JP3395770B2 - Digital still camera - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention carries out continuous photographing of the same subject at least twice, and a plurality of photographed images obtained by the continuous photographing are combined by a predetermined image combining process to obtain each photographed image. The present invention relates to a digital still camera capable of improving image quality and obtaining an image with enhanced video effect.

[0002]

2. Description of the Related Art In recent years, in the technical field of digital still cameras, a plurality of photographed images photographed consecutively are subjected to predetermined image processing and then combined so that the image quality and the image effect are higher than those of the photographed images. Digital still cameras that can obtain high-quality images have been commercialized.

For example, the digital still camera "GC-X1" PIXSTER "" manufactured by Victor Company, which has a high resolution by synthesizing the two photographed images by displacing the image pickup element for two consecutive photographing It has a function that can obtain. In addition, this digital still camera sets two types of exposure control values according to the bright part and the dark part of the subject, performs continuous shooting twice with these exposure control values, and combines both captured images. By doing so, it also has the function of being able to obtain a captured image with an appropriate density from the dark portion to the bright portion.

[0004]

By the way, when synthesizing two images obtained by continuously photographing the same subject with a digital still camera, it is basically necessary that the contents of both photographed images are the same. Is. However, when the photographer holds the digital still camera in his hand for continuous shooting even when the subject is stationary, the first shooting and the second shooting are caused by a slight change in the camera angle as shown in FIG. A framing (shooting range) shift occurs between the shooting and the shooting, so that the contents of the two shot images do not completely match.

For this reason, in the image synthesizing process of two photographed images, usually, after the position aligning process (registration process) of both photographed images, the predetermined pixel data of the corresponding pixel positions of both photographed images are determined. A synthetic calculation process is performed. In the registration process in the image combining process, generally, one image is used as a reference (hereinafter, referred to as a reference image), and the other image (hereinafter, referred to as a reference image) is translated and rotated with a predetermined movement amount. For each moving position, an index value for discriminating the degree of coincidence between the two images, such as a correlation coefficient, is calculated, and the moving amount having the largest correlation coefficient is calculated as the positional deviation amount between the two images. However, since the correlation coefficient calculation is repeated each time the reference image is moved, the processing load is large in the image combining processing.

In recent years, the number of pixels of an image pickup device applied to a digital still camera has increased, and a device using an image pickup device having 2 to 3 million pixels has been commercialized. When the above-mentioned image synthesizing function is provided in the digital still camera using the, the number of data of the photographed images becomes enormous and the image synthesizing process takes a long time, which causes a problem that the rapidity is deteriorated.

Of the image synthesizing processes, the alignment process, which is mainly repeated, requires a special processing time, and when a high-density image sensor is used, the alignment process time of the picked-up image is increased. Since it rapidly increases and the rapidity is remarkably deteriorated, the result that the image synthesizing function is not effectively utilized is brought about.

The present invention has been made in view of the above problems, and in a digital still camera capable of obtaining images with high image quality and video effect by synthesizing continuously photographed images, the processing load of the alignment process is It is intended to provide a digital still camera capable of effectively utilizing the image synthesizing processing function.

[0009]

SUMMARY OF THE INVENTION According to the present invention, an image pickup means for photoelectrically converting a subject light image into an image signal for output and an exposure operation of the image pickup means for the same subject at least twice in succession. First exposure control means for controlling and at least two images photographed under exposure control by the first exposure control means
A digital still camera including an image synthesizing unit that performs a mutual image alignment process and a predetermined synthesizing calculation process on a single photographic image to create one image having an image quality different from that of the photographic image. A second exposure control means for performing an exposure operation for capturing an image used for calculating a positional deviation amount between the main captured images before and after each exposure operation of the imaging means, and the exposure of the second exposure control means. The present invention further comprises a calculating means for calculating a positional deviation amount between the main photographed images by using at least two photographed images photographed under control.

In this digital still camera, the image synthesizing means performs the alignment processing between the plurality of main photographed images using the positional shift amount calculated by the calculating means (claim 2).

With the above arrangement, when the release is instructed, the exposure operation of the image pickup means (hereinafter, this exposure operation is referred to as the first exposure operation) is performed at least twice in succession, and the same subject is imaged. On the other hand, at least two images are taken. Hereinafter, the image obtained by the first exposure operation is referred to as a main captured image.

Further, before and after the first exposure operation, the exposure operation of the image pickup means (in order to capture an image for calculating a positional deviation amount between the main photographed images (hereinafter, this image is referred to as a calculation image)) ( Hereinafter, this exposure operation is referred to as a second exposure operation). Then, the amount of positional deviation between the two main captured images is calculated by the calculation means using the plurality of calculation images obtained by the second exposure operation.

When the first and second exposure operations are completed, the plurality of main photographed images are subjected to the alignment processing of the main photographed images by using the positional deviation amount calculated by the calculating means, and then a predetermined process is performed. Is performed (for example, weighted average calculation of data of pixel positions corresponding to each other is performed), and one image is synthesized. Since this composite image is a composite of a plurality of main captured images, it has higher image quality and video effect than each main captured image.

A second exposure operation is performed before and after the first exposure operation to capture a calculation image, and the calculation image is used to calculate the amount of positional deviation between the main photography images. In the position alignment processing of (1), the processing load is reduced and the processing time can be shortened by using this position shift amount.

In the digital still camera according to the present invention, there is further provided focus adjusting means for adjusting the focus of the image photographed by the first exposure control means, the focus adjusting means comprising the first exposure. The focus position is changed between a plurality of main shot images shot by the exposure control of the control means (claim 3).

The focus adjusting means calculates the in-focus position by using the image for calculating the positional deviation amount photographed by the exposure control of the second exposure control means before photographing each main photographed image. (Claim 4)

According to the above arrangement, in the first exposure operation, the focus is adjusted on the subject of the exposure operation for each exposure operation, so that a plurality of main shot images having different in-focus positions within the screen are obtained. can get. Therefore, an image in which the blur is adjusted can be obtained by synthesizing these main photographed images.

Further, since the focus adjustment in each exposure operation is performed using the image for calculating the positional deviation amount taken immediately before that, the focus adjustment can be performed even when the subject moves between each exposure operation. .

The second exposure with respect to the number of pixels of the image pickup means whose exposure is controlled by the first exposure control means.
The ratio of the number of pixels of the image pickup unit whose exposure is controlled by the exposure control unit is less than 1, and the calculation unit positions the plurality of photographed images photographed by the exposure control of the second exposure control unit. It is preferable that the displacement amount is calculated and the positional displacement amount is converted based on the ratio of the number of pixels to calculate the positional displacement amount between the main photographed images (claim 5).

According to the above arrangement, in the second exposure operation,
Since the image for calculation does not have a problem of image quality like the main captured image, for example, a part of the data received by each pixel of the image pickup means is read out, so that it is less than in the first exposure operation. Exposure control is performed by the number of pixels. As a result, the exposure time is not unnecessarily lengthened, and proper exposure control is performed for the second exposure operation. On the other hand, in the calculation of the position shift amount, the position shift amount calculated for the calculation image based on the ratio of the number of pixels of the calculation image to the main image is converted to the position shift amount for the main image. Therefore, no inconvenience occurs in the alignment processing in the synthesis processing of the main captured image.

The ratio of the number of pixels may be changed according to the change of the focus position (claim 6). By doing this, the ratio of the number of pixels of the calculation image to the main captured image is set according to the focus state of each main captured image.
Even if the number of pixels of the calculation image is smaller than that of the main captured image, the accuracy of focus adjustment for each main captured image does not decrease.

The exposure time of the image pickup means by the second exposure control means may be shorter than the exposure time of the image pickup means by the first exposure control means (claim 7). Further, in this case, it is preferable to further include level adjusting means for adjusting the level of the image signal output from the image pickup means based on the exposure time by the exposure control by the second exposure control means (claim 8).

By doing so, it is possible to prevent the shooting time of continuous shooting from becoming long due to the second exposure operation. Further, although the calculation image output from the image pickup means becomes darker as the exposure time is shortened, the level of the calculation image is adjusted in accordance with the exposure time, so that the calculation accuracy in the positional deviation amount calculation is lowered. There is no such thing.

Further, in the digital still camera according to the present invention, the exposure operation for the image for calculating the positional deviation amount captured between the first main photographed image and the second main photographed image is performed by the first book camera. It may be performed immediately after the exposure operation for the captured image or immediately before the exposure operation for the second main captured image (claim 9).

In this way, each calculation image is in substantially the same focus state as each actual photographed image, and therefore the calculation of the position shift amount using the calculation image can be performed on the focused image. The calculation accuracy is improved.

Further, in the digital still camera, the intervals of the exposure operations controlled by the first and second exposure control means may be equal intervals (claim 10). Further, it is preferable that the second exposure control means performs an exposure operation for taking in an image used for the positional deviation amount calculation after the exposure operation of the final main captured image (claim 11).

Further, in the present invention, in the digital still camera, the image for calculating the positional deviation amount photographed by the image pickup means by the exposure control of the second exposure control means is used, and then the first image is calculated. The exposure control means further comprises an exposure amount control means for setting an exposure control value of a main captured image which is exposure-controlled by the exposure control means (claim 12).

According to the above construction, the exposure control value in the exposure of each main photographed image is set using the calculation image photographed immediately before that, so that when the exposure condition changes during continuous photographing. It is also possible to shoot each main shot image under appropriate exposure conditions.

According to the present invention, in the digital still camera, the level adjusting means for adjusting the level of the image signal output from the image pickup means, and the image pickup means whose exposure is controlled by the second exposure control means. And a setting means for setting the level adjustment value of the image signal output from the image pickup means, the exposure of which is controlled by the first exposure control means thereafter. (Claim 16).

According to the above construction, the level of each actual photographed image output from the image pickup means is adjusted to an appropriate level by the level adjusting means, and the level adjustment value of the level adjusting means was photographed immediately before that. Since it is set using the calculation image, even if the subject brightness changes during continuous shooting and the level of each main captured image output from the image pickup means is not appropriate, the level of each main captured image is set to an appropriate level. Can be corrected.

