JP2004135029A - Digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To select and record a picture excellent in a focusing state among a plurality of pickup images, when a plurality of images are sequentially photographed while varying focal positions. <P>SOLUTION: When an automatic selection mode is set, focusing estimation values are calculated for each of more than one image sequentially photographed while while varying the focal positions by focal bracket photographing (step 102), the image with the highest focusing estimation value, i.e., the best image in sharp focus is automatically selected as a recording picture (step 106), the best image is recorded on a recording medium (step 134). When a user selection mode is set, by displaying a focusing estimation value graph indicating the focusing estimation value of each image together with the selected image (step 110), the user can quantitatively grasp the focusing state of each image, the selected image is changed in response to an instruction from the user (steps 130, 132), and the selected image, according to the instruction for recording, is recorded on the recording medium (step 134). <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a digital camera, and in particular, an imaging device, a signal processing unit that generates image data representing an image captured by the imaging device, and the image data generated by the signal processing unit is recorded on a recording medium. The present invention relates to a digital camera that includes a recording unit that performs a continuous shooting while moving a focal position.
[0002]
[Prior art]
2. Description of the Related Art In recent years, digital cameras that record images captured using an image sensor such as a CCD (Charge Coupled Device) as digital data on a recording medium such as a memory card or a built-in memory have become widespread. Generally, a digital camera includes a small display device such as an LCD (Liquid Crystal Display), and can display an image taken on the display device.
[0003]
By the way, in still image shooting, a bad image may be recorded because a person who is a subject closes his eyes at the time of shooting or a camera shake occurs when the shutter switch is pressed. It is conceivable to continuously shoot a plurality of images by pressing the button. However, in the case of a digital camera, it is not preferable to record all images that have been continuously shot because the recording capacity of the recording medium is limited. For this reason, some digital cameras have a so-called best shot selector function that records only images designated by the user from continuously taken images (see Patent Documents 1 and 2). Specifically, continuously shot images are displayed on the LCD, and the user is allowed to select a desired image.
[0004]
In a digital camera, a subject image is imaged on a light receiving surface of an image sensor by an imaging optical system such as a focus lens, and the subject image is photographed. If the object is scattered back and forth, it may not be clear which subject to focus on. For this reason, it is conceivable to employ a so-called focus bracket photographing function that performs continuous photographing while changing the focal position (see Patent Documents 3 and 4). Also in the case of this focus bracket shooting, it is required to record only the highest quality one that is in focus among the continuously shot images due to the limitation of the recording capacity of the recording medium.
[0005]
[Patent Document 1]
JP 2002-112077 A
[Patent Document 2]
JP 2001-212376 A (paragraph 0022)
[Patent Document 3]
JP-A-7-131698
[Patent Document 4]
JP 7-318785 A
[0006]
[Problems to be solved by the invention]
However, it is difficult to visually determine the focused state of the image, and simply adopting the conventional best shot selector function for focus bracket shooting cannot select the best image in focus. It was. In other words, an image of a person with his eyes closed or a blurred image due to camera shake can be visually discerned even when displayed on a small display device provided in the digital camera, but the image is in focus. I couldn't tell you. In order to grasp the in-focus state visually, the image data must be enlarged and displayed on a large display device by transferring image data to a PC (personal computer) equipped with a large display device. A user's work burden will become high.
[0007]
The present invention has been made to solve the above problems, and when a plurality of images are continuously photographed while changing the focal position, an image having a good in-focus state is selected and recorded from the plurality of photographed images. An object of the present invention is to provide a digital camera.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is an image pickup device, signal processing means for generating image data representing an image photographed by the image pickup device, and the image generated by the signal processing unit. A digital camera having a recording device for recording data on a recording medium and having a focus bracket photographing function for performing continuous photographing while moving a focal position, and a plurality of images continuously photographed by photographing with the focus bracket photographing function A calculation unit that calculates a focus evaluation value representing each focus state, and an image with a good focus state is selected based on the focus evaluation value of each of the plurality of images calculated by the calculation unit, And control means for controlling the operation of the recording means so as to record the image data representing the selected image on the recording medium. .
[0009]
According to the first aspect of the present invention, when continuous shooting is performed while changing the focal position by the focus bracket shooting function, the focus evaluation value is calculated for each of the plurality of continuously shot images by the calculation unit. Therefore, on the basis of this focus evaluation value, the control means selects an image in good focus, such as an in-focus image, as an image (recorded image) to be recorded on the recording medium, and the recording means selects the selected image. The image data representing the processed image can be recorded on a recording medium.
