JP2013123121A - Lens exchangeable camera system and image data correction method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress occurrence of a phenomenon where image data corrected on the basis of a code non-continuously changes without increasing a communication amount of the code corresponding to an operation amount of a lens unit from the lens unit to a camera body.SOLUTION: A lens exchangeable camera system performs data communication between a camera body 10 and a detachable lens unit 20. The lens unit includes an encoder 21 which detects an operation amount of the lens unit and generates a code corresponding to the operation amount. The camera body includes: imaging means 11 which generates image data of a moving image; and image processing means 12 which corrects the image data in response to the code and generates corrected image data. When the code changes from a first code to a second code with an operation of the lens unit, the image processing means generates an intermediate interpolation code ranging between the first and second codes, and sequentially generates the corrected image data in response to the respective codes.

Description

  The present invention relates to a camera system in which a lens can be exchanged, and more specifically, based on a code corresponding to an operation amount of a lens unit transmitted from a lens unit to image data taken through the lens unit. The present invention relates to a camera system capable of exchanging lenses in real time.

  In general, when an operation such as focusing or zooming is performed on a lens unit, various optical characteristics such as a decrease in the amount of light (shading) around the lens unit, chromatic aberration, and image distortion change. For this reason, the image obtained by capturing the subject image that has passed through the lens unit with the camera body is affected by the change in the optical characteristics of the lens unit. Therefore, a camera system that corrects image data in the camera body according to the operation amount of the lens unit has been put into practical use.

  An example of a technique for performing white balance adjustment according to the operation of a lens unit in a conventional camera system is described in Patent Document 1 below. In the camera system described in Patent Document 1, white balance adjustment is performed based on lens photographing conditions such as the pupil position and aperture value of the photographing lens.

  An example of a technique for performing shading correction according to the operation of a lens unit in a conventional camera system is described in Patent Document 2 below. In the camera system described in Patent Document 2, shading is performed on the camera body based on data relating to the exit pupil position of the interchangeable lens, aperture value data at the time of exposure, and correction data specific to the camera body corresponding to these data. Correction is being performed.

JP 2000-244930 A JP 2000-195953 A

  In the lens unit, the encoder detects an operation amount of the lens unit at every predetermined time (pitch), and generates a code corresponding to the operation amount. This code changes stepwise for each encoder pitch in accordance with the lens unit operation.

  By the way, for example, when the lens unit is manually operated quickly, the step of the code increases between the encoder pitches. As a result, a phenomenon may occur in which the image data corrected based on the code changes discontinuously at a portion corresponding to the step of the code. For example, when the zoom operation of the lens unit is performed, there may be a problem that the display image of the image data flickers.

  In order to make such a phenomenon that the image data changes discontinuously inconspicuous, it is conceivable that the pitch of the encoder is made very small to reduce the code step. However, if the encoder pitch is made very small, the amount of generated code becomes enormous. As a result, not only a very large data holding unit is required, but also the amount of communication data between the lens unit and the camera body is enormous. For this reason, in addition to the CPU for driving the motor incorporated in the camera body, a new CPU for processing communication data is required, resulting in a new problem that the system becomes enlarged. .

  Therefore, the present invention prevents the occurrence of a phenomenon in which image data corrected based on the code changes discontinuously without increasing the communication amount from the lens unit of the code corresponding to the operation amount of the lens unit to the camera body. It is an object of the present invention to provide a camera system that can be suppressed and interchangeable lenses and a method for correcting image data thereof.

  In order to achieve the above object, a camera system with interchangeable lenses according to the present invention comprises a camera body and a lens unit that is detachable from the camera body, and performs data communication between the camera body and the lens unit. A camera system capable of exchanging lenses, wherein the lens unit includes an encoder that detects an operation amount of the lens unit and generates a code corresponding to the operation amount, and the camera body passes through the lens unit. An image pickup unit that electrically picks up a subject image to generate moving image data, and corrects the image data generated by the image pickup unit based on the code received from the lens unit to generate corrected image data. Image processing means, wherein the image processing means is adapted to operate the lens unit so that the code is a first code. An intermediate interpolation code between the first code and the second code is generated when the first code and the second code are changed, and based on the first code, the interpolation code, and the second code Thus, the corrected image data respectively corrected are generated sequentially.

  According to the camera system with interchangeable lenses of the present invention configured as described above, when the code is changed from the first code to the second code by the operation of the lens unit, the image processing means is configured so that the first code An intermediate interpolation code between the first code and the second code is generated, and corrected image data corrected based on the first code, the interpolation code, and the second code are sequentially generated. By generating the interpolation code in this way, the code step between encoder pitches can be reduced without reducing the encoder pitch. As a result, it is possible to suppress the occurrence of a phenomenon in which the image data corrected based on the code changes discontinuously at the step portion of the code without increasing the communication amount of the code from the lens unit to the camera body.

