JP2011029875A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus for obtaining portrait images desired by users even if high-speed successive shooting and moving image capturing are performed under wobbling control to autofocus. <P>SOLUTION: The imaging apparatus includes an adjustment part for performing wobbling control of focusing to an optical system to perform moving body tracking of focusing of a subject of interest and adjusting an optical photographing distance from the subject of interest to an imaging surface of an imaging part, a detection part for detecting a frequency component of interest, namely a frequency component to be noticed for focusing, from an imaging signal and feeding back the detected value to the adjustment part, a control part for controlling frequency sensitivity, namely sensitivity for each frequency of the frequency component of interest, such that the detected value has a prescribed amount of change or more for each wobbling, and an image processing part for correcting luminance frequency characteristics of the imaging signal for performing image processing to generate the corrected image. The image processing part sets the luminance frequency characteristics based on the frequency sensitivity. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an imaging apparatus for obtaining a portrait image (video) desired by a user.

  In recent years, an imaging apparatus for obtaining a desired portrait image (an image in which a focused subject is in focus and a background subject is greatly blurred) is required from the market even if it is not an experienced user.

  For example, the imaging apparatus described in Patent Document 1 below can easily obtain a portrait effect similar to a film camera by adjusting the apparent depth of field of a captured image by image processing.

  On the other hand, the imaging device described in Patent Document 2 below detects the degree of blurring of an image and divides the image into a first area where the main subject is located and a second area that does not include the main subject. By amplifying the degree of image blur, the depth of field is artificially reduced, and a portrait photographic tone image with a good degree of blur such as a background can be generated.

Japanese Patent No. 4142199 JP 2007-124398 A

  However, since the imaging apparatus described in Patent Document 1 performs imaging twice based on the presence or absence of strobe light for determining the priority relationship of each partial region of an image, the user desires high-speed continuous shooting or moving image imaging. Has a first problem of unsuitable specifications.

  Further, in the imaging apparatus described in Patent Document 2, if it is assumed that the autofocus specification is based on wobbling control, extraction of pixel blocks whose blur degree value (S105) is equal to or greater than a threshold value fluctuates for each frame. There is a second problem of endangering.

  In view of the above-described problems, the present invention provides an imaging device for obtaining a portrait image desired by a user even when high-speed continuous shooting or moving image capturing is performed while wobbling control is performed on autofocus. With the goal.

  An embodiment of the present invention includes an optical system that generates an optical image from a composite subject including a subject of interest and a background subject, an imaging unit that photoelectrically converts the optical image and generates the imaging signal, In order to track the moving object in focus of the subject of interest, the optical wobbling control of the optical system is performed to adjust the optical photographing distance from the subject of interest to the imaging surface of the imaging unit. An adjustment unit, a detection unit that detects a frequency component of interest that is a frequency component of interest from the imaging signal, and that feeds back the detection value to the adjustment unit; and the detection value is greater than or equal to a predetermined value for each wobbling A control unit that controls a frequency sensitivity that is a sensitivity for each frequency of the frequency component of interest so as to have a change amount, and a luminance frequency characteristic of the imaging signal is corrected and image processing is performed to generate the corrected image Comprising an image processing unit, wherein the image processing unit, and sets the luminance frequency characteristic on the basis of the frequency sensitivity. Thus, by setting the luminance frequency characteristic based on the frequency sensitivity set in the wobbling control, it is possible to obtain a portrait image (video) desired by the user for the subject of interest.

  According to the present invention, there is an effect that a portrait image desired by a user can be obtained even when high-speed continuous shooting or moving image shooting is performed while wobbling control is performed on autofocus.

