Focus adjustment device, camera device, focus adjustment method and storage medium

Abstract

A focus adjustment device, an imaging device, a focus adjustment method, and a storage medium are provided. A selection unit repeatedly performs a selection process for selecting a main subject from one or more subjects included in a shooting range based on an auto focus (AF) setting. The focus adjustment unit performs a focus adjustment on an object position determined based on the selected main subject. A changing unit changes the AF setting. In a case where the AF setting is changed after the selection process was previously performed, the selection unit determines whether to perform the selection process based on the main subject selected in the previously performed selection process or to perform the selection process independently of the main subject selected in the previously performed selection process based on the changed content of the AF setting.

Description

Technical Field

[0001] The invention relates to a focus adjustment device, an imaging device, a focus adjustment method and a storage medium. Background Art

[0002] Image processing technology for automatically detecting a specific subject pattern (e.g., a human face region) from an image is known. An imaging device such as a digital camera detects a specific subject region from a captured image and optimizes AF and AE (focus and exposure) using the detected region as a control target. Therefore, being able to appropriately select a suitable subject (main subject) as a target for AF and AE control according to the user's intention is a very important element in determining the image quality of a captured image.

[0003] Japanese Patent Laid-Open No. 2010-141616 proposes a technique that involves calculating the priority of each detected subject based on the position or size or the nearest priority of the subject and determining the main subject. Thus, Japanese Patent Laid-Open No. 2010-141616 achieves more appropriate main subject selection that meets the user's intention.

[0004] The user can switch the setting when implementing AF control (hereinafter, auto focus (AF) setting) so as to perform AF tracking on a desired main subject. Examples of AF settings include an AF range setting for a range for performing AF control within a screen, a pupil AF setting for implementing AF control with the pupil of a subject as the target, a servo AF setting for implementing continuous AF control during shooting, and a priority subject setting for specifying the type of subject that is prioritized as an AF target.

[0005] However, with the technology of Japanese Patent Laid-Open No. 2010-141616, in the case where the AF setting is changed, there is a possibility that the main subject cannot be appropriately selected in a manner that matches the user's intention. Summary of the invention

[0006] The present invention has been made in consideration of these circumstances, and provides a technique for determining whether to select a main subject this time based on the main subject last time, or to select the main subject this time regardless of the main subject last time, according to the change content of AF setting.

[0007] According to a first aspect of the present invention, a focus adjustment device is provided, which includes: a selection unit, which is configured to repeatedly perform a selection process for selecting a main subject from one or more subjects included in a shooting range based on an autofocus setting, i.e., an AF setting; a focus adjustment unit, which is configured to perform focus adjustment on an object position determined based on the selected main subject; and a change unit, which is configured to change the AF setting, wherein, in a case where the AF setting is changed after the selection process was last performed, the selection unit determines whether to perform the selection process based on the main subject selected in the last selection process, or to perform the selection process regardless of the main subject selected in the last selection process, based on the change content of the AF setting.

[0008] According to a second aspect of the present invention, there is provided an image pickup apparatus including: the focus adjustment apparatus according to the first aspect; and an image sensor.

[0009] According to a third aspect of the present invention, there is provided a focus adjustment method performed by a focus adjustment device, which includes: repeatedly performing a selection process for selecting a main subject from one or more subjects included in a shooting range based on an autofocus setting, i.e., an AF setting; performing focus adjustment on an object position determined based on the selected main subject; changing the AF setting; and in a case where the AF setting is changed after the selection process was last performed, judging, based on the change content of the AF setting, whether to perform the selection process based on the main subject selected in the last selection process, or to perform the current selection process regardless of the main subject selected in the last selection process.

[0010] According to a fourth aspect of the present invention, a computer-readable storage medium is provided, which stores a program for causing a computer to execute a focus adjustment method, the focus adjustment method comprising: repeatedly executing a selection process for selecting a main subject from one or more subjects included in a shooting range based on an autofocus setting, i.e., an AF setting; performing focus adjustment on an object position determined based on the selected main subject; changing the AF setting; and in a case where the AF setting is changed after the selection process was last executed, judging, based on the change content of the AF setting, whether the selection process is to be executed based on the main subject selected in the last execution of the selection process, or to be executed independently of the main subject selected in the last execution of the selection process.

[0011] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figures 1A to 1C is a diagram illustrating a problem in selecting a desired main subject caused by changing the AF setting.

[0013] Figure 2 is a block diagram showing the configuration of an image pickup apparatus 100 including a focus adjustment apparatus.

[0014] Figure 3 is a flowchart of the overall operation of the imaging apparatus 100 .

[0015] Figures 4A to 4D This is a conceptual diagram of the basic main subject selection process.

[0016] Figure 5 is a diagram showing the main subject selection process ( Figure 3 Flow chart of the details of step S305).

[0017] Fig. 6A and 6B : is a diagram showing a specific example of the main subject selection process in the case where the AF range is reduced.

[0018] Figure 6C is a diagram showing a specific example of the main subject selection process in a case where the priority subject type is changed due to a change in the priority subject setting.

[0019] Fig. 7A : is a diagram showing a specific example of the main subject selection process in a case where the pupil AF setting is enabled or disabled.

