JP2004120298A - Electronic camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic camera capable of clear photographing at the time of photographing a moving object. <P>SOLUTION: The electronic camera comprises: an image processing part 86 for performing various image processings; an image preservation area A88 and an image preservation area B90 for tentatively preserving image data to which the various image processings are executed by the image processing part 86; a preserved image comparing operation part 92 for comparing (subtraction processing) the two pieces of the image data preserved in the image preservation area A88 and the image preservation area B90 and calculating the moving amount of the object; a compared result recording part 94 for time-sequentially recording a compared result by the preserved image comparing operation part 92; and a stop value and shutter speed deciding part 96 for deciding a stop value and a shutter speed on the basis of time-sequential compared results recorded in the compared result recording part 94. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic camera, and more particularly to an electronic camera having an automatic exposure adjustment function including a shutter speed and an aperture.
[0002]
[Prior art]
2. Description of the Related Art In recent years, many electronic cameras have been distributed as image pickup apparatuses using CCD image pickup devices that can be easily photographed. The electronic camera reads a charge (photoelectric conversion) corresponding to the amount of light with a CCD image sensor or the like for each pixel using an operation of a release switch as a trigger, and converts it into image data. Data is recorded on a recording medium such as a magnetic recording medium.
[0003]
In the process from shooting to recording, for each shooting frame, the main processes are digital conversion of the shot image, creation of an image for displaying the shot image, and recording processing for recording the shot image. .
[0004]
As described above, the electronic camera can easily record the captured image by operating the release switch.
[0005]
In addition, the electronic camera also has an automatic focus adjustment function (so-called AF function) for adjusting the focus on the subject and an automatic exposure adjustment function (so-called AE function) for adjusting the shutter speed and the aperture. As the AF function, for example, a focus sensor is provided to adjust the focus according to the result of measuring the distance to the subject. As the AE function, for example, an AE sensor that detects the amount of ambient light is provided, and the diaphragm and shutter speed are adjusted according to the light amount measurement result by the AE sensor.
[0006]
Furthermore, in the shooting where the subject moves, it is considered that the depth of focus changes, so if the depth of focus is detected and the movement position of the subject is within the allowable shooting depth, There has been proposed an electronic camera that adjusts an aperture and shoots an image by enlarging an allowable depth of focus (see Patent Document 1).
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 7-181545 (first page, FIG. 2)
[0008]
[Problems to be solved by the invention]
However, although the technique described in Patent Document 1 can adjust the focus according to the position of the moving subject, automatic exposure adjustment such as a shutter speed and an aperture according to the moving speed of the moving subject can be performed. There is a problem that it becomes impossible to perform clear photographing without blurring.
[0009]
The present invention has been made to solve the above problem, and an object of the present invention is to provide an electronic camera capable of clear photographing when photographing a moving subject.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, there is provided a photographing means for photographing a subject by photoelectric conversion and acquiring image data representing a photographed image, and entering the photographing means at the time of photographing by the photographing means. Adjusting means for adjusting the exposure amount to be performed, photographing control means for controlling the photographing means so as to acquire image data by the photographing means every predetermined time prior to the main photographing by the photographing means, and the photographing Under the control of the control means, at least two or more of the image data acquired every predetermined time are compared, a detection means for detecting the movement amount of the subject, and a storage means for storing the detection result by the detection means in time series And setting means for setting an adjustment amount by the adjustment means based on the movement amount stored in time series in the storage means.
[0011]
According to the first aspect of the present invention, in the photographing means, the subject is photographed by photoelectric conversion, and image data representing the photographed image is acquired.
[0012]
The adjusting unit adjusts the exposure amount of the light incident on the photographing unit when photographing by the photographing unit. For example, as in the invention described in claim 2, the adjusting means is at least one of shutter means for adjusting the exposure time of light incident on the photographing means and diaphragm means for adjusting light incident on the photographing means. Means can be applied. In other words, the adjustment means can adjust the exposure amount by performing at least one of so-called shutter speed adjustment and diaphragm adjustment.