1 is a block diagram illustrating a basic configuration of an imaging apparatus according to an embodiment of the present invention. It is a figure which shows an example in which an optical imaging distance is adjusted by wobbling control of a focus driver. It is a figure which shows an example in which the optical imaging distance is adjusted with respect to a dynamic subject by wobbling control of a focus driver. It is a figure which shows an example when there is no variation more than predetermined in a detection value in the case of wobbling control in focus drive. It is a figure which shows an example in case the amount of change more than predetermined appears in a detected value by control of the frequency sensitivity by a control part in the case of wobbling control. FIG. 10 is a diagram illustrating an example of a case where there is no change amount greater than or equal to a predetermined value even when the detected value is greater than or equal to a predetermined level during wobbling control in focus drive. It is a figure which shows an example in case the amount of change more than predetermined appears in a detected value by control of the frequency sensitivity by a control part in the case of wobbling control. It is a figure which shows an example which correct | amends a luminance frequency characteristic to an imaging signal in an image process part. It is a figure which shows an example of the luminance frequency characteristic used when a frequency sensitivity is controlled so that a sensitivity may become high to a Nyquist frequency in an image process part. It is a figure which shows an example of the luminance frequency characteristic used when a frequency sensitivity is controlled so that a sensitivity may become high to a Nyquist 1/2 frequency in an image process part. It is a figure which shows an example of the luminance frequency characteristic used for the predetermined period after a change generate | occur | produces in a frequency sensitivity in an image process part. It is a flowchart which shows an example of the control algorithm of the imaging device by embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram illustrating a basic configuration of an imaging apparatus 100 according to an embodiment of the present invention.

  In FIG. 1, an imaging apparatus 100 includes a focus lens (optical system) 101, an image sensor (imaging unit) 102, a focus driver (adjustment unit) 103, a detection unit 104, a control unit 105, and an image. The processing unit 106 and the limiting unit 107 are configured.

  The focus lens 101 generates an optical image from the composite subject 200 including the target subject 202 and the background subject 201, and the optical image is irradiated onto the imaging surface of the image sensor 102. The image sensor 102 photoelectrically converts and captures an optical image, generates an imaging signal, and outputs the imaging signal to the detection unit 104 and the image processing unit 106.

  The detection unit 104 detects a frequency component of interest, which is a frequency component of interest for focusing, from the imaging signal, and feeds back (feeds back) the detected value to the focus driver 103.

The detection of the frequency component of interest is expressed by, for example, Formulas 1-7. For example, in the image sensor 102 in which a pixel group of m rows and n columns is an effective pixel, if the signal level of the imaging signal at the address (x, y) of the pixel is I (x, y),
The detection value Fh1 detected with the Nyquist frequency in the horizontal direction as the frequency of interest is

  A detection value Fh2 that is detected using the horizontal frequency of Nyquist as a frequency of interest is:

  A detection value Fh3 detected with a frequency of 1/3 of Nyquist in the horizontal direction as a frequency of interest is

  Further, the detection value Fv1 detected using the Nyquist frequency in the vertical direction as the frequency of interest is

  The detection value Fv2 detected with the frequency of the Nyquist in the vertical direction as the frequency of interest is

  A detection value Fv3 detected using a 1/3 frequency of Nyquist in the vertical direction as a frequency of interest is

である。

It is.

  The Nyquist frequency defined here is a frequency representing the resolution of luminance (or brightness) in the minimum pixel unit when reading an imaging signal from the image sensor 102. In this embodiment, the Nyquist frequency, the Nyquist 1/2 frequency, and the Nyquist 1/3 frequency are exemplified, but the frequency sensitivity may be 1 / n of the Nyquist frequency (where n is a natural number).

  In addition, although the above-described mathematical expressions 1 to 6 focus on the horizontal and vertical directions, the detection values in the diagonal direction may be calculated by paying attention to the diagonal direction in addition to these.

  Here, the detection value F is a weighting coefficient (a, b, c, respectively) as shown in Expression 7 with respect to (Fh1, Fh2, Fh3, Fv1, Fv2, Fv3) calculated from Expressions 1-6. After multiplying by d, e, g), the sum is calculated.

ここで、重み付け係数（ａ，ｂ，ｃ，ｄ，ｅ，ｇ）とは、周波数感度の設定パラメータであって、この周波数感度については後述する。

Here, the weighting coefficients (a, b, c, d, e, g) are frequency sensitivity setting parameters, which will be described later.