[0010]
According to a second aspect of the present invention, there is provided an image pickup device, signal processing means for generating image data representing an image photographed by the image pickup device, and recording for recording the image data generated by the signal processing unit on a recording medium. A focus bracket photographing function that performs continuous photographing while moving the focal position, and represents a focus state of each of a plurality of images continuously photographed by the focus bracket photographing function. A calculation unit that calculates a focus evaluation value, a display unit that displays information representing the focus evaluation value of each of the plurality of images calculated by the calculation unit, and an instruction to select an image to be recorded on the recording medium And selecting an image to be recorded on the recording medium from the plurality of images according to an operation of the operation means. It is characterized by having a control means for controlling the operation of said recording means to record the image data representing the image the selected on the recording medium.
[0011]
According to the second aspect of the present invention, when continuous shooting is performed while changing the focus position by the focus bracket shooting function, each of a plurality of images continuously shot while changing the focus position by the focus bracket shooting function is calculated by the calculation unit. Since the focus evaluation value is calculated and information indicating the calculated focus evaluation value is displayed on the display means, the user can select the best focus image from the information displayed on the display means. An image with a good focus state can be easily confirmed.
[0012]
The control unit selects an image (recorded image) to be recorded on the recording medium from a plurality of continuously shot images according to the operation of the image instruction operation unit, and represents the selected image on the recording unit. Since the image data is recorded on the recording medium, if the user operates the image instruction operation unit so as to select an image with good focus state from the display of the display unit, image data representing an image with good focus state is obtained. It can be recorded on a recording medium.
[0013]
In this case, as described in claim 3, the display unit further displays the image together with the information indicating the focus evaluation value, while the user confirms the captured image. It is preferable that the recorded image can be selected. In addition, since the focus evaluation value of each of the plurality of images is calculated by the calculation means, it is possible to automatically determine whether the focus state of each image is good or not from this focus evaluation value. As described above, the control unit selects an image to be recorded on the recording medium according to the operation of the operation unit, or automatically based on the focus evaluation value of each of the plurality of images calculated by the calculation unit. The selection may be selectively switched.
[0014]
In the digital camera, as described in claim 5, the digital camera further includes an area instruction operation unit for designating a calculation target area of the focus evaluation value on the image, and the calculation unit However, it is preferable to calculate the focus evaluation value in the calculation target area instructed by the operation of the area instruction operation means. As a result, the user sets an arbitrary part on the image, such as the background on the image and the subject part of the subject, to the calculation target area by the area instruction operation, and records based on the focused state of the part. An image can be selected.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Next, an example of an embodiment according to the present invention will be described in detail with reference to the drawings.
[0016]
FIG. 1 shows a configuration of a digital camera according to the present embodiment. A digital camera 10 shown in FIG. 1 includes an optical unit 12 including a lens for forming a subject image, a CCD 14 disposed behind the optical axis of the optical unit 12 as an image sensor, and an output from the CCD 14. An analog signal processing unit 16 that performs predetermined analog signal processing on the image signal to be processed, and an analog / digital converter (hereinafter referred to as “A / D”) that converts the analog signal processed by the analog signal processing unit 16 into a digital signal. ”18, a CCD driving unit 20 for driving the CCD 14, motors 22 </ b> A to 22 </ b> C for adjusting each of the photographing magnification, the focal position, and the aperture value of the optical unit 12, and driving the motors 22 </ b> A to 22 </ b> C. A motor driving unit 24, a light emitting unit 26 that emits light when the subject brightness is low, and a light control unit that adjusts the amount of light emitted by the light emitting unit 26 The optical unit 28, a display unit 30 as a display means provided for displaying a photographed image and various information such as an LCD, an operation unit 32 operated by a photographer, and digital image data obtained mainly by photographing. A main memory 34 that temporarily stores data and a main control unit 36 that controls the overall operation of the digital camera 10 are provided.
[0017]
The optical unit 12 forms light representing an incident subject image on the light receiving surface of the CCD 14 and includes a lens group 40 including a photographing lens 40A and a focus lens 40B, and a stop 42. . The lens group 40 may be a lens having a single focal length (fixed focus), or may be a variable focal length such as a zoom lens or a telephoto / wide-angle bifocal switching lens. In the present embodiment, the case where the lens group 40 is configured by a zoom lens will be described. That is, by driving the motor 22A, the photographing lens 40A can be zoomed and the photographing magnification can be changed. Note that the motor 22A can be omitted in the case of a manual zooming configuration or a single focus lens.