[0013]
At this time, in the photographing control means, the photographing means is controlled so that the image data is acquired every predetermined time by the photographing means prior to the main photographing by the photographing means. That is, before the actual shooting, a plurality of image data is acquired by the shooting control means.
[0014]
The detecting unit compares at least two pieces of image data acquired by the photographing control unit, and detects the amount of movement of the subject. For example, as in the invention described in claim 3, by subtracting at least two or more image data, it is possible to detect a difference in the center of gravity position of an object remaining on the image data as a movement amount. . That is, the object that has not moved is deleted by the subtraction process, and only the moved object remains, so that the amount of movement of the moving subject can be detected by detecting the difference in the center of gravity position of the remaining object. it can. Note that image processing (for example, edge extraction, color normalization, gamma correction, flattening processing, etc.) for easily performing subtraction processing may be performed before subtracting at least two or more image data. .
[0015]
Thus, the movement amount detected by the detection means is stored in time series in the storage means. Then, in the setting means, the adjustment amount by the adjustment means is set based on the movement amount stored in time series. For example, when comparing the amount of movement of the subject stored in time series, the difference in the center of gravity of the object increases as the moving speed increases and decreases as the moving speed decreases. Therefore, the shutter speed increases as the moving amount increases. The adjustment means is adjusted so as to increase the speed and decrease the shutter speed as the movement amount decreases.
[0016]
That is, by adjusting the adjustment unit according to the amount of movement of the subject stored in time series, the exposure amount according to the movement speed of the subject can be set.
[0017]
Therefore, by setting the adjustment amount by the adjustment unit according to the movement amount stored in the storage unit in time series, the exposure amount according to the moving speed of the moving subject can be set, and the moving subject When shooting, clear shooting is possible.
[0018]
The setting by the setting means can be easily realized by using a lookup table or the like in which the adjustment amount by the adjustment means corresponding to the movement amount is determined in advance.
[0019]
Further, as in the invention described in claim 4, the invention further includes a plurality of storage means for storing image data acquired every predetermined time by the imaging control means, and according to the end of setting by the setting means, You may make it update the image data preserve | saved at several preservation | save means sequentially. Thus, by providing a plurality of storage means, it is possible to continuously perform adjustment by the adjustment means.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.
[0021]
As shown in FIG. 1A, the upper surface of the electronic camera 10 to which the present invention is applied pops up from the inside of the main body and emits light when the subject has low illuminance at which an appropriate exposure light amount cannot be obtained. A stroboscope 18 is provided, and a finder window 16 into which light showing an image substantially equivalent to a photographed subject image enters and an optical unit 14 for forming the subject image are provided on the front. . In addition, a portable recording medium (smart media in the present embodiment) 30 (see FIG. 2 and omitted in FIG. 1) that stores image data obtained by photographing as digital data is provided on the side of the electronic camera 10. A slot 24 that can be mounted, and a USB terminal 42 and other terminals 44 for transmitting image data obtained by photographing with the electronic camera 10 to an external device are provided. In addition, an AC adapter connection port 28 for connecting an AC adapter for obtaining power from an AC power supply is provided, so that AC power can be supplied to the electronic camera 10.
[0022]
The optical unit 14 is a so-called collapsible optical lens, and is retracted in the housing 12 of the main body of the electronic camera 10 except for photographing, and can be expanded and contracted in the optical axis direction during photographing. 15 is extended so that it appears outside the housing 12 as shown in FIG. The optical unit 14 includes a photographing lens 36, a focus lens 40, and a diaphragm mechanism 38 in the lens barrel 15 (see FIG. 2). The taking lens 36 is composed of one or a plurality of lenses, and may be a single focal length (fixed focus) lens, or a variable focal length such as a zoom lens or a telephoto / wide-angle bifocal switching lens. But you can.
