JP2007178480A - Digital camera, automatic focusing method and automatic focusing program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital camera capable of preventing a focusing accuracy from beimg degraded due to conflict of perspective and also preventing the focusing accuracy from being degraded due to camera shake and noise, and to provide an automatic focusing method and an automatic focusing program. <P>SOLUTION: An image signal processing circuit 12 calculates a first evaluated value for the focus adjustment of an image-forming optical system, based on the image signal of a first area in a picked-up image, and also calculates a second evaluated value, based on the image signal of a second area included in the first area and made smaller than the first area. The focusing position calculation part 19a of a CPU 19 calculates a first focusing position of the image-formation optical system based on the first evaluated value, and also calculates a second focusing position of the image-formation optical system, based on the second evaluated value. The reliability decision part 19c thereof decides whether the perspective conflict occurs in the first area and also decides on the reliability of the second focusing position. The focusing position selection part 19f thereof selects either the first focusing position or the second focusing position. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention calculates an in-focus position of an image forming optical system based on an image signal generated by photoelectric conversion of a subject image formed by an image forming optical system, and forms an image forming optical based on the calculated in-focus position. The present invention relates to a digital camera that performs system focusing and an automatic focusing method. The present invention also relates to an automatic focus adjustment program for causing a computer to execute the process related to the focus adjustment.

  As an autofocus (AF) method for adjusting the focus of a photographing lens of a digital camera, a subject image is photoelectrically converted by an image sensor such as a CCD to generate an image signal. A method is known in which an AF evaluation value, which is a contrast value of an image, is calculated by extracting a component, and the in-focus position of the photographing lens is detected based on the AF evaluation value. In this method, an AF evaluation value is calculated at each position (focus position) of the focus lens while moving the focus lens in the optical axis direction, and a position where the AF evaluation value is maximized is detected as a focus position.

  In order to avoid a decrease in focusing accuracy due to camera shake or noise, it is generally desirable to increase the AF area. However, when the AF area is increased, AF evaluation value peaks corresponding to both the subject that the photographer pays attention to and the subject farther from the subject appear, and these peaks compete to focus accuracy. It becomes easy to generate near-far competition that decreases. In order to avoid a decrease in focusing accuracy due to this distance conflict, it is generally desirable to reduce the AF area. However, if the AF area is reduced, focusing accuracy is likely to be reduced due to pseudo focusing in which focusing is detected at a pixel different from the original focused pixel due to camera shake or noise.

Details of the conventional autofocus technique are described in Patent Document 1 and Patent Document 2, for example. Japanese Patent Application Laid-Open No. 2004-151561 describes a technique for determining a distance measurement value of an area where the subject distance is the shortest among a plurality of areas as a main subject distance in order to avoid perspective conflict. Further, in Patent Document 2, in order to avoid erroneous determination due to camera shake or the like, it is assumed that the main subject extends over a plurality of areas for subject distance calculation, and a subject at an extremely close distance is detected in a single area. A technique for not adopting the subject distance of the area is described.
JP 2003-215437 A JP 2003-195152 A

  However, the technique described in Patent Document 1 has a problem that erroneous distance measurement may occur due to camera shake or the like. In addition, the technique described in Patent Document 2 has a problem that when the subject is at a long distance, there is a high possibility that the subject does not extend over a plurality of areas, and erroneous determination due to camera shake cannot be avoided. Thus, in the past, there has been no solution to both the reduction in focusing accuracy due to camera shake and noise and the reduction in focusing accuracy due to perspective conflict.

  The present invention has been made in view of the above-described problems, and avoids a decrease in focusing accuracy due to perspective conflict, and a digital camera and automatic focus adjustment that can avoid a decrease in focusing accuracy due to camera shake and noise. It is an object to provide a method and an autofocus program.