  The focus detection in the image sensor 102 in which the pixel group of m rows and n columns is an effective pixel does not necessarily need to be detected by m rows and n columns. It may be detection or various detection methods.

  In the case where the image sensor 102 includes a color filter, the calculation of I (x, y) may be a signal level after the white balance is matched.

  In addition, the detection value calculation method described above is represented by Equations 1 to 7 as an example, and is not limited thereto. Various applications are associated with various filters and image processing using frequency decomposition. There may be a form.

  The focus driver 103 receives the detection value from the detection unit 104 and performs wobbling control for focusing on the focus lens 101 (or focusing by a hill-climbing method) in order to track the moving object in focus of the subject 202 of interest. Focus control) to adjust the optical shooting distance from the subject 202 to the imaging surface of the image sensor 102.

  Here, the wobbling control will be described.

  FIG. 2 is a diagram illustrating an example in which the optical photographing distance is adjusted by the wobbling control of the focus driver 103.

  In FIG. 2, the magnitudes of the detected values corresponding to the positions of the left and right arrows shown in (1) are compared, and (1) the arrow is focus-driven in the direction in which the detected values become larger. As a result, as indicated by the arrow (2), it converges in the vicinity of the peak of the detected value, and the arrow (2) wobbles before and after this peak. In this way, the optical shooting distance is adjusted before and after the subject 202 is focused.

  FIG. 3 is a diagram illustrating an example in which the optical shooting distance is adjusted with respect to the dynamic subject by the wobbling control of the focus driver 103.

  In FIG. 3, the graph of the detected value (solid line) shows that the optical photographing distance moves in the direction of infinity compared to the time of FIG. 2 (broken line). This means that the dynamic subject of interest has moved in the far direction. Here, (2) near the peak of the detected value at the time of FIG. 2 has already deviated from the peak of the detected value, as indicated by the arrow (3), which is substantially the same optical imaging distance.

  However, in FIG. 3, as in FIG. 2, the magnitudes of the detected values corresponding to the positions of the left and right arrows shown in (3) are compared. 3) The arrow is focus driven. Eventually, as indicated by the arrow (4), convergence is made near the peak of the detected value, and the arrow (4) wobbling around this peak. In this way, the optical shooting distance is adjusted before and after the target subject 202 is focused on the dynamic subject.

  By the way, in the focus drive based on the wobbling control based on the detection value described above, the direction in which the focus drive should be performed (the near end direction or the infinity direction) is not determined unless there is a predetermined amount of change every time the detection value wobbles. There is no property.

  This is because, as shown by the arrow (1) in FIG. 2, when the left and right detected values are compared, if the left and right detected values are substantially equal, the peak of the detected value is displayed. It is because the direction which will be greeted cannot be predicted. Therefore, the detection value is input not only to the focus driver 103 but also to the control unit 105 in order to control the detection value to have a predetermined change amount or more for each wobbling.

  The control unit 105 (FIG. 1) controls the frequency sensitivity, which is the sensitivity for each frequency of the frequency component of interest, so that the detected value has a change amount greater than or equal to a predetermined value for each wobbling. The control value by the control unit 105 is output to the detection unit 104 and the image processing unit 106.

  An example of this frequency sensitivity control will be described.

  FIG. 4 is a diagram illustrating an example of a case where there is no change amount greater than or equal to a predetermined value in the wobbling control in the focus drive.

  FIG. 4 shows a state in which the detected value does not reach a predetermined level and the detected value does not have a change amount greater than or equal to a predetermined value, and (1) the arrow cannot find the peak of the detected value. That is, the direction in which the focus drive is to be performed is not determined.

  Here, regarding the target subject 202, for example, when it is a subject that does not include the Nyquist frequency, or even if it is a subject that includes the Nyquist frequency, the exposure period captured by the image sensor 102 is the motion of the target subject 202. In consideration of the case where the captured image is blurry because it is sufficiently long with respect to the target characteristic (blurring disappearance of the Nyquist frequency),

となるので、これらを数式７に代入すると、

Therefore, if these are substituted into Equation 7,

となる。

It becomes.

