JP2011248376A - Imaging apparatus, focusing method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the accuracy of automatic focusing processing.SOLUTION: An imaging apparatus 100 includes: an image region-specifying unit 7a for determining a shape of an image region of an attention subject that becomes an object to be focused in a captured image; a region-setting unit 7e for setting a plurality of AF estimation regions based on the shape of the image region of the specified attention subject; and a lens-driving unit 2 for focusing a lens unit 1 based on image data in these AF estimation regions.

Description

  The present invention relates to an imaging apparatus, an in-focus method, and a program that perform auto-focus (auto-focus) processing.

  Conventionally, in autofocus (AF) processing of a digital camera, a technique for setting a plurality of AF areas in an imaging frame (see, for example, Patent Document 1), and a technique for tracking a subject to perform AF (see, for example, Patent Document 1) )It has been known.

JP 2007-178576 A JP 2006-184742 A

However, in the technique according to Patent Document 1, the AF area is set at a predetermined position in the imaging frame, and the AF area is set according to the shape of a specific subject to be AF target. A plurality of AF areas are not set for one subject to be AF target. For this reason, when a subject whose contrast varies depending on the part is used as an AF target, there is a problem that an AF area is set in a low-contrast portion and AF accuracy is lowered. Further, even if the technique according to Patent Document 2 is applied, it has not been possible to prevent the AF area from being set in a low contrast portion.
On the other hand, if a large AF area is set so as to include the entire subject, the contrast gradient in the AF processing may be loosened. In this case, there is a problem in that the accuracy of detecting the contrast peak is lowered. End up.

  Therefore, an object of the present invention is to provide an imaging apparatus, a focusing method, and a program that can improve the accuracy of automatic focusing processing.

In order to solve the above problem, an imaging apparatus according to claim 1 is provided.
An imaging unit, a specifying unit that specifies a shape of an image area of a target subject to be focused in a captured image captured by the imaging unit, and a shape of the image area of the target subject specified by the specifying unit A region setting unit that sets a plurality of contrast evaluation regions, and a focusing control unit that focuses the imaging unit based on image data in the contrast evaluation region set by the region setting unit. It is characterized by.

The invention according to claim 2 is the imaging apparatus according to claim 1,
The area setting means sets a plurality of rectangular contrast evaluation areas adjacent to each other.

The invention according to claim 3 is the imaging apparatus according to claim 2,
The apparatus further comprises a determining unit that determines the number of the vertical and horizontal settings of the contrast evaluation region that are set adjacent to each other in accordance with the ratio of the vertical and horizontal lengths of the image area of the subject of interest. It is characterized by.

The invention according to claim 4 is the imaging apparatus according to claim 3,
The specifying means further specifies the size of the image area of the subject of interest, and the determining means is in accordance with the size of the temporary contrast evaluation area set based on the shape and size of the image area of the subject of interest. The number of set in the vertical direction and the horizontal direction of the contrast evaluation area is determined.

The invention according to claim 5 is the imaging apparatus according to claim 3 or 4,
The image processing apparatus further includes calculation means for calculating a dimension of the contrast evaluation area according to the number of vertical and horizontal settings of the contrast evaluation area determined by the determination means.

The invention described in claim 6 is the imaging apparatus according to claim 5,
The specifying means further specifies the size of the image area of the subject of interest, and the calculating means is the shape and size of the image area of the subject of interest, and the vertical direction of the contrast evaluation area determined by the determining means The size of the contrast evaluation area is calculated based on the set number in the horizontal direction.

The invention according to claim 7 is the imaging apparatus according to any one of claims 1 to 6,
The specifying means further specifies a size of the image area of the subject of interest and determines whether or not the size of the image area of the subject of interest is larger than a minimum dimension that can be set as the contrast evaluation area. The area setting means sets a plurality of contrast evaluation areas when the size of the image area of the subject of interest is larger than the minimum dimension of the contrast evaluation area as a result of the determination by the dimension determination means. When the size of the image area of the subject of interest is equal to or smaller than the minimum dimension of the contrast evaluation area, one contrast evaluation area is set.

The invention according to claim 8 is the imaging apparatus according to any one of claims 1 to 7,
Subject setting means for setting a minimum rectangle surrounding the image area of the subject of interest as a temporary shape of the image area of the subject of interest, and the temporary shape of the image area of the subject of interest set by the subject setting means An area determination unit that determines whether or not the image area of the subject of interest is included in a predetermined ratio or more for a plurality of contrast evaluation areas set by the area setting unit; and the area determination unit among the plurality of contrast evaluation areas And a means for excluding the contrast evaluation area determined not to include the image area of the subject of interest at a predetermined ratio or more from the evaluation target.

The invention according to claim 9 is the imaging apparatus according to any one of claims 1 to 8,
The region setting means sets the contrast evaluation region so as to intersect with a contour portion of an image region of the subject of interest.

The invention according to claim 10 is the imaging apparatus according to any one of claims 1 to 9,
The specifying means sequentially specifies the shape of the image area of the target object, and the area setting means sequentially specifies a plurality of contrast evaluation areas in accordance with the shape of the image area of the target object specified by the specifying means. It is characterized by setting.

The invention according to claim 11 is the imaging apparatus according to any one of claims 1 to 10,
The focus control unit has a contrast gradient detection accuracy of image data in each evaluation region of the plurality of contrast evaluation regions set by the region setting unit that is greater than or equal to a predetermined value and is the most from the imaging device. The output means of the contrast evaluation area having a contrast peak at a short distance is employed to focus the imaging means.

Invention of Claim 12 in the imaging device as described in any one of Claims 1-11,
The area setting means sets the contrast evaluation area by giving priority to the vertical direction with respect to the horizontal direction of the image area of the subject of interest.

The focusing method of the invention according to claim 13 is:
A focusing method using an imaging apparatus including an imaging unit, the process of specifying the shape of an image area of a target object to be focused in a captured image captured by the imaging unit, and the specified attention A process of setting a plurality of contrast evaluation areas in accordance with the shape of the image area of the subject, and a process of focusing the imaging unit based on image data in the set contrast evaluation areas Yes.

The program of the invention according to claim 14 is:
A computer of an imaging apparatus including an imaging unit; a specifying unit that specifies a shape of an image area of a subject of interest to be focused in a captured image captured by the imaging unit; a target of the target subject specified by the specifying unit Area setting means for setting a plurality of contrast evaluation areas in accordance with the shape of the image area, focusing control means for focusing the imaging means based on image data in the contrast evaluation area set by the area setting means, It is characterized by making it function as.

  According to the present invention, the accuracy of the automatic focusing process can be improved by the plurality of contrast evaluation areas set in accordance with the shape of the image area of the subject of interest.

