JP2005341448A - Electronic camera, imaging condition control method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a suitable imaging condition control depending on imaging circumstances. <P>SOLUTION: On standby for imaging, statuses of controlled results AE and AWB are each checked at through picture imaging timing. The numbers (En, We) of times in which the statuses were continuously within a given adequate range are updated and stored. When both the numbers (En, We) of the times are more than the specified number of times together at the time of imaging operation and besides the last variation of an image subject is extremely small (YES at SB16), imaging is performed by using the AE control and the AWB control that are based on control values obtained last on the standby for imaging. When either of both the numbers of times comes short of the specified number of times and the last variation of the photographing subject is significant (NO at SB16), a preliminary imaging process and an AE process and/or an AWB process (SB17 to SB20) that are prior to actual photographing are performed to take the photographic subject by the AE control, the AWB control that are based on new control values. Depending on the changing situation of the image subject directly before the imaging operation, an imaging condition for placing greater emphasis on a quick response different in feature and that for doing the same on accuracy are automatically selected and practiced. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electronic camera device, an imaging condition control method, and a program that record an image of a subject imaged by an imaging means.

  Conventionally, in a digital still camera equipped with a CCD or MOS type image sensor, when an object to be imaged is captured in accordance with a shooting operation when the shutter key is pressed (main shooting), automatic exposure (AE) control or Imaging condition control such as auto white balance (AWB) control is performed.

  As a specific control method, a value obtained by the control performed during the REC through operation for displaying a through image mainly immediately before the shutter key is pressed (appropriate exposure value in AE control, and appropriate balance adjustment value in AWB control). ) Based on the first method for controlling exposure and white balance, and taking a picture once when the shutter key is pressed to obtain a control value. And a second method for controlling exposure and white balance in shooting).

  Further, as a method similar to the first method, it is possible to detect the operation state of the shutter in two stages of “half-pressed” state and “full-pressed” state, and when the shutter key is fully pressed ( There is a third method of controlling the exposure and white balance based on the control value acquired at the time when the shutter is half-pressed (at the time of the shooting notice operation) prior to the shooting operation. Such a method is used, for example, in a digital still camera which has an autofocus (AF) function and allows a user to fix the focus position (AF lock) by half-pressing the shutter during the REC through operation.

Further, in Patent Document 1 below, regarding auto white balance control, in a digital still camera that can detect the operation state of the shutter in two stages, only the light source type is determined when the shutter is half-pressed, and the subsequent shutter When fully pressed, a new image is taken and a control value corresponding to the previously determined light source type is acquired, and the white balance is controlled based on the acquired control value, that is, the first method and the second method described above. An intermediate method is described.
JP 2000-299876 A

  However, in the imaging condition control by the second method described above, an appropriate exposure, white balance, etc. can be obtained even when the shutter operation is performed immediately after the power is turned on or immediately after the subject is changed, but there is a shutter operation. At this time, since an imaging operation for acquiring a control value is performed before the actual shooting, a time lag occurs in the actual shooting, and a photo opportunity may be missed. The same applies to the auto white balance control described in Patent Document 1.

  On the other hand, in the imaging condition control according to the first method and the third method described above, the time lag does not occur, but a new control value is not acquired when the shutter operation is performed. When the shutter is operated while the subject is changing significantly, such as when the shutter key is immediately operated before the main unit is stably held at the subject, appropriate exposure and white balance May not be obtained. In such a case, it is expected that there will be a problem that the photographing result is a white or black image or an image of an inappropriate color.

  Therefore, there are advantages and disadvantages in the imaging condition control by any of the methods, and thus there has been a problem of how to perform the imaging condition control according to the situation when the imaging operation is performed.

  The present invention has been made in view of such conventional problems, and provides an electronic camera device and an imaging condition control method that enable appropriate imaging condition control according to a shooting situation, and a program used for realizing them. The purpose is to do.