  The present invention has been made in order to solve the above-described problems, and determines the in-focus position of the imaging optical system based on an image signal generated by photoelectrically converting a subject image formed by the imaging optical system. In a digital camera that calculates and adjusts the focus of the imaging optical system based on the calculated in-focus position, a first focus adjustment for the focus of the imaging optical system is performed based on the image signal of the first region in the captured image. Evaluation value calculating means for calculating a first evaluation value and calculating a second evaluation value based on an image signal of a second area smaller than the first area included in the first area; A first in-focus position of the imaging optical system is calculated based on the evaluation value, and a second in-focus position of the imaging optical system is calculated based on the second evaluation value. A distance determining unit that determines whether or not a perspective conflict occurs in the first area; Based on the determination results of the competition determination means, the reliability determination means for determining whether or not the second in-focus position is reliable, the first focus based on the determination results of the distance competition determination means and the reliability determination means A focus position selection unit that selects any one of the position and the second focus position, and the focus position selection unit uses the first region by the perspective conflict determination unit. Selecting the second in-focus position when it is determined that there is a perspective conflict and the reliability determining means determines that the second in-focus position is reliable. It is a featured digital camera.

  As described above, the digital camera of the present invention can focus either one of the in-focus position obtained from the AF evaluation value of the normal area and the in-focus position obtained from the AF evaluation value of the small area. Since it is configured to select the position, if you want to suppress the degradation of focusing accuracy due to camera shake and noise, select the normal area focusing position, and if you want to suppress the degradation of focusing accuracy due to perspective conflict Makes it possible to select the focus position of the small area.

  According to the present invention, it is possible to obtain an effect that it is possible to avoid a decrease in focusing accuracy due to perspective competition and to avoid a decrease in focusing accuracy due to camera shake or noise.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of a digital camera according to an embodiment of the present invention. The zoom lens 1, the iris 2, and the focus lens 3 form an imaging optical system that forms an image of incident subject light. The position of the zoom lens 1 can be moved by a zoom motor 5. The opening degree of the iris 2 can be controlled by the iris motor 6. The position of the focus lens 3 can be controlled by the focus motor 7. The zoom motor 5 is driven by a motor driver 16, the iris motor 6 is driven by a motor driver 17, and the focus motor 7 is driven by a motor driver 18. The subject image light that has passed through the zoom lens 1, the iris 2, and the focus lens 3 forms an image on the light receiving surface of the image sensor 4.

  The image sensor 4 photoelectrically converts a subject image formed on the light receiving surface and outputs an image signal based on the subject image. As the image sensor 4, a CCD (Charge Coupled Device) sensor or a CMOS (Complementary MOS) sensor is used. The image sensor 4 is driven by a timing signal from the timing generator 8. A CDS (Corelated Double Sampling) / AGC (Automatic Gain Control) circuit 9 removes a noise component contained in the image signal output from the image sensor 4 and amplifies the image signal.

  The image signal processed by the CDS / AGC circuit 9 is input to the A / D converter 10 and converted into a digital signal by the A / D converter 10. The digitized image signal is captured by the image input controller 11 and stored in a memory 20 such as an SDRAM (Synchronous Dynamic Random Access Memory). The image signal processing circuit 12 performs image processing such as gamma correction, edge enhancement, and white balance processing on the captured image signal, and extracts a high-frequency component of the image signal in a predetermined area in the captured image. An AF evaluation value is calculated by integration.

  In the present embodiment, the AF area (area to be focused) in the captured image for calculating the AF evaluation value is included in the normal area (first area) and the normal area, which is more than the normal area. A small area (second region) having a small size is provided. The image signal processing circuit 12 calculates an AF evaluation value (first evaluation value) based on the normal area image signal, and calculates an AF evaluation value (second evaluation value) based on the small area image signal. To do.

  The compression / decompression processing circuit 13 compresses and encodes the image signal processed by the image signal processing circuit 12 when recording a captured image. The compression / decompression processing circuit 13 decompresses an image signal that has been compression-encoded and recorded on the recording medium 23 when reproducing the recorded image. An LCD (Liquid Crystal Display) driver 14 generates a component color video signal based on the image signal. The generated color video signal is developed in a VRAM (Video RAM) 21. This color video signal is output to a display device 15 such as an LCD. The display device 15 displays a captured image based on the image signal. The display device 15 is disposed on the back surface of the digital camera, for example.