It is a block diagram which shows schematic structure of the imaging device of one Embodiment to which this invention is applied. It is a flowchart which shows an example of the operation | movement which concerns on the automatic focusing process by an imaging device. 3 is a flowchart showing a continuation of the automatic focusing process of FIG. It is a figure which shows typically an example of the attention object extracted by the automatic focusing process of FIG. It is a figure which shows typically an example of the image which concerns on the automatic focusing process of FIG. It is a figure which shows typically an example of the image which concerns on the automatic focusing process of FIG. It is a figure which shows typically an example of the image which concerns on the automatic focusing process of FIG.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.
FIG. 1 is a block diagram illustrating a schematic configuration of an imaging apparatus 100 according to an embodiment to which the present invention is applied.

The imaging apparatus 100 according to the present embodiment includes an image region (for example, an image region A2) of a target subject (for example, a target subject S2) to be focused in a captured image (for example, the captured image G2; see FIG. 6A). ; FIG. 6B) is specified, and a plurality of AF evaluation areas (for example, AF evaluation area P2; see FIG. 6D) are set in accordance with the shape of the image area of the subject of interest. Based on the image data in the AF evaluation area, the lens unit 1 is focused.
Specifically, as illustrated in FIG. 1, the imaging device 100 includes a lens unit 1, a lens driving unit 2, an electronic imaging unit 3, a unit circuit 4, an imaging control unit 5, an image generation unit 6, an AF processing unit 7, An image processing unit 8, a display unit 9, an image recording unit 10, an operation input unit 11, a buffer memory 12, a program memory 13, a central control unit 14 and the like are provided.
The lens driving unit 2, the imaging control unit 5, the image generation unit 6, the AF processing unit 7, the image processing unit 8, the display unit 9, the image recording unit 10, the buffer memory 12, the program memory 13, and the central control unit 14 are They are connected via a bus line 15.

  The lens unit 1 includes, for example, a plurality of lenses, and specifically includes a focus lens, a zoom lens (both not shown), and the like.

  The lens driving unit 2 drives the focus lens and the zoom lens provided in the lens unit 1 in the optical axis direction. Specifically, the lens driving unit 2 includes a driving source such as a focus motor and a zoom motor, and a driver that drives the driving source in accordance with a control signal from the central control unit 14 (none of which is shown).

  The electronic imaging unit 3 is disposed on the optical axis of the lens unit 1. The electronic imaging unit 3 is composed of, for example, an image sensor such as a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS), and an optical image that has passed through various lenses of the lens unit 1 is converted into a two-dimensional image signal. Convert to

The unit circuit 4 receives an analog imaging signal corresponding to the optical image of the subject output from the electronic imaging unit 3, receives a CDS that holds the input imaging signal, and a gain adjustment amplifier (AGC) that amplifies the imaging signal. ), An A / D converter (ADC) that converts the amplified image signal into a digital image signal, and the like.
Then, the unit circuit 4 transmits a digital imaging signal to the image generation unit 6 and the AF processing unit 7.

  The imaging control unit 5 performs control to drive the electronic imaging unit 3 and the unit circuit 4 at a timing according to the frame rate set by the central control unit 14. Specifically, the imaging control unit 5 includes a TG (Timing Generator), a driver for driving the electronic imaging unit 3 and the like (all not shown), and controls the operation timing of the driver and the unit circuit 4 via the TG. . That is, when the central control unit 14 sets the shutter speed according to the program diagram read from the program memory 13, the TG of the imaging control unit 5 outputs the charge accumulation time corresponding to the shutter speed to the driver as a shutter pulse, The electronic image pickup unit 3 is operated in accordance with the drive pulse signal from the driver to control the charge accumulation time (exposure time).

  The lens unit 1, the electronic imaging unit 3, the unit circuit 4, and the imaging control unit 5 configured as described above constitute imaging means for imaging a subject.

  The image generation unit 6 performs processing such as γ correction processing and white balance processing on the image data sent from the unit circuit 4 and generates a luminance color difference signal (YUV data). Then, the image generation unit 6 outputs the generated image data of the luminance color difference signal to the central control unit 14 via the bus line 15.

The AF processing unit 7 detects the subject of interest (for example, the subjects of interest S1 and S2) in the captured images (for example, the captured images G1, G2, and G3; see FIGS. 5A, 6A, and 7A). , S3) includes an image region specifying unit 7a that specifies the image region (for example, image regions A1, A2, and A3; see FIGS. 5B, 6B, and 7B).
For example, every time image data is sent from the unit circuit 4, the image area specifying unit 7a performs a reduction process with a predetermined magnification on the image data in both the horizontal direction (horizontal) and the vertical direction (vertical). Low-resolution image data (for example, horizontal × vertical: 40 × 30 pixels; see FIG. 4) L is sequentially generated. Then, the image area specifying unit 7a uses a predetermined image recognition technique for the low-resolution image data L to specify a target subject to be focused and extracts an image area. Here, the target subject specifying process may be performed, for example, by extracting the contour of the target subject from the continuity of changes in color and brightness, or by specifying the type of the target subject in advance. It is also possible to extract the contour by comparing with the feature information of

5B, FIG. 6B, and FIG. 7B, the image data is represented by binarization, and the image areas A1, A2, and B, which are represented by white without dots, A3 corresponds to the subject of interest S1, S2, S3, and the image area represented by black with dots corresponds to a portion other than the subject of interest S1, S2, S3.
In addition, the subject of interest does not necessarily have to be independent as one subject, and a plurality of subjects may overlap in the front-rear direction, or a plurality of subjects may be separated in the left-right or vertical direction. It may be.

  Thereafter, the image area specifying unit 7a specifies the size of the image area of the extracted subject of interest, and then sets the minimum rectangular frame W surrounding the image area of the subject of interest as the provisional shape of the image area of the subject of interest. . Specifically, the image area specifying unit 7a calculates the horizontal width x from the difference between the maximum coordinate x2 and the minimum coordinate x1 in the x-axis direction (horizontal direction) of the image area of the subject of interest, and also in the y-axis direction. By calculating the vertical width y from the difference between the maximum coordinate y2 in the (vertical direction) and the minimum coordinate y1 (see FIG. 4), a rectangular frame (temporary contrast evaluation area) W having the horizontal width x and the vertical width y is calculated. Is set as the temporary shape of the image area of the subject of interest.

  Here, the image area specifying unit 7a is an image area of a subject of interest to be focused in a captured image captured by the lens unit 1, the electronic imaging unit 3, the unit circuit 4, and the imaging control unit 5 as an imaging unit. Is configured as a subject setting means for setting a minimum rectangular frame W surrounding the image as a temporary shape of the image area of the subject of interest. The image area specifying unit 7a constitutes specifying means for specifying the shape of the image area of the subject of interest in the captured image.