  Here, the frequency sensitivity setting parameters (a, b, c, d, e, g) are

に設定されている場合に於いては、これらを数式１０に代入して、

If these are set, then these are substituted into Equation 10 and

となる。ここで、Ｌとは、所定レベルのことである。

It becomes. Here, L is a predetermined level.

  Further, in the case where the frequency sensitivity is set as in Expression 11, the change amount ΔF of the detected value F for each wobbling is

となる。ここで、ΔＣとは、所定の変化量のことである。

It becomes. Here, ΔC is a predetermined change amount.

  At this time, in order for the change amount ΔF of the detected value to have a change amount ΔC that is greater than or equal to a predetermined value, for the frequency sensitivity setting parameters (a, b, c, d, e, g), for example,

とすれば良く、この数式１４を数式１３に代入して、

Substituting this equation 14 into equation 13,

となるようにすれば良い。

It should be so that.

  Note that if the detected value change amount ΔF has a change amount ΔC greater than or equal to a predetermined value, the wobbling control functions. At this time, the detected value is equal to or higher than the predetermined level L or lower than the predetermined level L. Does not matter.

  FIG. 5 is a diagram illustrating an example of a case where a change amount greater than or equal to a predetermined value appears in the detection value due to frequency sensitivity control by the control unit 105 during wobbling control.

  In FIG. 5, when the target subject 202 is a subject that does not include a Nyquist frequency component, or the exposure period captured by the image sensor 102 is sufficiently long with respect to the dynamic characteristics of the target subject 202. Even if the image is blurred, (2) wobbling control can be performed in the vicinity of the peak of the detection value as indicated by the arrow.

  Here, in FIG. 4 and FIG. 5, the reason why the change amount ΔF of the detection value can be expected is that the detection value graphs shown in FIG. 4 and FIG. In FIG. 4, the frequency sensitivity is controlled (Expression 11) so as to increase the sensitivity to the Nyquist frequency component not included in the subject 202 of interest, and this is the Nyquist in FIG. This is because the frequency sensitivity is controlled (Expression 14) so that the sensitivity is increased to half the frequency.

  If the frequency sensitivity setting parameters (a, b, c, d, e, g) are supplemented, when the sensitivity is controlled to be high in a certain parameter, the sensitivity is also left in the other parameters. Better.

  This is because, when the target subject 202 is a subject including the Nyquist frequency, the presence or absence of the Nyquist frequency changes even when the target subject 202 is moving and when it is stationary. Because it ends up. Therefore, in order to perform continuous wobbling control for sudden movement / stop of the subject of interest 202, it is better not to control the presence / absence of sensitivity, although the sensitivity level is controlled.

  Next, a case where the target subject 202 is substantially stationary and the wobbling control is not successful even when the target subject 202 includes the Nyquist frequency will be described.

  FIG. 6 is a diagram illustrating an example of a case where there is no change amount greater than or equal to a predetermined value even when the detected value is greater than or equal to a predetermined level during wobbling control in focus drive.

  FIG. 6 shows a case where the above-described frequency sensitivity setting parameters (a, b, c, d, e, g) are not appropriately controlled according to the state of the detected value. Even if N contains a Nyquist frequency component and is stationary, (1) the arrow cannot find the peak of the detected value.

  In FIG. 6, the frequency sensitivity setting parameters (a, b, c, d, e, g) are highly sensitive to 1/2 frequency of Nyquist even though the subject 202 has a Nyquist frequency component. This is a phenomenon that occurs because the frequency sensitivity is controlled (Formula 14).

  For example, the change amount (ΔFh2, ΔFv2) for each wobbling of the detection value (Fh2, Fv2) is a small Δt, and the frequency sensitivity setting parameters (a, b, c, d, e, g) are expressed by Equation 14: If it is,

となる。

It becomes.