[0020] Figure 7B : is a diagram showing the main subject selection process in the case where the servo AF setting is enabled.

[0021] Figure 8 It is shown in Figure 5 Flowchart showing details of the main subject selection process based on the previous AF position in step S504.

[0022] Fig. 9 3 is a diagram showing a specific example of the main subject selection process based on the previous AF position.

[0023] Fig. 10A and 10B It is shown Figure 8 FIG. 8 is a diagram of a specific example of the processing in step S801.

[0024] Fig.11 It is shown Figure 8 FIG. 5 is a diagram of a specific example of the selection range determination process in step S802 of FIG.

[0025] Fig.12 is a diagram showing the main subject selection process ( Figure 3 Flow chart of the details of step S305).

[0026] Figures 13A to 13E : is a diagram showing a specific example of the main subject selection process for a case where the AF setting has been changed according to the second embodiment. DETAILED DESCRIPTION

[0027] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments are not intended to limit the scope of the claimed invention. Multiple features are described in the embodiments, but the invention is not limited to all such features, and multiple such features can be appropriately combined. In addition, in the accompanying drawings, the same or similar configurations are given the same reference numerals, and their redundant descriptions are omitted. Figures 1A to 1C Describes the situation where the AF setting is changed so that the AF range is expanded. Figures 1A to 1C 4 shows a situation where a person 51 and a person 52 are included in the photographing screen and the user wants to set the person 51 as the main subject. Figure 1A As shown in FIG. 5 , in the case where the user sets a small AF range 53 shown by a solid line, the entire body part 54 of the person 51 shown by a dotted line can be selected as the main subject by framing the person 51 so as to fit within the AF range 53. Therefore, AF control of a subject that meets the user's expectations can be performed. Here, as shown in FIG. Figure 1B As shown in FIG. 1 , there is a case where a person 51 approaches and the subject becomes larger, thereby requiring focusing accuracy on the face. Figure 1C As shown, the face can now be selected as the main subject by switching to the large AF range 55 shown with a solid line. However, since the person 52 will be included in the AF range 55 as a result of increasing the AF range, there is also a possibility that the face 56 of the person 52 shown with a dotted line will be selected as the main subject and this will not meet the user's intention. On the other hand, depending on the change content of the AF setting, there is a possibility that the user wants to select the face 56 of the person 52 as the new main subject.

[0028] First embodiment

[0029] Figure 2 is a block diagram showing the configuration of an image pickup apparatus 100 including a focus adjustment apparatus. Figure 2, reference numeral 101 denotes a photographing lens including a zoom mechanism. Reference numeral 102 denotes an aperture for controlling the amount of incident light and adjusting the depth of field. Reference numeral 104 denotes a focus lens for focusing on an image sensor 108 described later. Reference numeral 105 denotes an AF processing unit (auto focus processing unit) including a driving mechanism for the focus lens 104. Reference numeral 108 denotes an image sensor including a photoelectric conversion unit for converting light reflected by a subject into an electrical signal. Reference numeral 109 denotes an A / D conversion unit, which includes a CDS (correlated double sampling) circuit for removing output noise of the image sensor 108 and a nonlinear amplification circuit for performing processing prior to A / D conversion.

[0030] Reference numeral 110 is an image processing unit, which includes a brightness calculation unit for calculating the brightness of the subject based on the output signal of the A / D conversion unit 109 and an extraction unit for extracting a signal component of a specific frequency band from the output signal of the brightness calculation unit. Reference numeral 111 denotes an AE processing unit (exposure processing unit). Reference numeral 112 denotes a format conversion unit. Reference numeral 113 denotes a high-speed built-in memory (DRAM). The DRAM 113 is used as a high-speed buffer for temporary image storage. In addition, the DRAM 113 is used as a working memory for compressing / decompressing images and other such purpose applications. Reference numeral 114 denotes an image recording unit including a recording medium such as a memory card and its interface.

[0031] Reference numeral 115 denotes a system control unit (CPU) for controlling the operation of the entire imaging apparatus 100. Reference numeral 116 denotes an image display memory (VRAM). Reference numeral 117 denotes a display unit for performing display such as image display, operation support display, and camera status display. The display unit 117 displays a captured image and an AF range at the time of shooting. The system control unit 115 can display a screen for switching AF settings on the display unit 117 so that the user can switch the AF settings.

[0032] Reference numeral 118 denotes an operation unit for externally operating the image pickup apparatus 100. The operation unit 118 includes, for example, a menu switch for configuring various types of settings such as settings of a shooting function of the image pickup apparatus 100 and settings of image playback, a zoom lever for instructing a zoom operation of the shooting lens 101, and an operation mode switching switch for switching a shooting mode and a playback mode. There is also a case where the user switches the AF setting by operating the operation unit 118 when switching the AF setting, while the shot image and the AF range are displayed on the display unit 117.

[0033] Reference numeral 121 denotes a shooting standby switch (SW1) for instructing the image pickup apparatus 100 to perform shooting standby operations such as AF and AE, etc. When the SW1 121 is operated, control for confirming the focal position of the focus lens 104 for shooting is performed.