[0018]
Further, the optical unit 12 can move the focus lens 40B in the optical axis direction by driving the motor 22B to move the focus position, and can adjust the aperture value of the diaphragm 42 by driving the motor 22C. It has become. Note that a stepping motor or a DC motor can be used as the motors 22A to 22C. These motors 22 </ b> A to 22 </ b> C are connected to the motor drive unit 24 and are driven by the motor drive unit 24.
[0019]
The CCD 14 is connected to the CCD driving unit 20 and the analog signal processing unit 16. The CCD 14 converts the light incident on the light receiving surface into an amount of signal charge corresponding to the amount of incident light, and synchronizes with the drive pulse supplied from the CCD drive unit 20 to analogize the voltage signal corresponding to the accumulated signal charge. The image signal is output to the analog signal processing unit 16.
[0020]
The CCD 14 is provided with a shutter drain via a shutter gate, and the accumulated signal charge can be swept out to the shutter drain by driving the shutter gate with a shutter gate pulse. That is, the CCD 14 has a so-called electronic shutter function that controls the accumulation time (shutter speed) of charges accumulated in each sensor by the shutter gate pulse.
[0021]
The analog signal processing unit 16 performs correlated double sampling (CDS) processing on the analog image signal output from the CCD 14 and color separation processing into R (red), G (green), and B (blue) color signals. The signal level is adjusted (for example, pre-white balance processing). The analog signal processing unit 16 is connected to the A / D 18, and the A / D 18 is connected to the main control unit 36.
[0022]
The analog image signal after processing by the analog signal processing unit 16 is by A / D18. After being converted into digital image signals of each color of RGB, it is input to the main controller 36.
[0023]
The main control unit 36 includes a focus evaluation value calculation unit 50 as a calculation unit that calculates a focus evaluation value for evaluating a focus state, and an AE / AWB calculation unit 52 that calculates optimal exposure and white balance. A digital signal processing unit 54 that performs predetermined digital signal processing on the input digital signal to generate digital image data; and compresses the digital image data by a predetermined compression method and converts the compressed digital image data As a recording means for reading and writing data to a compressing / decompressing processing unit 56 that expands, a memory control unit 58 that reads and writes data in the main memory 34, and a portable recording medium 60 that is detachably loaded in a slot (not shown). The media control unit 62, the display control unit 64 that controls the display operation of the display unit 30, and the CPU 66 that controls the entire main control unit 36. They are connected to each other by 68.
[0024]
Further, the CPU 66 is connected to the operation unit 32 and can always grasp the operation state of the operation unit 32 by the photographer. Here, the operation unit 32 has a release button for giving an instruction to record and record an image, a camera mode selection unit such as a shooting mode and a reproduction mode, a zoom operation unit, and other input units for inputting various instructions and information. Is included. These means have various forms such as a switch button, a dial, and a slide type knob, and there is an aspect in which a setting menu or a selection item is displayed on the screen of the touch panel or the display unit 30 and a desired item is selected with a cursor. The operation unit 32 may be disposed in the camera body, or may be configured as a remote control transmitter that is separated from the camera body.
[0025]
Further, particularly as related to the present invention, in the present embodiment, as the shooting mode, in addition to the normal shooting mode, a focus bracket shooting mode can be selected. The operation means includes input means 32A to 32D (see FIGS. 4 to 6) for inputting various instructions when selecting a recorded image when the focus bracket photographing mode is selected and photographing is performed. In the focus bracket shooting mode, it is possible to select either a user selection mode in which the user selects a recorded image using the input means A to D or an automatic selection mode in which the best image in focus is automatically selected. It has become.
[0026]
The CPU 66 is connected to the motor drive unit 24, the CCD drive unit 20, the light emitting unit 26, and the light receiving unit 28, and controls driving of these units according to the operation state of the operation unit 32.
