 are completely disconnected both electrically and mechanically.

  Here, the reason why the camera controller 140 stops correcting the distortion aberration in the state D will be described below. In the state D in which the camera body 100 and the interchangeable lens 200 are completely disconnected both electrically and mechanically, the image indicated by the image data captured by the CCD image sensor 110 is blurred, and what is captured There are many cases where it is not possible to see whether they are present. Therefore, even if such distortion of the blurred image data is corrected, the image indicated by the corrected image data is also blurred and there is no point in correcting the distortion much. Therefore, in the camera system 1 according to the present embodiment, in the state D, correction of distortion aberration of image data captured by the CCD image sensor 110 is stopped. In state A, state B, and state C, the image may be somewhat blurred, but it is possible to fully recognize what is being captured.

  As described above, in the camera system 1 according to the present embodiment, the camera controller 140 is in a case other than when the camera body 100 and the interchangeable lens 200 are completely disconnected both electrically and mechanically. Then, the distortion aberration of the image data captured by the CCD image sensor 110 is corrected, and an image indicated by the corrected image data is displayed on the liquid crystal monitor 120. Accordingly, the camera system 1 according to the present embodiment always performs distortion correction when there is a high possibility that the CCD image sensor 110 is capturing an image that can be viewed by the user.

[1-5. Summary of the present embodiment]
The camera system 1 according to the present embodiment is a camera system 1 including an interchangeable lens 200 and a camera body 100. The interchangeable lens 200 includes a flash memory 242 that stores optical data. Generated by the CCD image sensor 110 based on the CCD image sensor 110 that generates image data by capturing an image, the body mount 150 that acquires optical data from the interchangeable lens 200, and the optical data acquired by the body mount 150. A camera controller 140 that calculates a correction value for correcting the image data, and a flash memory 142 that stores the correction value calculated by the camera controller 140.

  Thus, the camera controller 140 does not need to calculate the distortion aberration correction gain G and gain TMG based on the optical data of the interchangeable lens 200 every time the initialization operation is performed. As a result, the camera system 1 according to the present embodiment can finish the second and subsequent initialization operations in a relatively short time with the same interchangeable lens attached.

  The camera system 1 according to the present embodiment is a camera system 1 including an interchangeable lens 200 and a camera body 100. The interchangeable lens 200 includes a flash memory 242 that stores optical data. A CCD image sensor 110 that generates image data by capturing a subject image, a body mount 150 that acquires optical data from the interchangeable lens 200, and a camera controller 140 that corrects image data generated by the CCD image sensor 110 The camera controller 140 that calculates a correction value for correcting the image data generated by the CCD image sensor 110 based on the optical data acquired by the body mount 150, and the correction value calculated by the camera controller 140 are And a camera controller 140 that suppresses the correction value to be within the range that can be corrected by the camera controller 140 when the value exceeds the range that can be corrected by the camera controller 140. The image data generated by the CCD image sensor 110 is corrected based on the correction value calculated by.

  As a result, the camera system 1 according to the present embodiment has a CCD image even when the distortion due to the optical characteristics of the interchangeable lens attached exceeds the limit of distortion correction by the camera controller 140. A relatively suitable correction of distortion can be performed on the image data captured by the sensor 110.

  The camera body 100 of the camera system 1 according to the present embodiment is a camera body 100 to which the interchangeable lens 200 can be attached and detached, and a CCD image sensor 110 that generates image data by capturing a subject image. The body mount 150 that acquires optical data from the interchangeable lens 200, the camera controller 140 that corrects image data generated by the CCD image sensor 110 based on the optical data acquired by the body mount 150, and the image data are shown. A liquid crystal monitor 120 for displaying an image, and after the correction of the image data generated by the CCD image sensor 110 by the camera controller 140 is completed, the liquid crystal monitor 120 displays an image indicated by the corrected image data.

  As a result, the camera system 1 according to the present embodiment can prevent the user from seeing a relatively unappealing image that has not been subjected to distortion correction.

  The camera body 100 of the camera system 1 according to the present embodiment is a camera body 100 to which the interchangeable lens 200 can be attached and detached, and a CCD image sensor 110 that generates image data by capturing a subject image. A body mount 150 that acquires optical data from the interchangeable lens 200, a camera controller 140 that corrects image data generated by the CCD image sensor 110 based on the optical data acquired by the body mount 150, and the interchangeable lens 200. A camera controller 140 that detects attachment / detachment, and the camera controller 140 stops the correction of the image data when the camera controller 140 detects attachment / detachment of the interchangeable lens 200.