[0031]

1 is a front view of a camera body of a digital still camera (color image pickup apparatus) applied to an image processing system according to the present invention, and FIG. 2 is a diagram showing main members incorporated in the digital still camera. Top view showing the arrangement, FIG.
FIG. 4 is a right side view showing an arrangement of main members built in the digital still camera, and FIG. 4 is a rear view of the digital still camera.

The digital still camera 1 includes a camera body 2
And a single-lens reflex camera consisting of an interchangeable lens 3 which is detachably attached to the front of the camera body 2 and is detachably attached. The camera body 2 is
A mount portion 20 on which the interchangeable lens 3 is mounted approximately in the center of the front surface.
1 is provided, and a grip part 202 is provided at the left end of the front surface.

Inside the grip portion 202, the battery storage chamber 2
03 and the card storage chamber 204 are provided, and the battery storage chamber 2
03 stores four AA dry batteries E1 to E4 (camera power supply batteries), and the card storage chamber 204 detachably stores a memory card MC for recording image data of captured images. It has become.

A plurality of contact points ST for electrical connection with the interchangeable lens 3 mounted on the lower part of the mount 201 and a plurality of couplers CP for mechanical connection.
And are provided. The electrical contact ST receives specific information (information such as open F value and focal length) from the lens ROM 301 (see FIG. 3) built in the interchangeable lens 3 in the camera body 2 as a whole control unit (see FIG. 6)) and outputs information on the position of the zoom lens and the position of the focus lens in the interchangeable lens 3 to the overall control unit. The coupler CP transmits the driving force of the zoom lens driving motor ZM (see FIG. 3) and the driving force of the focus lens driving motor FM (see FIG. 3) provided in the camera body 2 to the interchangeable lens 3 side. It is for doing.

A color image pickup element 205 is arranged at an appropriate position in the camera body 2 on the optical axis L of the interchangeable lens 3 when it is mounted on the mount portion 201.
Color image sensor 205 (hereinafter referred to as CCD 205)
Is a CCD (Charge-Coupled Devic
On the surface of each pixel of the area sensor 205A consisting of e),
R (red), G (green), B (blue) color filters 205
B is composed of a single-plate color area sensor, which is a so-called Bayer system, which is attached in a checkered pattern, and has, for example, 1600 × 1200 = 1920,000 pixels.

As shown in FIG. 5, the area sensor i
The pixel position of the row j-th column is (i, j) (i = 1, 2, ... N,
j = 1, 2, ... M), n = 1600, m = 1200
Then, the R, G, and B color filters have R; (2h + 1, 2k + 1) G; (2h + 2, 2k + 1), (2h + 1, 2k + 2) B; (2h + 2, 2k + 2), where h = 0, 1, 2, , ... n / 2 (= 800), k =
They are arranged at pixel positions of 0, 1, 2, ... M / 2 (= 600).

A shutter button 206 is provided on the upper surface of the grip portion 202 of the camera body 2. The half-pressing operation and the full-pressing operation of the shutter button 206 are detected by switches S1 and S2 described later. When the switch S1 is turned on (when the shutter button 206 is half-pressed), a preparatory operation (a preparatory operation such as setting an exposure control value and focus adjustment) for taking a still image of a subject is performed, and the switch S2 is turned on. When turned on (when the shutter button 206 is fully pressed), the photographing operation (a series of operations of exposing the CCD 205, performing predetermined image processing on the image signal obtained by the exposure, and recording the image signal in the memory card MC) Done.

An electronic view finder 4 (EVF; Electronic View Finder) and a pop-up type flash 5 are provided in the approximate center of the upper surface of the camera body 2. The electronic viewfinder 4 is a monitor image of the subject photographed by the CCD 205 (the CCD 2 in the photographing standby state).
Display unit 401 (hereinafter, L) including a color liquid crystal display device that displays a subject image captured as a moving image by S.05.
It is called the CD display unit 401. ) And an eyepiece 402 for guiding the monitor image displayed on the color liquid crystal display device to the outside of the finder window 403.

In the standby state for shooting, the electronic viewfinder 4
Since a monitor image (moving image) of the subject is displayed on, the photographer can visually recognize the subject by looking through the finder window 403.

Since the monitor image is to be displayed on the LCD display section 401, in the standby state,
Operation mode different from normal still image shooting CCD205,
The monitor image having the same size as the display size of the LCD display unit 401 is captured by operating in the so-called draft mode.
That is, in the present embodiment, since the LCD display unit 401 is configured by the number of pixels of 200 × 150, all the pixels receive light in the standby state, but the light reception data is read out at an 8 pixel pitch in both vertical and horizontal directions. Re (1/8
The thinning-out reading is performed), so that the number of pixels is 2
High-speed shooting of 00x150 monitor images is possible.

A display unit 207 (hereinafter, referred to as LCD display unit 207) formed of a color liquid crystal display device is provided at the substantially center of the back surface of the camera body 2. The LCD display unit 207 displays a menu screen for setting a shooting mode, shooting conditions, etc. in the recording mode, and reproduces and displays a shot image recorded in the memory card MC in the reproduction mode.

The shooting mode includes a mode related to exposure control and a mode related to image composition processing. The mode related to exposure control is a mode related to how to determine the exposure control value (aperture value of the diaphragm and the exposure time) at the time of release. Modes related to exposure control include at least a program mode, a shutter priority mode, and an aperture priority mode.
The exposure control value is set by using one of a plurality of preset program charts. In the program mode, the exposure control value is set by using a standard program chart, and the shutter is set. In the priority mode, the exposure control value is set using the program diagram that gives priority to the shutter speed (exposure time) over the aperture value, and in the aperture priority mode, the program diagram that gives priority to the aperture value over the shutter speed is used. The exposure control value is set.

The mode relating to the image synthesizing process means that the photographic condition is changed at the time of release, or two consecutive photographic images are taken while keeping the photographic condition as it is, and the two photographic images obtained by the photographing are combined into a predetermined image. This is a mode in which one image having a higher image quality and a higher image effect than the original photographed image is created by combining by processing, and is recorded in the memory card MC.

At least the "blurring adjustment mode", the "gradation adjustment mode", and the "super-resolution mode" are included in the mode relating to the image synthesizing process. The blur adjustment mode is one in which the focus position is changed by one shutter operation, and two consecutive shooting operations are performed. For example, a shot image A focused on a main subject (for example, a person) is displayed. In this mode, a photographed image B focused on the background of the main subject is captured, and both photographed images A and B are combined to obtain an image having a desired blur condition.

The gradation adjustment mode is one in which the exposure condition is changed by one shutter operation and two consecutive photographing operations are performed. For example, the photographed image A and the main subject exposed with the main subject exposed. By capturing a photographed image B whose exposure is adjusted to the background and synthesizing the two photographed images A and B, for example, an image having an appropriate density distribution on the entire screen or the contrast between the main subject and the background is intentionally increased. , This is a mode for obtaining highly original images.

The super-resolution mode is a camera in which the photographing operation is performed twice continuously without changing the focus and the exposure condition by one shutter operation, and the first photographing and the second photographing are slightly different from each other. A captured image A and a captured image B in which the position of the main subject has changed slightly due to the difference in angle is captured, and both captured images A and B are combined to obtain an image with a higher resolution than the original captured image. Mode.

A power switch 208 is provided on the left side of the LCD display unit 207. The power switch 208 also serves as a mode setting switch that switches and sets a recording mode (a mode that performs a function of taking a photograph) and a reproduction mode (a mode that reproduces a recorded image on the LCD display unit 207).
That is, the power switch 208 is a three-point slide switch, and when the contact is set to the central “OFF” position,
When the power is turned off and the contact is set to the upper “REC” position, the power is turned on and the recording mode is set. When the contact is set to the lower “PLAY” position, the power is turned on and the playback mode is set. Is set.

At the upper right position of the LCD display section 207, 4
A serial switch 209 is provided. 4 switches 20
Reference numeral 9 has a circular operation button, and pressing operations in four directions of up, down, left and right on the operation button are detected respectively. The quadruple switch 209 is multi-functional, and functions as an operation switch for changing an item selected on the menu screen displayed on the LCD display unit 207 or changing a frame to be reproduced selected on the index screen, for example. At the same time, the left and right switches also function as switches for changing the zoom ratio of the interchangeable lens 3.

On the menu screen, for example, a plurality of items are arranged and displayed, and the currently selected item is displayed to show the selected state (for example, a cursor or reverse display). For example, in the case of selecting a mode relating to image combining processing in the shooting mode, a menu screen as shown in FIG. 6 is displayed on the LCD display unit 207. The item of “normal shooting” on this menu screen is a mode for performing normal shooting similar to the shooting operation of the silver halide camera.

In the menu screen of FIG. 6, when the up switch of the quad switch 209 is pressed, the display position of the cursor K with a black triangle (that is, the item indicated by the cursor K) moves cyclically in the upward direction. 4 switches 2
When the downward switch of 09 is pressed, the item display position indicated by the cursor K cyclically moves downward. When the confirmation switch 210b of the switch group 210 is pressed, the item (gradation adjustment mode in FIG. 6) indicated by the cursor K at that time is set as the shooting mode.

Therefore, the photographer operates the quadruple switch 209 in the vertical direction on the menu screen for selecting the photographing mode to select the desired photographing mode, and the confirm switch 210.
The shooting mode can be set by operating d. It should be noted that a desired shooting mode can be set for the mode relating to the exposure control by the same method.

On the index screen, thumbnail images for 9 frames are displayed in an array from all the images recorded in the memory card MC, and the display selected for the currently selected frame (for example, blinking display or frame display). Etc.) is performed. When one of the up, down, left and right direction switches of the quad switch 209 is pressed, the display showing the selection state of the menu screen or index screen moves to the item or frame in that direction. For example, when the upward switch is pressed, the display showing the selection state of the menu screen or index screen moves to the upward item or frame.

In the zoom operation of the interchangeable lens 3, when the right switch of the quad switch 209 is pressed, the interchange lens 3 continuously moves to the wide side, and when the left switch of the quad switch 209 is pressed, the interchange lens is pressed. 3 moves to the tele side continuously.