  The CPU 19 controls the entire digital camera. When recording a photographed image, the image signal compressed and encoded by the compression / expansion processing circuit 13 is supplied to a recording medium 23 such as a flash memory via the media controller 22 and is recorded on the recording medium 23. When reproducing the recorded image, an image signal is read from the recording medium 23 and supplied to the compression / expansion processing circuit 13 via the media controller 22 to perform expansion processing. The operation member 24 includes a cross key (up / down / left / right key), a power switch, a shutter switch, a mode dial, and the like.

  The CPU 19 has various functions to control various processes executed in the digital camera, but only typical functions related to the AF process are listed below. The CPU 19 includes a focus position calculation unit 19a, a captured image magnification calculation unit 19b, a reliability determination unit 19c, a subject luminance detection unit 19d, a zoom focal length detection unit 19e, which are functional configurations that execute specific processing related to AF processing. And an in-focus position selector 19f.

  The focus position calculation unit 19a calculates a focus position from the AF evaluation value calculated by the image signal processing circuit 12. The in-focus position is calculated separately from both the AF evaluation value obtained from the normal area image signal and the AF evaluation value obtained from the small area image signal. The photographed image magnification calculator 19b calculates β of the subject (image magnification = focal length of the zoom lens / subject distance). The focal length of the zoom lens is stored in a ROM (Read Only Memory) (not shown) or the like, and the focal length corresponding to the zoom lens 1 is read by the zoom focal length detection unit 19e.

  The reliability determination unit 19c determines the reliability of the focus position (focus result) calculated by the focus position calculation unit 19a, particularly the focus position in a small area. Further, the reliability determination unit 19c determines whether the normal area is based on the result of comparing the focus position in the normal area (first focus position) and the focus position in the small area (second focus position). It also has a function of determining whether or not perspective conflict has occurred. The subject brightness detection unit 19d calculates the brightness value of the subject by a known method based on the image signal. The focus position selection unit 19f selects one of the focus positions in the normal area and the focus positions in the small area as the final focus position.

  Next, the operation of the digital camera according to the present embodiment will be described while focusing on the calculation method of the in-focus position. When the power switch of the operation member 24 is operated and the power of the digital camera is turned on, the CPU 19 outputs a control signal for starting imaging to each unit and controls its operation. In the still image recording mode, image signals are output from the image sensor 4 at regular intervals (for example, at intervals of 1/30 seconds). The image signal is subjected to A / D conversion, the above-described image processing, and the like, and an image is displayed on the display device 15.

  When the shutter switch of the operation member 24 is half-pressed by the photographer, the CPU 19 detects a half-press operation of the shutter switch based on a signal output from the operation member 24. AF (Video AF) operation is started by half-pressing the shutter switch. The CPU 19 outputs a control signal to the motor driver 18 to drive the focus motor 7 and move the focus lens 3 in the optical axis direction at a constant speed. In conjunction with this operation, the image signal processing circuit 12 calculates an AF evaluation value from each of the normal area image signal and the small area image signal.

  FIG. 2 shows the positions of the normal area and the small area. Normal areas 201a and 201b are arranged substantially at the centers of the captured images 200a and 200b formed by the image signal output from the image sensor 4. In addition, small areas 202a and 202b having an area smaller than that of the normal area are arranged approximately at the center of each normal area. After the shutter switch is half-pressed, until the shutter switch is fully pressed, only the normal area frame is displayed on the display device 15 and the small area frame is not displayed in consideration of user convenience. When the focus position of the small area is selected as the final focus position, a frame of the small area may be displayed.

  The shape of the displayed frame is not limited to a quadrangle as shown in FIG. Further, the display of the frame is not limited to the display with a solid line, and the frame may be displayed with a broken line or the like. Furthermore, instead of displaying the entire rectangle, for example, as a frame, only the apexes may be displayed. If the photographer can visually recognize at least the position and size of the normal area, the display method is limited to the above. It is not done.