[0027]
Specifically, when the shooting mode is selected by operating the operation unit 32, the CPU 66 drives the CCD 14 at a predetermined timing by the CCD drive unit 20 to shoot a subject image, and zooms by the operation unit 32. When an operation (zoom-in / zoom-out) is performed, the motor 22A is appropriately driven via the motor drive unit 24 to change the photographing magnification. As a result, photographing is performed at a desired photographing magnification, and the image signal representing the subject image is input from the CCD 14 to the main control unit 36 via the analog signal processing unit 16 and the A / D 18 as described above. The image signal (digital image signal) input to the main control unit 36 is stored as image data in the main memory 34 via the memory control unit 58, and the focus evaluation value calculation unit 50 and AE / AWB calculation. Input to the unit 52, focus evaluation value calculation, AE calculation, and AWB calculation are performed. Based on these calculations, the CPU 66 appropriately drives the motors 22B and 22C by the motor drive unit 24 to perform AF (Auto Focus) control for moving the focus lens 40B to the in-focus position and AE (Auto) for optimal exposure. (Exposure) control is performed, and an AWB adjustment value (digital gain described later) is set. That is, in the digital camera 10, only by directing the photographing lens 40A toward the subject, focusing is automatically performed, and optimal exposure adjustment and AWB adjustment are performed.
[0028]
Specifically, a contrast AF control method is employed in which the focus lens 40B is moved so that the high frequency component of the G image signal is maximized. That is, the CPU 66 drives the motor 22B via the motor driving unit 24 to position the focus lens 40B at a position where the contrast is maximized.
[0029]
Specifically, in the AF control, the focus evaluation value calculation unit 50 passes a high-pass filter with respect to the image signal (image data) acquired for each position of each focus lens 40B, and integrates the obtained output values. To obtain the focus evaluation value. The CPU 66 compares the focus evaluation value obtained for each position of each focus lens 40B by the focus evaluation value calculation unit 50, and sets the position of the focus lens 40B where the focus evaluation value is maximized to the maximum contrast. Determine as position.
[0030]
Note that it is not necessary to pass a high-pass filter for each of the RGB image signals (image data). For example, only the G image signal (image data) may be obtained through the high-pass filter. The high-pass filter may be a simple method that merely obtains a difference between adjacent pixels, for example.
[0031]
In the present embodiment, in order to select a recorded image at the time of focus bracket shooting described later, a focus evaluation value can be set for each of a plurality of predetermined areas on the image. .
[0032]
In addition to the method of controlling based on the image signal acquired from the CCD 14 as described above, the AF control measures the distance of the subject using a well-known distance measuring sensor including an AF light projecting / receiving sensor. You may do it. In addition, when multi-point distance measurement is possible with such a distance measuring sensor, an evaluation value (AF evaluation value) obtained from each evaluation area is used for selecting a recorded image at the time of focus bracket shooting described later. It may be used as a focus evaluation value.
[0033]
In the AE control, the AE / AWB calculation unit 52 obtains subject luminance (photographing EV) based on an integrated value obtained by integrating image signals (image data) of each color of RGB in one frame, and exposure is performed based on the photographing EV. The aperture value and shutter speed are determined as control values, and the CPU 66 drives the motor 22C via the motor drive unit 24 to adjust the aperture 42 so that the determined aperture value is obtained, and the determined shutter speed. AE control is performed by controlling the charge accumulation time of the CCD 14 with an electronic shutter. The AE control may be performed using a known photometric sensor or the like in addition to the method of controlling based on the image signal acquired from the CCD 14 as described above.
[0034]
In the AWB adjustment, the AE / AWB calculation unit 52 determines the light source type using the subject luminance (shooting EV) and color information such as R / G, B / G, and the CPU 66 relates to the color temperature of the light source. Instead, the digital gain for adjusting the white balance in the digital signal processing unit 54 is adjusted so that the white subject is reproduced in white.
[0035]
The image signal (digital image signal) input to the main control unit 36 is also input to the digital signal processing circuit 64 and subjected to predetermined digital image processing. Specifically, the digital signal processing unit 54 performs AWB adjustment by applying a digital gain corresponding to the light source type, performs gamma processing and sharpness processing, generates predetermined digital image data, and further performs YC conversion processing. , Converted into luminance data Y and chroma data Cr, Cb (hereinafter referred to as “YC signal”). The YC signal generated by the digital signal processing circuit 64 is written back to the main memory 34 as image data. Then, the YC signal written back as image data in the main memory 34 is supplied to the display control unit 64, converted into a predetermined signal (for example, an NTSC color decoded video signal), and output to the display unit 30. Is done.