[0023]
On the other hand, as shown in FIG. 1B, the electronic camera 10 is incident from a finder window 16 and a display device (LCD) 26 for displaying subject images, various menus, parameters, and the like obtained by photographing. The light is guided through an optical member (not shown), and the finder eyepiece 16a to be looked at by the photographer when determining the composition of the subject image to be photographed, and the photographing magnification is increased or decreased, or displayed on the display device 26 An eight-way key 3434 operated by the photographer when selecting a desired menu item or parameter from the menu screen. Further, in the vicinity of the display device 26, a power switch 20 is provided for switching between supply / stop of supply of power to each unit of the electronic camera 10.
[0024]
Furthermore, on the upper surface of the electronic camera 10, a shutter switch (so-called release switch) 22 that is pressed by the photographer to input an instruction for photographing recording, and a mode that is rotated by the photographer when selecting the photographing mode. A dial 17 is provided.
[0025]
Next, the configuration of the electrical system of the electronic camera 10 according to the embodiment of the present invention will be described with reference to FIG.
[0026]
As shown in FIG. 2, the electronic camera 10 includes a CCD (Charge Coupled Device) 50 disposed behind the optical axis of the optical unit 14 and an output signal representing a subject image read from the CCD 50 by correlated double sampling (CDS). : Correlated Double Sampling), color separation processing into R, G, and B color signals and adjustment of the signal level of each color signal, and an analog signal processed by the CDS circuit 52 as a digital signal A digital / analog converter (hereinafter referred to as an A / D converter) 54 for converting to a CCD, a timing generator (TG) 56 for generating a timing signal for driving the CCD 50, and a photographing lens 36 included in the optical unit unit 14. Zoom mode for moving the lens Motor driver 58 for driving each motor, such as an AF (Auto Focus) motor for moving the focus lens 40 and an iris motor for driving the aperture mechanism 38, and the overall operation of the electronic camera 10. And a main control unit 60 that performs the control.
[0027]
The main control unit 60 also has an image input control unit 62 for inputting a signal after digital conversion by the A / D converter 54 as image data representing a photographing result (subject image) by the CCD 50, and input image data. An image signal processing circuit 64 for performing predetermined digital signal processing, a VRAM 66 for storing image data to be displayed on the display device 26, and a display device for displaying an image based on the image data stored in the VRAM 66. 26, a compression signal processing circuit 70 for compressing / decompressing image data, a media control unit 72 for reading / writing various information with respect to the recording medium 30 loaded in the slot 24, AE (Auto Exposure) that detects optimal exposure and white balance based on the result of photographing by CCD 50 An AWB (Auto White Balance) detection circuit 74, an SDRAM (Synchronous Dynamic Random Access Memory) 78 used as a work memory, and an EEPROM (Electrically Removable Memory 80) in which information such as various programs and parameters are stored in advance. The CPU 82 that reads out information from the EEPROM 80 and controls the above-described units is mutually connected by a bus 84. The CPU 82 is connected to the TG 56 and the motor driver 58.
[0028]
Further, the CPU 82 is connected with an eight-direction key 34, a power switch 20, a shutter switch 22, and a mode dial 17 provided in the electronic camera 10 as operation means operated by the user. Can always grasp the operation information.
[0029]
Specifically, when the still image or moving image shooting mode is selected with the mode dial 17, the CPU 82 drives the TG 56 to cause the CCD 50 to shoot a subject image at a predetermined timing.
[0030]
In general, the CCD 50 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 50 controls the accumulation time (shutter speed) of charges accumulated in each sensor by the shutter gate pulse. Although it has a so-called electronic shutter function, a mechanical shutter may be provided instead of the electronic shutter.
[0031]
The analog signal indicating the subject image output from the CCD 50 is processed by the CDS circuit 52, converted into a digital image signal by the A / D converter 54, and then subjected to main control from the image input control unit 62 as image data. It is input in the part 60. The input image data is temporarily stored in the SDRAM 78 via the bus 84.