Further, the AF processing unit 7 determines that the size of the image region (for example, the image regions A1, A2, A3) of the target subject (for example, the target subjects S1, S2, S3) specified by the image region specifying unit 7a is the AF evaluation region. (For example, AF evaluation areas P1, P2, and P3; see FIGS. 5C, 6C, and 7C) A dimension determination unit 7b that determines whether or not the minimum dimension can be set. It has.
Specifically, the dimension determining unit 7b determines whether or not the dimension of the rectangular frame W set by the image area specifying unit 7a is larger than the minimum dimension of each AF evaluation area set in advance. The minimum dimension of the AF evaluation area is, for example, a minimum horizontal width Xmin of 6 pixels and a minimum vertical width Ymin of 4 pixels for image data L of low resolution (for example, horizontal x vertical: 40 x 30 pixels). Is set. As a result of the determination by the size determination unit 7b, the region setting unit 7e (described later) sets a plurality of AF evaluation regions when the size of the rectangular frame W is larger than the minimum size of each AF evaluation region. When the dimension of W is equal to or smaller than the minimum dimension of each AF evaluation area, one AF evaluation area having the minimum dimension is set.
Here, the dimension determining unit 7b constitutes a dimension determining unit that determines whether or not the dimension of the image area of the subject of interest is larger than the minimum dimension that can be set in the AF evaluation area (contrast evaluation area).

Further, the AF processing unit 7 includes a division number determining unit 7c that determines the number of divisions of the rectangular frame W according to the size of the rectangular frame (temporary contrast evaluation region) W set by the image region specifying unit 7a. ing.
The division number determination unit 7c determines the number of divisions of the rectangular frame W according to the ratio of the vertical width y and the horizontal width x of the rectangular frame W (the aspect ratio Rate), that is, a plurality of AF evaluation areas P1 set by the area setting unit, The set number of P2 and P3 is calculated. Specifically, the division number determination unit 7c first calculates the aspect ratio Rate of the rectangular frame W from the vertical width y and the horizontal width x according to the following formula (1).
Rate = (x / y) × 100 (1)

Next, the division number determination unit 7c determines the overall shape of the AF evaluation area (for example, “1 × n type”, “2 × n type”, “n × n type”, “n”) according to the calculated aspect ratio Rate. n × 1 type ”,“ n × 2 type ”; n is a natural number), and is then defined by the size of the rectangular frame W and the minimum size of each AF evaluation region according to the overall shape of the AF evaluation region. The division numbers Nx and Ny of the rectangular frame W are calculated from a predetermined calculation formula.
For example, when the aspect ratio Rate is smaller than 44, the division number determination unit 7c determines the overall shape of the AF evaluation area to be “1 × n type” and then sets the vertical width y of the rectangular frame W to the AF evaluation area. The vertical division number Ny of the rectangular frame W is calculated by dividing by the minimum vertical dimension Ymin. The horizontal division number Nx of the rectangular frame W is “1” because the overall shape of the AF evaluation area is “1 × n type”.
For example, when the aspect ratio Rate is 44 or more and smaller than 66, the division number determination unit 7c determines the overall shape of the AF evaluation area to be “2 × n type”, and then the vertical width of the rectangular frame W The vertical division number Ny of the rectangular frame W is calculated by dividing y by the minimum vertical dimension Ymin of the AF evaluation area. The horizontal division number Nx of the rectangular frame W is “2” because the overall shape of the AF evaluation area is “2 × n type”.
For example, when the aspect ratio Rate is 66 or more and smaller than 266, the division number determination unit 7c determines the overall shape of the AF evaluation area to be “n × n type”, and then the vertical width of the rectangular frame W The vertical division number Ny of the rectangular frame W is calculated by dividing y by the minimum vertical dimension Ymin of the AF evaluation area. Note that the horizontal division number Nx of the rectangular frame W is equal to the vertical division number Ny because the overall shape of the AF evaluation area is “n × n type”.
For example, when the aspect ratio Rate is 266 or more and smaller than 400, the division number determination unit 7c determines the overall shape of the AF evaluation area to be “n × 2 type”, and then the horizontal width of the rectangular frame W The horizontal division number Nx of the rectangular frame W is calculated by dividing x by the minimum horizontal dimension Xmin of the AF evaluation area. Note that the number of divisions Ny in the vertical direction of the rectangular frame W is “2” because the overall shape of the AF evaluation area is “n × 2 type”.
Further, for example, when the aspect ratio Rate is 400 or more, the division number determination unit 7c determines the overall shape of the AF evaluation area to be “n × 1 type”, and then performs the AF evaluation on the horizontal width x of the rectangular frame W. The horizontal division number Nx of the rectangular frame W is calculated by dividing the area by the minimum horizontal dimension Xmin. The vertical division number Ny of the rectangular frame W is “1” because the overall shape of the AF evaluation area is “n × 1 type”.
Here, the division number determination unit 7c determines the number of AF evaluation areas set in the vertical direction and the horizontal direction that are set adjacent to each other in accordance with the ratio of the vertical length and the horizontal length of the image area of the subject of interest. A determining means for determining is configured.
The aspect ratio Rate, the overall shape of the AF evaluation area (AF frame), and the division numbers Nx and Ny are merely examples, and are not limited to these, and can be arbitrarily changed as appropriate.

In addition, the AF processing unit 7 includes a dimension calculation unit 7d that calculates the dimensions of the rectangular AF evaluation areas (for example, AF evaluation areas P1, P2, and P3).
The dimension calculation unit 7d calculates the vertical width Y of the AF evaluation area by dividing the vertical width y of the rectangular frame W by the vertical division number Ny of the rectangular frame W determined by the division number determination unit 7c. The horizontal width X of the AF evaluation area is calculated in accordance with the defined shape of the AF evaluation area (for example, the ratio of horizontal: vertical 4: 3).
Here, the size calculation unit 7d sets the shape and size of the image region of the subject of interest (the shape and size of the rectangular frame W), and the vertical and horizontal settings of the AF evaluation region determined by the division number determination unit 7c. According to the number (the number of divisions of the rectangular frame W), a calculation unit is configured to calculate the size of the AF evaluation area.

Further, the AF processing unit 7 uses the AF evaluation area (for example, AF evaluation areas P1, P2, and P3) having the dimensions calculated by the dimension calculation unit 7d as the image area of the target subject (for example, the target objects S1, S2, and S3). For example, a plurality of area setting sections 7e are provided for setting in accordance with the shape of the image areas A1, A2, A3.
The area setting unit 7e sequentially sets a plurality of AF evaluation areas in accordance with the shape of the image area of the subject of interest every time the dimension of the AF evaluation area is set by the dimension calculation unit 7d. Specifically, the area setting unit 7e determines that the size of the rectangular frame W is larger than the minimum dimension that can be set as a predetermined AF evaluation area by the dimension determining unit 7b. A plurality of rectangular AF evaluation areas are arranged adjacent to each other so that the midpoint of the image and the midpoint of the horizontal width X of the AF evaluation area (AF frame) substantially overlap. That is, the area setting unit 7e sets the AF evaluation area by giving priority to the vertical direction with respect to the horizontal direction of the image area of the subject of interest. As a result, the area setting unit 7e sets a rectangular frame expanded as a whole, which includes a plurality of AF evaluation areas.
5C, FIG. 6C, and FIG. 7C show a state where AF evaluation areas P1, P2, and P3 are set for binarized image data.
Here, the area setting unit 7e constitutes area setting means for setting a plurality of AF evaluation areas in accordance with the shape of the image area of the subject of interest.
The region setting unit 7e sets only one AF evaluation region P1 when the size determination unit 7b determines that the size of the rectangular frame W is equal to or less than the minimum size of the AF evaluation region P1 (FIG. 5). (See (a) to FIG. 5 (c)).