  At this time, in order to obtain a change amount ΔC in which the change amount ΔF of the detected value is equal to or greater than a predetermined value, the frequency sensitivity setting parameters (a, b, c, d, e, g) may be set as shown in Equation 11, If controlled to increase the sensitivity of the Nyquist frequency component,

となる。

It becomes.

  FIG. 7 is a diagram illustrating an example of a case where a change amount greater than or equal to a predetermined value appears in the detection value due to frequency sensitivity control by the control unit 105 during wobbling control.

  As indicated by the broken line in FIG. 7, if control is performed so that the sensitivity of the Nyquist frequency component is increased (Formula 11), the detection value that is insufficient for the frequency component of the half frequency of Nyquist indicated by the solid line. (2) As shown by the arrow, wobbling control is performed near the peak of the detected value.

  Next, an example of a method for appropriately controlling the frequency sensitivity will be described.

  Comparing FIG. 4 and FIG. 6, although FIG. 4 shows that the detected value does not reach the predetermined level or higher (Equation 12), FIG. It is also shown that the detected value has reached a predetermined level or higher.

  In FIG. 4, since the detection value does not reach a predetermined level or more as a result of controlling so that the sensitivity becomes higher with respect to the Nyquist frequency not included in the target subject 202 (Equation 11), the frequency sensitivity is reduced to 1/2 of Nyquist What is necessary is just to control so that the sensitivity to a frequency may become high (Formula 14). That is, when the detected value does not reach a predetermined level or higher (Formula 12), control may be performed so that the sensitivity on the low frequency side is increased.

  On the other hand, in FIG. 6, the target object 202 includes both the Nyquist frequency and a half frequency of Nyquist, and the frequency sensitivity is sensitive to the half frequency of Nyquist. Yes.

  However, the amount of change in the detected value is less than the predetermined value because the sensitivity is controlled to be low with respect to the Nyquist frequency included in the subject of interest 202 (Equation 14). In order to obtain the focusing accuracy, the frequency sensitivity may be controlled (Expression 11) so as to increase the sensitivity to the Nyquist frequency. That is, when the detected value reaches a predetermined level or higher, control may be performed so that the sensitivity on the high frequency side is increased.

  In this way, by appropriately controlling the frequency sensitivity, the moving subject tracking (wobbling control) with a good focus is performed on the subject 202 of interest. The frequency sensitivity control value is output not only to the detection unit 104 but also to the image processing unit 106.

  The image processing unit 106 (FIG. 1) corrects the luminance frequency characteristic of the imaging signal, performs image processing, and generates a corrected image. Further, the image processing unit 106 sets the luminance frequency characteristic based on the above-described frequency sensitivity control.

  FIG. 8 is a diagram illustrating an example of correcting the luminance frequency characteristic of the imaging signal by the image processing unit 106.

  In FIG. 8, a graph indicated by a broken line indicates a characteristic when the luminance frequency characteristic is not corrected for the imaging signal. A graph indicated by a solid line indicates characteristics when the luminance frequency characteristic is corrected for the imaging signal so that both the target subject 202 and the background subject 201 are substantially in focus.

  The contrast reproducibility (dB) on the vertical axis in FIG. 8 is the contrast reproducibility of the corrected image with respect to the contrast of the subject. As shown in FIG. 8, the contrast reproducibility has a characteristic that the reproducibility varies depending on the luminance frequency (MHz).

  If the luminance frequency characteristic is not corrected (broken line), even if the moving subject tracking with good focus is performed on the target subject 202, the target subject 202 is not affected by the apparent image quality. It does not appear to be in focus. Therefore, it is essential that the image processing unit 106 has a function of correcting the luminance frequency characteristic.

  However, there is a concern that the corrected image when the luminance frequency characteristic is corrected (solid line) may be an image having no perspective such as pan focus, and the portrait desired by the user, which is the subject of the present invention. An image is not always obtained.

  Therefore, a device for correcting the luminance frequency characteristics so that the subject 202 of interest looks in focus and obtaining a portrait image with a sense of perspective in which the background subject 201 is moderately blurred. Will be needed.