  In the present invention, it is preferable that the image processing unit generates a plurality of interpolation codes so that the code changes from the first code to the second code at a first predetermined speed.

  In this way, by generating a plurality of interpolation codes so that the code change speed, that is, the code change amount per unit time, becomes the first predetermined speed, the image data corrected based on the code is obtained. Occurrence of a phenomenon that changes discontinuously at the step portion of the cord can be suppressed.

In the present invention, it is preferable that the lens unit transmits data including the first predetermined speed to the camera body, and the camera body receives the first data based on the data received from the lens unit. Set a predetermined speed.
Thereby, the optimal first predetermined value for each lens unit can be set in the camera body.

  In the present invention, it is preferable that the code changing at the first predetermined speed is further away from the first code than the second code before reaching the second code. The image processing means generates a plurality of interpolation codes so that the code changes to the third code at a second predetermined speed greater than the first predetermined speed. To do.

  Thereby, even if the code changes suddenly, it is possible to suppress an increase in the difference between the code after the change and the correction code.

In the present invention, it is preferable that the lens unit transmits data including the second predetermined speed to the camera body, and the camera body receives the second predetermined speed based on the data received from the lens unit. Set the speed.
Thereby, the optimal second predetermined value for each lens unit can be set in the camera body.

  In the present invention, it is preferable that the image processing unit generates corrected image data in which shading of the image data is corrected based on the code.

  In the present invention, it is preferable that the image processing unit generates corrected image data in which the luminance distribution of the image data is corrected based on the code.

  In the present invention, it is preferable that the image processing unit generates corrected image data in which the black level of the image data is corrected based on the code.

  The image data correction method in the camera system in which the lens can be exchanged according to the present invention generates an image data of a moving image by electrically capturing a subject image that has passed through a lens unit detachably attached to the camera body, The operation amount of the lens unit is detected every predetermined time, the lens unit code corresponding to the operation amount is generated by an encoder, transmitted to the camera body, and the image data generated by the camera body is An image data correction method in a camera system capable of exchanging lenses, wherein correction image data is generated based on the code received from the lens unit, wherein the code is changed from the first code to the first code by an operation of the lens unit. An intermediate interpolation code between the first code and the second code Generated, the first code, is characterized by sequentially generate corrected image data corrected on the basis of each of the interpolation code and the second code.

  According to the image data correction method in the camera system with interchangeable lenses according to the present invention, when the code is changed from the first code to the second code by the operation of the lens unit, the image processing means An interpolation code intermediate to the second code is generated, and corrected image data corrected respectively based on the first code, the interpolation code, and the second code are sequentially generated. By generating the interpolation code in this way, the code step between encoder pitches can be reduced without reducing the encoder pitch. As a result, it is possible to suppress the occurrence of a phenomenon in which the image data corrected based on the code changes discontinuously at the step portion of the code without increasing the communication amount of the code from the lens unit to the camera body.

  According to the lens replaceable camera system and the image data correction method of the present invention, the code corresponding to the operation amount of the lens unit is corrected based on the code without increasing the communication amount from the lens unit to the camera body. Occurrence of a phenomenon that the image data changes discontinuously can be suppressed.

It is a block diagram explaining the structure of the camera system in which the lens exchange of embodiment of this invention is possible. It is a schematic diagram which shows the pitch of an encoder, and the level | step difference of a code | cord | chord. (A) And (b) is a graph which shows the example of an interpolation code.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a camera system with interchangeable lenses and an image data correction method thereof according to the present invention will be described below with reference to the accompanying drawings. First, with reference to the block diagram of FIG. 1, the configuration of the camera system with interchangeable lenses according to the embodiment will be described. A camera system 1 shown in FIG. 1 includes a camera body 10 and a lens unit 20 that can be attached to and detached from the camera body 10. Data communication is performed between the camera body 10 and the lens unit 20 via a signal line.

  The lens unit 20 includes a lens control system 21 of the lens unit 20 and an encoder 22 that detects an operation amount such as focus and zoom of the lens control system 21 and generates a code corresponding to the operation amount.

  Here, FIG. 2 shows an example of a code generated by the encoder 22. The horizontal axis in FIG. 2 represents time, and the vertical axis represents code. Line I in FIG. 2 represents a code for each encoder pitch. As shown in FIG. 2, the encoder 22 detects the operation amount of the lens unit 20 for each predetermined pitch P, and generates a code corresponding to the operation amount. This code changes stepwise for each pitch of the encoder 22 according to the operation of the lens unit 20. For this reason, a step S is generated in the cord between the pitches.