At the lower right position of the LCD display unit 207, L
A switch group 210 is provided for operating the display of the CD display unit 207 and the display contents. The switch group 210 includes a cancel switch 210a and a confirmation switch 210.
b, menu display switch 210c and display switch 2
10d is included.

The cancel switch 210a is a switch for canceling the contents selected on the menu screen. The confirmation switch 210b is a switch for confirming the content selected on the menu screen. Menu display switch 21
Reference numeral 0c is a switch for displaying a menu screen on the LCD display unit 207 and for switching the contents of the menu screen. Each time the menu display switch 210c is pressed, the screen switches to the menu screen. The display switch 210d is an LCD
This is a switch for displaying on the display unit 207 and switching the contents of the menu screen. Power battery E1
In order to save E4 power, LCD display 2
The display of 07 is not displayed. Each time the display switch 210d is pressed, the display and non-display of the LCD display unit 207 are alternately performed.

FIG. 7 is a block diagram showing the internal structure of the digital still camera 1.

The digital still camera 1 mainly includes the lens 1.
01, imaging unit 102, signal processing unit 103, light emission control unit 1
04, lens control unit 105, display unit 106, operation unit 10
7 and the overall control unit 108.

The lens 101 corresponds to the interchangeable lens 3. The lens 101 is a focusing lens 101a.
Also, a zoom lens 101b is provided, and a diaphragm 101c for adjusting the amount of transmitted light is provided inside.

The image pickup section 102 photoelectrically converts a subject light image incident through the lens 101 into an image signal (electrical image) and takes it in. The image pickup unit 102 includes a CCD 102a corresponding to the CCD 205, a timing generator 102b that controls the image pickup operation of the CCD 102a, and a timing control circuit 102c that controls the driving of the timing generator 102b.

The CCD 102a has a drive control signal (integration start signal / integral start signal / input from the timing generator 102b).
The subject light image is received for a predetermined time (exposure time) based on the integration end signal) and converted into an image signal (charge accumulation signal), and the image signal is read out from the timing generator 102b (horizontal synchronization signal). Signal, vertical synchronization signal, transfer signal, etc.) to the signal processing unit 103. At this time, the image signal is separated into R, G, and B color components and output to the signal processing unit 103. That is, the image signal of the R color component is output by sequentially reading the image signal received by each pixel at the pixel position (2h + 1, 2k + 1), and the pixel position (2h + 2, 2k + 1), (2h + 1,
The image signal of the G color component is output by sequentially reading the image signal received by each pixel of 2k + 2), and the image signal received by each pixel of the pixel position (2h + 2, 2k + 2) is sequentially read by The image signal of the color component is output.

The timing generator 102b generates a drive control signal based on the control signal input from the timing control circuit 102c and a read control signal based on the reference clock, and outputs the read control signal to the CCD 102a. The timing control circuit 102c controls the photographing operation of the image pickup unit 102. Timing control circuit 102
c generates a shooting control signal based on the control signal input from the overall control unit 108. The shooting control signal is a shooting control signal for displaying a moving image of a subject (hereinafter, referred to as a live view image) on the electronic viewfinder 4 in a monitor mode in the recording mode, and the shutter button 6 is operated to operate the subject. Signal, reference clock, CC for shooting still images (hereinafter referred to as recorded images)
The image signal output from D102a is processed by the signal processing unit 103.
Timing signal (synchronous clock) for signal processing by
Etc. are included. This timing signal is sent to the signal processor 10
Signal processing circuit 103a and A / D conversion circuit 103 in 3
Input to b.

The signal processing section 103 performs predetermined analog signal processing and digital signal processing on the image signal output from the CCD 102a. The signal processing of the image signal is performed for each light receiving signal of each pixel forming the image data. Hereinafter, for convenience of explanation, in order to distinguish the light receiving signal of each pixel from the image signal forming the captured image by these sets, the light receiving signal of each pixel is converted into a pixel signal (analog signal) or pixel data (digital signal) as necessary. Signal).

The signal processing unit 103 includes an analog signal processing circuit 103a, an A / D conversion circuit 103b, a black level correction circuit 103c, a WB circuit 103d, a γ correction circuit 103e and an image memory 103f. The black level correction circuit 103c, the WB circuit 103d, and the γ correction circuit 103
e constitutes a circuit that performs digital signal processing.

The analog signal processing circuit 103a is mainly a CD
The CCD 102a includes an S circuit (correlated double sampling) circuit and an AGC (auto gain control) circuit.
The sampling noise and the signal level of the image signal (the signal received by each pixel. The analog signal) output from are reduced.

For the gain control in the AGC circuit, the level of the photographed image when proper exposure cannot be obtained by the aperture value of the aperture 101c and the exposure time of the CCD 205 (for example, when photographing a very low brightness subject) This includes the case of compensating for shortages.

The A / D conversion circuit 102b converts the image signal output from the analog signal processing circuit 103a into a digital signal (hereinafter referred to as image data). The A / D conversion circuit 102b converts the pixel signal received by each pixel into, for example, 10-bit pixel data.

The black level correction circuit 103c corrects the black level of each A / D converted pixel data to a reference black level. The WB circuit 103d adjusts the white balance of the captured image. The WB circuit 103d adjusts the white balance of the captured image by converting the levels of the pixel data of the R, G, and B color components using the level conversion table input from the overall control unit 108. The conversion coefficient of each color component of the level conversion table is set for each captured image by the overall control unit 108. γ correction circuit 1
03e is for correcting the γ characteristic of pixel data. γ
The correction circuit 103e corrects the level of each pixel data using a preset correction table.

The image memory 103f is a memory for temporarily storing the image data for which signal processing has been completed. Image memory 1
03f has a capacity capable of storing at least two frames of image data. This is because exposure is performed twice in succession in shooting in the blur adjustment mode and the like, and image data for two frames is captured, so that these can be stored respectively. The storage capacity that can store one frame of image data is, for example, the CCD 102.
If the number of pixels of a is 1600 × 1200 = 1920,000,
This is a capacity capable of storing 1.92 million pieces of pixel data.

The light emission control unit 104 controls the light emission of the flash 5 based on the light emission control signal input from the overall control unit 108. The light emission control signal includes a light emission preparation instruction, a light emission timing, and a light emission amount. When the light emission control unit 104 receives a light emission preparation instruction from the overall control unit 108, the main capacitor is charged to enable light emission, and the flash 5 is emitted by discharging the accumulated charge of the main capacitor in synchronization with the light emission timing signal. Let Then, the discharge of the accumulated charge of the main capacitor is stopped based on the light emission stop signal input from the overall control unit 108. This causes the flash 5 to emit a required amount of light.

The lens controller 105 controls the driving of each member of the focusing lens 101a, the zoom lens 101b and the diaphragm 101c in the lens 101.
The lens control unit 105 includes an aperture control circuit 105a that controls the aperture value of the aperture 101c, a focus control circuit 105b that controls the drive of the focus motor FM, and a zoom control circuit 105c that controls the drive of the zoom motor ZM.

The aperture control circuit 105a is the overall control unit 108.
The aperture 101a is driven on the basis of the aperture value input from, and the aperture amount is set to the aperture value. The focus control circuit 105b controls driving of the focus motor FM, and the driving force of the focus motor FM is transmitted to the focusing lens 101a via the coupler CP1. The focus control circuit 105b drives the focus motor FM based on an AF control signal (for example, a control value such as the number of drive pulses) input from the overall control unit 108 to set the focus lens at the focus position. Zoom control circuit 105c
Is a zoom control signal (4
The zoom motor ZM is driven based on (operation information of the serial switch 209) to move the zoom lens 101b in the direction designated by the quad switch 209. That is, the zoom control circuit 105c drives the zoom motor ZM in the positive direction to move the zoom lens 101b to the wide side when the right operation information of the quad switch 209 is input from the overall control unit 108. When the left operation information of the serial switch 209 is input, the zoom motor ZM is driven in the reverse direction to move the zoom lens 101b to the tele side.

The display section 106 performs display on the LCD display section 207 and display on the electronic viewfinder 4. The display unit 106 includes a display 106a and a VRAM 106b corresponding to the LCD display unit 207, and a display 106c and a VRAM 106d corresponding to the LCD display unit 401 in the electronic viewfinder 4. The display 106a is, for example, 200 × 150 = 300.
The display 106c has a pixel count of 200 × 150 = 30000, for example. Therefore, the VRAM 106b can store approximately 30,000 pixel data corresponding to the number of pixels of the display 106a, and the VRAM 106d can store approximately 30,000 pixel data corresponding to the number of pixels of the display 106c. There is.

During the standby for photographing, the CCD 102a is driven in the draft mode, and the number of pixels is 200 × from the CCD 102a.
150 frame images are sequentially output. The image signal of each frame image is subjected to predetermined signal processing, then stored in the image memory 103f, read sequentially by the overall control unit 108, and transferred to the VRAM 106d. As a result, a live view image of the subject is displayed on the display 106c (display surface of the LCD display unit 401). When the display switch 210d is instructed to display on the LCD display unit 207, it is transferred to the VRAM 106b, and a monitor image of the subject is also displayed on the display 106a (display surface of the LCD display unit 207).

Further, when the menu display is instructed by operating the menu switch 210c, the image data of the menu screen stored in the R0M 108a in the overall control unit 108 is read out to the VRAM 106b, whereby the display content of the display 106a is changed to the menu. Switch to the screen.

In the reproduction mode, the thumbnail image of the photographed image is read out from each frame image file recorded in the memory card MC by the overall control unit 108, arranged in a predetermined format, and image data for index display is created. The image data is read out to the VRAM 106b. As a result, a list of photographed images recorded in the memory card MC is displayed on the display 106a. When the frame to be reproduced is specified by operating the quad switch 209, the image data of the captured image recorded in CCDRAW format is read from the image file corresponding to the frame recorded in the memory card MC, VRAM1 adjusted to the display size of the display 106a
It is transferred to 06b. As a result, the captured image is reproduced and displayed on the display 106a (display surface of the LCD display unit 207).