[0032]
The main control unit 60 performs focus evaluation calculation in the AF detection circuit 74 and AE calculation and AWB calculation in the AE / AWB detection circuit 76 based on the input image data, and the CPU 82 performs the calculation based on these calculations. Then, the motor driver 58 and the CCD 50 are controlled to drive the drive means (for example, AF motor and iris motor) of the focus lens 40 and the diaphragm mechanism 38 and the electronic shutter function of the CCD 50 to move the focus lens 40 to the in-focus position. At the same time, the aperture mechanism 38 and the electronic shutter function are set to appropriate exposure control values (aperture value and shutter speed), and an AWB adjustment value (digital gain described later) is set.
[0033]
For example, a contrast AF method in which the focus lens 40 is moved so that the high-frequency component of the G signal is maximized can be used for the AF control.
[0034]
In the AE control, subject luminance (shooting EV) is obtained based on an integrated value obtained by integrating R, G, and B signals of one frame, and an aperture value and a shutter speed are determined as exposure control values based on the taken EV. The aperture mechanism 38 is controlled by the motor driver 58 and the electronic shutter function of the CCD 50 is controlled by the CPU 82.
[0035]
For AWB adjustment, the light source type is discriminated using subject luminance (photographing EV) and color information such as R / G and B / G, and a white subject is reproduced in white regardless of the color temperature of the light source. The digital gain for adjusting the white balance is determined.
[0036]
Therefore, in the electronic camera 10, the optical unit 14 (the photographic lens 36) is directed toward the subject, the focus is automatically adjusted, and the optimum exposure adjustment and AWB adjustment are performed.
[0037]
Specifically, when the still image shooting mode is selected with the mode dial 17, that is, during still image shooting and recording, the above-mentioned photometric operation is repeated a plurality of times when the shutter switch 22 is "half-pressed", and the focus lens The camera 40 is moved to focus, and an accurate shooting EV is obtained. Based on the shooting EV, an aperture value and a shutter speed as exposure control values at the time of shooting are finally determined, and a digital gain is determined. Then, after the aperture mechanism 38 is driven so that the aperture value is finally determined when the shutter switch 22 is “fully pressed”, the electronic shutter function of the CCD 50 is driven so that the shutter speed is finally determined. Further, the image signal processing circuit 64 performs AWB adjustment processing on the image data obtained at this time using the determined digital gain.
[0038]
Further, when the moving image shooting mode is selected by the mode dial 17, that is, during moving image shooting and recording, this control operation is always repeated, and appropriate AF control, AE control, and AWB adjustment are performed during the mode selection period. Will continue.
[0039]
In the main control unit 60, predetermined digital image processing is performed on the input image data by the image signal processing circuit 64. Specifically, the image signal processing circuit 64 performs AWB adjustment by applying a digital gain corresponding to the light source type, performs gamma processing, sharpness processing, and the like to generate predetermined digital image data, and further performs YC conversion processing. Thus, the luminance data Y and the chroma data Cr and Cb (hereinafter referred to as YC signals) are converted. The YC signal generated by the image signal processing circuit 64 is written into the VRAM 66.
[0040]
The YC signal stored in the VRAM 66 is supplied to the display control unit 68, converted into a predetermined signal (for example, an NTSC color decoded video signal), and output to the display device 26. As a result, an image showing the subject image photographed by the CCD 50 is displayed on the display device 26.
[0041]
Further, the image data is appropriately rewritten by the image signal output from the CCD 50, and a video signal generated from the image data is supplied to the display device 26, so that the subject image captured by the CCD 50 is a moving image in substantially real time. Or as a continuous image on the display device 26.
[0042]
The display device 26 also functions as an electronic viewfinder, and a photographer can display a display image (so-called through image) of the display device 26 or an optical viewfinder (light that has entered through the viewfinder window 16 in FIG. 1 with an optical member (not shown)). This is realized by guiding the eyepiece unit 16a), so that the shooting angle of view can be confirmed. In response to a predetermined recording instruction (photographing instruction) operation such as a pressing operation of the shutter switch 22, capturing of image data for recording is started.