  The camera body 10 electrically captures an image of a subject that has passed through the lens unit 20 to generate moving image data, and captures image data generated by the imaging unit 11 from the lens unit 20. And image processing means (image processing block) 12 for generating correction image data by correcting based on the received code. The imaging means 11 is composed of a solid-state imaging device array such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor.

  The code received from the lens unit 20 is decoded by the optical data conversion function 13 into optical data of an operation amount of the operation such as focusing and zooming of the lens unit 20. The image processing unit 12 stores a function and a table in which optical data and a correction amount are associated with each other. Then, in the block of the image processing 12, the image data is corrected based on the decoded optical data based on this function and table.

The image processing unit 12 generates corrected image data in which one or more combinations of shading, luminance distribution, and black level of the image data are corrected based on the code. In the case of shading correction, for example, a table in which optical characteristic data and a luminance correction value for each pixel are associated with each other is prepared, and shading correction of image data is performed based on the luminance correction value of this table.
Further, the luminance distribution and black level of the image data can be corrected in the same manner as the shading correction.

  The optical data conversion function 12 that decodes the code generated by the lens unit 20 may be stored in the camera body 10 in advance, or a function that is sent from the lens unit 20 to the camera body 20 as data is used. May be. Further, a table or function in which optical characteristic data and correction values such as brightness correction values are associated may be stored in the camera body 10 in advance, or sent from the lens unit 20 to the camera body 20 as data. May be used.

  Here, the generation of the interpolation code by the image processing means will be described with reference to FIG. In FIG. 3A, the horizontal axis represents time, and the vertical axis represents code. Line II in FIG. 3A represents a code for each encoder pitch. The optical data conversion function 13 of the image processing means calculates the first code c1 and the second code when the code received by operating the lens unit 20 changes from the first code c1 to the second code c2 at time t1. An interpolation code c12 intermediate to the code c2 is generated. Then, the image processing unit 12 sequentially generates corrected image data corrected based on the first code c1, the interpolation code c12, and the second code c2.

  Furthermore, as shown in FIG. 3A, a plurality of interpolation codes c11, c12, and c13 may be generated between the first code c1 and the second code c2. Thus, if a plurality of interpolation codes are generated for each step, smoother corrected image data can be generated.

Further, when generating the interpolation code, the plurality of interpolation codes c11, c12, and c13 are set at predetermined time intervals so that the code changes from the first code c1 to the second code c2 at the first predetermined speed v1. Generate sequentially. The predetermined time interval is, for example, a time for two frames of a moving image. The gradient of the broken line IIa in FIG. 3A corresponds to the predetermined speed v1. In other words, the steep slope of the broken line IIa increases the predetermined speed v1.
Note that the value of the predetermined speed v1 is set to a value in which the phenomenon that the image data corrected based on the code changes discontinuously at the step portion of the code based on the characteristics of the camera body 10 and the lens unit 20 is not conspicuous. Good.

  In this way, by sequentially generating a plurality of interpolation codes at predetermined time intervals so that the code change speed, that is, the code change amount per unit time becomes the first predetermined speed v1, the code is converted into the code. It is possible to suppress the occurrence of a phenomenon in which the image data corrected on the basis of the code changes discontinuously at the step portion of the code.

  The first speed v <b> 1 may be set as a unique value of the camera body 10 or may be set as a unique value of the lens unit 20. In the case of the eigenvalue of the lens unit 20, data including the first predetermined speed v <b> 1 is transmitted from the lens unit 20 to the camera body 10, and the camera body 10 receives the first predetermined speed based on the data received from the lens unit 20. It is good to set v1. Thereby, the optimal first predetermined value v1 for each lens unit 20 can be set in the camera body.

  By the way, when the focus and zoom of the lens unit 20 are suddenly operated and the code changes greatly one after another, the lens that gradually changes at the first predetermined speed v1 before the second code c2 reaches the lens. The code received from the unit 20 may be further changed. In this case, the code gradually changing at the first predetermined speed v1 and the actual code received from the lens unit 20 are deviated.

  Therefore, with reference to FIG. 3B, generation of an interpolation code by the image processing unit when the lens unit 20 is operated rapidly will be described. In FIG. 3B, the horizontal axis represents time, and the vertical axis represents code. A line III in FIG. 3B represents a code for each encoder pitch. In the example shown in FIG. 3B, before the code that changes at the first predetermined speed v1 indicated by the gradient of the broken line IIIa from the time t1 reaches the second code c2, as shown by the line III, the time t2 Furthermore, the third code c3 is further separated from the first code c1 than the second code c2.