[0034] Reference numeral 123 denotes a subject detection module. The subject detection module 123 detects various types of subjects using the image signal processed by the image processing unit 110, and acquires subject information (type, position, size, reliability, distance, etc.) of each of one or more detected subjects. In addition, the subject detection module 123 determines (selects) a main subject to be processed by the AF processing unit 105 and the AE processing unit 111. The subject detection module 123 determines (selects) a main subject from among one or more detected subjects based on the subject information (type, position, size, reliability, distance, etc.).

[0035] Next, refer to Figure 3 The overall operation of the image pickup apparatus 100 is described. The processing of this flowchart is repeatedly executed in a predetermined cycle.

[0036] In step S301, the subject detection module 123 acquires an image signal from the image processing unit 110. In step S302, the subject detection module 123 performs subject detection processing using the image signal acquired in step S301. For example, subjects to be detected include humans, animals, and subjects with significant color brightness. Subject detection with subjects with significant color brightness as targets will be referred to as "object detection". The subject detection module 123 acquires subject information (type, position, size, reliability, distance, etc.) of each of one or more detected subjects.

[0037] In step S303, the system control unit 115 determines whether the AF setting has been changed after the previous main subject selection processing was performed (step S304 or step S305). If the AF setting has not been changed, the processing step proceeds to step S304, and if the AF setting has been changed, the processing step proceeds to step S305. The variable setting items of the AF setting include, for example, a setting item (AF range setting) for specifying the object range (AF range) of the main subject selection processing within the shooting range and a setting item related to AF control with the pupil of the subject as the object (pupil AF setting). Other examples include a setting item related to continuous AF control during shooting (servo AF setting) and a setting item (priority subject setting) for setting the type of subject to be preferentially selected as the main subject (priority subject type).

[0038] In step S304 , the subject detection module 123 performs basic main subject selection processing. Figures 4A to 4D 2 is a conceptual diagram of a basic main subject selection process. In the basic main subject selection process, the subject detection module 123 calculates the priority of subjects based on subject information and selects a main subject.

[0039] For example, Figure 4A As shown in FIG. 1 , in the case where a subject with a larger size has a higher priority as the main subject, the subject detection module 123 compares the person 401 and the person 402 and increases the priority of the person 401 with a larger face size. Figure 4B As shown in FIG. 1 , in the case where the subject closer to the center of the screen has a higher priority as the main subject, the subject detection module 123 compares the person 401 and the person 402 and increases the priority of the person 401 closer to the center of the screen. Figure 4C As shown, consider a case where the subject selected as the main subject at the previous main subject selection has a higher priority as the main subject. In this case, if the person 401 was selected as the main subject at the previous time, the subject detection module 123 increases the priority of the person 401. In addition, in the case where there is a setting item (priority subject setting) for setting the type of subject (priority subject type) to be preferentially selected as the main subject in the AF setting, the subject detection module 123 increases the priority of the main subject among the subjects corresponding to the priority subject type set by the user. Figure 4D As shown on the left side of FIG. 1 , when a person is set as the priority subject type, the subject detection module 123 increases the priority of the person 401 corresponding to the priority subject type among the person 401 and the animal 403. Figure 4D As shown on the right side of , in the case where animals are set as the priority subject type, the subject detection module 123 increases the priority of the animal 403 corresponding to the priority subject type among the person 401 and the animal 403 .

[0040] By adopting this configuration, the subject detection module 123 calculates various types of priorities based on factors such as the size and position of the subject, the previous main subject, and the type of the subject. Then, the subject detection module 123 calculates the final priority of each subject by taking the weighted average of the values ​​of the calculated priorities of the various types, and selects the subject with the highest priority as the main subject. Therefore, the subject most suitable as the object of shooting can be selected as the main subject in consideration of various viewpoints such as the size and position of the subject, the previous main subject, and the type of the subject.

[0041] Furthermore, in addition to the above, the priority may be calculated based on the reliability, the subject distance, and other such information obtained as the subject information.

[0042] return Figure 3 In step S305, the subject detection module 123 performs a main subject selection process for the case where the AF setting has been changed. Figure 5 Details of the main subject selection process for a case where the AF setting has been changed are described.

[0043] In step S306, the system control unit 115 determines whether the main subject has been selected in step S304 or step S305. If the main subject has been selected, the processing step proceeds to step S308. If the main subject has not been selected (for example, in a case such as subject detection failure), the processing step proceeds to step S307.

[0044] In step S307, the AF processing unit 105 determines an AF control area. For example, the AF processing unit 105 determines an area near both the center of the AF range and the close-up position, an area having high continuity with the previous AF position (the object position of focus adjustment), or other such areas as the AF control area based on the camera setting, the scene determination result, etc.

[0045] In step S308, the AF processing unit 105 performs focus adjustment on the AF position (target position of focus adjustment) determined based on the main subject determined in step S304 or step S305 or the AF control area determined in step S307. In addition, the AE processing unit 111 performs AE processing based on the main subject determined in step S304 or step S305 or the AF control area determined in step S307. Note that in the case where AF has been locked by single-shot AF (described in detail later), the AF processing in step S308 can be omitted.