  In order to solve the above-mentioned problem, in the first aspect of the invention, in the electronic camera device that records the image of the subject imaged by the imaging unit, a predetermined control value based on the image captured by the imaging unit is acquired. Control value acquisition means, imaging condition control means for controlling imaging conditions based on the control value acquired by the control value acquisition means, and history information indicating a change state of the image quality control result by the image quality adjustment means during shooting standby History information acquisition means for acquiring, a determination means for determining whether or not a change state immediately before indicated by the history information acquired by the history information acquisition means meets a predetermined condition in response to a shooting request; An image to be recorded based on the control value acquired by the acquisition unit during shooting standby when the determination unit determines that the change state meets a predetermined condition When the imaging condition control means performs the imaging condition control, and it is determined that the change state does not correspond to the predetermined condition, the imaging operation is performed in advance prior to the imaging operation of the image to be recorded, and the recording is performed. Control means for causing the control value acquisition means to acquire a new control value used by the imaging condition control means for controlling the image to be performed.

  In such a configuration, importance is attached to the responsiveness based on the control value acquired during shooting standby according to the change status immediately before the control result of the imaging condition during shooting standby, that is, the change status immediately before the subject during shooting. Automatically select and execute imaging condition control with different characteristics, such as imaging condition control and imaging condition control that emphasizes accuracy based on a new control value acquired by an imaging operation prior to the imaging operation of the image to be recorded Can be made.

  Further, in the invention of claim 2, the predetermined condition is that the change state immediately before indicated by the history information is within a predetermined appropriate range in which the control result by the imaging condition control means is centered on the control target. It was assumed that the degree of continuous accommodation was above the specified level.

  In such a configuration, it is possible to more accurately determine the state of change immediately before the subject that serves as a selection criterion for imaging condition control with different characteristics.

  According to a third aspect of the present invention, the predetermined condition is controlled such that a change state immediately before indicated by the history information is controlled after the control result by the imaging condition control means is finally within a predetermined allowable range. It was assumed whether or not the degree of continuously falling within a predetermined appropriate range centered on the target was more than a specified level.

  In such a configuration, it is possible to more accurately determine the state of change immediately before the subject that serves as a selection criterion for imaging condition control with different characteristics.

  According to a fourth aspect of the present invention, the predetermined control value acquired by the control value acquisition means includes a control value required for exposure control, and the imaging condition control means controls exposure based on the control value. It included exposure control means for controlling.

  In such a configuration, at the time of shooting, exposure control with different characteristics such as exposure control that emphasizes quick response and exposure control that emphasizes accuracy is automatically selected and executed according to the change state immediately before the subject. be able to.

  In the invention of claim 5, the predetermined control value acquired by the control value acquisition means includes a control value required for white balance control, and the imaging condition control means White balance control means for controlling the balance is included.

  In such a configuration, at the time of shooting, white balance control with different characteristics, such as white balance control with emphasis on quick response and white balance control with emphasis on accuracy, is automatically selected according to the change situation immediately before the subject. Can be executed.

  Further, in the invention of claim 6, the history information acquisition means is in a standby state for taking a picture of a control result by the imaging condition control means until a shooting advance notice operation is performed prior to the shooting operation. Information indicating the change status was obtained.

  In such a configuration, at the time of shooting, according to the change status immediately before the shooting preview operation, imaging condition control that emphasizes quick response based on the control value acquired during shooting standby and imaging of the image to be recorded It is possible to automatically select and execute imaging condition control with different characteristics, such as imaging condition control focusing on accuracy based on a new control value acquired by an imaging operation prior to the operation.

  The invention according to claim 7 includes an automatic focusing function for automatically controlling the focus, stops the automatic focusing function, and ensures a longer depth of field within a predetermined control range. A pan-focus mode that is a shooting mode for setting a shooting environment for the camera, and the control means, when shooting in the pan-focus mode, when the determining means determines that the change state meets a predetermined condition The imaging condition control unit performs imaging condition control of an image to be recorded based on the control value last acquired by the acquisition unit during shooting standby, while the change state is determined not to satisfy a predetermined condition. In this case, a new imaging operation control unit is used to control the imaging condition of the image to be recorded by performing an imaging operation prior to the imaging operation of the image to be recorded. His value was assumed to be acquired in the control value obtaining means.

