JP2018019249A - Imaging apparatus and control method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus which allows for recognizing an area to focus, regardless of a subject.SOLUTION: An imaging apparatus 100 performs focus adjustment processing by selecting a focus adjustment area. A main controller 30 in the imaging apparatus 100 performs a first switch operation of switching from a first composition to a second composition before imaging. After completion of the first switch operation, the main controller 30 performs a second switch operation of switching from the first composition to the second composition.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging apparatus and a control method thereof.

  There has been proposed an imaging apparatus that displays a focus area such as a square display frame in the vicinity of a subject and clearly indicates an area to be focused. Patent Document 1 discloses a camera that changes the shape of a display mark indicating a distance measuring point. In addition, there has been proposed a camera that displays whether the focus is in focus by changing the color of the display frame to red or green.

JP 2007-171870 A

The display of the area using a square display frame or the like hides a part of the subject itself, making it difficult for the user to see the subject. Further, when the shape of the display frame is close to the subject, it is difficult to recognize the position. In the camera disclosed in Patent Document 1, it is necessary to change the display frame in accordance with the subject. Also, a camera that changes the color of the display frame makes it difficult to recognize the focus state when the color of the display frame overlaps the color of the subject.
SUMMARY OF THE INVENTION An object of the present invention is to provide an imaging device that can recognize a focus area regardless of a subject.

  An imaging apparatus according to an embodiment of the present invention includes a focus adjustment unit that performs a focus adjustment process, a selection unit that selects a focus adjustment region, and a control unit that performs a composition change control. In addition, after performing the first switching operation for switching from the first composition to the second composition, the second switching operation for switching from the second composition to the first composition is performed.

  According to the imaging apparatus of the present invention, it is possible to recognize a focus area regardless of a subject.

It is a figure which shows the structural example of the imaging device of this embodiment. It is a figure which shows the external appearance of an imaging device. It is a flowchart explaining the operation processing of an imaging device. It is a flowchart explaining the operation | movement at the time of focusing, and the operation | movement at the time of focusing impossible. It is a figure which shows the example of the composition observed with an observation means. It is a figure which shows composition movement at the time of focusing impossible. It is a figure which shows the relationship between the movement control of composition, a focus adjustment process, and blur correction control. It is a flowchart explaining the operation | movement at the time of focusing. It is a figure which shows the example of the composition observed with an observation means. It is a figure which shows the relationship between the movement control of composition, a focus adjustment process, and blur correction control.

Example 1
FIG. 1 is a diagram illustrating a configuration example of an imaging apparatus according to the present embodiment.
The imaging apparatus 100 includes a lens group 10 to an observation unit 40. The lens group 10 has an optical element for collecting the luminous flux from the subject. In the present embodiment, a fixed lens 11 located closest to the subject is installed in the lens group 10. The zoom lens 12 is a lens that changes the angle of view. The zoom lens 12 is installed so as to be movable in the optical axis direction, and is held in a state in which the backlash during movement is set small by a guide bar or the like. In addition, the zoom lens 12 can be moved in the optical axis direction using a cam. The zoom lens 12 moves in the optical axis direction by a drive signal from an angle-of-view changing unit 15 including a motor (not shown).

  The correction lens 13 is used for composition movement and image blur correction. Image blur correction is correction of blur (image blur) that occurs in a captured image due to shake applied to the imaging apparatus. The correction lens 13 is composed of an optical element that moves in a plane orthogonal to the optical axis. When the correction lens 13 moves in response to the drive signal from the composition moving unit 16, composition movement that can be observed by the observation means 40 is performed. By arbitrarily outputting the composition signal of the composition moving unit 16, it is possible to move to an arbitrary composition.

  The shake detection unit 32 detects shake of the imaging device 100 such as a gyro. As the shake detection unit 32, a plurality of sensors can be installed for each shake direction, and a shake signal can be detected. The main controller 30 outputs a correction signal to the composition moving unit 16 to drive the correction lens 13 so as to cancel the shake from the detected shake signal. Thereby, blur correction control for correcting image blur due to shake is executed. While the main controller 30 drives the correction lens 13 with a control signal (movement signal) in which a correction signal for shake correction control and a composition signal for composition change control are superimposed, the shake correction control is performed. Arbitrary composition movement is possible.