  FIG. 9 is a diagram illustrating an example of the luminance frequency characteristic used when the image processing unit 106 controls the frequency sensitivity so that the sensitivity is increased to the Nyquist frequency.

  In FIG. 9, this graph shows that the contrast reproducibility of the frequency band near the Nyquist frequency is higher than that of the solid line graph of FIG. It is also shown that the contrast reproducibility in the frequency band far from the Nyquist frequency is low.

  As shown in FIG. 9, in order to obtain a luminance frequency characteristic in which the frequency band on the high frequency side is an emphasized frequency band, a gain is applied to the high frequency band of luminance and / or the low frequency band of luminance. Apply a low-pass filter.

  FIG. 10 is a diagram illustrating an example of luminance frequency characteristics used when the image processing unit 106 controls the frequency sensitivity so that the sensitivity is increased to the Nyquist 1/2 frequency.

  In FIG. 10, this graph shows that the contrast reproducibility of the frequency band near the Nyquist 1/2 frequency is higher than that of the solid line graph of FIG. It is also shown that the contrast reproducibility in the frequency band far from the Nyquist 1/2 frequency is low.

  As shown in FIG. 10, in order to obtain a luminance frequency characteristic having the frequency band on the low frequency side (near Nyquist 1/2 frequency) as an emphasized frequency band, a gain is applied to the intermediate frequency band of luminance, and Alternatively, a low pass filter may be applied to the low frequency band of luminance.

  FIG. 11 is a diagram illustrating an example of luminance frequency characteristics used in a predetermined period after the frequency sensitivity is changed in the image processing unit 106.

  11, this graph shows that the frequency characteristic of contrast reproducibility is an intermediate graph characteristic (transition band) between the graph characteristic of FIG. 9 and the graph characteristic of FIG.

  The reason why the luminance frequency characteristic having the transition band as the emphasized frequency band as shown in FIG. 11 is used is that the high frequency side is the emphasized frequency band (FIG. 9) and the low frequency side is the emphasized frequency band. This is because when the luminance frequency characteristic (FIG. 10) is switched based on the change in the control of the frequency sensitivity described above, the sudden change in the luminance frequency characteristic becomes inconspicuous.

  It is desirable that the emphasis frequency band is set to the transition band (FIG. 11) for a predetermined period after the frequency sensitivity control (Formula 11 or 14) is changed. This is because the subject of interest moves, stops, or suddenly starts moving again when it thinks that it is stationary, and the frequency sensitivity control is changed for tracking the moving object in focus. This is because it is not preferable that the setting of the luminance frequency characteristic (FIG. 9 or FIG. 10) is switched in conjunction with the movement of the subject 202 of interest.

  In addition, as another measure for making the setting of the luminance frequency characteristic inconspicuous, a limiting unit that restricts the amplitude of the luminance to be equal to or less than a predetermined width when correcting the luminance frequency characteristic. 107 (FIG. 1) may be further provided. This is because the limit value of the luminance amplitude is output from the limiting unit 107 to the image processing unit 106, thereby preventing the reproducibility of the luminance contrast from being excessively corrected.

  The embodiment of the present invention has been described above with reference to FIGS. 1 to 11, and a supplementary description of the control algorithm will be given.

  FIG. 12 is a flowchart illustrating an example of a control algorithm of the imaging apparatus 100 according to the embodiment of the present invention.

    In FIG. 12, first, starting from the start, the process proceeds to step S1, and the frequency component of interest of the imaging signal is detected. This detection is performed by the detection unit 104 (FIG. 1), and the detection value F is calculated as shown in the above-described Equations 1 to 7. Then, the process proceeds to step S2.

  Next, in step S2, it is determined whether or not the change amount ΔF of the detection value F is less than a predetermined ΔC. If the change amount ΔF of the detected value is not less than the predetermined ΔC, the process proceeds to step S1 again. If the detected value change amount ΔF is less than the predetermined ΔC, the process proceeds to step S3. This determination is made by the control unit 105 (FIG. 1), and is determined as shown by the above-described Expression 13 and Expressions 15-17.