  In such a configuration, when shooting in a pan focus mode different from the normal shooting mode, the imaging condition control that emphasizes quick response and the imaging condition control that emphasizes accuracy according to the change state immediately before the subject. It is possible to automatically select and execute different imaging condition controls.

  According to an eighth aspect of the present invention, there is provided an imaging condition control method for an electronic camera device that records an image of a subject imaged by an imaging unit, and imaging of an image captured by the imaging unit during imaging standby Acquiring control values required for condition control, performing imaging condition control based on the acquired control values, acquiring history information indicating the change status of the control results, and waiting for shooting when there is a shooting request A step of determining whether or not the state of change immediately before indicated by the acquired history information satisfies a predetermined condition, and when the result of the determination corresponds to the predetermined condition, shooting standby When the imaging condition control of the image to be recorded is performed based on the control value acquired during the determination, and the result of the determination does not correspond to the predetermined condition, the imaging unit performs the imaging operation of the image to be recorded Get the new control value by prior imaging operation standing and the method includes a step of performing image capturing condition control of recording an image on the basis of the new control value acquired.

  According to such a method, at the time of shooting, importance is attached to responsiveness based on the control value acquired during shooting standby according to the change status immediately before the control result of the image quality during shooting standby, that is, the change status immediately before the subject. It is possible to selectively execute imaging condition control and imaging condition control that emphasizes accuracy based on a new control value acquired by an imaging operation prior to the imaging operation of the image to be recorded.

  According to the ninth aspect of the present invention, the computer of the electronic camera device that records the subject image picked up by the image pickup means is required for controlling the image pickup condition of the image picked up by the image pickup means during the image pickup standby. Acquired control value, performed imaging condition control based on the acquired control value, and acquired history information indicating the change status of the control result, and when there was a shooting request, it was acquired during shooting standby Acquired during shooting standby when the process of determining whether or not the change state immediately before indicated by the history information meets a predetermined condition, and the result of the determination meets the predetermined condition The imaging condition control of the image to be recorded is performed based on the control value, and when the result of the determination does not correspond to the predetermined condition, the imaging operation of the image to be recorded by the imaging unit is performed. One pre-acquired a new control value by the imaging operation of, and a program for executing the acquired based on the new control values for imaging condition control of the recording image processing.

  In the electronic camera device and the imaging condition control method of the present invention, when shooting in a normal shooting mode or a different pan focus mode, the change status immediately before the subject in shooting standby or the subject immediately before the shooting preview operation Depending on the changing conditions, imaging condition control with different features such as exposure control and white balance control that emphasizes responsiveness, and imaging condition control such as exposure control and white balance control that emphasizes accuracy Enabled to automatically select and execute. Therefore, it is possible to perform appropriate imaging condition control according to the shooting situation such as when a shooting operation is performed.

  Further, in the electronic camera device of the present invention, it is possible to more accurately or more accurately determine the change state immediately before the subject, which is a selection criterion for imaging condition control with different characteristics. Therefore, more appropriate imaging condition control according to the shooting situation such as when a shooting operation is performed can be performed.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a perspective view showing an external configuration of a digital still camera 1 according to the present invention. The digital still camera 1 is capable of recording and reproducing still images and moving images, and has a photographing lens 2, an optical viewfinder window 3, and a strobe light emitting unit 4 on the front surface of a substantially rectangular thin plate-shaped metal exterior body. , And a grip bar 5, and a power key 6 and a shutter key 7 are arranged on the right end side (for the user) of the upper surface of the grip bar 5.

  The photographic lens 2 has a zoom function and an AF function to change the focal length steplessly, and is configured to retract in the body when the power is off and the playback mode is set, and the shutter key 7 can be operated in two stages of a half-pressed position and a fully-pressed position.

  Although not shown, a mode switch, a new key, a cross key, a set key, an optical viewfinder, a strobe charge lamp, a liquid crystal monitor, and the like are disposed on the back of the digital still camera 1. On the bottom surface, a memory card slot for attaching / detaching a memory card used as a recording medium is provided.