  The focus lens 14 is an optical element that can move in the optical axis direction for focus adjustment. The focus lens 14 is driven by receiving a drive signal from the focus adjustment unit 18, whereby the focus adjustment process (focusing operation) starts. The focus lens 14 stops at a predetermined position, and the focusing operation ends. The above is the description of the lens group 10. In FIG. 1, it is possible to install a diaphragm whose aperture diameter is not shown in FIG. Although the lens group 10 is a part of the imaging apparatus 100, it can be exchanged to another lens group as a so-called interchangeable lens. The present invention can also be applied to an imaging apparatus in which a lens and a camera body are integrated, in which a lens cannot be exchanged.

  The imaging unit 20 is a photoelectric conversion element such as a CMOS and receives a light beam from a subject and converts a subject image to be photographed into an electrical signal. The observation means 40 is an observation optical system installed at a point where a light beam transmitted through the lens group 10 is guided through a half mirror 19 installed on the optical axis. In the observation means 40, an image transmitted through the lens group 10 is observed. Therefore, the photographer can observe an image close to the image to be photographed. In the present embodiment, the observation means 40 is an observation optical system, but an image converted into an electric signal by the imaging unit 20 can be displayed on a liquid crystal monitor (not shown) or the like.

  The main controller 30 controls the entire imaging apparatus 100. The main controller 30 processes various input electric signals and outputs them as electric signals. The main controller 30 also performs an operation of selecting a focus area for automatic focus adjustment, which will be described later. Further, the main controller 30 controls composition change by controlling the composition moving unit 16 and switches the composition.

  The focus detection unit 31 performs focus detection processing according to the distance from the imaging unit 20 to the subject. In this example, the focus detection unit 31 performs a focus detection process based on the light beam transmitted through the lens group 10 using a known phase difference detection method. Note that a method of detecting the in-focus state of the subject from the contrast of the light beam received by the imaging device, called a contrast method, may be applied. Any focus detection method may be used as long as information for focusing can be detected. Whether or not focusing is possible is determined by the detection result of the focus detection unit 31. An example of inability to focus is when the subject is darker than the brightness detection limit and cannot be detected. The main controller 30 receives an electrical signal from the focus detection unit 31 and determines whether focus adjustment is possible according to the result.

  The main controller 30 has a mode for automatically determining a focus area which is a focus adjustment area. It is also possible for the photographer to select an arbitrary area from a plurality of predetermined focus areas. Also, depending on the focus detection method, it is possible to select an arbitrary area from all of the screen. The recording unit 33 stores the electrical signal of the subject image acquired by the imaging unit 20. The recording unit 33 is a memory card, for example.

FIG. 2 is a diagram illustrating an appearance of the imaging apparatus.
The shooting instruction unit 34 is a two-stage button switch. When the photographing instruction unit 34 is lightly pressed, a focus adjustment operation and a photometry operation are performed. When the photographing instruction unit 34 is further pressed, photographing is performed. The focus adjustment operation is an operation of driving the focus lens 14 by generating drive vibration from the focus adjustment unit 18 according to the detection result of the focus detection unit 31. When shooting is started, the imaging unit 20 transmits the received light flux as an electrical signal to the main controller 30 and is recorded in the recording unit 33 after appropriate image processing, format conversion, and the like.

  The zoom operation unit 36 includes an operation ring and a seesaw switch. The main controller 30 receives the electrical signal from the zoom operation unit 36 and outputs the electrical signal to the view angle changing unit 15. Thereby, the zoom lens 12 operates and zooming is performed.

  The area selection unit 35 includes a plurality of buttons and can select a two-dimensional position. The photographer can specify a focus area by an operation using the area selection unit 35. Specifically, the focus area can be designated by moving a cursor or the like displayed as an overlay on the observation means 40.

FIG. 3 is a flowchart for explaining operation processing of the imaging apparatus according to the present embodiment.
In S101, the main controller 30 determines whether there has been a focus adjustment instruction. If there is no focus adjustment instruction, the process returns to S101. If there is a focus adjustment instruction, the process proceeds to S102.