[0043]
In the main control unit 60, when photographing recording is instructed by pressing the shutter switch 22, the YC signal generated by the image signal processing circuit 64 is also stored in the SDRAM 78 under the control of the CPU 82. The YC signal is compressed by the compression / decompression processing circuit 70 using a predetermined compression method such as JPEG, and then recorded on the recording medium 30 via the media control unit 72. Note that the compression of the image data is not essential, and when the cancellation of the compression is designated by the operator's operation, the compression processing by the compression / decompression processing circuit 70 is omitted and the image data is recorded on the recording medium 30.
[0044]
In addition to the smart media, the recording medium 30 can take various forms such as a PC card, a micro drive, a multimedia card (MMC), a magnetic disk, an optical disk, a magneto-optical disk, a memory stick, and the like. Depending on the media used, signal processing means and interfaces are applied.
[0045]
Further, at the time of image reproduction, the image data to be reproduced stored in the recording medium 30 is read via the media control unit 72 and stored in the SDRAM 78. The image data stored in the SDRAM 78 is decompressed by the compression / decompression processing circuit 70, written back to the SDRAM 78, accumulated as reproduced image data in the VRAM 66, and displayed on the display device 26 via the display control unit 68. Is done.
[0046]
By the way, the AE control of the electronic camera 10 according to the embodiment has a moving body photographing AE mode in which the moving speed of the subject is detected and the aperture and the shutter speed are controlled in addition to the general AE control described above. The AE / AWB detection circuit 76 includes the configuration shown in FIG.
[0047]
In the moving body shooting AE mode, the moving amount of the subject image is detected from the image data obtained by shooting with the CCD 50 to determine the aperture value and the shutter speed.
[0048]
Specifically, as shown in FIG. 3, the AE / AWB detection circuit 76 temporarily stores an image processing unit 86 that performs various image processing and image data that has been subjected to various image processing by the image processing unit 86. An image storage area A88 and an image storage area B90 to be stored, and a stored image comparison operation unit that compares (subtracts) two image data stored in the image storage area A88 and the image storage area B90 and calculates a movement amount of the subject. 92, a comparison result recording unit 94 for recording the comparison results by the stored image comparison calculation unit 92 in time series, and an aperture value and a shutter speed are determined based on the time series comparison results recorded in the comparison result recording unit 94. And an aperture value and shutter speed determination unit 96.
[0049]
The image processing unit 86 samples image data obtained by photographing with the CCD 50 at regular intervals, performs image processing such as edge extraction, color normalization, gamma correction, and flattening processing, and then stores a stored image connected to the subsequent stage. Image data is preprocessed so that the comparison operation unit 92 can easily perform image comparison. The image processing unit 86 may be omitted, and the image signal processing circuit 64 may perform the processing.
[0050]
The image storage area A88 and the image storage area B90 alternately store the image data processed by the image processing unit 86. In addition to the newly written image data, the image data of the previous frame is stored and overwritten alternately so that the image data of the previous frame is always retained.
[0051]
The stored image comparison calculation unit 92 compares the two image data stored in the image storage area A88 and the image storage area B90 by performing a subtraction process or the like. That is, since the object portion that has not moved exists in the two images in the same manner, only the moving subject remains by performing the subtraction process. Then, the center of gravity of the two objects as the moved subjects existing in the subtracted image data is calculated, and the difference between the positions is calculated as the amount of movement of the subject.
[0052]
The comparison result recording unit 94 records the calculation result of the saved image comparison calculation unit 92, that is, the difference between the centroid positions of the two objects in time series.
[0053]
The aperture value and shutter speed determination unit 96 uses the time-series data recorded in the comparison result recording unit 94 to move the subject at a higher speed as the interval is larger (the difference in the center of gravity position of the object is larger). Therefore, the shutter speed of the electronic camera 10 is increased in inverse proportion to the speed, the exposure (aperture) is increased, and the shutter speed is determined with priority. The aperture value and shutter speed determination unit 96 may determine the aperture value and shutter speed using a lookup table or the like in which an EV value corresponding to the difference in the center of gravity of the object is determined in advance.