The operation unit 107 displays operation information of operation members provided in the camera body 2 for shooting and reproducing, as a whole control unit 1.
08 is input. The operation information input from the operation unit 107 includes shutter button 206 and power switch 2
The operation information of each operation member such as the 08, the quadruple switch 209, and the switch group 210 is included.

The overall control unit 108 centrally controls the photographing function and the reproducing function of the digital still camera 1. The card interface 1 for the overall control unit 108
The memory card MC is connected via 09. Further, the computer PC is externally connected via the communication interface 110.

The overall control unit 108 is composed of a micro computer, and includes a processing program for performing various specific processes in the photographing function and the reproduction function, the above-described image pickup unit 102, signal processing unit 103, light emission control unit 104, lens. A ROM 108a in which a control program for controlling the drive of the control unit 105, the display unit 106 and the like is stored, and a RAM 108b for performing various arithmetic operations according to the processing program and the control program are provided.

Specific processing performed by the overall control unit 108 includes exposure control values (exposure time Tv [E of CCD 102a when capturing a live view image or photographing a subject.
v value] and the aperture value Av [Ev value] of the aperture 101c) (exposure control value calculation process), displaying the live view image captured from the CCD 102a to the image memory 103f in the recording mode on the electronic viewfinder 4. In the playback mode, the recorded image read from the memory card MC to the image memory 103f is displayed on the LCD display unit 20.
7 processing (image display processing), processing for recording the recording image captured in the image memory 103f from the CCD 102a in the card memory MC in the recording mode (recording processing), recording image to be reproduced from the memory card MC in the reproduction mode. Image for calculating the position shift amount of the continuously photographed images before and after each exposure operation while performing the exposure operation continuously in the special photographing mode such as the blur adjustment mode or the like (reproduction processing) The process includes a process for performing an exposure operation for capturing (special exposure control process), a process for synthesizing two captured images obtained by the exposure control (image synthesizing process), and the like.

Exposure value calculator 108c, display controller 108
The d, the recording control unit 108e, the reproduction control unit 108f, the special exposure control unit 108g, and the image processing unit 108h are functional blocks representing the above-described processes in the overall control unit 108.

The exposure value determining unit 108c performs an exposure value calculation process, determines the brightness of the subject using the image data of the G color component of the live view image, and calculates the exposure control value based on the determination result. To do.

The display control unit 108d performs image display processing, and the display operation of the display unit 106, that is,
After the image data temporarily stored in the image memory 103f is read and the image size is adjusted to the image size of the display destination as necessary, the VRAM 106c or VRAM 10 is read.
The operation of transferring to 6d is performed.

The recording control section 108e performs recording processing. When shooting is instructed by the shutter button 206 in the normal shooting mode, the recording control unit 108e reads out the image data (image data of a still image) temporarily stored in the image memory 103f to the RAM 108b after the shooting instruction, and for example, two-dimensionally. Image data for recording is created by performing a predetermined compression process by the JPEG system such as DCT conversion and Huffman coding.

Further, the number of pixels is 200 × 1 by reading the frame image photographed in the draft mode immediately before the release and stored in the image memory 103f into the RAM 108b.
Create 50 thumbnail images. Further, tag information regarding a captured image recorded along with these recording image data is created. This tag information includes the lens name, frame number, focal length at the time of shooting, F number at the time of shooting, focus position, subject brightness, white balance adjustment value, shooting mode, compression rate, shooting date, whether flash light is emitted, etc. Be done.

Then, the recording control unit 108e attaches tag information to the image data of the compressed photographed image and thumbnail image, and EXIF (Exchangeable Image File Format).
An image file of the format is created and this image file is recorded in the memory card MC.

In the blurring adjustment mode, gradation adjustment mode, and super-resolution mode, the JPEG method such as two-dimensional DCT conversion and Huffman coding is applied to the combined image combined by the image processing unit 108h. The image data for recording is created by performing a predetermined compression process by, and tag information is attached to the image data of the compressed composite image and the thumbnail image to create an image file in the TIFF (Tag Image File Format) format. The image file is recorded in the memory card MC.

Therefore, the two photographed images before composition are not recorded in the memory card MC. This is for efficiently utilizing the memory card MC because the camera body also performs image combining processing. In consideration of the convenience of separately synthesizing images on a personal computer or the like, the two photographed images before the synthesizing may be recorded in the memory card MC.

FIG. 8 is a diagram showing a method of recording an image file in the memory card MC.

The image files are stored in the memory card MC in order of the file number X from the beginning. Each image file is given a file name of "Pn.Y", "n" is a 6-digit number indicating the order in which the image files were created, and "Y" is a symbol indicating the format of the image data. is there. For example, when "Y" is "JPG", the image data is JPE.
It shows compressed by G method.

The recording area of each image file in the memory card MC consists of three areas, and tag information data, photographed image data, and thumbnail image data are stored in each area from the top. The data size of the tag information data and the thumbnail image data does not change depending on the image file, but the data size of the shot image data changes depending on the compression rate and the shooting mode. Therefore, the memory card MC
The number of files that can be stored in the storage area of each image file changes depending on the data size of the captured image data of each image file.

The reproduction controller 108f is for reproducing the photographed image recorded in the memory card MC on the LCD display 207. When the reproduction mode is set by the power switch 208, the reproduction control unit 108f reads thumbnail images from each image file recorded in the memory card MC and sequentially stores the thumbnail images in the VRAM 106b according to a predetermined index format. For example, 9 thumbnail images per page are stored in the VRAM 106b so as to be secondarily arranged in 3 × 3. Accordingly, nine thumbnail images arranged two-dimensionally are index-displayed on the LCD display unit 207.

When the thumbnail image of the frame to be reproduced with respect to the thumbnail image displayed in the index is designated by the quad switch 209 and the switch group 210, the reproduction processing unit 108f causes the captured image from the image file corresponding to the frame. Data is read out, subjected to predetermined decompression processing, and then stored in the image memory 103f. The data size of the data read out to the image memory 103f is adjusted by the display control unit 108d as described above.
The data is transferred to the RAM 106b, so that the LCD display unit 2
It is reproduced and displayed on 07.

The special exposure control section 108g is a CCD when the shutter button 6 is fully pressed in the state where the blur adjustment mode, gradation adjustment mode and super-resolution mode are set.
The exposure operation of 102a is controlled. Special exposure control unit 108
When the S2 switch is turned on, g basically captures an image for image combination (hereinafter, this image is referred to as a main captured image), and therefore the exposure operation of the CCD 102a is continuously repeated twice. Since at least two images for calculating the positional deviation amount of the main captured image (hereinafter, this image is referred to as a calculation image) are captured, the exposure for the calculation image is performed before and after each exposure operation for the main captured image. Take action.

The calculation image is for calculating the amount of positional deviation, and does not require high image quality as in the actual photographed image.
In the present embodiment, the CCD 102a is driven in the draft mode to capture the calculation image. That is, the calculation image is captured with a smaller number of pixels than the actual captured image.

In the photographing standby state, the CCD 102a
Since the exposure operation is repeated in the draft mode,
When the S2 switch is turned on in this state, the special exposure control unit 108g, for example, drives the CCD 102a in the draft mode (a mode in which the predetermined number of pixels of the received light data of all pixels are thinned out and read out. The thinning rate is set to 1/8.) To the normal mode (the mode in which the received light data of all pixels are read) to perform the first exposure operation for the main shot image, and then to the draft mode again for calculation. The exposure operation for the target image is performed at least twice, and then the normal mode is switched to perform the second exposure operation for the main captured image. Note that the calculation image does not necessarily have to be continuously captured before and after the main captured image, and the main captured image and the calculation image may be alternately captured.

The details of the photographing operation in the blur adjustment mode, gradation adjustment mode and super-resolution mode will be described later.

The image processing unit 108h performs registration processing (positioning processing) on the two main photographed images continuously photographed in the blur adjustment mode, the gradation adjustment mode and the super-resolution mode, and thereafter, Predetermined arithmetic processing is performed using the data of both main captured images for each corresponding pixel position of the main captured image to create data of a composite image.

The registration process aligns the positions of two images to be combined in order to accurately combine the same symbols on the screen in the image combining process.
In the registration processing, generally, for example, one captured image A is used as a reference and the other captured image B is enlarged / reduced, translated, rotated, or the like, and the two captured images A and B are collated with each other to obtain the two captured images A. , B, the enlargement ratio of the captured image B,
A translation amount, a rotation angle, etc. are calculated. The degree of coincidence between the one captured image A and the other captured image B is, for example, the minimum sum (correlation function) of the absolute values of the level differences between the captured images A and B using the parallel movement amount of the captured image B as an argument. The parallel movement amount is calculated as a movement amount (that is, a positional shift amount) for matching the captured image B with the captured image A.

In the present embodiment, two images are continuously photographed, and in consideration of the fact that the positional deviation between the two photographed images due to camera shake is mainly due to the linear blur, A parallel movement amount (X, Y) for matching the shot image B with the main shot image A (that is, the main shot images A, B).
Only the position displacement amount) is calculated. Further, in this calculation, since the calculation of the correlation function is repeated while moving the photographed image B at a predetermined pitch, if the registration process is directly performed using the main photographed image having 1.92 million pixel data, the repetition calculation is repeated. Therefore, in the present embodiment, in the present embodiment, a captured image having a smaller number of pixels than the main captured image (calculation image captured in the draft mode before and after the exposure operation of the main captured image is substantially used as the main captured image. (This corresponds to an image obtained by thinning out the image data to 1/8.)
The registration processing is performed by using, and the number obtained by multiplying the processing result by 8 of the thinning rate (for example, if the moving amount of the thumbnail image is (3, 4), it is set to (24, 32)). The initial value of the movement amount of the main captured image B in the registration processing on the main captured image is set.

Therefore, when the special exposure control unit 108g captures a plurality of calculation images by the CCD 102a, the image processing unit 108h performs the above-described registration processing using these calculation images, and the first main photographing is performed. The amount of positional deviation between the image A and the second actual shot image B (X,
Y) is calculated.