  FIG. 2 is a block diagram showing an electrical configuration of the digital still camera 1. The lens optical system 12 constituting the photographing lens 2 described above is driven by a motor (M) 11 to adjust the zoom magnification and focus position. A diaphragm 32 is disposed behind the optical axis of the lens optical system 12, and the degree of opening of the diaphragm 32 is adjusted by an actuator (A) 33. Further, a CCD 13 as an image pickup device is disposed behind the optical axis of the lens optical system 12, and the CCD 13 is scanned and driven by a timing generator (TG) 14 and a vertical driver 15 in the photographing mode, and is exposed on the exposure surface. A photoelectric conversion output corresponding to the formed optical image is output for one screen at a constant period.

  The output of the CCD 13, that is, the imaging signal is sampled and held by a sample and hold circuit (S / H) 16, and converted to digital data (imaging signal) for each RGB primary color component by an A / D converter 17. The converted image signal is subjected to color process processing including pixel interpolation processing and γ correction processing in the color process circuit 18 and then converted into a digital luminance signal Y and color difference signals Cb, Cr as DMA (Direct Memory Access). It is output to the controller 19.

  The DMA controller 19 temporarily transmits the luminance signal Y and the color difference signals Cb and Cr output from the color process circuit 18 to an internal buffer using the composite synchronization signal, memory write enable signal, and clock signal from the color process circuit 18. The DMA transfer is performed via the DRAM interface (I / F) 20 to the DRAM 21 used as a buffer memory. The luminance and color difference signals for one screen transferred to the DRAM 21 are read from the DRAM 21 via the DRAM interface 20 by the control unit 22 and written to the VRAM 24 via the VRAM controller 23.

  The control unit 22 includes a CPU, a ROM storing an operation program necessary for controlling each unit by the CPU, a RAM used as a work memory, and the like, and controls the entire digital still camera 1. The ROM causes the CPU to perform AF control, AE control, and AWB control in the shooting mode, and to perform processing described later according to the operation of the shutter key 7, thereby allowing the CPU to control the control value of the present invention. A program for functioning as acquisition means, imaging condition control means, history information acquisition means, determination means, and control means is also stored.

  The digital video encoder 25 periodically reads the luminance and color difference signals from the VRAM 24 via the VRAM controller 23, generates a video signal based on these data, and outputs the video signal to the display unit 26.

  The display unit 26 is composed of a liquid crystal monitor or the like provided on the back side of the digital still camera 1. In the shooting mode, the display unit 26 displays an image captured at that time by a display operation based on a video signal from the digital video encoder 25, that is, a through image. Display images in real time. Then, the through image is updated at a scanning drive cycle of the CCD 13 (for example, 30 sheets / second), whereby the liquid crystal monitor functions as an electronic viewfinder.

  The key input unit 30 includes the power key 6, the shutter key 7, the mode switch, the menu key, the cross key, the set key, and the like described above, and signals associated with these key operations are sent directly to the control unit 22.

  When the through image is displayed on the display unit 26, when the user fully presses the shutter key 7, a trigger signal is output from the key input unit 30 accordingly. In response to this trigger signal, the controller 22 temporarily stops the flow of signals from the CCD 13 to the DRAM 21 immediately after the completion of the DMA transfer of the luminance and color difference signals for one screen captured from the CCD 13 to the DRAM 21 at that time. , Transition to the record storage state.

  In this recording and storage state, the control unit 22 sends the luminance and color difference signals for one frame written in the DRAM 21 to 8 pixels × 8 pixels for each of Y, Cb, and Cr components via the DRAM interface 20. The data is read out in units called basic blocks, and written into a JPEG (Joint Photographic Coding Experts Group) circuit 27. In the JPEG circuit 27, data compression is performed by processing such as ADCT (Adaptive Discrete Cosine Transform) and Huffman coding which is an entropy coding method.

  The compressed code data is read out as a data file of one image by the control unit 22, or a memory card 28 that is detachably attached to the digital still camera 1 or a built-in unit that is fixedly incorporated in the digital still camera 1. It is written in either one of the memories 29. When the writing operation is completed, the signal flow from the CCD 13 to the DRAM 21 is resumed by the control unit 22.