[0054]
Next, the operation of the electronic camera 10 configured as described above will be described with reference to the flowcharts of FIGS. Note that AF control will be omitted.
[0055]
First, when the power of the electronic camera 10 is turned on, in step S10, the system is reset. At this time, when the lens cover is provided, the lens cover may be opened.
[0056]
In step S12, it is determined whether or not the mode is a shooting mode. The determination is made based on the operation position of the mode dial 17, and when the determination is affirmed, the process proceeds to step S14 and the photographing mode is activated.
[0057]
Here, the photographing mode will be described with reference to the flowchart of FIG.
[0058]
In step S20, the captured image represented by the image data output from the CCD 50 is displayed on the display device 26.
[0059]
In step S22, it is determined whether or not the shutter switch 22 is half pressed. The process waits until the determination is affirmed and proceeds to step S24.
[0060]
In step S24, AE control is activated. Here, the AE control will be described with reference to FIG. The AE control will be described by taking the case of the above-described moving body shooting AE mode as an example. The moving body shooting AE mode may be set as a default setting or may be set by operating a menu screen or the like.
[0061]
In step S40, image processing such as edge extraction, color normalization, gamma correction, and flattening processing is performed on the image data sampled at regular intervals by the image processing unit 86, and the process proceeds to step S42.
[0062]
In step S42, the image data subjected to the image processing is sequentially stored in the image storage area A88 and the image storage area B90, and the process proceeds to step S44.
[0063]
In step S44, image comparison is performed by the saved image comparison calculation unit 92 using the saved images saved in the image saving area A88 and the image saving area B90, and the process proceeds to step S46. That is, by performing subtraction processing by the saved image comparison operation unit 92 using two image data, as shown in FIG. 8, objects that have not moved are deleted, and only the moved objects remain as two objects.
[0064]
In step S46, the stored image comparison calculation unit 92 calculates the centroid position of the two objects, calculates the difference between the calculated centroid positions, and proceeds to step S48.
[0065]
In step S48, the calculation results are recorded in the comparison result recording unit 94 in time series, and the process proceeds to step S50.
[0066]
In step S50, the aperture value and the shutter speed are determined from the calculation result recorded in the comparison result recording unit 94. The process proceeds to step S52, and the motor driver 58 is driven so as to obtain the determined aperture value. Then, the diaphragm mechanism 38 is adjusted, and the process proceeds to step S26 in FIG. As for the shutter speed, shooting is performed at the determined shutter speed at the time of recording a shot image to be described later. That is, by comparing the difference in the center of gravity recorded in the comparison result recording unit 94 in time series, the larger the difference in the center of gravity position, the more the subject moves at a higher speed. The speed can be estimated. Therefore, by determining the aperture value and the shutter speed according to the difference in the center of gravity position, the exposure amount according to the moving speed of the subject can be set, and appropriate photographing can be performed. The aperture value and shutter speed may be stored in advance as a table corresponding to the difference between the center of gravity positions, and the aperture value and shutter speed may be selected according to the difference between the center of gravity positions. Further, the moving speed of the subject may be estimated, and the aperture value and the shutter speed may be determined according to the estimated moving speed. Here, the movement speed is estimated by calculating the movement amount of the moving object based on, for example, the difference in the center of gravity position, the photographing magnification, and the like, and the movement speed of the object is calculated from the sampling time of the image data and the calculated movement amount. The exposure amount (aperture and shutter speed) can be determined according to the estimated moving speed.
[0067]
On the other hand, in step S26 of FIG. 5, it is determined whether or not the shutter switch 22 has been fully pressed. If the determination is negative, the process returns to the above step S22 and the above processing is repeated.
[0068]
If the determination in step S26 is affirmative, the process proceeds to step S28, the captured image is recorded, and the process returns to step S12 of the “power on” program shown in FIG. That is, image data obtained by shooting is recorded on the recording medium 30.
[0069]
Returning to step S12 of the “power on” program shown in FIG.
[0070]
If the determination in step S12 is negative, the process proceeds to step S16 and the playback mode is activated.