FIG. 5 is a diagram illustrating an example of a composition observed by the observation unit.
When the photographer defines the composition as shown in FIG. 5A, the photographer operates the switch of the photographing instruction unit 34 to proceed to photographing. As a result, a focus adjustment instruction is issued. FIG. 5A is a first composition that is a composition that the photographer wants to photograph. The first composition is a composition that the photographer intends to set. In the first composition, shake correction control using the correction lens 13 may be performed, and when the imaging device 100 is attached to a tripod, shake correction control may not be performed.

  Returning to the description of FIG. In S102, the main controller 30 performs automatic focus area selection. Specifically, the main controller 30 automatically selects a region (focus area) to be focused from the first composition in FIG. 5A determined by the photographer. In this embodiment, the focus area is automatically selected, but may be set in advance according to the photographer's intention. There are various methods for automatic focus area selection. When the main controller 30 detects a face from the composition, an area with the face may be selected as the focus area. In this example, the face of the person in the foreground is selected as the focus area.

  In the first composition shown in FIG. 5A, a focus area 151 that is a broken line area is selected. In FIG. 5, the focus area 151 is indicated by a broken line and an alternate long and short dash line for explanation. A broken line indicates a state before the focusing operation is started, and an alternate long and short dash line indicates a state after the focusing operation is finished. In actual shooting, the focus area 151 is not displayed. As will be described later, the focus area 151 can be recognized by the photographer by moving the composition. In the present embodiment, by not performing the focus area display, it is possible to eliminate the difficulty in seeing the subject due to the frame display of the focus area.

  Next, in S103, the main controller 30 determines whether focus detection is possible for the focus area selected in S102. If focus detection is possible, the process proceeds to S104. In step S104, the main controller 30 performs an in-focus operation. If focus detection is not possible, the process proceeds to S105. In S105, the main controller 30 performs an operation when focusing is impossible.

FIG. 4 is a flowchart for explaining the in-focus operation in S104 of FIG. 3 and the out-of-focus operation in S105.
FIG. 4A is a flowchart for explaining the operation during focusing. In S111, the main controller 30 drives the focus lens according to the focus detection result. Specifically, the main controller 30 moves the focus lens to a predetermined position. Accordingly, as shown in FIG. 5B, the person shown by the focus area 151 is focused on in the state of the first composition.

  Next, in S112, the main controller 30 switches from the first composition to the second composition (executes the first switching operation). Specifically, the main controller 30 switches the first composition shown in FIG. 5B to the second composition shown in FIG. 5C by driving the correction lens 13. In the second composition, in order for the photographer to recognize the position of the focus area 151, the focus area 151 is arranged at a predetermined position of the composition (center in FIG. 5C). It is desirable that the speed of the first switching operation is slow enough to allow the photographer to confirm that the composition is moving. This is to make it easier for the photographer to follow the movement of the focus area 151.

  Next, in S113, the main controller 30 ends the first switching operation and keeps the state stopped in the second composition for a predetermined time. By stopping in the second composition, the focus area can be easily recognized without depending on the display frame, and the in-focus state can be confirmed without depending on the color. In addition, since the composition is moved while the background is displayed, it is easy to recognize how the composition has moved. Also, by moving the focus area to the approximate center of the composition, the photographer can easily recognize the focus area. Thereby, the focus area and the in-focus state can be easily communicated regardless of the subject. However, for example, when a message is displayed at the center of the composition, the focus area does not necessarily have to be the center in the second composition, and may be a specific place other than the center. By arranging the focus area at a position avoiding the message display, the focus area and the focused state can be communicated in an easy-to-understand manner.

  In S114, the main controller 30 switches from the second composition to the first composition shown in FIG. 5D (executes the second switching operation). Since the photographer has already been able to recognize the focus area 151, it is desirable that the photographer move quickly for the composition movement by the second switching operation in S113. This is to reduce the time from when the photographer recognizes the focus area to when shooting. In S115, the main controller 30 captures a subject image. The main controller 30 performs appropriate image processing, format conversion, and the like on the photographed image and records it in the recording unit 33. As described with reference to FIG. 4A, the main controller 30 performs the first switching operation for switching from the first composition to the second composition before shooting, and then performs the second composition to the second composition. A second switching operation for switching to the composition of 1 is performed.