  In this case, in the image processing 12, a plurality of interpolation codes are sequentially generated at predetermined time intervals so that the code changes to the third code c3 at a second predetermined speed v2 that is higher than the first predetermined speed v1. Generate. The gradient of the broken line IIIb shown in FIG. 3B corresponds to the second predetermined measurement v2. For this reason, the gradient of the broken line IIIb is steeper than the gradient of the broken line IIIa. Thereby, even if the code changes suddenly, it is possible to suppress an increase in the difference between the code after the change and the correction code.

When the received code further changes to c4 after the broken line IIIb in FIG. 3B reaches the third code c3, the image processing means 12 again performs the fourth processing at the first predetermined speed v1. A plurality of interpolation codes are sequentially generated at predetermined time intervals so as to change to the code c4.
Also, the value of the predetermined speed v2 is set based on the characteristics of the camera body 10 and the lens unit 20 so that the occurrence of a phenomenon in which the image data corrected based on the code changes discontinuously at the step portion of the code is set. Good.

  By generating the interpolation code in this way, the code step between encoder pitches can be reduced without reducing the encoder pitch. As a result, it is possible to suppress the occurrence of a phenomenon in which the image data corrected based on the code changes discontinuously at the step portion of the code without increasing the communication amount of the code from the lens unit to the camera body.

  In the above-described embodiment, the example in which the present invention is configured under specific conditions has been described. However, the present invention can be variously modified and combined, and is not limited thereto. In the above-described embodiment, an example in which one or three interpolation codes are generated between the first code c1 and the second code c2 has been described. However, in the present invention, the number of interpolation codes is limited to these. Not.

  The interpolation code may be generated whenever the code changes, or may be selectively generated when the code change amount is equal to or greater than a predetermined value. Further, the number of interpolation codes generated at one code step may be always constant or may be changed according to the step size.

  The present invention is applicable to both a moving image capturing device for a visible image and a moving image capturing device for an infrared image.

DESCRIPTION OF SYMBOLS 1 Camera system 10 Camera main body 11 Imaging block 12 Image processing means 13 Optical data conversion function 20 Lens unit 21 Lens control system 22 Encoder

Claims (9)

A camera system comprising a camera body and a lens unit detachably attached to the camera body, wherein the lens body is exchangeable and performs data communication between the camera body and the lens unit,
The lens unit includes an encoder that detects an operation amount of the lens unit and generates a code corresponding to the operation amount.
The camera body includes an imaging unit that electrically captures a subject image that has passed through the lens unit and generates moving image data;
Image processing means for correcting the image data generated by the imaging means based on the code received from the lens unit and generating corrected image data;
With
The image processing means generates an interpolation code intermediate between the first code and the second code when the code is changed from the first code to the second code by the operation of the lens unit. A lens-replaceable camera system that sequentially generates corrected image data corrected based on each of the first code, the interpolation code, and the second code. The lens according to claim 1, wherein the image processing unit generates a plurality of interpolation codes so that the code changes from the first code to the second code at a first predetermined speed. Interchangeable camera system. The lens unit transmits data including the first predetermined speed to the camera body,
The camera system according to claim 2, wherein the camera body sets the first predetermined speed based on the data received from the lens unit. When the code that changes at the first predetermined speed changes to a third code that is further away from the first code than the second code before reaching the second code, The image processing means generates a plurality of interpolation codes so that the code changes to the third code at a second predetermined speed larger than the first predetermined speed. The camera system in which the lens can be exchanged according to 2 or 3. The lens unit transmits data including the second predetermined speed to the camera body,
The lens-replaceable camera system according to claim 4, wherein the camera body sets the second predetermined speed based on the data received from the lens unit. The lens-replaceable camera system according to claim 1, wherein the image processing unit generates corrected image data obtained by correcting shading of the image data based on the code. The lens-replaceable camera system according to claim 1, wherein the image processing unit generates corrected image data in which a luminance distribution of the image data is corrected based on the code. . The lens-replaceable camera system according to claim 1, wherein the image processing unit generates corrected image data in which a black level of the image data is corrected based on the code. . A subject image that has passed through a lens unit that is detachably attached to the camera body is electrically captured by the camera body to generate video image data,
The operation amount of the lens unit is detected every predetermined time, the code of the lens unit corresponding to the operation amount is generated by an encoder, and transmitted to the camera body,
An image data correction method in a camera system capable of exchanging lenses, wherein the image data generated by the camera body is corrected based on the code received from the lens unit to generate corrected image data,
When the code is changed from the first code to the second code by the operation of the lens unit, an intermediate interpolation code between the first code and the second code is generated, and the first code An image data correction method in a camera system with interchangeable lenses, wherein corrected image data corrected based on each of the interpolation code and the second code is sequentially generated.

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