  In step S3, it is determined whether or not the detection value F is equal to or higher than a predetermined level L. If the detected value F is greater than or equal to the predetermined level L, the process proceeds to step S4. If the detected value F is less than the predetermined level L, the process proceeds to step S5. This determination is made by the control unit 105 (FIG. 1) and is determined as shown by the above-described equation 12.

  In step S <b> 4, the frequency sensitivity is controlled to increase the sensitivity on the high frequency side, and this control value is output to the detection unit 104 and the image processing unit 106. This control is performed by the control unit 105 (FIG. 1), and the frequency sensitivity setting parameter is controlled as shown by the equation (11). Then, the process proceeds to step S6.

  In step S5, the frequency sensitivity is controlled to increase the sensitivity on the low frequency side, and this control value is output to the detection unit 104 and the image processing unit 106. This control is performed by the control unit 105 (FIG. 1), and the frequency sensitivity setting parameter is controlled as shown by the equation (14). Then, the process proceeds to step S6.

  In step S6, the emphasis frequency of the luminance frequency characteristic is based on the frequency sensitivity control value (Formula 11 or 14 or a predetermined period after the control value is changed) input from the control unit 105. Each band is set and updated. The setting of the emphasized frequency band is performed by the image processing unit 106 (FIG. 1), and the characteristics thereof are the graph characteristics shown in FIGS. And it transfers to step S1 again.

  As described above, the image capturing apparatus 100 according to the embodiment of the present invention can obtain a portrait image desired by the user even when high-speed continuous shooting or moving image capturing is performed while wobbling control is performed on autofocus. it can.

  The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like without departing from the gist of the present invention.

  Further, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be obtained as an invention.

100 Imaging device 101 Focus lens (optical system)
102 Image sensor (imaging unit)
103 Focus driver (adjustment unit)
104 detection unit 105 control unit 106 image processing unit 107 restriction unit

Claims (5)

An optical system that generates an optical image from a composite subject including a target subject and a background subject;
An imaging unit that photoelectrically converts the optical image and generates the imaging signal;
In order to track the moving object for focusing the subject of interest, the wobbling control of the focusing is performed on the optical system to adjust the optical photographing distance from the subject of interest to the imaging surface of the imaging unit. Adjusting part to be
A detection unit that detects a frequency component of interest that is a frequency component of interest regarding the in-focus from the imaging signal, and returns the detection value to the adjustment unit;
A control unit that controls a frequency sensitivity that is a sensitivity for each frequency of the frequency component of interest so that the detected value has a predetermined amount of change or more for each wobbling;
An image processing unit that corrects a luminance frequency characteristic of the imaging signal, performs image processing, and generates the corrected image;
With
The image processing unit sets the luminance frequency characteristic based on the frequency sensitivity. The controller is
If the detected value is less than a predetermined amount of change and equal to or greater than a predetermined level, the frequency sensitivity is controlled to increase the sensitivity on the high frequency side of the frequency component of interest,
If the detected value is less than a predetermined change amount and less than a predetermined level, the frequency sensitivity is controlled to increase the sensitivity on the low frequency side of the frequency component of interest,
The image processing unit
The imaging apparatus according to claim 1, wherein an enhanced frequency band emphasized by the luminance frequency characteristic is set on the high frequency side or the low frequency side based on the control of the frequency sensitivity. The image processing unit
The imaging apparatus according to claim 2, wherein an enhancement frequency band that is emphasized by the luminance frequency characteristic is set as a transition band for a predetermined period after a change occurs in the control of the frequency sensitivity. The imaging device according to claim 1, wherein the frequency sensitivity is a sensitivity for each 1 / n (where n is a natural number) of a Nyquist frequency of the imaging signal. The imaging apparatus according to claim 1, further comprising: a limiting unit configured to limit the amplitude of the luminance to be a predetermined width or less when correcting the luminance frequency characteristic.

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