[0046] Next, refer to Figure 5 Describes the main subject selection process for a case where the AF setting has been changed ( Figure 3 The system control unit 115 performs the main subject selection processing for the case where the AF setting has been changed according to the changed content of the AF setting (the relationship between the setting contents before and after the change of the changed setting item). Note that the system control unit 115 is capable of performing display control for controlling whether to display the shooting screen (the image of the shooting range) on the display unit 117.

[0047] In step S501, the subject detection module 123 determines whether the AF setting is switched (changed) while the shooting screen (image of the shooting range) is displayed on the display unit 117. If the AF setting is switched while the shooting screen is displayed on the display unit 117, the processing step proceeds to step S502, and if this is not the case, the processing step proceeds to step S503.

[0048] The case where the AF setting is switched in a state where the shooting screen is displayed on the display unit 117 is, for example, a case where the user switches to the setting content of the AF setting registered in advance by operating the operation unit 118 while checking the shooting scene. The case where the AF setting is switched in a state where the shooting screen is not displayed on the display unit 117 is, for example, a case where the user switches the AF setting after a menu for switching the AF setting is displayed on the display unit 117.

[0049] In step S502, the subject detection module 123 switches the selection method of the main subject according to the changed content of the AF setting. For example, if the AF setting is changed to narrow the AF range (the object range of the main subject selection processing within the shooting range), or if the priority subject type is changed due to the change of the priority subject setting, the processing step proceeds to step S503. In addition, if the AF setting is changed to expand the AF range (the object range of the main subject selection processing within the shooting range), the processing step proceeds to step S504. In addition, if the pupil AF setting is enabled or disabled, or if the servo AF setting is enabled, the processing step proceeds to step S505. In the case of other changed contents, the processing step also proceeds to one of steps S503 to S505 according to the nature of the changed content.

[0050] Note that, in the case where the priority subject setting is changed, the priority subject type is changed. In addition, in the case where the pupil AF setting is enabled, the priority subject type is changed to the pupil, and in the case where the pupil AF setting is disabled, the priority subject type is returned to the state before the pupil AF setting is enabled. Therefore, this means that, although in principle the processing step is transferred from step S502 to step S503 in the case where the priority subject type is changed in the conditional branch of step S502, if the priority subject type set before or after the change is the pupil, the processing step is changed from step S502 to step S505.

[0051] Next, the processing of step S503 will be described. As described above, the processing of step S503 is performed in cases such as when the AF range is reduced or the priority subject type is changed due to a change in the priority subject setting. In these cases, there is a high possibility that the main subject of the previous time does not match the user's intention. In view of this, in step S503, the subject detection module 123 selects the main subject of this time regardless of the main subject of the previous time. The selection processing performed here is, for example, the same as Figure 3 The basic main subject selection process described in step S304 of FIG. 1 is substantially the same, but is not referred to. Figure 4C The setting of the priority of the main subject based on the previous one.

[0052] Reference Fig. 6A and 6B A specific example of the main subject selection process when the AF range is reduced will be described. Regarding the user's intention when the AF range is reduced, the following situation is envisioned: the main subject selected by the camera 100 cannot be properly focused within a large AF range, and therefore the user wants to properly refocus by limiting the AF range to a narrow range.

[0053] For example, Fig. 6A As shown, in the case of setting the AF range 610 of the entire area shown by the dotted line, subject detection may be unstable due to factors such as the violent movement of the person or the presence of a hat and goggles. In the case of performing AF control in such a situation, on the contrary, the focus may be adversely affected. Therefore, the user can try to refocus by switching to a small AF range 611 near the person's body.

[0054] like Figure 6B As shown on the left side of , in the case where a plurality of subjects exist within the screen in the case where a large AF range 620 is set, the main subject selection result is not what the user intended, and it is also assumed that the user therefore intends to switch the AF range to a small range. Figure 6B The left side of FIG. 1 shows a case where the AF range 620 shown by the dotted line is set with the intention of sequentially photographing the runners as they run. However, although the user envisions person 622 as the main subject, person 623 slightly closer to the center of the screen is selected as the main subject. In view of this, as shown in FIG. Figure 6B As shown on the right side of , by switching to a small AF range 621 shown with double lines, a part of the body of a person 622 used as a subject by the user can be selected as a main subject.

[0055] Next, refer to Figure 6C A specific example of main subject selection processing is described in the case where the priority subject type is changed due to the priority subject setting being changed. In this case, a situation is assumed in which the user intends to prioritize a subject type different from the type before switching the AF setting. Therefore, in this case as well, main subject selection is performed without considering the main subject selected before switching the AF setting.

[0056] Figure 6C 1 shows a scene where the priority subject type switches from people to animals. Figure 6C On the left side, the priority subject type is people, and the person 632 surrounded by the solid line is preferentially selected as the main subject. Figure 6CAs shown on the right side of , in the case where the user switches the priority subject type to animals, it is assumed that the user's intention is to switch the subject from people to animals. Therefore, the animal 633 surrounded by a solid line is selected as the main subject, regardless of the person 632 that was the main subject in the previous AF setting.

[0057] Furthermore, the process of step S503 is also performed in the case where the AF setting is switched in a state where the shooting screen is not displayed on the display unit 117. In this case, since the user cannot check the change of the subject during the switching of the AF setting, it is assumed that the user does not track the subject and switches the AF setting with the switching of the scene. Therefore, it is assumed that the user is thinking about the situation without considering the main subject selected before the switching. Therefore, in this case, regardless of the change content of the AF setting, the main subject of this time is selected regardless of the main subject of the previous time.