  In addition, a strobe driving unit 31 is connected to the control unit 22. The strobe driving unit 31 includes a strobe capacitor (not shown), a charging circuit for the strobe, and a booster circuit. The strobe driving unit 31 flashes the strobe light emitting unit 4 based on the control from the control unit 22 when the still image is captured.

  On the other hand, in the playback mode, the control unit 22 selectively reads out the image data recorded in the memory card 28 or the built-in memory 29 according to a key operation by the user, and the JPEG circuit 27 compresses the data in the shooting mode. The compressed image data is decompressed in the reverse procedure. The decompressed image data is held in the DRAM 21 via the DRAM interface 20, and the content held in the DRAM 21 is stored in the VRAM 24 via the VRAM controller 23, and based on the image data periodically read from the VRAM 24. When the video signal is generated, the recorded image is reproduced and output on the display unit 26.

  Next, in the digital still camera 1 having the above configuration, an operation at the time of still image shooting when the shooting mode is set will be described.

  Here, the basic operation in the shooting mode will be described first. In this embodiment, when the shutter key 7 is half-pressed, the focus state by the AF operation is locked, and at the same time, the exposure control state by AE control and the white balance state by AWB control are locked, and then the shutter is released. When the key 7 is fully pressed, shooting is performed in the previously locked focus state, exposure control state, and white balance state. The AF control is control by a contrast detection method using a predetermined focus area as an evaluation area. The AWB control is based on the values of the color difference signals Cb and Cr separated in the color process circuit 18, and when the Cb value and Cr value of a certain pixel constituting the image are included in a predetermined white detection range, While determining that the color is white, the Cb value and the Cr value of all the pixels determined to be white are individually integrated so that the integrated value of Cb and the integrated value of Cr are “0” (Cb = Cr = 0) Control for adjusting the gain of the R component and the gain of the B component of the image signal.

  3 and 4 are flowcharts showing processing contents according to the present invention by the control unit 22 during still image shooting in the shooting mode.

  When the shooting mode is set, the control unit 22 first initializes the number of exposure convergence (En) and the number of white balance convergence (Wn) used in the processing described later (step SA1), and AF, AE, AWB. Each control is started (step SA2). The number of exposure convergence (En) and the number of white balance convergence (Wn) are history information of the present invention and data stored in the work memory of the control unit 22. Thereafter, imaging processing (image capture) is performed at a fixed period, for example, a frame rate of 30 frames / second (step SA3), and a through image is displayed on the display unit 26 (step SA4).

  Subsequently, it is determined whether or not the exposure state during the AE control in the frame is within an appropriate range. If the exposure state is within the appropriate range (YES in step SA5), the number of exposure convergence (En) is incremented (step SA6). . If the exposure state is not within the proper range but is within the allowable range (step SA5 is NO, SA7 is YES), the exposure convergence count (En) is negatively counted (step SA8). Note that the minimum value of the number of exposure convergence (En) is “0”. Furthermore, when the exposure state is in an unacceptable range (NO in step SA7), the number of exposure convergence (En) is initialized (step SA9).

  FIG. 5A is a diagram showing the discrimination criteria of steps SA5 and SA7. In this embodiment, the exposure state is evaluated as an exposure value of 8 bits (256 levels) in the AE control. , “105” is set as a control target value (y_target), the range of ± 5 is determined as an appropriate range, the range up to ± 15 exceeding the allowable range, and the range beyond the range is further determined as an unacceptable range. .

  Further, the control unit 22 determines whether or not the white balance state during the AWB control in the same frame is within an appropriate range. If the white balance state is within the appropriate range (YES in Step SA10), the control unit 22 sets the number of times of white balance convergence (Wn). A plus count is performed (step SA11). If the white balance state is not within the proper range but is within the allowable range (step SA10 is NO, SA12 is YES), the white balance convergence frequency (Wn) is negatively counted (step SA13). Note that the minimum value of the number of times of white balance convergence (En) is “0”. Further, when the white balance state is outside the allowable range (NO in step SA14), the white balance convergence count (En) is initialized (step SA14).