Further, in the registration processing of the two main photographed images A and B in the image processing after the exposure operation is completed, for example, the positional deviation amount of the second main photographed image B with respect to the first main photographed image A ( 8X, 8Y) is the initial state, and the main captured image B is (8X ± m, 8Y ±
The position shift amount between the main photographed images A and B is calculated by calculating the above-mentioned correlation function by moving one pixel pitch in the range of n) and calculating the above-mentioned correlation function. In the initial state, the position shift amount of the second main shot image B with respect to the first main shot image A is small, so that the parallel movement amount (X, Y) is calculated with a relatively small number of repeated calculations.

Next, the photographing operation of the digital still camera 1 in the blur adjustment mode, the gradation adjustment mode and the super-resolution mode will be described in detail.

FIG. 9 is a time chart showing the photographing operation in the blur adjustment mode.

In the figure, the upper waveform diagram shows the ON timing of the S1 switch and the S2 switch based on the operation of the shutter button 6. The second waveform diagram shows the exposure operation of the CCD 102a. The ON period indicates the exposure period, and the OFF period indicates the period during which the data accumulated in the exposure period is read.

The exposure operation of the CCD 102a is repeated in a short cycle before the S2 switch is turned on, which means that the live view image is captured in the shooting standby state. In the shooting standby state, the CCD 102a
The exposure is repeated in the draft mode, and frame images are captured every 1/30 seconds. On the other hand, the long ON period E1 immediately after the S2 switch is turned on is an exposure period for capturing the first main captured image A, and the long ON period E2 thereafter is for capturing the second main captured image B. Exposure period. Hereinafter, the shootings corresponding to these exposure operations are referred to as main shootings Q1 and Q2, respectively.

The three short ON periods E3, E4, E5 between the ON period E1 and the ON period E2 indicate that the exposure operation is repeated three times in order to capture the image for calculation. . This exposure operation is the same as the capture of the live view image in the shooting standby state. Hereinafter, the shooting corresponding to these exposure operations will be described as thinning shooting MQ.
1, MQ2, MQ3.

The thinning photographing MQ1, MQ2, MQ3 is performed in the draft mode only in the main photographing Q1 and the main photographing Q2.
This is because the distance between and is shortened as much as possible and the amount of positional deviation between the main photographed images A and B is minimized. It should be noted that the level of the image signal output from the CCD 102a is lowered by performing the thinning photographing MQ1, MQ2, MQ3 in the draft mode.
Since the level adjustment is performed at 03a, the accuracy of movement amount calculation is not reduced.

Further, after the ON period E2, the exposure operation of the CCD 102a is repeated again in a short cycle. This indicates that the photographing standby state has been returned, and that the live view image has been captured again. There is.

The waveform diagram of the third stage shows the main processing contents controlled by the overall control unit 108. The ON period or ON signal indicates that a predetermined control process directly related to the shooting in the blur adjustment mode is being performed. In the processing period C1 immediately after the S1 switch is turned on, distance measurement using the frame image immediately before the S1 switch is turned on in preparation for the subsequent release and AF based on the distance measurement result are performed.
(Auto Focus) calculation (hereinafter referred to as the first AF calculation) and AE (Automatic Exposure) using the same frame image
Calculation (hereinafter referred to as the first AE calculation) and AWB (Auto
matic white balance) calculation (hereinafter referred to as “first AWB calculation”). The ON signals S1 and S3 are for switching the driving mode of the CCD 102a from the draft mode to the normal mode,
The ON signals S2 and S4 switch the driving mode of the CCD 102a from the normal mode to the draft mode.

The processing period C2 immediately after the thinning-out photographing MQ3 is
An AF calculation for the second actual photographing Q2 (hereinafter referred to as a second AF calculation) using the calculation image obtained in the thinned-out photographing MQ3 and an AE calculation (hereinafter referred to as a second A calculation) using the same calculation image.
This is called E calculation. ) And AWB calculation (hereinafter, referred to as second AWB calculation).

In the processing period C3, the thinning-out photographing MQ1 and MQ are performed.
2 shows that the movement amount (X, Y) of the second main captured image B with respect to the first main captured image A is calculated by using the three calculation images obtained in MQ2. The processing period C4 indicates that signal processing such as AWB adjustment and γ correction of the main captured images A and B is being performed, and the processing period C5
Indicates that image processing is performed on both main captured images A and B (composition processing for registration processing and blur adjustment), and processing period C6 compresses the composite image of both main captured images A and B. It indicates that the process of recording on the memory card MC is being performed.

The waveform diagram at the bottom shows the focusing lens 1
This shows the change in the relative position of 01b. The rising change R1 of the waveform immediately after the processing period C1 indicates that the focusing lens 101b is moving from the current position to the position at the object distance ∞. In the present embodiment, in the bokeh adjustment mode, the focus is first adjusted to the infinity position and the actual shooting Q1 is performed.
After that, the focus is adjusted to a predetermined subject distance (for example, 1 m) set in advance, the second main shooting Q2 is performed, and the main shooting images A and B obtained in the main shooting Q1 and Q2.
Since S1 signal and processing period C
The AF calculation process in 1 and the movement R1 of the focusing lens 101b are performed by pressing the shutter button 6 halfway to fully press the shutter button 6 (release instruction) in preparation for the first actual shooting Q1 in the blur adjustment mode. Indicates that you are doing.

Further, the falling change R2 of the waveform after the end of the main photographing Q1 indicates the AF processing for the second main photographing Q2, and the focusing lens 101b is moved from the current position to the focus position of a predetermined object distance (1 m). It indicates that it is moving.

From the time chart shown in FIG. 9, in the blurring adjustment mode, the shutter button 6 is pressed in the shooting standby state.
When is pressed halfway to turn on the S1 switch, AF processing is performed for the ∞ position, and the exposure control value (aperture value of the aperture 101c and exposure time of the CCD 102a) and WB adjustment value are set, and then the shutter is released. When the button 6 is fully pressed and S2 is turned on, the CCD drive mode is switched to the normal mode and the set exposure time E1 is set.
First exposure after performing exposure operation of CCD 102a
1 is performed.

Upon completion of this exposure operation, the CCD 102
The image signals of all the pixels are read out from a, and the focusing lens 101b is moved from the current position to the focal position at a subject distance of 1 m. When the reading of the image signal is completed, the driving mode of the CCD is continuously switched to the draft mode by using the moving period of the focusing lens 101b, and the exposure operation of the CCD 102a is continuously performed three times at a predetermined exposure time. Thinning photography MQ1, MQ2, MQ3
And the AE calculation for the main photographing Q2 is performed using the calculation image obtained in the thinning photographing MQ3.

In the blurring adjustment mode, since the focus position is changed to perform the main photographing Q1 and Q2, there is a large possibility that the exposure value for the first main photographing Q1 and the exposure value for the second main photographing Q1 change. , In the second AE calculation, the actual shooting Q
The exposure control value for the actual shooting Q2 is set using the calculation image obtained in the thinning shooting MQ3 performed immediately before the second shooting.

The main photographing Q2 is continuously performed after the main photographing Q1. However, in the blur adjusting mode, if the aperture value is not the same as that of the main photographing Q1 (for example, the maximum aperture value), the blurring does not occur. The effect of taste adjustment cannot be obtained. Therefore, in the actual shooting Q2, the aperture value of the aperture 101c is fixed and C
The exposure control is performed only by the exposure time of the CD 102a. Therefore, in this exposure control, the CCD is given priority to the aperture.
The exposure time of 102a is set.

Considering the movement of the subject, it is desirable to make the shooting interval between the main shooting Q1 and the main shooting Q2 as short as possible. Therefore, in the main shooting Q1, the gain of the AGC is quadrupled and the exposure time is set to ¼. ing. If the exposure time is sufficiently short, it is not necessary to increase the gain. Further, as shown in FIG. 10, an ND filter 102d is provided between the lens 101 and the CCD 102a so as to be insertable into and removable from the optical axis of the lens 101, and the ND filter 102d is also provided.
It is also possible to provide a drive circuit 102e for controlling the inserting / removing operation of and to set a suitable exposure time for the main photographing Q2 in combination with the ND filter 102d.

Further, in the present embodiment, the photographed image of the thinned-out photographing MQ3 which is performed immediately before the main photographing Q2 is used for the calculation of the exposure control value, but it is performed between the main photographing Q1 and the main photographing Q2. The images obtained by the other thinned-out photographing MQ1 and MQ2 may be used.

Further, the second AF calculation and the second AWB calculation are performed using the calculation image obtained in the thinning-out photographing MQ3, and the first main photographing Q1 and the second main photographing Q1 are used by using these calculation results. A determination process is performed to determine changes in shooting conditions such as subject brightness, subject distance, and light source color between and.

The determination process of the change in the photographing condition is performed in the following procedure using the flowchart shown in FIG.

First, the object distance Dv2, the object brightness Bv2, and the AWB adjustment gain (R2 / G2, B2 / G2) are calculated in the second AF calculation, the second AE calculation, and the second AWB calculation, respectively.
Is calculated (# 1, # 3). Then, the subject distance Dv
2, subject brightness Bv2, AWB adjustment gain (R2 / G
2, B2 / G2) is the subject distance Dv1 calculated by the first AF calculation, the first AE calculation, and the first AWB calculation, respectively.
Subject brightness Bv1, AWB adjustment gain (R1 / G1, B
1 / G1) is compared with each other (# 5).

Subject brightness difference ΔBv = | Bv2-Bv1 |
Exceeds a predetermined value (for example, 1 EV), the subject distance difference ΔDv = | Dv2-Dv1 | exceeds a predetermined value (for example, 1 m), or the AWB adjustment gain difference ΔG _AWB = |
R2 / G2-R1 / G1 | + | B2 / G2-B1 / G1
If either | exceeds a predetermined value (for example, 0.5) (NO in # 7, # 9, and # 11), the shooting conditions have changed significantly between the main shooting Q1 and the main shooting Q2. Since it is estimated that an appropriate composite image cannot be obtained, the exposure operation of the main photographing F2 is prohibited, and a warning to that effect is displayed in the infiner screen of the EVF 4 (# 17). This warning display is performed, for example, by setting the display color to a specific warning color or by blinking. A warning message in characters may be displayed or a warning sound may be emitted.