[0058] Next, the processing of step S504 will be described. As described above, the processing of step S504 is performed in the case where, for example, the AF setting is changed to expand the AF range. In step S504, the subject detection module 123 selects the main subject of this time based on the main subject of the previous time. For example, the subject detection module 123 selects the main subject of this time based on the previous AF position (the target position of focus adjustment) determined based on the main subject of the previous time. Figures 8 to 11 Details of the main subject selection process in step S504 are described.

[0059] Next, the processing of step S505 will be described. As described above, the processing of step S505 is performed in cases such as enabling or disabling the pupil AF setting or enabling the servo AF setting. In these cases, there is a high possibility that the user intends to continuously track the same subject before and after changing the AF setting. In view of this, in step S505, the subject detection module 123 selects the main subject of this time based on the main subject of the previous time. For example, the subject detection module 123 preferentially selects a subject related to the main subject of the previous time as the main subject of this time.

[0060] Will refer to Fig. 7A A specific example of the main subject selection process in the case where the pupil AF setting is enabled or disabled is described. In the case where the pupil AF setting is enabled, there is a user demand involving the desire to focus on the pupil of the same subject as the previous main subject. Fig. 7A On the left side of , the pupil AF setting is disabled, and the face of the person 711 shown by the solid rectangular frame is the main subject. Fig. 7A, the pupil AF setting is enabled, wherein the pupil of person 711, which was the main subject selected before switching the AF setting, is selected as the main subject instead of the pupil of person 712 located at the center of the screen. This achieves the main subject selection that meets the user's intention. Afterwards, if the pupil AF setting is disabled, as shown in Fig. 7A As shown on the left side of Figure 7B subjects related to the pupil of the subject selected as the main subject in the image).

[0061] Next, refer to Figure 7B The main subject selection process in the case where the servo AF setting is enabled is described. There is a user demand related to wanting to enable the servo AF setting according to the movement of the subject while maintaining the same subject as the main subject. Figure 7B On the left side of , the animal 721 shown in the solid rectangular frame is stationary, so the servo AF setting is disabled and single-shot AF (AF that performs only one focus adjustment in response to a single focus adjustment instruction from the user) is performed. Figure 7B , the animal 721 shown in the solid rectangular frame has started to move, so the user enables the servo AF setting and performs servo AF (AF that continuously repeats focus adjustment in response to one focus adjustment instruction from the user). With the servo AF setting enabled in this way, it is assumed that the same subject is continuously selected as the main subject, which is in line with the user's intention. Therefore, the animal 721 that was the main subject before switching the AF setting is selected as the main subject, rather than the animal 722 that is larger and closer to the center of the screen.

[0062] Next, refer to Figures 8 to 11 describe Figure 5 The main subject selection process based on the previous AF position in step S504 is described in detail. The main subject selection process based on the previous AF position is performed in a case such as when the AF setting is changed to expand the AF range. In this case, it can be considered that there is a high possibility that the main subject intended by the user is located near the previous AF position. In view of this, the subject detection module 123 is configured to be able to implement AF control on the main subject that meets the user's intention by selecting the main subject located near the previous AF position.

[0063] Fig. 9 3 is a diagram showing a specific example of the main subject selection process based on the previous AF position. Fig. 9The case where the AF setting is changed so that the AF range is switched from the AF range 903 (the AF range set before the AF setting is changed) shown with a dotted line to the AF range 904 shown with a double line. The user intends to perform AF control by switching the main subject to the face of the person 901 from the case where the AF control is performed with a part of the body of the person 901 within the AF range 903 as the main subject. In this case, by selecting the main subject near the previous AF position, the person 901 can be appropriately selected as the main subject instead of the person 902 located near the center of the screen with a larger face size.

[0064] Figure 8 It is shown Figure 5 Flowchart of details of the main subject selection processing based on the previous AF position in step S504 of . In step S801, the subject detection module 123 determines the type of subject to be selected as the main subject within the vicinity of the AF position set before the AF setting is changed. For example, the subject detection module 123 may determine only the priority subject type (human, animal, etc.) based on the priority subject setting as the object. In addition, the subject detection module 123 may determine the same type of subject as the type of the main subject set before the AF setting is switched as the object. In addition, in connection with the case where a part of the subject is tracked by object detection before the AF setting is switched, the subject detection module 123 may determine the priority subject type as the object.

[0065] Fig. 10A and 10B A specific example of the processing in step S801 is shown. Fig. 10A and 10B In the scene of FIG. 1001, a person 1001 and an animal 1002 are close together. In this scene, consider the case where the AF range is changed from an AF range 1003 where a part of the body of the person 1001 and the animal 1002 overlap to an AF range 1004 of the entire area shown with double lines. In this case, if the priority subject type is a person, it is assumed that the user wants to focus on the person 1001. Fig. 10A The scene of the face of the person 1001 shown by the solid rectangle is shown, thereby determining the person as the object selected as the main subject. In addition, if the priority subject type is an animal, it is assumed that the user wants to focus on the animal. Fig. 10B The scene of the face of the animal 1002 indicated by the solid-line rectangle is shown, thereby determining the animal as the object selected as the main subject. In this way, the type of subject to be selected as the main subject within the vicinity of the previous AF position (the AF position set before the AF setting is changed) is determined, so that the subject on which the user focused before the AF setting is switched can be continuously tracked.