  FIG. 3 shows an example of the calculation result of the AF evaluation value. The horizontal axis indicates the position of the focus lens 3 (focus position), and the vertical axis indicates the AF evaluation value. Each AF evaluation value and the focus position are stored in the memory 20 in association with each other. The image when the maximum AF evaluation value among the calculated AF evaluation values is obtained is an in-focus image, and the focus position corresponding to the AF evaluation value is finally the focus lens. 3 is an in-focus position to be moved. The focus position calculation unit 19a of the CPU 19 calculates the focus position of each of the normal area and the small area based on the information on the correspondence between the AF evaluation value and the focus position.

  Then, the in-focus position calculation unit 19a uses subject data corresponding to the in-focus positions of the normal area and the small area, using data indicating the correspondence between the focus position and the subject distance, which is recorded in advance in a ROM or the like. Is also calculated. The data indicating the correspondence between the focus position and the subject distance is usually adjusted at the time of shipment from the factory in order to calibrate variations due to individual differences among digital cameras. In response to the calculation result of the in-focus position by the in-focus position calculating unit 19a, the in-focus position selecting unit 19f selects one of the in-focus position in the normal area and the in-focus position in the small area. Is selected as the final focus position. Details of this processing will be described later. Further, the CPU 19 outputs a control signal to the motor driver 18 to drive the focus motor 7 and move the focus lens 3 to this in-focus position.

  When the shutter switch changes from being half-pressed to being fully depressed, the CPU 19 outputs a control signal for photographing and recording an image to each unit and controls its operation. Under the control of the CPU 19, an image signal for one screen is output from the image sensor 4, and after noise removal, amplification processing, A / D conversion, and the like are performed, the image signal is stored in the memory 20. The image signal stored in the memory 20 is subjected to image processing such as gamma correction and compression encoding, and then the image signal is recorded on the recording medium 23.

  Hereinafter, the final method for determining the in-focus position will be described with reference to the flowchart shown in FIG. In FIG. 4, only the determination process necessary for determining the in-focus position is shown, but information necessary for each determination process only needs to be obtained before each determination process, and each information is obtained. The process is not specifically shown.

  First, determination processing related to luminance is performed using the subject luminance calculated by the subject luminance detection unit 19d of the CPU 19. The reliability determination unit 19c compares the subject brightness (calculated from at least one of the normal area image signal and the small area image signal) with a predetermined determination brightness value, and determines whether the subject brightness is equal to or less than the determination brightness value. And the determination result is notified to the in-focus position selection unit 19f (step S401). The level of the determination luminance value is a level at which the influence of noise starts to appear in a small area. For example, BV (Brightness Value) = 0 is used as the determination luminance value. When the subject brightness is equal to or less than the determination brightness value, the focus position selection unit 19f adopts the focus position of the normal area as the final focus position (step S407). This is because when the image is dark, the influence of the reduction in focusing accuracy due to noise is large.

  When the subject brightness exceeds the determination brightness value, a determination process related to the subject β calculated by the captured image magnification calculation unit 19b is performed. The captured image magnification calculation unit 19b calculates β in advance based on the calculation result of the subject distance in the normal area and the focal length of the zoom lens 1 detected by the zoom focal length detection unit 19e. The reliability determination unit 19c determines whether or not the calculated β exceeds a predetermined value, and notifies the focus position selection unit 19f of the determination result (step S402). This predetermined value is the value of β which is the limit at which a human (face) can sufficiently cover a normal area when a human is assumed to be a subject. FIG. 2A shows an example of an image when β is large, and FIG. 2B shows an example of an image when β is small.

  When β is large, perspective conflict is less likely to occur, and when β is small, perspective conflict is likely to occur. In step S402, when β exceeds a predetermined value, the reliability determination unit 19c determines that the subject (such as a person) is in focus and no perspective conflict has occurred, and the focus position selection unit 19f The focus position in the normal area with high reliability is adopted as the final focus position (step S407). Here, it is assumed that the subject is a human, but since the subject is not limited to a human, step S402 may be omitted.