[0036]
Thereby, an image showing a subject image photographed by the CCD 14 is displayed on the display unit 30. Further, the image data is periodically rewritten by the image signal output from the CCD 14, and a video signal generated from the image data is supplied to the display unit 30, so that the subject image captured by the CCD 14 is a moving image in substantially real time. Or as a continuous image on the display unit 30.
[0037]
The display unit 30 can be used as an electronic viewfinder, and the photographer can check the shooting angle of view with a display image (so-called through image) of the display unit 30 or an optical viewfinder (not shown). In response to a predetermined recording instruction (photographing instruction) operation such as a release button pressing operation, capturing of image data for recording is started.
[0038]
That is, at the time of shooting recording, the AF control described above is performed when the release button is “half-pressed”, and the photometric operation is repeated a plurality of times to obtain an accurate shooting EV, and the aperture value at the time of shooting is determined based on this shooting EV. The shutter speed is finally determined. Then, when the release button is “fully pressed”, the charge accumulation time of the aperture 42 and the CCD 14 is controlled so that the final determined aperture value and shutter speed are obtained, and a subject image is taken for recording. .
[0039]
Further, when shooting the subject image for recording, the CPU 66 can cause the light emitting unit 26 to emit light in accordance with the strobe mode set by the operation of the operation unit 32. Specifically, the strobe mode includes a “low-brightness automatic light-emitting mode” in which the light-emitting unit 26 automatically emits light at low luminance, a “forced light-emitting mode” in which the light-emitting unit 26 emits light regardless of subject brightness, and the subject Any one of the “light emission prohibiting modes” for prohibiting the light emission of the light emitting unit 26 regardless of the brightness is selected and set.
[0040]
The CPU 66 controls charge control of the main capacitor of the light emitting unit 26 and discharge (light emission) timing according to the strobe mode selected by the user. Further, the CPU 66 controls light emission stop based on the measurement result of the light receiving unit 28. Specifically, the light receiving unit 28 receives reflected light from the subject image illuminated by the light emitted from the light emitting unit 26 and converts it into an electrical signal corresponding to the amount of received light. This electrical signal is integrated by an integration circuit (not shown). Then, the CPU 66 stops the light emission of the light emitting unit 26 when the integrated light reception amount reaches a predetermined appropriate light reception amount.
[0041]
An analog signal processing unit 16 performs analog signal processing on the recording result of such a subject image, converts the result into a digital signal by the A / D 18, and digital signal processing by the digital signal processing unit 54 generates a YC signal. After being stored in the main memory 34, the data is compressed by the compression / decompression processing unit 56 using a predetermined compression method such as JPEG, and then recorded on the recording medium 60 via the media control unit 62. That is, the analog signal processing unit 16, A / D 18, digital signal processing unit 54, and compression / decompression processing unit 56 constitute a signal processing unit of the present invention. Note that the compression of the image data is not essential, and the compression processing by the compression / decompression processing unit 56 is omitted when the compression cancellation is designated by the photographer's operation.
[0042]
The recording medium 60 can be in various forms such as smart media, PC cart, micro drive, multimedia card (MMC), magnetic disk, optical disk, magneto-optical disk, memory stick, etc. Corresponding signal processing means and interfaces are applied.
[0043]
At the time of image reproduction, image data to be reproduced is selected from the image data stored in the recording medium 60 and read out via the media control unit 62. The image data is decompressed by the compression / decompression processing unit 56, written to the main memory 34 via the memory control unit 58, and displayed on the display unit 30 via the display control unit 64.
[0044]
Here, in the digital camera 10 according to the present embodiment, it is possible to perform focus bracket shooting in addition to the normal shooting as described above. Specifically, when the focus bracket shooting mode is set by the operation of the operation unit 32 of the user, when the release button is “fully pressed” and shooting recording is instructed, the CPU 66 causes the motor driving unit 24 to be turned on. As shown in FIG. 2, the focus lens 40B is moved back and forth in two steps by a predetermined step a with the position determined by the AF control as the center (center). The focus lens 40B is set at each of the positions, and photographing is continuously performed. That is, five images are continuously shot while changing the focal position. The position of the focus lens 40B is set in the order of -2a, -a, center, a, 2a.