Due to the prohibition and warning processing of photographing, photographing which is substantially failed photographing is stopped, the processing efficiency of the photographing operation is not lowered, and the data of the image having no composite value is recorded in the memory card MC. Without
Recording efficiency does not decrease.

On the other hand, when the photographing conditions do not significantly change between the main photographing Q1 and the main photographing Q2, that is, the subject brightness difference ΔBv = | Bv2-Bv1 | and the subject distance difference ΔD.
v = | Dv2-Dv1 | and the AWB adjustment gain difference ΔG
If all of the _AWB are below a predetermined value (# 7, # 9, # 1
1 is YES), and the exposure control value (aperture value, exposure time) is set based on the subject brightness Bv2 for the main shooting Q2 (#
13), the process ends.

Returning to FIG. 9, the focusing lens 101b.
When the movement to the focal position of the subject distance of 1 m is completed, 2
If the second main photographing Q2 is not prohibited, the CCD driving mode is switched to the draft mode, and the CCD 102a is exposed for the preset exposure time E2 to perform the main photographing Q2. Further, during this exposure period, the main shot image B obtained in the main shot Q2 with respect to the main shot image A obtained in the main shot Q1 using the three calculation images obtained in the thinned shots MQ1, MQ2, MQ3. The movement amount (X, Y) of is calculated.

The calculation processing of the movement amount (X, Y) of the main photographed image is performed by the following procedure using the flowchart shown in FIG.

The images MF2 and M obtained by thinning photographing MQ2 and MQ3 with respect to the image MF1 obtained by thinning photographing MQ1.
Suppose F3 is moving as shown in FIG. Three images MF1 and MF in thinned-out photography MQ1, MQ2 and MQ3
2, when MF3 is obtained (# 21), first, the movement amount (x1, y1) of the calculation image MF2 with respect to the calculation image MF1.
Is calculated using the G color component data (# 23).
The G color component data is used because the number of data is larger than the other color components and the image contrast is clearer than the other color components. Therefore, the movement amount (x1, y
This is because the calculation of 1) can be performed. Amount of movement (x1, y1)
Of the calculation image MF1 and the calculation image MF2 while moving the calculation image MF2 by 0 to 40 pixels in the x direction and 0 to 30 pixels in the y direction by one pixel pitch with reference to the calculation image MF1. Compute the correlation function,
It is calculated by the amount of movement in the x and y directions that minimizes the correlation function.

The calculation image MF2 in this calculation
Is set to 40 pixels in the x direction and 30 pixels in the y direction because the calculation images MF1 and MF2 are continuously photographed, and the positional shift due to camera shake is minute, and the calculation image MF1 , MF2 has 200 pixels
Since it is (y direction) × 150 (x direction), it is possible to normally calculate the minimum value of the correlation function by moving about 1/5 of the overall size in both directions unless abnormal camera shake occurs. Because it can be considered.

When the movement amount (x1, y1) is calculated, it is judged whether or not the correlation function for the movement amount (x1, y1) is 0.5 or more (# 25), and the correlation function is 0. 5
Smaller than (NO in # 25), the calculation image MF1
Does not match the calculation image MF2, that is, it is estimated that an abnormal camera shake has occurred, so that the actual photographed images A and B cannot be aligned and an appropriate composite image cannot be obtained. Therefore, the exposure operation of the main photographing F2 is interrupted, and a warning to that effect is displayed in the infiner screen of the EVF 4 (# 35). As a result, the shooting which is substantially failed shooting is stopped, the processing efficiency of the shooting operation is not reduced, and the data of the image having no composite value is not recorded in the memory card MC, and the recording efficiency is also reduced. There is nothing to do.

On the other hand, if the correlation function is 0.5 or more ((#
25 is YES), and the movement amount (x2, y2) of the calculation image MF3 with respect to the calculation image MF2 by the same method as described above.
Is calculated using the data of the G color component (# 27).
Then, when the movement amount (x2, y2) is calculated, it is determined whether or not the correlation function for the movement amount (x2, y2) is 0.5 or more (# 29), and the correlation function is 0.5. If it is smaller than (NO in # 29), the calculation image MF2 and the calculation image MF3 do not match, that is, it is estimated that an abnormal camera shake has occurred.
The process shifts to step 35 and the shooting of the main shooting F2 is interrupted, and a warning to that effect is displayed in the infiner screen of the EVF4.

On the other hand, if the correlation function is 0.5 or more ((#
(YES in 29), main shooting Q1, Q2 and thinning shooting MQ
1, MQ2, MQ3 timing and movement amount (x1, y
From (1) and (x2, y2), the movement amount (x, y) between the actual shooting Q1 and the actual shooting Q2 is calculated (# 31).

Specifically, for example, in the case of the movement amount x, the timings T1 and T of the thinning photographing MQ1, MQ2 and MQ3 are performed.
Since the relationship between T2 and T3 and the movement amounts x1 and x2 is as shown in FIG.
The relative positions P1, P2, P3 in the x direction at T3 can be determined. Therefore, since the movement amount curve N (T) in the x direction can be approximated using these three points P1 to P3,
From the approximate curve N (T) and the timings T4 and T5 of the main photographing Q1 and Q2, x between the main photographing Q1 and the main photographing Q2
The movement amount x in the direction is calculated by x = N (T5) -N (T4). The movement amount y is also calculated by the same method.

Then, the moving amount (x, y) is multiplied by 8 and the moving amount (X = 8x, Y) of the main photographed image B with respect to the main photographed image A.
= 8y) is calculated (# 33), and the process ends. Note that the movement amount (x, y) is multiplied by 8 because the size of the calculation images MF1 to MF3 is 1/8 of the actual photographed images A and B, and therefore the movement calculated by the size of the calculation image is used. Quantity (x,
y) is converted into a movement amount (X, Y) in the size of the main captured image.

Returning to FIG. 9, when the actual photographing Q2 ends, the photographing standby state is entered, the CCD drive mode is switched to the draft mode, and the live view image is captured by the CCD 102a and displayed on the EVF 4.

When the main photographing Q2 is normally performed, the main photographed images A and Q photographed in the main photographing Q1 and Q2 are recorded.
After the predetermined signal processing is performed for each of B, the registration processing is performed according to the flowchart shown in FIG. 15 (# 41, # 43), and the predetermined image combining processing is performed to create the blurring adjustment image. (# 45, # 47, # 49), the bokeh adjustment image is recorded in the memory card MC (# 51).

The registration processing of the main photographed images A and B is also performed using the data of the G color component. First, the main captured image B is moved by the movement amount (X, Y), and
The position is shifted by (X, Y) with respect to the main captured image A as shown in FIG. Then, with the main captured image A as a reference, the main captured image B is arranged by one pixel pitch, for example, from (X-40) to (X + 40) pixels in the x direction and from (Y-30) to (Y + 30) pixels in the y direction. While moving, the correlation function between the main captured image and the main captured image B is calculated, and the movement amounts (X1, Y1) in the x direction and the y direction that minimize the correlation function are calculated (# 43).

The image synthesizing process of the main photographed images A and B is performed by R,
This is performed for each of the G and B color components. First, the main captured image B is translated in parallel by the movement amount (X1, Y1) to bring the main captured image A and the image into the same state as shown in FIG. rear,
The non-overlapping data (the data in the hatched portion) is deleted from the data of both the captured images A and B to create the data for the combining process (# 47). In the example of FIG. 17, the composition processing data created from the main captured image A is i = 1 to (n−Y
1), j = (X1 + 1) to m in the range of pixel positions, and the synthesis processing data created from the main captured image B is i = (Y1 + 1) to n, j = 1 to (m- X
It is composed of data of pixel positions in the range of 1).

Then, the blurring adjustment image data is created by, for example, averaging or weighted averaging the data of the corresponding pixel positions of the combination processing data of the two main photographed images A and B. That is, the combined processing of the both main photographed images A and B is performed (# 49). In the example of FIG. 17, for the data included in the white part, new pixel position addresses (k, h) (k = 1, 2, ... (n−X1), h = 1,
2, (m-Y1)) is set, the synthesis processing data of the main captured image A is D _A (k, h), and the synthesis processing data of the main captured image B is D _B (k, h). , For example (w _A · D _A (k, h) +
Data B _C (k, h) of the blur adjustment image is created by calculating w _B · D _B (k, h)) / 2.

Then, the data D of this bokeh adjustment image
_C (k, h) is recorded in the memory card MC after being compressed by the JPEG method.

FIG. 18 is a time chart showing the photographing operation in the gradation adjustment mode.

The contents of the waveform at each stage are the same as those shown in FIG. Further, the same reference numerals are given to signals and processing periods having the same contents as the signals and processing periods shown in FIG.

As shown in the figure, the basic shooting operation is the same as the shooting operation in the blur adjustment mode. Therefore, here, the part different from the shooting operation in the blur adjustment mode and the operation specific to the gradation adjustment mode will be described.

As shown in the waveform chart of the exposure operation of FIG.
In the present embodiment, thinning-out photographing is performed only twice.
The first thinning shooting MQ1 is performed between the main shootings Q1 and Q2, and the second thinning shooting MQ1 is performed immediately after the end of the main shooting Q2. Therefore, the movement amount (X, Y) is calculated after the second actual photographing Q2 ends and the photographing standby state is entered. Further, in the gradation adjustment mode, the focus state of the main photographic image A and the main photographic image B must be the same, so if the AF process is performed by turning on the S1 switch (the movement R1 of the focusing lens in FIG. 18).
After that, the focus position is fixed.