  When β is equal to or smaller than a predetermined value, a determination process related to the focusing result of the normal area and the small area is performed. The reliability determination unit 19c calculates the difference between the focus position of the normal area and the focus position of the small area (absolute value of the difference), and whether the difference is equal to or less than a predetermined value (within the depth of field). And the determination result is notified to the in-focus position selection unit 19f (step S403). When the difference between the focus positions is equal to or less than the predetermined value, the focus position selection unit 19f determines that there is no influence due to the perspective conflict, and adopts the focus position in the normal area with high reliability as the final focus position. (Step S407).

  When the difference in focus position exceeds a predetermined value, a determination process related to the reliability of the focus result of the small area is performed. As an index indicating the reliability of the focus position in the small area, the slope before and after the peak value in the AF evaluation value graph (in other words, the absolute value of the slope, in other words, the peak value as a reference and the peak value before and after the peak value) Either or both of whether or not (deviation) exceeds a predetermined value and whether or not the AF evaluation value (particularly the peak value) itself exceeds a predetermined value are used. The reliability determination unit 19c determines the reliability of the focus position of the small area based on the above index. When the slope before and after the peak value of the AF evaluation value exceeds a predetermined value and / or when the value of the AF evaluation value exceeds a predetermined value, it is determined that the focus position of the small area is reliable, In this case, it is determined that the focus position of the small area is not reliable (step S404).

  When the focus position of the small area is not reliable, the focus position selection unit 19f determines that the error of the calculation result of the focus position of the small area is large, and finally determines the focus position of the normal area with high reliability. This is adopted as a specific focus position (step S407).

  When the focus position of the small area is reliable, the reliability determination unit 19c compares the subject distance of the normal area and the subject distance of the small area (or the focus position of the normal area and the focus position of the small area), It is determined whether the subject distance in the area is closer than the subject distance in the normal area. Thus, it is determined whether or not the focusing result in the normal area is affected by the background subject due to the perspective conflict (that is, the perspective conflict occurs in the normal area). The reliability determination unit 19c notifies the determination result to the focus position selection unit 19f (step S405).

  If the subject distance in the small area is closer than the subject distance in the normal area, the focusing result in the normal area is affected by the subject in the background due to perspective conflict (the perspective conflict occurs in the normal area). Is determined). In this case, the focus position selection unit 19f employs the focus position of a small area that is not easily affected by the perspective conflict as the final focus position (step S406). In other cases, the focus position selection unit 19f adopts the focus position of the normal area with high reliability as the final focus position (step S407). Note that the order in which the above-described determination processes are executed is not limited to the above, and may be changed as appropriate.

  Hereinafter, an example of an AF evaluation value in a typical case will be described with reference to FIG. FIG. 3A shows an example of the AF evaluation value in the case of low luminance. Compared with FIGS. 3B, 3C, and 3D, the AF evaluation value of FIG. 3A is generally low, and particularly the AF evaluation value of a small area is affected by noise. Appears. In this case, the focus position of the normal area with high reliability is selected as the final focus position. FIG. 3B shows an example of the AF evaluation value when the reliability of the AF evaluation value of the small area is low. Compared with FIGS. 3C and 3D, the peak value of the AF evaluation value is low, and the change of the AF evaluation value before and after the peak value is smooth. Also in this case, the focus position of the normal area with high reliability is selected as the final focus position.

  FIG. 3C shows an example of the AF evaluation value when the AF evaluation value of the small area is highly reliable and no near-far conflict occurs. The focus position corresponding to the peak value of the AF evaluation value of the normal area and the focus position corresponding to the peak value of the AF evaluation value of the small area are substantially the same position. FIG. 3D shows an example of the AF evaluation value when the AF evaluation value of the small area is highly reliable and the perspective conflict occurs. The focus position corresponding to the peak value of the AF evaluation value of the normal area is different from the focus position corresponding to the peak value of the AF evaluation value of the small area. When the subject distance of the small area is closer than the subject distance of the normal area, the focus position of the small area is selected as the final focus position, otherwise, the focus of the normal area is selected. The position is selected as the final focus position.