The AF processing unit 7 also includes an image region (for example, the subject of interest S1, S2, S3) within the AF evaluation region (for example, AF evaluation regions P1, P2, P3) set by the region setting unit 7e. For example, an area determination unit 7f that determines whether or not the image areas A1, A2, and A3) are included in a predetermined ratio or more is provided.
The area determination unit 7f serves as an area determination unit for a plurality of AF evaluation areas set by the area setting unit 7e according to the rectangular frame W as the temporary shape of the image area of the target object, from within each AF evaluation area. After the image area (target subject area) is detected, it is determined whether or not the target subject area includes a predetermined ratio (for example, 50%) or more.

In addition, the AF processing unit 7 determines an image area (for example, the image areas A1, A2, and A3) of the target subject (for example, the target objects S1, S2, and S3) according to the determination result of the area determination unit 7f at a predetermined ratio. An evaluation object exclusion unit 7g that excludes AF evaluation areas not included above is provided.
As an exclusion means, the evaluation target exclusion unit 7g uses, as an invalid AF frame, an AF evaluation region determined by the region determination unit 7f as not including a predetermined ratio or more of the target subject region among a plurality of AF evaluation regions as an invalid AF frame. exclude. Thereby, only the AF evaluation area determined by the area determination unit 7f to include the subject area of interest at a predetermined ratio or more is set as the effective AF frame.

In addition, the AF processing unit 7 includes an evaluation value calculation unit 7h that calculates an AF evaluation value related to the determination of the in-focus state.
The evaluation value calculation unit 7 h calculates an AF evaluation value for each image data sent from the unit circuit 4 to the AF processing unit 7. Specifically, the evaluation value calculation unit 7h includes the region determination unit 7f in the low-resolution image data (for example, horizontal × vertical: 40 × 30 pixels; see FIG. 4) L generated by the image region specifying unit 7a. Based on the image data of the AF evaluation area (for example, AF evaluation areas P1, P2, and P3) set as the effective AF frame, an AF evaluation value (contrast evaluation value) indicating the level of contrast of the image is calculated.

  The image processing unit 8 includes an encoding unit (not shown) that compresses and encodes image data (YUV data) generated by the image generation unit 6 using a predetermined encoding method (for example, JPEG method), and image recording. The image processing apparatus includes a decoding unit (not shown) that decodes the encoded image data read from the unit 10 using a decoding method corresponding to the encoding method.

The display unit 9 converts the YUV data for one frame stored in the buffer memory 12 into a video signal, and then displays it as a live view image on the display screen. Specifically, the display unit 9 displays a live view image based on a plurality of image frames generated by imaging a subject, or displays a REC view image captured as a main captured image.
At the time of image reproduction, the display unit 9 displays an image based on the image data read from the image recording unit 10 and decoded by the image processing unit 8.

  The image recording unit 10 is configured by, for example, a nonvolatile memory (flash memory). The image recording unit 10 also includes still image data and moving image data that have been compressed and encoded by a coding unit (not shown) of the image processing unit 8 using a predetermined coding method (for example, JPEG method, MPEG method, etc.). Remember.

  The operation input unit 11 is for performing a predetermined operation of the imaging apparatus 100. Specifically, the operation input unit 11 includes a shutter button related to an instruction to shoot a subject, a selection determination button related to an instruction to select an imaging mode or a function, a zoom button related to an instruction to adjust the zoom amount, and the like (all shown) Abbreviation), a predetermined operation signal is output to the central control unit 14 in accordance with the operation of these buttons.

  The buffer memory 12 is a buffer for temporarily storing image data and the like, and is also used as a working memory for the central control unit 14.

  The program memory 13 stores various programs and data related to the functions of the imaging apparatus 100. The program memory 13 also includes a combination of an aperture value (F) and a shutter speed corresponding to an appropriate exposure value (EV) at each shooting such as still image shooting, continuous shooting, and live view image shooting. Program AE data constituting the program diagram shown and an EV value table are also stored.

The central control unit 14 is a one-chip microcomputer that controls each unit of the imaging apparatus 100.
The central control unit 14 controls each unit of the imaging apparatus 100 based on the operation signal output from the operation input unit 11 and input. Specifically, when an imaging signal output in accordance with a predetermined operation of the shutter button of the operation input unit 11 is input, the central control unit 14 performs electronic imaging with a TG according to a predetermined program stored in the program memory 13. A process of taking a still image is executed by controlling the drive timing of the unit 3 and the unit circuit 4. One frame of YUV data stored in the buffer memory 12 by shooting this still image is compressed and encoded by the image processing unit 8 by the JPEG method or the like, and recorded as still image data in the image recording unit 10. .

Further, the central control unit 14 calculates the AF evaluation calculated by the evaluation value calculation unit 7h of the AF processing unit 7 based on the image data of the AF evaluation area (for example, AF evaluation areas P1, P2, and P3) that are effective AF frames. Based on the value, the focus position of the lens unit 1 is adjusted by outputting a predetermined control signal to the lens driving unit 2 to drive the focus motor. At this time, the central control unit 14 among the plurality of AF evaluation regions set by the region setting unit 7e of the AF processing unit 7 calculates the contrast gradient of the image data in each evaluation region calculated by the evaluation value calculation unit 7h. The output of the AF evaluation area 3 having a detection accuracy of a predetermined value or higher and a contrast peak at the closest distance from the imaging apparatus 100 may be used to focus the imaging means. In other words, even when a plurality of AF evaluation areas are set for a plurality of attention subjects, the focus may be focused on one attention subject with close priority.
Here, the central control unit 14 and the lens driving unit 2 constitute a focusing control unit that focuses the imaging unit based on the image data in the AF evaluation region set by the region setting unit 7e.

Next, the automatic focusing process according to the focusing method method performed by the imaging apparatus 100 will be described with reference to FIGS.
2 and 3 are flowcharts showing an example of the operation related to the automatic focusing process. FIG. 4 is a diagram schematically illustrating an example of a subject of interest extracted by the automatic focusing process.
The automatic focusing process is repeatedly executed under the control of the central control unit 14 when the user performs a predetermined operation (for example, half-pressing operation) on the shutter button of the operation input unit 11 while the live view image is displayed. Process. Note that it may be executed during the display of the live view image regardless of whether or not the shutter button is operated.