[0066] In step S802, the subject detection module 123 determines the object range of the main subject selection processing within the vicinity of the AF position set before switching (changing) the AF setting (hereinafter referred to as the selection range). Note that the AF range also specifies the object range of the main subject selection processing in the same way as the selection range, but in the main subject selection processing based on the previous AF position, the selection range is used with priority over the AF range. However, the selection range is determined based on the AF range. For example, the selection range is determined according to the size of the AF range after switching (changing) the AF setting, which makes it possible to set the selection range of an appropriate size according to the size of the AF range. Thereby, the possibility of setting an irrelevant subject as the main subject due to the selection range being too large or the possibility of not being able to select the subject used by the user as the object due to the selection range being too small can be reduced.

[0067] Fig.11 is a diagram showing a specific example of the selection range determination process in step S802. Fig.11 As shown in FIG. 1 , the length obtained by multiplying the long side 1104 of the AF range 1101 shown by the double-line rectangle set after switching the AF setting by a predetermined specified coefficient N can be taken as the length of the diameter 1105 of the selection range 1103 shown by the solid-line circle. The center of the selection range 1103 is the previous AF position 1102. In addition, the selection range may be other shapes such as an ellipse or a rectangle other than a circle. In addition, for the setting of the selection range, in addition to the range within the screen, the range in the depth direction centered on the AF position set before switching the AF setting can also be set as the selection range.

[0068] In step S803, the subject detection module 123 selects a main subject from the subjects detected in the selection range. Here, in the case where multiple subjects are detected in the selection range, the subject detection module 123 selects the subject closest to the AF position set before switching the AF setting as the main subject. In addition, the subject detection module 123 does not select a subject other than the type determined in step S801 as the object of the main subject selection.

[0069] exist Fig. 9 , a circular range shown by a solid line with the AF position 905 set before switching the AF setting as the center is set as a selection range 906. Here, persons 901 and 902 are included in the selection range 906, but person 907 is not included in the selection range 906, so person 907 is not a target of main subject selection. Then, person 901 included in the selection range 906 and closest to the AF position 905 set before switching the AF setting is selected as the main subject.

[0070] In step S804, the subject detection module 123 determines whether the main subject has been selected in step S803. If the main subject has been selected, the process proceeds to step S806. If the main subject has not been selected, the process proceeds to step S805.

[0071] If the main subject is not selected within the selection range, the process of step S805 is executed. This situation can be considered as a scenario in which the user wants to re-determine a new main subject regardless of the main subject selected before the AF setting is switched. Therefore, the system control unit 115 and Figure 3 In step S304, basic main subject selection processing is performed in the same manner.

[0072] Note that if the main subject is not selected in step S805, the processing steps are changed from Figure 3 Step S306 is transferred to step S307, and thus processing for determining the AF control area is performed in step S307. At this time, in the case where the servo AF setting is enabled before and after the AF setting is switched, it can be considered that the user has a strong intention to track the subject selected before the AF setting is switched. In view of this, the AF processing unit 105 selects a position with high continuity with the previous AF position as the AF control area. Thereby, AF control that meets the intention of the following user is implemented in scenes where subject detection cannot be performed (such as scenes where subject detection is difficult due to factors such as violent movement of the subject or scenes where the user wants to perform AF tracking on subjects other than the detection object), where the user also wants to continuously track the subject selected before the AF setting is switched.

[0073] In step S806, the subject detection module 123 configures a setting so that the main subject is not transferred to other subjects (hereinafter referred to as a lock setting). The lock setting enables AF control that meets the user's intention of continuously tracking the subject he or she is using as a target without switching the main subject, even if a subject with a higher priority than the determined main subject is detected after the AF setting is switched. Thus, it is also possible to maintain the person 901 as the main subject without switching the main subject. Fig. 9 After selecting person 901 as the main subject, the main subject is shifted to person 902 with a larger face size. In addition, the time for which the lock setting is continued can be set to a limited time so that the user can re-frame and achieve a stable composition. Fig. 9After selecting person 901 as the main subject in the image, the lock setting can be continuously performed until the user reframes and switches to a composition in which the face of person 901 is arranged in the center of the screen and persons 902 and 907 are arranged at the edge of the screen. If an appropriate composition with person 901 as the main subject is achieved, the priority as the main subject increases, and it is no longer necessary to maintain the main subject using the lock setting. In addition, after releasing the lock setting for a limited time, the user can also switch the main subject from person 901 to another subject by intentionally switching the composition.

[0074] As described above, according to the first embodiment, in the case where the AF setting is changed after the previous main subject selection process is performed, the imaging apparatus 100 determines whether to perform the main subject selection process this time based on the previous main subject or to perform the main subject selection process this time regardless of the previous main subject, based on the change content of the AF setting. Therefore, the possibility of selecting the main subject that meets the user's intention is increased.