In the special photographing modes such as the blur adjusting mode, the gradation adjusting mode and the super-resolution mode, the main photographing Q1 is performed as much as possible.
It is desirable to shorten the distance between the main photographing and the main photographing Q2 to reduce the camera shake between the main photographing, but in the blur adjustment mode, the focusing lens is intentionally set between the main photographing Q1 and the main photographing Q2. Since it is moved, the second actual shooting Q2 cannot be performed until the movement of the focusing lens is completed. Therefore, it is necessary to provide a certain interval between both main photographing, and the positional deviation of the main photographing is predicted by effectively utilizing this period and performing thinning photographing three times. However, since there is no such limitation in the gradation adjustment mode, the actual shooting Q1 and the actual shooting Q
In order to make the interval between the first and second scannings as short as possible, only the first thinning shooting MQ1 is performed, and the second thinning shooting MQ2 is performed immediately after the main shooting Q2. Further, the main photographing Q1, the thinning photographing MQ1 and the main photographing Q2 are performed at equal intervals.

Before and after the main photographing Q1 and Q2, the thinning photographing MQ1, MQ2, ...
This is for reducing the load of the registration process of (1), and therefore the movement amount (X, X, calculated using the calculation images MF1, MF2 obtained in the thinned-out images MQ1, MQ2).
To make the accuracy of Y) as high as possible
It is advisable to perform 1 and Q2 immediately after the main photographing Q1 and Q2, respectively. In addition, in the present embodiment, thinning-out photographing MQ
1 and Q2 are performed immediately after the main photographing Q1 and Q2, respectively, but thinned-out photographing MQ1 and Q2 are respectively performed to the main photographing Q1 and Q2.
You may make it just before 2.

Further, in the present embodiment, in order to make the interval between the main photographing Q1 and the main photographing Q2 as short as possible, the main photographing Q1
Although the above-described determination processing for the change in the imaging conditions is not performed between the main shooting and the actual shooting Q2, this determination processing may be performed.
Further, in the present embodiment, the thinning-out photographing is performed only twice, but it may be performed three times or more.

The image synthesizing process in the gradation adjusting mode is also performed by the same method as the image synthesizing process in the blur adjusting mode described above. That is, after the registration processing is performed on the main captured images A and B, synthesis processing data is created for each, and the data of the pixel positions corresponding to the synthesis data is averaged or weighted averaged, for example. The data of the adjustment image is created.

FIG. 19 is a time chart showing the photographing operation in the super-resolution mode.

The contents of the waveform at each stage are the same as those shown in FIG. Further, the same reference numerals are given to signals and processing periods having the same contents as the signals and processing periods shown in FIG.

As shown in the figure, the shooting operation in the super-resolution mode is basically the same as the shooting operation in the blur adjustment mode. Therefore, also here, the part different from the shooting operation in the blur adjustment mode and the operation unique to the super-resolution mode will be described.

As shown in the waveform chart of the exposure operation of FIG.
In this embodiment, thinning-out photographing is performed twice between the main photographing Q1 and Q2. Even in the super-resolution mode, in order to shorten the shooting operation from the main shooting Q1 to the main shooting Q2 as much as possible,
The main photographing Q1, the thinning photographing MQ1, the thinning photographing MQ2, and the main photographing Q2 are performed at equal intervals. In this embodiment, the thinning-out photographing MQ1 and MQ2 are performed between the main photographing Q1 and Q2, so that the movement amount (X, Y) is calculated during the exposure operation of the second main photographing Q2. There is.

The same exposure process can be performed in the gradation adjustment mode. On the other hand, even in the super gradation mode, there is no restriction that a fixed period has to be provided between the main photographing Q1 and the main photographing Q2, so a modification example regarding the timing and the number of thinning photographing explained in the gradation adjustment mode. It can be applied to the super resolution mode.

Further, in the present embodiment, the thinning-out photographing is the main photographing Q.
Although only once between 1 and Q2, the third thinning-out photography may be performed immediately after the second main photography Q2. By doing so, the number of data for calculating the movement amount increases, so that the movement amount calculation accuracy is improved. Therefore,
As a mode of the thinning-out photographing, once after the main photographing Q1, and once before or immediately after the main photographing Q2, the thinning-out photographing is performed twice in total. A mode in which thinning-out photography is performed, a mode in which thinning-out photography is performed twice or more between the main photography Q1 and Q2, and at least one thinning-out photography is performed immediately after the main photography Q2 can be considered. An appropriate shooting mode can be selected as appropriate depending on the content.

Further, even in the super-resolution mode, the focus state of the main photographic image A and the main photographic image B must be the same, so that the AF process is performed by turning on the S1 switch (moving the focusing lens in FIG. 19). (See R1), after that the focus position is fixed.

Further, in the present embodiment as well, in order to make the interval between the main photographing Q1 and the main photographing Q2 as short as possible, the above-mentioned discrimination processing of the change of the photographing condition is not performed between the main photographing Q1 and the main photographing Q2. You may make it perform a discrimination process.

The image synthesizing process in the super-resolution mode is different from the image number synthesizing process in the blurring adjustment mode and gradation adjusting mode described above.

The contents of the super-resolution processing will now be described with reference to FIG.
A brief description will be given using 0. For convenience of explanation, one-dimensional image data will be described.

When the photographer holds the camera and operates the shutter with respect to the subject, the two photographed images obtained by successively performing two exposure operations are normally taken by the photographer completely. Since it is not stationary, the shooting positions for the subject are slightly displaced from each other due to a slight camera shake.

In the super-resolution processing, the first real shot image A and the second real shot image A are interpolated, and
A high-definition image with high resolution is obtained by aligning and synthesizing the two main photographed images A and B.

That is, the image data of the first main shot image A is shown in FIG. 20A, the image data of the second main shot image B is shown in FIG. 20B, and the second main shot image B is It is assumed that the shooting position for the subject is shifted to the right by Δx with respect to the first actual shot image B. Note that FIG.
In (b), a curve P indicates the luminance characteristic of the subject, and
(1), a (2), ... And b (1), b (2) ,.
(1), C (2), ... And D (1), D (2), ... Show the light receiving level of each pixel. Further, C (1) ′, C (2) ′, ... Are pixel positions a (1), a (1), a (2), ... Using the light receiving levels C (1), C (2) ,.
It is the level that interpolates between (2), ..., D (1) ', D
(2) ', ... Are levels interpolated between the pixel positions b (1), b (2), ... Using the received light levels D (1), D (2) ,.

As shown in FIGS. 20 (a) and 20 (b), the light receiving position of each pixel in the first main captured image A for the subject and the light receiving position of each pixel in the second main captured image B for the subject are different. Both images A, B
The image data of the pixel position twice that of the image sensor can be obtained from the image data of 1.

Therefore, as shown in (c) of the figure, the first real shot image A and the second real shot image B are aligned and the two image data are simply combined to form pixels of the image sensor. Image data having a pixel density twice as high as the density is obtained.

In this embodiment, since the shift of the light receiving position of the image pickup element with respect to the subject due to the camera shake is used, the shift amount Δ between the pixel position a (i) and the pixel position b (i) is used.
Since x is not constant and the pixel position b (i) is not always located between the pixel position a (i) and the pixel position a (i + 1),
When the deviation amount Δx is very small, the two main image images A and B
There is a possibility that the registration of the may not be performed with sufficient accuracy.

Therefore, in order to improve this, in the present embodiment, the image data of the first main captured image A and the image data of the second main captured image B are interpolated and then combined. There is. By doing so, FIG.
As shown in (c), the pixel position b (i) and the pixel position a (i + 1)
Since the image data C (i) 'and D (i)' are interpolated and the two main photographed images A and B are aligned with high accuracy, an image with high resolution can be obtained.

Therefore, in the image synthesizing process in the super-resolution mode, the registration process is performed after increasing the number of data for each of the main photographed images A and B by a predetermined interpolation process. Then, synthesis processing data is created from both of the main captured images A and B, and data of the super-resolution image is created by averaging the data of the pixel positions corresponding to the synthesis processing data.

As described above, in the digital still camera 1 according to this embodiment, in the special photographing modes such as the blur adjustment mode, the gradation adjustment mode and the super-resolution mode, the shutter button 6 is fully pressed to release the shutter. , The main photographing Q1 and Q2 are continuously performed twice, but the thinning photographing MQ1 and MQ2 are performed at least twice before and after the main photographing Q1 and Q2, and the thinning photographing is performed. Since the positional deviation amount (X, Y) between the main captured images A and B is calculated using at least two calculation images, the main captured images A and B are aligned and a predetermined image combination is performed. It is possible to reduce the processing load of the alignment processing when performing the processing, and to shorten the processing time.

In the above-described embodiment, the thinning-out photographing is performed at most three times in succession. However, as shown in FIG. 21, the thinning-out photographing may be continuously performed four times or more. Shows the second thinned-out photography MQ2 as shown in FIG.
2 obtained by thinning photography MQ1, MQ2 at the time
It is advisable to immediately perform the amount of positional deviation (X, Y) between the main photographed images A and B by using one calculation image. By doing so, the positional deviation amount (X, Y) can be calculated quickly.

In the above embodiment, the main photographed image A,
Although the calculation images MF1, MF2, ... Are photographed separately from B, the first actual photographed image A may be used as the calculation image MF1 as shown in FIG. In the example of FIG. 22, the exposure operation for the main captured image A is made shorter than the regular exposure time, while the insufficient exposure due to this is corrected by level adjustment in the signal processing, and the processing period C2 ′
Then, the data of the main photographed image A is thinned out to obtain the calculation image MF.
I have acquired 1. Then, during the exposure period of the main photographing Q2, the movement amount (X, Y) is calculated using the calculation image MF1 and the calculation image MF2 photographed in the thinning photographing MQ2. If this is done, thinning shooting M
Since Q1 can be omitted, there is an advantage that the interval between the main photographing Q1 and the main photographing Q2 can be made narrower, and the positional deviation amount (X, Y) between the main photographing images A and B can be reduced.