[0045]
Therefore, in focus bracket shooting, the image data for five images continuously shot with the focus lens 40B shifted at every predetermined step a, that is, with the focus position shifted, is temporarily stored in the main memory 34 via the memory controller 58. Will be stored. Further, the CPU 66 functions as the control means of the present invention when shooting in the focus bracket shooting mode, selects any one of the five image data obtained by the shooting, and selects the selected image data. Are read from the main memory 34 via the memory control unit 58 and recorded on the recording medium 60 via the media control unit 62. The recorded image to be recorded on the recording medium 60 can automatically select the best focused image based on the focus evaluation value, or the user can select a desired image by operating the operation unit 32. You can also
[0046]
Next, as a function of the present embodiment, a recording image selection process at the time of focus bracket shooting will be described.
[0047]
When the focus bracket shooting mode is set by the user's operation of the operation unit 32 and the release button is “fully pressed” to instruct shooting, the digital camera 10 is centered on the position determined by the AF control ( As the center), the position of the focus lens 40B is changed in the order of -2a, -a, center, a, 2a, and photographing is performed at the position of each focus lens 40B. That is, five images are continuously photographed while changing the focal position, and the image data for the five images are temporarily recorded in the main memory 34. Then, the CPU 66 starts the recorded image selection process shown in FIG.
[0048]
That is, as shown in FIG. 3, when five images are continuously photographed while changing the focal position, the CPU 66 first sets an evaluation area for evaluating the in-focus state as a calculation target region in step 100. Specifically, in the present embodiment, an evaluation area can be selected from a total of nine regions 200A to 200I (see FIG. 4) around the center of the image and its periphery. The selection of the evaluation area may be performed by selecting an area targeted for AF control at the time of shooting, or may be selected by operating the operation unit 32 by the user. In the following description, an example in which the region 200B located at the upper center of the image is set as the evaluation area will be described.
[0049]
In the next step 102, the CPU 66 causes the focus evaluation value calculation unit 50 to calculate the focus evaluation value in the selected evaluation area, that is, the region 200B, for each of the five captured images. In the CPU 66, based on the calculated focus evaluation value of each image, in the next step 104, a graph (focus evaluation value graph) representing the correspondence between the calculated focus evaluation value and the image is evaluated. At the same time, the image having the highest focus evaluation value is selected as an appropriate image.
[0050]
If the user selection mode is set, an affirmative determination is made in the next step 108, and the process proceeds to step 110, where the selected image and the created focus evaluation value graph are displayed via the display control unit 64. Display on the unit 30.
[0051]
At this time, in this embodiment, as an example, a selection screen 220 as shown in FIG. 4 is displayed on the display unit 30. The selection screen 220 in FIG. 4 is provided with an image display area 222 for displaying a selected image and a graph display area 224 for displaying a focus evaluation value graph. In the initial state immediately after the selection screen 220 is displayed, the appropriate image selected in the above-described step 106 is displayed in the image display area 222. On the image, the areas 200A to I are displayed in the evaluation area. , That is, the region 200B is indicated by a solid line, and the others are indicated by a dotted line, and is clearly indicated so that the user can grasp in which region on the image the focus evaluation value is calculated. Yes. In the graph display area 224, the focus evaluation value graph created in the above-described step 106. More specifically, the horizontal axis represents the position of the focus lens 40B at the time of image capturing, and the vertical axis represents the above-described step 102. A graph showing the in-focus evaluation value is displayed.
[0052]
On the selection screen 220, selectable menu items are “evaluation area change”, “whole / enlarged display switching”, “change selected image”, and “record” corresponding to the input means 32A to 32D. Four items are displayed. That is, when the selection screen 220 is displayed, the input unit 32A inputs an evaluation area change instruction, the input unit 32B inputs an entire / enlarged display switching instruction, and the input unit 32C In order to input a change instruction, the input unit 32D is used to input a recording instruction.
[0053]
By displaying the selected image and the focus evaluation value graph in this manner, the user can select the state of the selected image from the displayed selected image (the influence of camera shake, the presence or absence of blinking, and the general tendency of the focused state). Can be visually confirmed, and the in-focus state in the evaluation area of each image can be quantitatively confirmed from the displayed focus evaluation value graph.
[0054]
After the selection image and the focus evaluation value graph are displayed, that is, after the selection screen 220 is displayed, the CPU 66 is in a state of waiting for an instruction input from the user. When the user wants to confirm the in-focus state of another area, the user presses the input unit 32A.