[0075] Second embodiment

[0076] The first embodiment describes Figure 5 The main subject selection process shown for a case where the AF setting has been changed ( Figure 3 The second embodiment describes another example of the main subject selection process in the case where the AF setting has been changed. In the second embodiment, the basic configuration of the imaging apparatus 100 is the same as that of the first embodiment. Hereinafter, the description will focus on the differences from the first embodiment.

[0077] The operation unit 118 of the image pickup device 100 is provided with one or more operation members (e.g., buttons) for changing the AF setting. Each setting content of the AF setting is associated with each of the one or more operation members. For example, the activation of the servo setting is associated with the first operation member, and the activation of the pupil AF setting is associated with the second operation member. In response to the individual operation member switching to the working state (e.g., the button is pressed), the system control unit 115 changes the AF setting so as to reflect the setting content associated with the operation member. In addition, in response to the individual operation member switching to the non-working state (e.g., the pressed button is released), the system control unit 115 changes the AF setting so as to cancel the reflection of the setting content associated with the operation member. For example, in the case where the activation of the servo setting is associated with a specific button, the system control unit 115 changes the AF setting so as to enable the servo setting when the button is pressed. Thereafter, in the case where the pressed button is released, the system control unit 115 changes the AF setting so as to cancel the activation of the servo setting (disable the servo setting). In addition, the user can set a plurality of operation members to the working state at the same time, in which case the setting content associated with each operation member is reflected in the AF setting.

[0078] Fig.12 is a diagram showing the main subject selection process ( Figure 3 Detailed flowchart of step S305). Fig.12 In the flowchart, Figure 5 The same or similar processing steps are given to Figure 5 Same reference numerals.

[0079] In step S1201, the subject detection module 123 determines whether the change in the AF setting is due to the release of the operating state of the operating member for changing the AF setting (switching to the non-operating state). If the change in the AF setting is due to the release of the operating state, the processing step proceeds to step S1202, and if the change in the AF setting is not due to the release of the operating state, the processing step proceeds to step S502.

[0080] In step S1202, the subject detection module 123 determines whether the AF setting has returned to the initial state (whether one or more operating members are all in the non-operating state). If the AF setting has returned to the initial state, the processing step proceeds to step S503, and if this is not the case, the processing step proceeds to step S502. Therefore, in the case where the AF setting has been changed in response to the individual operating member being switched to the non-operating state, and the one or more operating members are all in the non-operating state, regardless of the change content of the AF setting, the main subject selection process of this time is performed regardless of the previous main subject.

[0081] Here, the case where there is still an enabled setting content in the setting content in the AF setting reflected by the operating member for changing the AF setting of the operating unit 118 is a state where the user continuously operates the operating unit 118 while viewing the display unit 117. Therefore, it can be considered that the user still has the intention to continuously track the subject, and thus the main subject selection process (step S502) depending on the change content of the AF setting is performed. On the other hand, in the case where all the setting contents reflected by the operating member for changing the AF setting of the operating unit 118 are canceled, it can be considered that the user no longer has the intention to continuously track the subject. Therefore, regardless of the change content of the AF setting, the main subject selection process of this time is performed regardless of the main subject of the previous time (step S503).

[0082] Figures 13A to 13E is a diagram showing a specific example of the main subject selection process for a case where the AF setting has been changed according to the second embodiment. Figures 13A to 13E In the example of , the servo AF setting and the pupil AF setting are registered to the physical button A and the physical button B included in the operation unit 118, respectively. Then, in a case where the user presses the physical buttons A and B, the servo AF setting and the pupil AF setting are enabled, respectively, and in a case where the user releases the physical buttons A and B, the servo AF setting and the pupil AF setting are disabled, respectively.

[0083] Fig.13A 13 shows a state where both physical buttons A and B are not pressed. In this state, the single shot setting is enabled, and a stationary animal 1301 shown by a solid rectangle is selected as the main subject. Fig. 13B In the example, the animal 1301 has already started to move, so the user presses the physical button A and enables the servo setting. In this case, based on the main subject set before switching the AF setting, the animal 1301 is continuously selected as the main subject. Fig. 13C , the user presses the physical button B and enables the pupil AF setting. Likewise, in this case, the pupil of the animal 1301, which was the main subject before the AF setting was switched, is selected as the main subject this time, rather than the animal 1302 located at the center of the screen. Fig.13D In , the user cancels (disables) the pupil AF setting by releasing the physical button B, but since the physical button A is still pressed, the user still has the intention to continue tracking the original main subject with the servo AF. Therefore, the animal 1301 corresponding to the pupil that was the previous main subject is selected as the main subject. Fig.13EIn the example, by releasing the physical button A by the user, all setting contents using the operating member for changing the AF setting are canceled, and thus the AF setting returns to the initial state. Therefore, it is assumed that the user has the intention to reset the AF setting and redo the main subject selection. Therefore, the main subject selection process of this time is performed regardless of the main subject of the previous time, and the animal 1302 at the center of the screen is selected as the main subject.

[0084] As described above, according to the second embodiment, in the case where the AF setting has been changed in response to the individual operating member having been switched to the non-operating state, and one or more operating members are all in the non-operating state, regardless of the change content of the AF setting, the imaging apparatus 100 performs the main subject selection process of this time regardless of the main subject of the previous time. Therefore, the possibility of selecting the main subject that meets the user's intention increases.