As shown in FIG. 2, a plurality of image frames (FIG. 5A, FIG. 6A, and FIG. 7A) of a captured image (for example, captured images G 1, G 2, and G 3) generated by capturing a subject. Each time image data related to the image processing unit 7 is sent from the unit circuit 4 to the AF processing unit 7, the AF processing unit 7 reads the image area of the subject of interest (for example, the subject of interest S1, S2, S3) from the image data. A process of extracting (for example, the image areas A1, A2, A3) is performed (step S1).
Specifically, the image area specifying unit 7a of the AF processing unit 7 performs a reduction process at a predetermined magnification on each image data sent from the unit circuit 4 to obtain low resolution image data (for example, horizontal × vertical). : 40 × 30 pixels; see FIG. 4) After generating L, the subject of interest S1, S2, S3 (FIG. 5 (FIG. 5)) to be focused using low-resolution image data L using a predetermined image recognition technique. b), FIG. 6B, FIG. 7B, etc.) are specified and extracted.

Next, the image area specifying unit 7a sets the minimum rectangular frame W surrounding the extracted image area of the subject of interest as a temporary shape of the image area of the subject of interest (step S2).
Specifically, the image area specifying unit 7a uses the horizontal width x in the x-axis direction (horizontal direction) and the vertical width in the y-axis direction (vertical direction) of the image areas A1, A2, and A3 of the subject of interest S1, S2, and S3. y is calculated (see FIG. 4), and a rectangular frame W having the horizontal width x and the vertical width y is set.

Subsequently, the size determination unit 7b of the AF processing unit 7 sets the size of the rectangular frame W set by the image region specifying unit 7a to an AF evaluation region (for example, AF evaluation regions P1, P2, P3) set in advance. It is determined whether it is larger than the minimum dimension that can be set as (step S3).
Here, if it is determined that the size of the rectangular frame W is not larger than the minimum size of the AF evaluation region (step S3; NO), the region setting unit 7e of the AF processing unit 7 sets the minimum to the center coordinate of the rectangular frame W. One AF evaluation area P1 (see FIG. 5C) of the minimum dimension is set so that the center coordinates of the AF evaluation area (AF frame) of the dimensions overlap (step S4).
Thereafter, the central control unit 14 displays the AF frame display F1 (see FIG. 5D) corresponding to the edge portion of the AF evaluation area P1 having the minimum dimension set by the area setting unit 7e, as the subject S1 of interest in the live view image. The display 9 is displayed so as to overlap S2 and S3 (step S5), and the AF evaluation value calculated by the evaluation value calculation unit 7h of the AF processing unit 7 based on the image data of the AF evaluation areas P1, P2, and P3. The focus position of the lens unit 1 is adjusted by outputting a predetermined control signal to the lens driving unit 2 and driving the focus motor.

On the other hand, when it is determined in step S3 that the size of the rectangular frame W is larger than the minimum size of the AF evaluation area (step S3; YES), the division number determination unit 7c of the AF processing unit 7 The ratio of the vertical width y and the horizontal width x (the aspect ratio Rate) is calculated from the vertical width y and the horizontal width x according to the following formula (1) (step S6).
Rate = (x / y) × 100 (1)

Thereafter, the AF processing unit 7 branches the process according to the aspect ratio Rate of the rectangular frame W (step S7).
Specifically, when the aspect ratio Rate is smaller than 44, the division number determination unit 7c determines the overall shape of the AF evaluation area to be “1 × n type” (step S711), and then continues to the rectangular frame. The vertical division number Ny of the rectangular frame W is calculated by dividing the vertical width y of W by the minimum vertical dimension Ymin of the AF evaluation area, and the horizontal division number Nx of the rectangular frame W is set to “1”. (Step S712).
If the aspect ratio Rate is 44 or more and smaller than 66, the division number determination unit 7c determines the overall shape of the AF evaluation area to be “2 × n type” (step S721), and then continues to the rectangular frame. The vertical division number Ny of the rectangular frame W is calculated by dividing the vertical width y of W by the minimum vertical dimension Ymin of the AF evaluation area, and the horizontal division number Nx of the rectangular frame W is set to “2”. (Step S722).
If the aspect ratio Rate is 66 or more and smaller than 266, the division number determination unit 7c determines the overall shape of the AF evaluation area to be “n × n type” (step S731), and then continues to the rectangular frame. The vertical division number Ny of the rectangular frame W is calculated by dividing the vertical width y of W by the minimum vertical dimension Ymin of the AF evaluation area, and the horizontal division number Nx of the rectangular frame W is calculated in the vertical direction. A value equal to the division number Ny is set (step S732).
If the aspect ratio Rate is 266 or more and smaller than 400, the division number determination unit 7c determines the overall shape of the AF evaluation area to be “n × 2 type” (step S741), and then continues to the rectangular frame. The horizontal division number Nx of the rectangular frame W is calculated by dividing the horizontal width x of W by the minimum horizontal dimension Xmin of the AF evaluation area, and the vertical division number Ny of the rectangular frame W is set to “2”. (Step S742).
When the aspect ratio Rate is 400 or more, the division number determination unit 7c determines the overall shape of the AF evaluation area to be “n × 1 type” (step S751), and then continues to the horizontal width of the rectangular frame W. The horizontal division number Nx of the rectangular frame W is calculated by dividing x by the horizontal minimum dimension Xmin of the AF evaluation area, and the vertical division number Ny of the rectangular frame W is set to “1” ( Step S752).

Next, the size calculation unit 7d of the AF processing unit 7 divides the vertical width y of the rectangular frame W by the vertical division number Ny of the rectangular frame W determined by the division number determination unit 7c, and calculates an AF evaluation area (for example, After calculating the vertical width Y of the AF evaluation areas P2, P3), the horizontal width X of the AF evaluation area is calculated according to the shape of the predetermined AF evaluation area (for example, the ratio of horizontal: vertical 4: 3). Thus, the dimension of the AF evaluation area is calculated (step S8).
Subsequently, the area setting unit 7e of the AF processing unit 7 uses the AF evaluation area (for example, the AF evaluation areas P2 and P3) having the dimensions calculated by the dimension calculation unit 7d as the subject of interest with respect to the low-resolution captured image L. (For example, subject areas S2 and S3) are arranged so as to be adjacent to each other in accordance with the shape of the image area (for example, image areas A2 and A3) (step S9; see FIGS. 6C and 7C). ).

Then, the area setting unit 7e determines whether or not each of a plurality of AF evaluation areas (for example, AF evaluation areas P2 and P3) protrudes from the end of the low-resolution captured image L (step S10).
Here, when it is determined that the AF evaluation area protrudes from the edge of the captured image (step S10; YES), the area setting unit 7e does not include an AF evaluation area that protrudes from the edge of the captured image. The arrangement of all AF evaluation areas is adjusted (step S11). That is, when the subject of interest (for example, the subject of interest S2 and S3) is in a portion close to the top, bottom, left, and right ends of the captured image, the AF evaluation area may protrude from the end of the captured image. In this case, the area setting unit 7e changes the size and shape of each AF evaluation area so that none of the AF evaluation areas protrude from the captured image when determining the AF evaluation values of the AF evaluation areas equally. Without shifting, all the AF evaluation areas are arranged in the captured image.