  As described above, the digital camera according to the present embodiment is based on at least the subject distance among the focus position obtained from the AF evaluation value of the normal area and the focus position obtained from the AF evaluation value of the small area. Thus, one of the in-focus positions is selected. In particular, if there is a perspective conflict where the subject distance in the small area is closer than the subject distance in the normal area, and the AF evaluation value of the small area can be trusted, the focus position of the small area is selected. Is done. In addition, when there is no perspective conflict or when the luminance is low, a focus position in the normal area with high reliability is selected.

  In this way, select the focus position in the normal area when you want to suppress the drop in focus accuracy due to camera shake or noise, and select the focus position in the small area when you want to suppress the drop in focus accuracy due to distance conflict. Since it is possible to select, it is possible to avoid a decrease in focusing accuracy due to perspective conflicts and to avoid a decrease in focusing accuracy due to camera shake or noise. Further, by comparing the subject distance of the small area and the subject distance of the normal area and determining the reliability of the AF evaluation value of the small area, it is possible to reliably detect the perspective conflict.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and includes design changes and the like without departing from the gist of the present invention. . For example, a plurality of small areas may be provided in the normal area, or a plurality of sets of normal areas and small areas may be provided on the captured image. Further, the above-described method may be applied to conventional SPOT AF.

  Further, by recording a program for realizing the operation and function of the digital camera according to the above-described embodiment on a computer-readable recording medium, and causing the computer to read and execute the program recorded on the recording medium, A desired function may be realized.

  Here, the “computer” includes a homepage providing environment (or display environment) if the WWW system is used. The “computer-readable recording medium” refers to a storage device such as a portable medium such as a flexible disk, a magneto-optical disk, a ROM, and a CD-ROM, and a hard disk built in the computer. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The above-described program may be transmitted from a computer storing the program in a storage device or the like to another computer via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. Further, the above-described program may be for realizing a part of the above-described function. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer, what is called a difference file (difference program) may be sufficient.

It is a block diagram which shows the structure of the digital camera by one Embodiment of this invention. It is a reference diagram showing an arrangement example of normal areas and small areas for AF evaluation value calculation in an embodiment of the present invention. It is a reference figure which shows the example of the calculation result of AF evaluation value in one Embodiment of this invention. It is a flowchart which shows the procedure of the determination method of the focus position in one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Zoom lens, 2 ... Iris, 3 ... Focus lens, 4 ... Image sensor, 5 ... Zoom motor, 6 ... Iris motor, 7 ... Focus motor, 8 * ..Timing generator, 9 ... CDS / AGC circuit, 10 ... A / D converter, 11 ... Image input controller, 12 ... Image signal processing circuit, 13 ... Compression / decompression processing circuit , 14 ... LCD driver, 15 ... display device, 16, 17, 18 ... motor driver, 19 ... CPU, 19a ... focus position calculation unit, 19b ... calculated image magnification calculation , 19c: Reliability determination unit, 19d: Subject luminance detection unit, 19e: Zoom focal length detection unit, 19f: Focus position selection unit, 20 ... Memory, 21 ... VRAM, 22. Controller, 23 ... recording media

Claims (11)