[0085] Other embodiments

[0086] The embodiments of the present invention may also be implemented by providing software (program) for performing the functions of the above-described embodiments to a system or device via a network or various storage media, and a computer or a central processing unit (CPU) or a microprocessing unit (MPU) of the system or device reads and executes the program.

[0087] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A focus adjustment device, include: a selection unit configured to repeatedly perform a selection process for selecting a main subject from one or more subjects included in a photographing range based on an automatic focus setting, namely, an AF setting; a focus adjustment unit configured to perform focus adjustment on a subject position determined based on the selected main subject; as well as a changing unit configured to change the AF setting, In which, when the AF setting changes after the selection processing was last performed, the selection unit determines whether to perform the selection processing based on the main subject selected in the last selection processing, or to perform the selection processing regardless of the main subject selected in the last selection processing, based on the change content of the AF setting.

2. The focus adjustment device according to claim 1, in, The AF setting includes a setting item for specifying a priority subject type indicating a type of a subject to be preferentially selected in a selection process, and The selection unit executes a selection process independently of a main subject selected in a previous execution of a selection process, in a case where the AF setting is changed to change the priority subject type.

3. The focus adjustment device according to claim 2, in, Even if the AF setting is changed to change the priority subject type, if the priority subject type set before or after the change is the pupil, the selection unit performs selection processing based on the main subject selected in the previous execution of selection processing.

4. The focus adjustment device according to any one of claims 1 to 3, in, The AF setting includes a setting item for specifying whether the focus adjustment of the focus adjustment unit is performed only once or continuously and repeatedly in response to a focus adjustment instruction of a user, and In a case where the AF setting is changed to continuously repeat the focus adjustment of the focus adjustment unit in response to the one-time focus adjustment instruction, the selection unit performs a selection process based on the main object selected in the previous execution of the selection process.

5. The focus adjustment device according to any one of claims 1 to 3, in, The AF setting includes setting items for specifying a subject range of a selection process within the photographing range, and The selection unit performs selection processing regardless of a main subject selected in a previous execution of selection processing, in a case where the AF setting is changed to narrow down the object range.

6. The focus adjustment device according to claim 5, in, The selection unit performs selection processing according to a subject position determined based on a main subject selected in a previous execution of selection processing, in a case where the AF setting is changed to expand the subject range.

7. The focus adjustment device according to any one of claims 1 to 3, in, The AF setting includes setting items for specifying a subject range of a selection process within the photographing range, and The selection unit performs selection processing according to a subject position determined based on a main subject selected in a previous execution of selection processing, in a case where the AF setting is changed to expand the subject range.

8. The focus adjustment device according to claim 6, in, Executing the selection process according to the target position determined based on the main subject selected in the previous execution of the selection process includes limiting the target range of the selection process within a prescribed range from the target position.

9. The focus adjustment device according to claim 8, in, The prescribed range is determined based on the size of the object range prescribed by the AF setting.

10. The focus adjustment device according to any one of claims 1 to 3, further comprising: include: one or more operating components, wherein each setting content of the AF setting is associated with each operating member of the one or more operating members, the changing unit is configured to, in response to an individual operating member among the one or more operating members being switched to an operating state, change the AF setting to reflect a setting content associated with the individual operating member, and, in response to the individual operating member being switched to a non-operating state, change the AF setting to cancel reflection of the setting content associated with the individual operating member, and In a case where the AF setting changes in response to an individual operating member among the one or more operating members being switched to a non-working state, and the one or more operating members are all in a non-working state, the selection unit performs selection processing regardless of the content of the change in the AF setting, regardless of the main subject selected in the previous selection processing.

11. The focus adjustment device according to any one of claims 1 to 3, further comprising: include: a display control unit configured to control whether to display the image of the photographing range on a display, Wherein, when the AF setting is changed while the image of the shooting range is not displayed on the display, the selection unit performs the selection process regardless of the change content of the AF setting regardless of the main subject selected in the previous selection process.

12. A camera device, include: The focus adjustment device according to any one of claims 1 to 3; as well as Image sensor.

13. A focus adjustment method performed by a focus adjustment device, wherein include: repeatedly executing a selection process for selecting a main subject from one or more subjects included in a photographing range based on an automatic focus setting, namely, an AF setting; performing a focus adjustment on a subject position determined based on the selected main subject; changing the AF setting; as well as In the case where the AF setting is changed after the selection processing was last performed, it is determined based on the change content of the AF setting whether the selection processing is performed based on the main subject selected in the last selection processing, or whether the current selection processing is performed regardless of the main subject selected in the last selection processing.

14. A computer-readable storage medium storing a program for causing a computer to execute a focus adjustment method, wherein the focus adjustment method include: repeatedly executing a selection process for selecting a main subject from one or more subjects included in a photographing range based on an automatic focus setting, namely, an AF setting; performing a focus adjustment on a subject position determined based on the selected main subject; changing the AF setting; as well as In the case where the AF setting is changed after the selection processing was last performed, it is determined whether the selection processing is performed based on the main subject selected in the last selection processing or is performed regardless of the main subject selected in the last selection processing based on the change content of the AF setting.

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