  Subsequently, the area setting unit 7e calculates the center coordinates of all the AF evaluation areas (for example, AF evaluation areas P2 and P3) (step S12), and then the AF evaluation area in which the dimensions of the AF evaluation area are set in advance. Larger than the maximum dimension that can be set as (for example, for a low resolution image data L composed of horizontal x vertical: 40 x 30 pixels, the maximum horizontal width Xmax is 8 pixels and the maximum vertical width Ymax is 6 pixels) Whether or not (step S13). If it is determined in step S10 that the AF evaluation area does not protrude from the end of the captured image (step S10; NO), the area setting unit 7e shifts the process to step S12 and thereafter. Perform the process.

  If it is determined in step S13 that the AF evaluation area (for example, AF evaluation areas P2 and P3) is larger than the maximum dimension (step S13; YES), the area setting unit 7e is already placed in the AF. Instead of the evaluation area, the AF evaluation area of the maximum size is arranged so as not to shift the center coordinates (step S14). That is, since the size of the subject of interest (for example, the subjects of interest S2 and S3) is large, even if a plurality of divided AF evaluation regions are set for the subject of interest, the size of each AF evaluation region becomes large. There is a possibility that the contrast evaluation in the AF evaluation area cannot be properly performed. In this case, by resetting the AF evaluation area having the maximum dimension, the AF evaluation areas are not adjacent to each other, but the contrast evaluation in the AF evaluation area can be appropriately performed.

  Next, the area determination unit 7f of the AF processing unit 7 selects a subject of interest (for example, for example, from within each AF evaluation area for a plurality of AF evaluation areas (for example, AF evaluation areas P2 and P3) set by the area setting unit 7e. After detecting the image region (target subject region) of the subject of interest S2, S3 (step S15), it is determined whether or not the subject subject region includes a predetermined ratio (for example, 50%) or more (step S16). Also, when it is determined in step S13 that the AF evaluation area is not larger than the maximum dimension (step S13; NO), the area determination unit 7f shifts the process to step S15 and performs the subsequent processes. Do.

  If it is determined in step S16 that the target subject area does not include a predetermined ratio or more (step S16; NO), the evaluation target exclusion unit 7g of the AF processing unit 7 includes a plurality of AF evaluation areas (for example, AF Among the evaluation areas P2 and P3), an AF evaluation area that does not include the target subject area in a predetermined ratio or more is set as an invalid AF frame and excluded from the evaluation target (step S17). On the other hand, when it is determined that the target subject area is included at a predetermined ratio or more (step S16; NO), the evaluation target exclusion unit 7g of the AF processing unit 7 includes the target subject area at a predetermined ratio among the plurality of AF evaluation areas. The AF evaluation area including the above is set as an effective AF frame (step S18).

  Next, the central control unit 14 displays AF frame displays F2 and F3 (FIG. 6C and FIG. 7) corresponding to the edge portions of the AF evaluation areas (for example, AF evaluation areas P2 and P3) set in the effective AF frame. (See (c) etc.) is displayed on the display unit 9 in accordance with the shape of the subject of interest (for example, the subject of interest S2, S3) of the live view image (step S19), and the evaluation value calculator 7h of the AF processor 7 Based on the AF evaluation value calculated based on the image data of the AF evaluation area, which is an effective AF frame, a predetermined control signal is output to the lens driving unit 2 to drive the focus motor, so that the focusing of the lens unit 1 is achieved. Adjust the focal position.

Therefore, according to the above-described automatic focusing process, for example, as shown in FIGS. 5A to 5D, when a “flower” or the like is photographed in a macro, the central portion of the “petal” is displayed. Even if the size of the rectangular frame W that is extracted as the subject of interest S1 and surrounds the image region A1 of the subject of interest S1 is not larger than the minimum size of the AF evaluation region, the AF evaluation region P1 having the minimum size (FIG. 5C). One reference) is set, and the AF frame display F1 (see FIG. 5D) corresponding to the edge portion of the AF evaluation area P1 having the smallest dimension is displayed so as to overlap the target subject S1 in the live view image.
On the other hand, for example, as shown in FIGS. 6A to 6D, the subject has no contrast as in an environment where a “white ball” such as a ping-pong ball is photographed outdoors on a sunny day. Even in this case, after detecting “white ball” as the subject of interest S2 and determining the set number of AF evaluation regions P2 from the aspect ratio Rate of the rectangular frame W surrounding the image region A2 of the subject of interest S2, each AF The dimension of the evaluation region P2 can be calculated. Then, four 2 × 2 type AF evaluation areas P2 are set so as to be adjacent to each other according to the shape of the image area A2 of the subject of interest S2 (see FIG. 6C), and at the edge of the AF evaluation area P2. Four corresponding AF frame displays F2 (see FIG. 6D) are displayed so as to overlap the subject of interest S2 in the live view image.
Further, for example, as shown in FIGS. 7A to 7D, even if the composition has a subject (for example, “stacked multiple dice”) at the end, the “plural dice” is displayed. It can be detected as the subject of interest S3, and similarly to the above, four 1 × 4 type AF evaluation regions P3 are set to be adjacent to each other according to the shape of the image region A3 of the subject of interest S3 (FIG. 7 ( c), and four AF frame displays F3 (see FIG. 7D) corresponding to the edge portion of the AF evaluation area P3 are displayed so as to overlap with the target subject S3 in the live view image.

As described above, according to the imaging apparatus 100 of the present embodiment, the target subject (for example, the target subjects S1, S2, and S3) to be focused in the captured image (for example, the captured images G1, G2, and G3). The shape of the image area (for example, image areas A1, A2, A3) is specified, and a plurality of AF evaluation areas (for example, AF evaluation areas P2, P3) are set according to the shape of the image area of the subject of interest, Based on the image data in these AF evaluation areas, the lens unit 1 can be focused. That is, in the automatic focusing process, the shape of the image area of the target object is sequentially specified, and a plurality of AF evaluation areas are sequentially set in accordance with the shape of the image area of the target object that has been sequentially specified. Even when a different subject of interest is used as an AF target, an AF area can be prevented from being set in a low-contrast portion, and a large AF area can be set to include the entire subject of interest. It is possible to prevent the contrast gradient in the image data in the AF evaluation area from becoming gradual as in the case of doing.
Therefore, the accuracy of the automatic focusing process can be improved by a plurality of AF evaluation areas set in accordance with the shape of the image area of the subject of interest.

  In addition, the size of the image area (for example, image areas A1, A2, and A3) of the target subject (for example, target objects S1, S2, and S3) is the minimum dimension of the AF evaluation area (for example, AF evaluation areas P1, P2, and P3). Is larger than the rectangular AF evaluation areas P2 and P3, and when the size of the image area of the subject of interest is equal to or smaller than the minimum dimension of the AF evaluation area, the AF evaluation of the minimum dimension is performed. Since one area P1 is set, the AF evaluation area can be set appropriately regardless of the size of the image area of the subject of interest.