[0055]
When the input means 32A is pressed by the user, the CPU 66 determines that an evaluation area change instruction has been input, and proceeds from step 112 to step 120 in FIG. 3 to change the setting of the evaluation area. The method for changing the setting of the evaluation area is not particularly limited. For example, if the selection of the areas 200A to 200I is switched according to the number of times the input unit 32A is pressed, the evaluation area is set. Good. Subsequently, in step 122, the focus evaluation value calculation unit 50 recalculates the focus evaluation value of each image within the changed evaluation area, and in the next step 122, the recalculated focus evaluation value is used. Recreate the focus evaluation value graph. In the next step 126, the display on the display unit 30 is updated via the display control unit 64.
[0056]
That is, in step 126, as shown in FIG. 5, the display of the graph display area 224 on the selection screen 220 is changed to the re-created focus evaluation value graph and the area on the selection screen of the image display area 222 The solid line / dotted line display of 200A to I is also changed. FIG. 6 shows a case where the evaluation area is changed to the area 200A. Thereby, the user can confirm the focus evaluation value of each image in the evaluation area after the change. After this display update, the process returns to step 112 and again enters the instruction input standby state.
[0057]
In addition, when the user displays the entire selected image in the image display area 222 and wants to confirm the in-focus state in the evaluation area in detail with the naked eye, or in the image display area 222, a portion in the evaluation area of the selected image. Is enlarged and the input means 32B is pressed when it is desired to check the state of the entire image. Note that immediately after the selection screen is displayed, that is, in the initial state, the entire selected image is displayed in the image display area 222.
[0058]
When the input unit 32B is pressed by the user, the CPU 66 determines that an instruction to switch the entire image / enlarged display is input, and proceeds from step 112 to step 128 via step 114, and in the image display area 222. When the entire selected image is displayed in the image display area 222, the display of the selected image is switched from the entire image display to the enlarged display in the evaluation area as shown in FIGS. When the evaluation area of the selected image is enlargedly displayed in 222, the display from the enlarged display in the evaluation area to the entire image display is performed via the display control unit 64 as shown in FIGS. The display of the unit 30 is switched. After the display is switched, the process returns to step 112 and again enters the instruction input standby state.
[0059]
Further, when the user wants to check the state of another image, the user operates the input unit 32C.
[0060]
When the input unit 32C is pressed by the user, the CPU 66 determines that an image change instruction has been input, proceeds from step 112 to step 130 through step 114 and step 116, and changes the selected image. The method for changing the selected image is not particularly limited in the present invention. For example, the selection from among the five images may be switched according to the number of times the input unit 32C is pressed. In the next step 132, the display on the display unit 30 is updated via the display control unit 64. That is, in step 132, the display of the image display area 222 on the selection screen 220 is changed to the image after the selection change. Thereby, the user can check the state of the image after the selection change. After this display update, the process returns to step 112 and again enters the instruction input standby state.
[0061]
In addition, the user confirms the display of the selected image and the focus evaluation value graph in this way, and the selected image, that is, the five images captured in the image display area by the focus bracket shooting. If it is determined that the image is the most preferable, the input unit 32D is pressed.
[0062]
When the input unit 32D is pressed by the user, the CPU 66 determines that a recording instruction has been input, and proceeds from step 112 to step 134 via step 114, step 116, and step 118, and is currently selected. An image is selected as a recorded image, image data of the recorded image is read from the main memory 34 via the memory control unit 58, compressed by the compression / decompression unit 56 as necessary, and then recorded on the recording medium via the media control unit 62. 60.
[0063]
On the other hand, if the automatic selection mode is set, a negative determination is made in step 108 and the process proceeds to step 134 as it is, and the currently selected image, that is, the image with the highest focus evaluation value is selected as the recorded image. Then, the image data of the recorded image is read from the main memory 34 via the memory control unit 58, compressed as necessary by the compression / decompression unit 56, and then recorded on the recording medium 60 via the media control unit 62.
[0064]
When the selected image is recorded on the recording medium 60 in this way, the processing in FIG. 3 is terminated, and the digital camera 10 proceeds to shooting processing and playback processing according to the operation of the operation unit 32 of the user. Note that other image data not recorded on the recording medium 60 in step 134 is deleted from the main memory 34 via the media control unit 62 in order to secure a memory area for the next shooting or reproduction.