FIG. 4B is a flowchart for explaining the operation when focusing is impossible. FIG. 6 is a diagram showing composition movement when focusing is impossible.
In FIG. 6, in order to explain photographing in a dim place, a dim state is shown by cross-hatching. FIG. 6A shows a first composition that the photographer wants to photograph. When shooting in a dim place, focus detection may not be successful in S103 of FIG. If the focus cannot be detected, the process cannot proceed to the focus adjustment operation, and shooting cannot be performed. However, depending on the mode of the image capturing apparatus 100, it is possible to permit photographing in a state where focusing cannot be performed.

  In S122 of FIG. 4B, as shown in FIG. 6B, the main controller 30 changes the composition in which the subject is moved to the left with respect to the first composition. Set to one of the compositions. Then, the main controller 30 switches from the first composition to the second composition (executes the first switching operation).

  One of the second compositions is the composition shown in FIG. 6C in which the subject is moved to the right with respect to the first composition. In S123, the main controller 30 switches from the composition shown in FIG. 6B, which is one of the second compositions, to the composition shown in FIG. 6C, which is a second composition different from this composition (first). 3) is performed. In the present embodiment, the main controller 30 performs the third switching operation a predetermined number of times. For example, in the first third switching operation, the composition shown in FIG. 6B is switched to the composition shown in FIG. In the second third switching operation, the composition shown in FIG. 6C is switched to the composition shown in FIG. Thus, for example, the main controller 30 switches the composition alternately between the composition shown in FIG. 6B and the composition shown in FIG. Of course, the second composition may be a plurality of three or more compositions, and the composition of the switching destination may be determined according to a predetermined order or randomly.

  Next, in S124, the main controller 30 determines whether the third switching operation has been performed a predetermined number of times. If the third switching operation has not been executed a predetermined number of times, the process returns to S123. If the third switching operation has been executed a predetermined number of times, the process proceeds to S125. In this example, the predetermined number of times is three. Accordingly, the last composition switched in the third switching operation is the composition shown in FIG. In S125, the main controller 30 moves the composition from the composition of FIG. 6C, which is one of the second compositions, to FIG. 6A, which is the first composition (executes the second switching operation). ).

  In the in-focus operation, unlike the in-focus operation in FIG. 4A, the third switching operation starts without stopping in the second composition after the end of the first switching operation. Further, after the third switching operation is completed, the second switching operation is performed from the second composition, and the first composition is switched to.

  When viewed from the first composition, the composition shown in FIG. 6B and the composition shown in FIG. 6C are opposite in the direction of composition movement and have the same amount of movement. As a result, the composition movement seems to swing left and right without stopping. In other words, by not stopping in the second composition, it is possible to inform the photographer that focusing cannot be performed. In this way, in the operation when focusing cannot be performed, the photographer can recognize that focusing cannot be performed by performing the second switching operation.

  After completion of the second switching operation in S125, the composition returns to the original composition shown in FIG. 6A, the composition movement is stopped, and the photographing is completed. If the reason for the inability to focus is due to brightness, the photographer tries a method such as using a flash.

FIG. 7 is a diagram illustrating the relationship among composition movement control, focus adjustment processing, and blur correction control in the first embodiment.
The vertical axis of each graph in FIG. 7 indicates the state of each item. The horizontal axis indicates time. Each item will be described in the order of timing. T101 indicates a focus adjustment instruction. The focus adjustment instruction corresponds to S101 in FIG. The vertical axis of T101 indicates that the switch of the photographing instruction unit 34 has been pressed at the timing of turning from OFF to ON as in T101a.

  T103 indicates the focus detection timing in S103 of FIG. The vertical axis of T103 indicates that focus detection is not detected at the level of T103a. The level of T103c indicates that focus detection in the selected focus area has been completed and focus detection has been completed. T103b indicates that focus detection has been performed at the timing of T103b.

  T111 indicates the focus adjustment timing in S111 of FIG. The vertical axis of T111 indicates the in-focus state, and changes between unfocused and in-focus. During the focusing operation, the focus lens 14 starts moving at the timing of T111a. Further, at the timing of T111c, the focus lens 14 finishes moving, and the focusing operation ends.