  FIG. 5B is a diagram showing the discrimination criteria of steps SA10 and SA12. In the present embodiment, the white balance state, that is, the color shift amount, the R component gain and the B component are described above. Evaluation is based on the average value of the gain adjustment rate. In steps SA10 and SA12, “0%” is set as the control target value (c_target), and the range of ± 5 exceeds the appropriate white balance range. A range up to ± 10 is determined as an allowable range, and a range exceeding the range is determined as an unacceptable range.

  Thereafter, until the shutter key is half-pressed (NO in step SA15), the processing from steps SA3 to SA14 described above is repeatedly executed. In other words, every time imaging with the CCD 13 is performed while adjusting the in-focus position, the exposure time, R component gain, and B component gain values at the next imaging are adjusted based on the captured image, while the work memory The exposure convergence count (En) and the white balance convergence count (Wn) are updated.

  When the shutter key 7 is half-pressed (YES in step SA15), as shown in FIG. 4, the contents of each control of AF, AE, and AWB are locked (step SA16). That is, the focus position at the time when the shutter is half-pressed, the exposure time of the CCD 13, and the R component and B component gain setting values in the imaging signal are held. The exposure time and the set value of the gain are the control values of the present invention. In addition, after locking the shooting conditions, it is confirmed whether or not the shutter key 7 has been fully pressed. If the shutter key 7 has not been fully pressed (NO in step SA17), the shutter key 7 is half pressed. While confirming that the push operation has been performed (step SA18), it waits for the full push operation.

  Although not shown in the figure, the through image is updated by performing imaging at regular intervals during that period. In the meantime, if the half-press operation of the shutter key 7 is released (NO in step SA18), the process returns to step SA1 to repeat the above-described processing from the beginning.

  If the shutter key 7 is pressed halfway without releasing the shutter key 7 from the state where the shooting conditions are locked (YES in step SA17), the shutter key 7 is first pressed halfway. Accordingly, it is determined whether or not the AF control immediately before locking is completed, that is, whether or not the movement of the lens optical system 12 to the in-focus position is completed, and if it is completed (YES in step SA19). The image to be recorded is picked up with the photographing conditions locked in step SA16 as it is, and the data of the picked up image is recorded and stored in the memory card 28 or the built-in memory 29 (step SA27).

  That is, when the user intentionally focuses on the main subject and then performs shooting, shooting processing based on the basic operation is performed.

  On the other hand, when the AF control is not completed when the shutter key 7 is fully pressed (NO in step SA19), for example, the half-pressing operation and the full-pressing operation of the shutter key 7 are almost immediately after the focus area is changed. If they are performed simultaneously, first, both the number of exposure convergence (En) and the number of white balance convergence (Wn) stored in the work memory are equal to or greater than a predetermined number of times determined in advance. It is determined whether or not there is (step SA20).

  When the number of times (En, Wn) is equal to or greater than the specified number of times (YES in step SA20), that is, the AE immediately before the time point when the half-pressing operation and the full-pressing operation of the shutter key 7 are performed almost simultaneously. The change in the control result of the AWB is that there is no significant variation in the brightness of the subject, and the brightness (exposure value) of the captured image is finally within the allowable range (90 to 120). 110)) The white balance is appropriate after the degree of continuous fit is more than the specified value, the color balance does not fluctuate significantly, and the color misregistration amount finally falls within the predetermined tolerance (± 10). When the degree of continuously falling within the range (± 5) is greater than or equal to the specified value, the following processing is executed.

  First, pan focus setting is performed so that the in-focus position is set to a predetermined in-focus position corresponding to the zoom position of the photographic lens 2 at that time and the depth of field is as deep as possible so as to be close to the pan focus ( In step SA21), based on the exposure time in the AE control performed immediately before the shutter key 7 is half-pressed, a so-called aperture AE process is performed in which the maximum aperture value is set to a maximum value and the shutter speed is decreased accordingly. Then (step SA22), an image to be recorded is captured, and the captured image data is recorded and stored in the memory card 28 or the built-in memory 29 (step A27). Thus, photographing is performed in a state where so-called out-of-focus is unlikely to occur.