  Further, according to the ratio of the vertical direction and the horizontal direction of the image area (for example, the image areas A1, A2, and A3) of the target object (for example, the target objects S1, S2, and S3), that is, the shape of the image area of the target object. The number of AF evaluation areas set in the vertical and horizontal directions is determined according to the dimensions of the rectangular frame W set as the temporary shape of the image area of the subject of interest based on the dimensions of the subject area. The number of AF evaluation areas set can be changed according to the shape and dimensions, and a plurality of AF evaluation areas can be set appropriately.

In addition, the shape and size of the image area (for example, the image areas A1, A2, and A3) of the target object (for example, the target objects S1, S2, and S3) and the AF evaluation area (for example, the AF evaluation areas P1, P2, and P3). Since the size of the AF evaluation area is calculated based on the set number in the vertical direction and the horizontal direction, it depends on the shape of the image area of the subject of interest, the size of the image area, and the set number in the vertical and horizontal directions of the AF evaluation area. Thus, the dimension of the AF evaluation area can be changed, and a plurality of AF evaluation areas can be set appropriately.
The size of the AF evaluation area may be calculated on the basis of the number of AF evaluation areas set in the vertical and horizontal directions, and does not necessarily have to be based on the shape and size of the image area of the subject of interest.

  Further, a plurality of AF evaluation areas (for example, set in accordance with a rectangular frame W as a temporary shape of an image area (for example, the image areas A1, A2, A3) of the target object (for example, the target objects S1, S2, S3) , AF evaluation areas P1, P2, and P3), when the image area of the subject of interest is not included in a predetermined ratio or more, the AF evaluation area is excluded from the evaluation target. Therefore, the rectangular frame W surrounding the image area of the subject of interest AF evaluation areas that do not correspond to the image area of the subject of interest can be set as invalid AF frames and excluded from the evaluation object, and AF evaluation corresponding to the image area of the subject of interest Only an area can be set as an effective AF frame, and a plurality of AF evaluation areas can be set appropriately.

The present invention is not limited to the above-described embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention.
For example, in setting the AF evaluation area by the area setting unit 7e, the AF evaluation area may be arranged so as to intersect with the contour portion of the image area of the subject of interest. That is, even if the subject of interest itself has a low contrast, since there is a contrast difference at least at the boundary between the subject of interest and the other parts, a more appropriate AF evaluation value can be calculated by the evaluation value calculator 7h. Thus, the automatic focusing process can be performed more appropriately.

Further, in specifying the image area of the subject of interest, low-resolution image data L is generated from the image data sent from the unit circuit 4, and the image data L is used. It is not necessary to generate the resolution image data L, and the image data itself sent from the unit circuit 4 may be used.
Furthermore, the shape and size of the image area of the subject of interest are specified, but the present invention is not limited to this, and at least if the shape of the image area of the subject of interest is specified, whether or not the size is specified is arbitrarily determined as appropriate. Can be changed.

  Further, although the central control unit 14 and the lens driving unit 2 are illustrated as the focus control means, the present invention is not limited to this, and a driving mechanism (not shown) for moving the electronic imaging unit 3 in the optical axis direction is provided. The drive mechanism may be driven under the control of the central control unit 14.

  Further, the configuration of the imaging apparatus 100 is merely an example illustrated in the above-described embodiment, and is not limited thereto. The configuration of the imaging device 100 includes at least an imaging unit, a specifying unit, a region setting unit, and a focusing control unit. It can be arbitrarily changed as appropriate.

In addition, in the above-described embodiment, the functions as the specifying unit, the region setting unit, and the focusing control unit are realized by driving the AF processing unit 7 under the control of the central control unit 14. However, the present invention is not limited to this, and a configuration realized by executing a predetermined program or the like by the central control unit 14 may be adopted.
That is, a program including a specific processing routine, an area setting processing routine, and a focusing control processing routine is stored in the program memory 13 that stores the program. Then, the CPU of the central control unit 14 causes the CPU of the central control unit 14 to execute a specific processing routine so as to focus an object to be focused in the captured images (for example, captured images G1, G2, and G3) (for example, the focused objects S1 and S2). , S3) may be made to function as specifying means for specifying the shape of the image area (for example, the image areas A1, A2, A3). In addition, the CPU of the central control unit 14 in the area setting process routine causes the CPU of the image area (for example, image areas A1, A2, and A3) of the target object (for example, the target objects S1, S2, and S3) specified by the specifying process routine. You may make it function as an area | region setting means which sets several contrast evaluation area | regions according to a shape. Further, the focusing control processing routine may cause the imaging unit to function as a focusing control unit based on the image data in the contrast evaluation region set by the region setting processing routine.

DESCRIPTION OF SYMBOLS 100 Imaging device 1 Lens part 2 Lens drive part 3 Electronic imaging part 7 AF process part 7a Image area specific | specification part 7b Size determination part 7c Division number determination part 7d Dimension calculation part 7e Area setting part 7f Area determination part 7g Evaluation object exclusion part 14 Central control unit

To solve the above problem, an imaging apparatus of the present invention includes an imaging means, specifying means for specifying the shape of the image region of interest subject to be the focusing target in the captured image captured by the imaging means, a plurality of the contrast evaluation region, a region setting unit that sets side by side according to the shape of the image area of the target object specified by the specifying means, on the basis of the image data of the contrast evaluation region set by the region setting means, The focus control means for focusing the imaging means, and the vertical of a plurality of contrast evaluation areas set side by side by the area setting means according to the ratio of the vertical and horizontal lengths of the image area of the subject of interest Determining means for determining the set number of directions and horizontal directions .

Further, as a preferred aspect, the area setting means sets a plurality of contrast evaluation areas having the same shape adjacent to each other, and the determination means sets the length of the image area of the subject of interest in the vertical direction and the horizontal direction. According to the ratio, the number of sets in the vertical direction and the horizontal direction of a plurality of contrast evaluation regions set adjacently by the region setting means is determined.

Further, as a preferred aspect, the specifying means further specifies the size of the image area of the target object, and the determining means is a temporary contrast evaluation set based on the shape and size of the image area of the target object. The set number of the vertical direction and the horizontal direction of the contrast evaluation region is determined according to the size of the region.

Moreover, as a preferable aspect, the image processing apparatus further includes a calculation unit that calculates a dimension of the contrast evaluation region according to the number of vertical and horizontal settings of the contrast evaluation region determined by the determination unit. .

Further, as a preferred aspect, the specifying means further specifies the size of the image area of the subject of interest, and the calculating means is determined by the shape and size of the image area of the subject of interest and the determining means. The size of the contrast evaluation area is calculated based on the set number of vertical and horizontal directions of the contrast evaluation area.

In a preferred aspect, the area setting means sets a plurality of rectangular contrast evaluation areas adjacent to each other.

Further, as a preferred aspect, the area setting means sets the contrast evaluation area so as to intersect with a contour portion of the image area of the subject of interest.