  T1121 indicates a drive signal (correction signal) for correcting image blur due to the detected shake. The vertical axis of T1121 indicates the signal level. When the correction lens 13 is operated with the correction signal of T1121, the observation unit 40 can observe with the shake canceled and the subject stationary. The direction of shake is usually represented by two directions, usually yaw and pitch, but in this example, only one direction will be described as a representative for the sake of simplicity of explanation. T1121a is the same as the timing of T101a, and the correction operation is started from the timing of T1121a.

  T1122 represents a drive signal (composition signal) for composition movement in S112 of FIG. The vertical axis of T1122 is the signal level. T1121a indicates that the signal level is 0 and the first composition state shown in FIG. The first switching operation for composition movement starts at the timing of T1121b. At the timing of T1121c, the first switching operation of composition movement ends, and stops at the second composition. T1121, which is the timing of completion of the first switching operation for composition movement, is later than T111b, which is the timing of completion of the focusing operation for focus adjustment. Yes. By completing the focusing operation before the end of the first switching operation, it is possible to check the position of the focus area in the focused state, and it becomes easier for the photographer to check that it is in the focused state. T1121d is a timing at which the composition switching second switching operation starts. The second switching operation ends at the timing of T1121e, and the composition moves to the first composition.

  T 1123 indicates a drive signal (movement signal) to the correction lens 13. The vertical axis of T1123a is the signal level, and the movement signal is a signal obtained by superimposing the correction signal and the composition signal. T1123a is the same as the timing of T101a, and the correction operation is started from the timing of T1123a. As described above, since the image blur correction is performed during the first switching operation and the second switching operation of the composition movement, it is possible to observe with the shake canceled during the composition movement. It is.

  Normally, when the amount of correction is excessively increased in image blur correction, the surrounding image is distorted and deteriorated. Therefore, the maximum movable amount of the correction lens 13 for image blur correction is set. One side of the maximum movable amount of the correction lens 13 is a range indicated by T1123c.

  T1123c is the maximum movable amount of the correction lens 13 for image blur correction when the first composition movement switching operation is not performed. The movement amount of the correction lens 13 is set to be larger than T1123c in order to reliably operate the range of T1123c.

  T1123b indicates the maximum movement amount of the correction lens 13 when the first composition movement switching operation and the image blur correction operation are performed simultaneously in the present embodiment. T1123b is larger than T1123c. Therefore, the movement amount during the first switching operation of composition movement is larger than the maximum movable amount of the correction operation when the first switching operation is not performed. Although there is a concern that the surrounding image may be distorted during the first switching operation of the composition movement, since shooting is not performed, the first switching of the composition movement is performed based on the maximum movable amount of the correction operation when the composition movement is not performed. The amount of movement during operation can be set large. When the composition moves to a state determined by the photographer, the photographing shown in T114 is executed. T114a indicates the timing at which shooting is performed.

  The above is the details of composition movement. According to the control described with reference to FIG. 7, by performing the first switching operation and the second switching operation while performing image blur correction control, the in-focus state is easily communicated with smooth composition movement. be able to.

(Example 2)
An imaging apparatus of Example 2 will be described. Since the configuration of the image pickup apparatus according to the second embodiment is the same as that in FIG. 1, the description thereof is omitted. Only the parts different from the first embodiment will be described below. The flow of shooting is the same as the flowchart described with reference to FIG. The difference from the first embodiment is the in-focus operation in S104 of FIG.

  FIG. 8 is a flowchart for explaining the focusing operation in the second embodiment. FIG. 9 is a diagram illustrating an example of a composition observed by the observation unit in the second embodiment. In FIG. 9, the focus area 251 is indicated by a broken line and a one-dot chain line for convenience of explanation. A broken line shows a state before the focusing operation is started. A one-dot chain line indicates a state after the focusing operation is completed.

  First, in S211 of FIG. 8, the main controller 30 switches from the first composition to the second composition (executes the first switching operation). FIG. 9A shows a first composition that the photographer wants to photograph. By the first switching operation, the main controller 30 moves to the second composition shown in FIG. 9B by moving the composition so that the focus area 251 is at the center of the composition. The focus area 251 is not in focus as shown by the broken line. By displaying the focus area 251 in the center without being in focus, the photographer can first recognize the position of the focus area.