  In addition, the determination result in step SA20 is NO, and one of the exposure convergence count (En) and the white balance convergence count (Wn) stored in the work memory is set to a predetermined specified number. If not, that is, the time when the half-pressing operation and the full-pressing operation of the shutter key 7 are performed almost simultaneously, at least the time when the brightness of the subject has changed significantly or the color balance has changed significantly If so, the following processing is executed. That is, when the CCD 13 performs imaging once at that time (step SA23), the exposure convergence count (En) has not reached the specified count (the brightness of the subject has changed significantly) ( In step SA24, YES), AE processing and AWB processing based on the image signal during the imaging operation are performed (steps SA25 and SA26). Further, even when the exposure convergence number (En) is equal to or greater than the prescribed number, the white balance convergence number (Wn) has not reached the prescribed number (the color balance has changed significantly) (step SA24). NO), only the AWB process is performed (step SA26).

  Thereafter, based on the new AE processing and AWB processing, or the shooting conditions by the AWB processing, the above-described pan focus setting and narrowing AE processing are executed (step SA22), and then an image to be recorded is captured. The captured image data is recorded and saved in the memory card 28 or the built-in memory 29 (step A27). Thus, photographing is performed in a state where so-called out-of-focus is unlikely to occur.

  Thereafter, the process returns to step SA1, and the above-described processing is repeated until the photographing mode is ended or the power is turned off.

  As described above, in the digital still camera 1 of the present embodiment, when the half-pressing operation and the full-pressing operation of the shutter key 7 are performed almost immediately after the focus area is changed, the pan focus setting is performed. In addition, by performing the narrowing-down AE process, it is possible to perform shooting in a state where so-called defocusing is unlikely to occur.

  On the other hand, in this case, when the shooting operation using the shutter key 7 as described above is performed during a period in which the change of the subject is extremely small, the prior imaging process and the AE process and / or the AWB process (steps) prior to the actual shooting are performed. By omitting a series of imaging condition control processes such as SA23 to 26), it is possible to minimize the time lag from the time when the shutter key 7 is fully pressed until the actual shooting, and to perform the imaging condition control with an emphasis on responsiveness. . Therefore, the probability of missing a photo opportunity can be reduced when shooting under a situation where there is very little change in the subject.

  Further, when the shooting operation using the shutter key 7 as described above is performed during a period in which the brightness and color balance of the subject are remarkably changed, the above-described series of processing is performed to secure the focus on the shooting result. As well as more accurate exposure and white balance can be ensured. Therefore, when shooting under conditions in which the brightness or color balance of the subject has changed significantly, for example, immediately after the power is turned on, the shutter key is immediately operated before the camera body is stably held at the subject. In such a case, it is possible to reduce the probability that the photographing result is a white or black image or an image of an inappropriate color.

  In other words, appropriate imaging condition control can be performed by selectively executing imaging condition control with different characteristics according to the shooting situation at that time.

  Further, in the present embodiment, during the REC through operation before the shutter key 7 is half-pressed, the exposure state and the white balance state are respectively divided into three steps of an appropriate range, an allowable range, and an out of allowable range. The number of exposure convergence (En) and the number of white balance convergence (Wn) are counted up, counted down, and cleared as described above according to the evaluation result, so that the exposure state and white balance state after the shooting operation Therefore, it is possible to more accurately determine the shooting situation that requires readjustment. Therefore, the frequency of unnecessary readjustment after the shooting operation is small, and higher-quality control suitable for the situation during the shooting operation can be performed.

  In particular, in the present embodiment, when the evaluation result is in an unacceptable range, the exposure convergence number (En) and the white balance convergence number (Wn) are cleared, and the continuity between the exposure state and the white balance state is emphasized. The shooting situation can be judged more accurately. Note that the evaluation criteria such as the appropriate range, allowable range, and non-allowable range shown in FIGS. 5A and 5B are exemplary.