Further, as a preferred aspect, the specifying means sequentially specifies the shape of the image area of the subject of interest, and the area setting means is adapted to match the shape of the image area of the subject of interest sequentially specified by the specifying means. A plurality of contrast evaluation areas are sequentially set.

Further, as a preferable aspect, the focus control unit has a detection accuracy of a contrast gradient of image data in each evaluation region out of the plurality of contrast evaluation regions set by the region setting unit, a predetermined value or more, In addition, the imaging unit is focused by using an output result of a contrast evaluation region having a contrast peak at the closest distance from the imaging device.

In addition, an imaging apparatus according to another aspect is specified by an imaging unit, a specifying unit that specifies a shape of an image area of a subject of interest to be focused in a captured image captured by the imaging unit, and the specifying unit. An area setting means for setting a plurality of contrast evaluation areas according to the shape of the image area of the subject of interest, and the contrast of image data in each evaluation area among the plurality of contrast evaluation areas set by the area setting means A focus control means for focusing the imaging means by adopting an output result of a contrast evaluation region having a gradient detection accuracy equal to or higher than a predetermined value and having a contrast peak at the closest distance from the imaging device; It is characterized by providing.

In order to solve the above problems, a focusing method of the present invention is a focusing method using an imaging device, and is focused on a computer in the imaging device as a focusing target in a captured image captured by an imaging unit. A specifying process for specifying the shape of the image area of the subject, an area setting process for setting a plurality of contrast evaluation areas in line with the shape of the image area of the subject of interest specified by the specifying process, and the area setting process Based on the image data in the contrast evaluation area set by the focusing control processing for focusing the imaging means, and the ratio of the vertical and horizontal lengths of the image area of the subject of interest, And a determination process for determining a set number in the vertical direction and a horizontal direction of a plurality of contrast evaluation areas set side by side by the area setting process.

In order to solve the above problems, a program according to the present invention is a program for controlling an imaging device, and the computer of the imaging device is used to cause an image region of a subject of interest to be focused in a captured image captured by an imaging unit. Specifying means for specifying the shape of the object, area setting means for setting a plurality of contrast evaluation areas in line with the shape of the image area of the subject of interest specified by the specifying means, and the area setting means Based on the image data in the contrast evaluation area, the focusing control means for focusing the imaging means, and the area setting means according to the ratio of the vertical and horizontal lengths of the image area of the subject of interest. It functions as a determining means for determining the number of vertical and horizontal setting numbers of a plurality of contrast evaluation areas set side by side. To.

Claims (14)

Imaging means;
Specifying means for specifying the shape of the image area of the subject of interest to be focused in the captured image captured by the imaging means;
Area setting means for setting a plurality of contrast evaluation areas in accordance with the shape of the image area of the target object specified by the specifying means;
A focusing control means for focusing the imaging means based on the image data in the contrast evaluation area set by the area setting means;
An imaging apparatus comprising:   The imaging apparatus according to claim 1, wherein the area setting unit sets a plurality of rectangular contrast evaluation areas adjacent to each other.   The apparatus further comprises a determining unit that determines the number of the vertical and horizontal settings of the contrast evaluation region that are set adjacent to each other in accordance with the ratio of the vertical and horizontal lengths of the image area of the subject of interest. The imaging apparatus according to claim 2. The specifying means further specifies the size of the image area of the subject of interest,
The determining means includes
4. The number of set in the vertical direction and the horizontal direction of the contrast evaluation area is determined according to the size of the temporary contrast evaluation area set based on the shape and size of the image area of the subject of interest. The imaging device described in 1.   5. The calculation device according to claim 3, further comprising a calculation unit configured to calculate a dimension of the contrast evaluation region in accordance with the set number in the vertical direction and the horizontal direction of the contrast evaluation region determined by the determination unit. Imaging device. The specifying means further specifies the size of the image area of the subject of interest,
The calculating means includes
The size of the contrast evaluation area is calculated based on the shape and size of the image area of the subject of interest and the set number in the vertical and horizontal directions of the contrast evaluation area determined by the determining means. The imaging device according to claim 5. The specifying means further specifies the size of the image area of the subject of interest,
Dimensional determination means for determining whether or not the size of the image area of the subject of interest is larger than a minimum dimension that can be set as the contrast evaluation area;
The area setting means includes
As a result of the determination by the dimension determining means, when the size of the image area of the target object is larger than the minimum dimension of the contrast evaluation area, a plurality of contrast evaluation areas are set, while the size of the image area of the target object is The imaging apparatus according to claim 1, wherein when the size is equal to or smaller than a minimum dimension of the contrast evaluation area, one contrast evaluation area is set. Subject setting means for setting a minimum rectangle surrounding the image area of the target object as a temporary shape of the image area of the target object;
Whether a plurality of contrast evaluation regions set by the region setting unit according to the temporary shape of the image region of the target subject set by the subject setting unit include the image region of the target subject at a predetermined ratio or more. Area determination means for determining
An exclusion means for excluding a contrast evaluation area that is determined not to include an image area of the subject of interest of a predetermined ratio or more by the area determination means from the evaluation target among the plurality of contrast evaluation areas; The imaging device according to any one of claims 1 to 7.   The imaging apparatus according to claim 1, wherein the area setting unit sets the contrast evaluation area so as to intersect with a contour portion of an image area of the subject of interest. The specifying means sequentially specifies the shape of the image area of the subject of interest,
The said area setting means sets a some contrast evaluation area | region sequentially according to the shape of the image area | region of the said to-be-photographed object sequentially specified by the said specifying means, The any one of Claims 1-9 characterized by the above-mentioned. The imaging device described. The focusing control means includes
Among the plurality of contrast evaluation regions set by the region setting means, the contrast accuracy of the image data in each evaluation region is equal to or higher than a predetermined value, and a contrast peak is displayed at the closest distance from the imaging device. The imaging apparatus according to claim 1, wherein the imaging unit is focused using an output result of a contrast evaluation area having the imaging apparatus.   The imaging according to any one of claims 1 to 11, wherein the area setting means sets the contrast evaluation area in preference to a vertical direction with respect to a horizontal direction of an image area of the subject of interest. apparatus. A focusing method using an imaging device including an imaging means,
Processing for specifying the shape of the image area of the subject of interest to be focused in the captured image captured by the imaging means;
A process of setting a plurality of contrast evaluation areas in accordance with the shape of the identified image area of the subject of interest;
A process of focusing the imaging means based on the image data within the set contrast evaluation area;
Focusing method characterized by performing. A computer of an imaging apparatus comprising imaging means;
A specifying unit for specifying a shape of an image area of a subject of interest to be focused in a captured image captured by the imaging unit;
Area setting means for setting a plurality of contrast evaluation areas in accordance with the shape of the image area of the target object specified by the specifying means;
Focusing control means for focusing the imaging means based on image data in the contrast evaluation area set by the area setting means;
A program characterized by functioning as

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