Accordingly, the camera system 1 according to the present embodiment always performs distortion correction when there is a high possibility that the CCD image sensor 110 is capturing an image that can be viewed by the user.
[2. Other Embodiments]
As described above, the first embodiment has been described as the embodiment of the present invention. However, the present invention is not limited to these. Therefore, other embodiments of the present invention will be described collectively in this section.

  In the camera system 1 according to the first embodiment, distortion is corrected, but the present invention is not necessarily limited to this. The present invention can also be applied, for example, when correcting chromatic aberration and peripheral light quantity. Accordingly, it is possible to efficiently correct chromatic aberration correction, peripheral light amount correction, and the like.

  In Embodiment 1 of the present invention, a camera body that does not include a movable mirror is illustrated, but the present invention is not limited to this. For example, a movable mirror may be provided in the camera body, or a prism for separating the subject image may be provided. Moreover, the structure provided with a movable mirror not in a camera body but in an adapter may be sufficient.

  In the first embodiment of the present invention, the CCD image sensor 110 is exemplified as the imaging device, but the present invention is not limited to this. For example, it may be composed of a CMOS image sensor or an NMOS image sensor.

  The present invention can be applied to an imaging apparatus such as a digital still camera or a digital video camera.

1 is a block diagram of a camera system according to a first embodiment. Diagram showing distortion (barrel type) Diagram showing distortion (pincushion type) Diagram showing gain G (barrel type) Diagram showing gain G (pincushion type) Diagram showing gain TG (barrel type) Diagram showing gain TG (pincushion type) Diagram showing gain MG (A) Graph showing an example of distortion aberration amount DY, (B) Graph showing an example of gain G, (C) Graph showing an example of gain TMG The figure which shows an example of a correction coefficient table Explanatory drawing for explaining the initialization operation (first time) Schematic diagram for explaining clip processing when gain G exceeds a limit value Explanatory drawing for explaining the initialization operation (second and subsequent times) Flowchart for explaining distortion correction processing when an interchangeable lens is removed Schematic diagram for explaining distortion correction processing when an interchangeable lens is removed

Explanation of symbols

100 Camera Body 110 CCD Image Sensor 111 AD Converter 112 Timing Generator 120 LCD Monitor 130 Release Button 140 Camera Controller 141 DRAM
142 Flash Memory 150 Body Mount 160 Power Supply 170 Card Slot 171 Memory Card 200 Interchangeable Lens 210 Zoom Lens 211 Drive Mechanism 212 Detector 220 OIS Lens 221 Actuator 222 Position Detection Sensor 223 OIS IC
230 Focus lens 233 Focus motor 240 Lens controller 241 SRAM
242 Flash memory 243 Counter 250 Lens mount 260 Aperture 261 Aperture motor

Claims (6)

A camera system comprising an interchangeable lens and a camera body,
The interchangeable lens is
Comprising first storage means for storing optical data;
The camera body is
Imaging means for generating image data by capturing a subject image;
Obtaining means for obtaining the optical data from the interchangeable lens;
Calculation means for calculating a correction value for correcting the image data generated by the imaging means based on the optical data acquired by the acquisition means;
Second storage means for storing the correction value calculated by the calculation means,
Camera system. The second storage means is nonvolatile;
The camera system according to claim 1. The second storage means stores the correction value calculated by the calculation means in association with the ID of the interchangeable lens;
The camera system according to claim 1 or 2. The calculating means includes
Based on the optical data acquired by the acquisition unit, a correction value for correcting distortion of the image data generated by the imaging unit is calculated.
The camera system according to claim 1. The calculating means includes
Based on the optical data acquired by the acquisition unit, a correction value for correcting chromatic aberration of the image data generated by the imaging unit is calculated.
The camera system according to claim 1. The camera body is
An identification means for identifying the interchangeable lens mounted;
Determination means for determining whether the correction value for the identified interchangeable lens is stored in the second storage means;
When the determination means determines that the correction value for the identified interchangeable lens is stored in the second storage means, based on the correction value stored in the second storage means Correcting means for correcting the image data generated by the imaging means;
The camera system according to claim 1, further comprising:

Images