[0071]
Next, the playback mode will be described with reference to the flowchart of FIG.
[0072]
In step S70, it is determined whether or not the current mode is the playback mode. If the determination is negative, the process returns to step S12 of the “power on” program.
[0073]
If the determination in step S70 is affirmative, the process proceeds to step S72, and the image recorded at the currently designated address is displayed on the display device by the pointer representing the address on the VRAM 66 of the already recorded image data. 26, and the process proceeds to step S74.
[0074]
In step S74, it is determined whether or not a reproduction image is selected by the eight-direction key 34. If the determination is affirmative, the process proceeds to step S76, the pointer is incremented so that another recorded image is reproduced and displayed, and the process returns to step S72.
[0075]
On the other hand, if the determination in step S74 is negative, the process exits this subroutine and returns to step S12 of the “power on” program.
[0076]
As described above, in the electronic camera 10 according to the embodiment of the present invention, it is possible to control appropriate exposure according to the moving speed of the subject by setting the aperture and the shutter speed based on the moving amount of the subject. And blurring of the subject can be minimized. Therefore, a clear image can be obtained.
[0077]
In the above embodiment, the aperture value and the shutter speed are adjusted based on the movement amount of the subject. However, the present invention is not limited to this. For example, the aperture value and the shutter speed are adjusted based on the movement amount of the subject. Either one of the shutter speeds may be adjusted.
[0078]
【The invention's effect】
As described above, according to the present invention, the amount of movement of the subject is detected by comparing the image data acquired every predetermined time, and the exposure amount is adjusted based on the amount of movement of the subject detected in time series. By setting the adjustment amount of the adjusting means, it is possible to set the exposure amount according to the moving speed of the subject, so that there is an effect that clear shooting is possible when shooting the moving subject. .
[Brief description of the drawings]
FIG. 1 is a perspective view showing an external appearance of an electronic camera according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of an electric system of the electronic camera according to the embodiment of the present invention.
FIG. 3 is a block diagram showing a configuration for operating a moving body shooting AE mode included in an AE / AWB detection circuit;
FIG. 4 is a flowchart showing a flow of operation of the electronic camera according to the embodiment of the present invention.
FIG. 5 is a flowchart showing a shooting mode subroutine;
FIG. 6 is a flowchart showing a subroutine of AE control.
FIG. 7 is a flowchart showing a playback mode subroutine;
FIG. 8 is a diagram illustrating an example of a stored image comparison operation;
[Explanation of symbols]
10 Electronic camera 38 Aperture mechanism 50 CCD
52 CDS
54 A / D converter 88 Image storage area A
90 Image storage area B
92 Saved image comparison calculation unit 94 Comparison result recording unit 96 Aperture value and shutter speed determination unit

Claims (4)

Photographing means for photographing a subject by photoelectric conversion and acquiring image data representing the photographed image;
An adjusting unit that adjusts an exposure amount incident on the photographing unit when photographing by the photographing unit;
Prior to the main photographing by the photographing means, photographing control means for controlling the photographing means so as to acquire image data by the photographing means every predetermined time;
Detection means for detecting the amount of movement of the subject by comparing at least two or more of the image data acquired every predetermined time under the control of the photographing control means;
Storage means for storing the detection results by the detection means in time series;
Setting means for setting an adjustment amount by the adjustment means based on the movement amount stored in time series in the storage means;
Including electronic camera. The adjusting means includes at least one of shutter means for adjusting an exposure time of light incident on the photographing means and diaphragm means for adjusting light incident on the photographing means. The electronic camera according to 1. 3. The detection unit according to claim 1, wherein the detection unit detects, as the amount of movement, a difference in the center of gravity position of a remaining object by performing a subtraction process on the at least two or more pieces of the image data. Electronic camera. The image processing apparatus further includes a plurality of storage units that store the image data acquired every predetermined time by the imaging control unit, and sequentially updates the image data acquired every predetermined time according to the end of the setting by the setting unit. The electronic camera according to any one of claims 1 to 3, wherein the electronic camera is stored.

Images