[0065]
As described above, in this embodiment, the focus evaluation value is calculated for each of a plurality of images continuously shot while changing the focus position by focus bracket shooting, and the image with the highest focus evaluation value, that is, the focus focus value is calculated. The best matching image can be automatically selected as a recorded image and recorded on the recording medium 60.
[0066]
Also, by displaying a focus evaluation value graph showing the focus evaluation value of each image, the user can quantitatively grasp the focus state of each image, and the user selects a desired image as a recorded image You can also. At this time, by displaying the selected evaluation image together with the focus evaluation value graph, the user can visually grasp the general tendency of the in-focus state of the currently selected image, and also the camera shake. It is possible to select a recorded image by checking whether or not there is an influence, and if the subject is a person, whether or not the person has closed his eyes. The display with the focus evaluation value graph is not limited to the selected image. For example, five images captured by focus bracket shooting are displayed simultaneously, and the user can display the state of all images at once (in-focus). The general tendency of the state, the influence of camera shake, the presence or absence of blinking, etc.) may be visually confirmed.
[0067]
In addition, since an evaluation area for calculating a focus evaluation value can be selected from a plurality of regions 200A to 200I on the image, among the background and the subject on the image, the subject portion that the user particularly wants to pay attention to can be obtained. An arbitrary portion above can be set as the evaluation area, and the focused state of the portion can be confirmed.
[0068]
【The invention's effect】
As described above, according to the present invention, when a plurality of images are continuously photographed while changing the focal position, it is possible to select and record an image having a good focus state from the plurality of photographed images. Has an excellent effect.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a digital camera according to an embodiment.
FIG. 2 is a diagram for explaining focus bracket shooting performed by the digital camera according to the present embodiment;
FIG. 3 is a flowchart showing a recorded image selection process at the time of focus bracket shooting executed by the CPU of the digital camera according to the present embodiment.
FIG. 4 is an example of a selection screen displayed on the display unit for selecting a recorded image.
FIG. 5 is an example of a selection screen displayed on the display unit for selecting a recorded image.
FIG. 6 is an example of a selection screen displayed on the display unit for selecting a recorded image.
[Explanation of symbols]
10 Digital camera
12 Optical unit
14 CCD
30 Display section
32 Operation unit
32A to D Input means
34 Main memory
36 Main control unit
40A photographic lens
40B Focus lens
42 aperture
50 Focus evaluation value calculator
58 Memory controller
60 recording media
62 Media control unit
64 Display controller
66 CPU
220 Selection screen
222 Image display area
224 Graph display area

Claims (5)

An image sensor, a signal processing unit that generates image data representing an image captured by the image sensor, and a recording unit that records the image data generated by the signal processing unit on a recording medium, and has a focal position In a digital camera with a focus bracket shooting function that performs continuous shooting while moving,
Calculating means for calculating a focus evaluation value representing a focus state of each of a plurality of images continuously shot by shooting with the focus bracket shooting function;
Based on the focus evaluation value of each of the plurality of images calculated by the calculation means, the image having a good focus state is selected, and the image data representing the selected image is recorded on the recording medium. Control means for controlling the operation of the recording means;
A digital camera comprising: An image sensor, a signal processing unit that generates image data representing an image captured by the image sensor, and a recording unit that records the image data generated by the signal processing unit on a recording medium, and a focal position In a digital camera with a focus bracket shooting function that performs continuous shooting while moving
Calculating means for calculating a focus evaluation value representing a focus state of each of a plurality of images continuously shot by shooting with the focus bracket shooting function;
Display means for displaying information representing a focus evaluation value of each of the plurality of images calculated by the calculation means;
Image instruction operation means operated to instruct selection of an image to be recorded on the recording medium;
The recording unit selects an image to be recorded on the recording medium from the plurality of images according to an operation of the image instruction operation unit, and records image data representing the selected image on the recording medium. Control means for controlling the operation of
A digital camera comprising: The digital camera according to claim 2, wherein the display unit further displays at least one of the plurality of images together with information representing the focus evaluation value. Whether the control means selects an image to be recorded on the recording medium according to an operation of the operation means, or automatically selects based on a focus evaluation value of each of the plurality of images calculated by the calculation means The digital camera according to claim 2, wherein the digital camera can be selectively switched. An area instruction operation means for designating a calculation target area of the focus evaluation value on the image;
5. The digital according to claim 1, wherein the calculation unit calculates a focus evaluation value in a calculation target region instructed by an operation of the region instruction operation unit. camera.

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