Further, in the digital still camera 1 according to the present embodiment, the movement amount calculation is performed during the exposure period of the second main photographing Q2, and the main photographing images A and B are calculated according to the calculation result.
If the amount of positional deviation between the two is large, interrupt the main shooting Q2,
Since the EVF 4 is warned to that effect, the thinning-out photographing MQ1, MQ2 is also performed between the main photographing Q1 and the main photographing Q2.
And perform the main shooting using the images obtained by this thinning shooting Q
It is determined whether or not shooting conditions such as the subject brightness, the subject distance, and the color balance of the light source have changed between 1 and the actual shooting Q2.
When the shooting condition is changed as a result of the determination, the main shooting Q2 is stopped and the EVF 4 is warned to that effect. Therefore, the shooting that is substantially failed shooting is stopped, and the processing efficiency of the shooting operation is improved. Does not decrease. Further, the data of the image having no composite value is not recorded in the memory card MC, so that the deterioration of the recording efficiency can be prevented.

In the present embodiment, the case where two captured images are continuously captured has been described.
It can also be applied to the case of capturing one or more shot images.

[0172]

As described above, according to the present invention,
Take at least two consecutive shots of the same subject,
In a digital still camera capable of creating a single image by performing mutual image alignment processing and predetermined combining calculation processing on at least two main captured images obtained by the shooting, each main captured image Since the exposure operation is performed before and after the exposure operation for obtaining the image capturing operation, and the positional deviation amount between the main captured images is calculated using at least two captured images obtained by the exposure operation. In the alignment processing, the processing load is reduced and the processing time can be shortened by using this positional deviation amount.

Further, since the focus is adjusted on the subject of the exposure operation for each exposure operation for the main shot image,
It is possible to obtain a plurality of main shot images having different in-focus positions on the screen, and combine them to obtain an image with adjusted blur. In addition, the focus adjustment in each exposure operation is performed using the image for calculating the amount of positional deviation taken immediately before that, so even if the subject moves during continuous shooting, the focus adjustment in each exposure operation is possible. Next to
It is possible to obtain a plurality of actual shot images that are in focus.

Further, in the exposure control for the image for calculating the positional deviation amount, the number of pixels is smaller than that for the exposure control for the actual photographed image, so that the exposure time does not become unnecessarily long and the exposure amount for calculating the positional deviation amount is not required. Appropriate exposure control for the image becomes possible.

Further, since the exposure control value in the exposure of each main photographed image is set by using the calculation image photographed immediately before that, even if the exposure condition changes during continuous photographing, The main shot image can be shot under appropriate exposure conditions.

Further, the level of each main photographed image output from the image pickup means is adjusted to an appropriate level by the level adjusting means. The level adjustment value of the level adjusting means is used as the arithmetic image taken immediately before. Since the subject brightness changes during continuous shooting and the level of each main shot image output from the image pickup means is not appropriate, the level of each main shot image is corrected to an appropriate level. You can

[Brief description of drawings]

FIG. 1 is a front view of a camera body of a digital still camera according to the present invention.

FIG. 2 is a diagram showing an arrangement of main members of the digital still camera.

FIG. 3 is a right side view showing an arrangement of main members incorporated in the digital still camera.

FIG. 4 is a rear view of the digital still camera.

FIG. 5 is a diagram showing a configuration of an image pickup surface of a color image pickup element.

FIG. 6 is a diagram illustrating a method of selecting a shooting mode.

FIG. 7 is a block diagram showing an internal configuration of a digital still camera.

FIG. 8 is a diagram showing a method of recording an image file in a memory card.

FIG. 9 is a time chart showing a shooting operation in a blur adjustment mode.

FIG. 10 is a block configuration diagram showing an internal configuration of another digital still camera in which an ND filter is detachably provided between a lens and a CCD.

FIG. 11 is a flowchart showing a process of determining a change in shooting conditions between two main shot images obtained by actual shooting using three calculation images obtained by thinning shooting.

FIG. 12 is a flowchart showing a process of calculating a movement amount between two main captured images obtained by actual photographing using three calculation images obtained by thinned photographing.

FIG. 13 is a diagram showing an example of a movement amount between three calculation images.

FIG. 14 is a diagram for explaining a method of calculating the amount of movement between two main captured images from each timing of three times thinning photography and the amount of movement between images obtained by each thinning photography. is there.

FIG. 15 is a flowchart showing a processing procedure of creating two bokeh adjustment images by combining two main captured images.

FIG. 16 is a diagram showing an initial state of registration processing on a main captured image.

FIG. 17 is a diagram for explaining a method of creating data for image combination processing from data of two pieces of main captured images after registration processing.

FIG. 18 is a time chart showing the shooting operation in the gradation adjustment mode.

FIG. 19 is a time chart showing a shooting operation in super-resolution mode.

FIG. 20 is a diagram for explaining super-resolution processing.

FIG. 21 is a time chart showing another aspect of thinned-out photographing.

FIG. 22 is a time chart showing an aspect of thinning-out photographing in which the first main photographing is combined with the first thinning-out photographing.

FIG. 23 is a diagram showing how the camera angle changes when exposure operations are continuously performed.

[Explanation of symbols]

1 Digital Still Camera 101 Lens 102 Imaging Unit 102a CCD (Imaging Unit) 103 Signal Processing Unit (Level Adjusting Unit) 104 Emission Control Unit 105 Lens Control Unit (Focus Adjusting Unit) 106 Display Unit 107 Operation Unit 108 Card I / F 108 Overall Control unit (level adjustment value setting unit) 108a ROM 108b RAM 108c Exposure value calculation unit (exposure amount control unit) 108d Display control unit 108e Recording control unit 108f Reproduction control unit 108g Special exposure control unit (first and second exposure control) 108h Image processing unit (calculating unit, image synthesizing unit) 109 Card interface 110 Communication interface 2 Camera body 205 Color image sensor 206 Shutter button 207 Display unit 208 Power switch 209 Quad switch 210 Switch group 3 Interchangeable lens 4 Power The view finder 5 flash MC memory card

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H04N 5/235 G02B 7/11 N // H04N 101: 00 G03B 3/00 A (56) Reference JP 2000-224460A (JP) , A) JP-A-11-252445 (JP, A) JP-A-9-261526 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 5/232 H04N 5/235

Claims (17)

(57) [Claims] 1. An image pickup means for photoelectrically converting a subject light image into an image signal and outputting the image signal, and at least 2 for the same subject.
First exposure control means for performing the exposure operation of the image pickup means in succession, and at least two main photographed images photographed by the exposure control by the first exposure control means,
In a digital still camera including an image synthesizing unit that performs a process of aligning images with each other and a predetermined synthesizing calculation process to create one image having an image quality different from the main captured image, each exposure operation of the image pickup unit A second exposure control means for performing an exposure operation for capturing an image used for calculating a positional deviation amount between main captured images before and after, and at least two images photographed by the exposure control of the second exposure control means. A digital still camera, comprising: a computing unit that computes a positional shift amount between the main photographed images using photographed images. 2. The image synthesizing means performs alignment processing between the plurality of main photographed images using the positional shift amount calculated by the calculating means.
The described digital still camera. 3. The digital still camera according to claim 1, further comprising focus adjusting means for adjusting a focus of an image photographed by the exposure control of the first exposure controlling means, the focus adjusting means comprising: 3. The digital still camera according to claim 1, wherein the focus position is changed between a plurality of main shot images shot by the exposure control of one exposure control unit. 4. The focus adjusting means calculates a focus position by using an image for calculating a positional deviation amount photographed by the exposure control of the second exposure control means before photographing each main photographed image. The digital still camera according to claim 3, wherein the digital still camera is a digital still camera. 5. The ratio of the number of pixels of the image pickup unit whose exposure is controlled by the second exposure control unit to the number of pixels of the image pickup unit whose exposure is controlled by the first exposure control unit is less than one. The computing means is the second
The positional shift amount between the plurality of photographed images photographed by the exposure control of the exposure control means is calculated, and the positional shift amount is converted based on the ratio of the number of pixels to shift the positional relation between the main photographed images. The digital still camera according to claim 2 or 3, wherein the amount is calculated. 6. The digital still camera according to claim 5, wherein the ratio of the number of pixels is changed according to the change of the focus position. 7. The digital still camera according to claim 1, wherein an exposure time of the image pickup means by the second exposure control means is shorter than an exposure time of the image pickup means by the first exposure control means. . 8. The digital still camera according to claim 7, further comprising level adjusting means for adjusting the level of the image signal output from the image pickup means based on the exposure time by the exposure control by the second exposure control means. A digital still camera characterized by having. 9. The exposure operation for the image for calculating the positional deviation amount captured between the first main captured image and the second main captured image is performed immediately after the exposure operation for the first main captured image.
Alternatively, the digital still camera according to claim 8, wherein the digital still camera is performed immediately before an exposure operation for the second main captured image. 10. The digital still camera according to claim 1, wherein the intervals of the exposure operations controlled by the first and second exposure control means are equal intervals. 11. The method according to claim 1, wherein the second exposure control means performs an exposure operation for taking in an image used for the positional deviation amount calculation after the exposure operation of the final main shot image. Digital still camera. 12. The digital still camera according to claim 1, wherein the image for calculating the positional deviation amount photographed by the image pickup means under the exposure control of the second exposure control means is used, and then the first The digital still camera, further comprising an exposure amount control means for setting an exposure control value of a main captured image that is exposure controlled by the exposure control means. 13. The digital still camera according to claim 12, wherein the exposure control value set by the exposure amount control means is an aperture value set with aperture priority. 14. The digital still camera according to claim 12, wherein the exposure control value set by the exposure amount control means is an exposure time of the image pickup means set with shutter priority. 15. The digital still camera according to claim 12, further comprising an ND filter that is removably provided on an optical path of the subject light image to the imaging means, and is set by the exposure amount control means. The digital still camera, wherein the control value is an aperture value in a combination of the ND filter and the aperture value. 16. The digital still camera according to claim 1, wherein the level adjusting means for adjusting the level of the image signal output from the image pickup means, and the image pickup means whose exposure is controlled by the second exposure control means. And a setting means for setting the level adjustment value of the image signal output from the image pickup means, the exposure of which is controlled by the first exposure control means thereafter. And a digital still camera. 17. The digital still camera according to claim 1, wherein the predetermined synthesis calculation process is a blur adjustment process for adjusting a blur condition of an image.