A focusing position of the imaging optical system is calculated based on an image signal generated by photoelectrically converting a subject image formed by the imaging optical system, and the imaging optical system is calculated based on the calculated focusing position. In a digital camera that adjusts the focus of
A first evaluation value for focus adjustment of the imaging optical system is calculated based on an image signal of the first region in the captured image, and a second smaller than the first region included in the first region. Evaluation value calculating means for calculating a second evaluation value based on the image signal of the region;
A first in-focus position of the imaging optical system is calculated based on the first evaluation value, and a second in-focus position of the imaging optical system is calculated based on the second evaluation value. Focusing position calculation means;
Perspective conflict determination means for determining presence / absence of occurrence of perspective conflict in the first region;
Reliability determination means for determining whether or not the second in-focus position is reliable;
An in-focus position for selecting one of the first in-focus position and the second in-focus position based on the determination results of the near-far conflict determination means and the reliability determination means A selection means;
With
The in-focus position selecting unit determines that the near-field conflict has occurred in the first region by the near-field conflict determining unit, and the second in-focus position is reliable by the reliability determining unit. The digital camera is characterized in that the second in-focus position is selected when it is determined.   The perspective conflict determination unit determines that perspective conflict has occurred in the first region when the second focus position is closer to the first focus position than the first focus position. The digital camera according to claim 1. Further provided is a photographing magnification detecting means for detecting a photographing magnification,
The perspective conflict determination unit determines that perspective conflict does not occur in the first region when the shooting magnification detected by the shooting magnification detection unit is equal to or greater than a predetermined value. Or the digital camera of Claim 2.   The said reliability determination means determines the presence or absence of the reliability of the said 2nd focus position based on the result of having compared the said 2nd evaluation value and predetermined value. Item 4. The digital camera according to any one of Items 3.   The reliability determination means detects a peak value in the second evaluation value group calculated for each position of the imaging optical system, and based on a deviation of the second evaluation value before and after the peak value, The digital camera according to claim 1, wherein presence or absence of reliability of the second in-focus position is determined.   The focus position selection unit selects the first focus position when the reliability determination unit determines that the second focus position is not reliable. The digital camera according to any one of claims 1 to 5.   The reliability determination unit is configured such that a difference between the first focus position and the second focus position is equal to or greater than a predetermined value, and the first focus position is more than the second focus position. The digital camera according to claim 6, wherein the second focus position is determined to be unreliable when located on a short distance side. A luminance value calculating means for calculating a luminance value based on at least one of the image signal of the first region and the image signal of the second region;
The reliability determination unit determines that the second in-focus position is not reliable when the luminance value calculated by the luminance value calculation unit is equal to or less than a predetermined value. Or the digital camera of Claim 7.   The display apparatus according to claim 1, further comprising: a display unit that displays an image based on the image signal and displays a frame of only the first region out of the first region and the second region. Item 9. The digital camera according to any one of Item 8. A focusing position of the imaging optical system is calculated based on an image signal generated by photoelectrically converting a subject image formed by the imaging optical system, and the imaging optical system is calculated based on the calculated focusing position. In the automatic focus adjustment method for performing focus adjustment of
A first evaluation value for focus adjustment of the imaging optical system is calculated based on an image signal of the first region in the captured image, and a second smaller than the first region included in the first region. A first process for calculating a second evaluation value based on the image signal of the region;
A first in-focus position of the imaging optical system is calculated based on the first evaluation value, and a second in-focus position of the imaging optical system is calculated based on the second evaluation value. A second process;
A third process for determining whether or not there is a perspective conflict in the first area;
A fourth process for determining whether or not the second in-focus position is reliable;
Based on the determination results in the third process and the fourth process, a fifth one that selects one of the first focus position and the second focus position is selected. And processing
Run
In the fifth process, it is determined that a perspective conflict has occurred in the first area in the third process, and the second focus position is determined to be reliable in the fourth process. In such a case, the second focus position is selected. A focusing position of the imaging optical system is calculated based on an image signal generated by photoelectrically converting a subject image formed by the imaging optical system, and the imaging optical system is calculated based on the calculated focusing position. In an automatic focus adjustment program for causing a computer to execute a process of performing the focus adjustment of
A first evaluation value for focus adjustment of the imaging optical system is calculated based on an image signal of the first region in the captured image, and a second smaller than the first region included in the first region. A first process for calculating a second evaluation value based on the image signal of the region;
A first in-focus position of the imaging optical system is calculated based on the first evaluation value, and a second in-focus position of the imaging optical system is calculated based on the second evaluation value. A second process;
A third process for determining whether or not there is a perspective conflict in the first area;
A fourth process for determining whether or not the second in-focus position is reliable;
Based on the determination results in the third process and the fourth process, a fifth one that selects one of the first focus position and the second focus position is selected. And processing
To the computer,
In the fifth process, it is determined that a perspective conflict has occurred in the first area in the third process, and the second focus position is determined to be reliable in the fourth process. In this case, the second focus position is selected.

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