  In S212, the main controller 30 ends the first switching operation, and stops the composition at the first composition. Subsequently, in S213, the main controller 30 drives the focus lens in accordance with the focus detection result, thereby performing a focusing operation. By moving the focus lens to a predetermined position, the focus area 251 is brought into focus as shown in FIG. That is, focus adjustment is actually started from a state in which the photographer recognizes the focus area located at the center of the composition. Thus, the photographer can surely confirm that the subject is in focus.

  In S214, the main controller 30 executes the second switching operation. As a result, the composition returns to the first composition as shown in FIG. However, in the state of the composition shown in FIG. 9A, it was not in focus, whereas in the state of composition shown in FIG. 9D, it was in focus and preparation for shooting was completed. doing.

  Returning to the description of FIG. In S215, the main controller 30 captures a subject image. The main controller 30 performs appropriate image processing, format conversion, and the like on the shooting result, and then records the result in the recording unit 33 to complete shooting.

FIG. 10 is a diagram illustrating the relationship among composition movement control, focus adjustment processing, and blur correction control in the second embodiment.
The first switching operation for composition movement is started at the timing of T2122b. The first switching operation ends at the timing of T1121c. Subsequently, the focus adjustment focusing operation is started at timing T211a, and the focusing operation is ended at timing T111b. Thereafter, the second switching operation for composition movement is started at the timing of T2121d, the second switching operation is completed at the timing of T2121e, and the preparation for photographing is completed. That is, in the present embodiment, the focus adjustment process is started after the first switching operation is completed, and the focusing is completed before the second switching operation is started.

  In the second embodiment, the main controller 30 starts the focusing operation after the first switching operation is completed, and completes the focusing operation before starting the second switching operation. As a result, the photographer can first identify the focus area and then check the in-focus state, so that the in-focus operation can be confirmed with certainty.

(Other embodiments)
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

16 Composition moving unit 30 Main controller 100 Imaging device

Claims (13)

Focus adjusting means for performing focus adjustment processing;
A selection means for selecting a focus adjustment area;
Control means for performing composition change control,
The control means performs a second switching operation for switching from the second composition to the first composition after performing a first switching operation for switching from the first composition to the second composition before photographing. An imaging apparatus characterized by that. Comprising correction means used for correcting image blur due to shake applied to the imaging device;
The imaging apparatus according to claim 1, wherein the control unit executes the composition change control by driving the correction unit. The imaging apparatus according to claim 2, wherein the control unit corrects the image blur by driving the correction unit and executes change control of the composition. 4. The control unit according to claim 2, wherein the control unit is capable of moving the correction unit beyond a maximum movement amount when correcting the image blur during the first switching operation. 5. Imaging device. 5. The control unit according to claim 1, wherein the control unit performs the second switching operation after performing the first switching operation when focusing by the focus adjusting unit is possible. The imaging apparatus of Claim 1. A second composition in which the focus adjustment region is a predetermined position of the composition from the first composition by the first switching operation when the focus adjustment means is capable of focusing; The imaging apparatus according to any one of claims 1 to 5, wherein the imaging apparatus is switched to. The imaging apparatus according to claim 6, wherein the predetermined position of the composition is a center position of the composition. The focus adjustment process by the focus adjustment unit and the first switching operation by the control unit are started after the selection unit has selected the focus adjustment region. The imaging apparatus of Claim 1. The imaging apparatus according to any one of claims 5 to 8, wherein the focusing is completed before the first switching operation is completed. 10. The focus adjustment process by the focus adjustment unit starts after the end of the first switching operation, and the focusing is completed before the start of the second switching operation. The imaging device according to any one of the above. A third switching operation for switching the composition to a second composition different from the second composition after performing the first switching operation when focusing by the focus adjusting means is not possible; The imaging device according to any one of claims 1 to 10, wherein: 12. The control unit according to claim 11, wherein when the third switching operation is executed a predetermined number of times, the control unit ends the third switching operation and switches the composition to the first composition. Imaging device. A selection step of selecting a focus adjustment area;
A focus adjustment process for performing focus adjustment processing;
And a control process for performing composition change control,
In the control step, a first switching operation for switching from the first composition to the second composition is performed before shooting, and then a second switching operation for switching from the second composition to the first composition is performed. And a method of controlling the imaging apparatus.

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