  The width of each evaluation criterion may be set (or selected) by the user. Further, in the present embodiment, the change state of the control result of AE or AWB immediately before the half-press operation of the shutter key 7 is acquired as a numerical value by the number of exposure convergence (En) and the number of white balance convergence (Wn). However, you may make it acquire the said change condition by methods other than this.

  Further, in the present embodiment, when the AF control immediately before locking is not completed when the shutter key 7 is fully pressed at the time when the shutter key 7 is fully pressed, the pan focus setting and the narrowing AE are performed. Shooting was performed after processing, but in these processing, the time from the half-pressing operation of the shutter key 7 to the full-pressing operation was less than a specified time (for example, 1 second or less). It may be performed in the case of. Furthermore, the specified time may be set by the user.

  In the present invention, the above-described pan focus setting and narrowing AE processing are not essential, and when the AF control immediately before locking is not completed due to the half-pressing operation of the shutter key 7, or when the shutter key 7 is half-pressed. When the time from when an operation is performed to when the full-press operation is performed is less than a predetermined time (for example, 1 second or less), the state of the subject when the shutter key 7 is half-pressed in advance is the exposure convergence described above. The determination may be made based on the number of times (En) and the number of times of white balance convergence (Wn), and a series of imaging condition control processes for the main imaging may be performed or omitted in accordance with the determination. Even in this case, the time lag from when the shutter key 7 is fully pressed until the actual shooting can be minimized, and at the same time, more appropriate exposure and white balance can be ensured.

  Further, although the case where the present invention is applied to the control of both AE and AWB has been described, the present invention may be applied only to either one of the imaging condition controls.

Further, in the present embodiment, it has an AF function and the shutter key 7 can be operated in two stages of a half-pressed position and a fully-pressed position, and when the shutter key 7 is half-pressed, an AF operation is performed. Although the case where the present invention is applied to the one that locks the in-focus state and simultaneously locks the exposure control state and the white balance state has been shown, the present invention is not limited to this, and the present invention does not have so-called panning. The present invention can also be applied to a digital still camera in which the shutter key 7 can perform only a single shooting operation, such as a digital still camera with a focus specification. Even in such a case, the state of the subject when the photographing operation is performed with the shutter key 7 is determined based on the exposure convergence number (En) and the white balance convergence number (Wn) described above, and accordingly, for the actual photographing. By performing or omitting a series of imaging condition control processes, it is possible to perform more appropriate imaging condition control according to the situation when a shooting operation is performed.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. In this embodiment, the present invention is applied to a mobile phone with a camera function. Note that the communication method of the mobile phone is a CDMA (Code Division Multiple Access) method.

  6A and 6B are perspective views showing the external configuration of the mobile phone 40 according to the present embodiment. The mobile phone 40 includes two housings 42 and 43 with a hinge 41 interposed therebetween. It is a foldable type that is integrally constructed so as to be rotatable within a certain angle range, and the upper housing shown in FIG. It is a figure which shows the outer surface of 42. FIG.

  As shown in FIG. 6A, a speaker 44 and a main display 45 serving as a receiver are provided on the inner surface of the upper housing 42, while various keys including a dial key are provided on the inner surface of the lower housing 43. 46 and a microphone 47 serving as a transmitter are provided.

  Further, as shown in FIG. 6B, a camera unit 48, a photographing light 49, and a sub display unit 50 are provided on the outer surface of the upper casing 42, and a distal end portion is provided in the lower casing 43. The antenna 51 which protrudes from the hinge part 41 is accommodated so that insertion / removal is possible. The camera unit 48 has a pan focus specification.

  Specifically, the various keys 46 include a dial key, a power key, a line connection, a line disconnection, and other keys, a camera key 46a for setting a camera mode, and a set (SET) key 46b that also functions as a shutter key. Further, a shutter key 46c on the side end surface of the hinge portion 41 on which the antenna 51 is not provided, and a ring key 46d that is used for instructing an exposure value and the like in the camera portion 48 and is centered on the set key 46b.

  FIG. 7 is a block diagram showing an electrical configuration of the mobile phone 40. The antenna 51 is connected to the RF unit 61. At the time of reception, the RF unit 61 separates a signal received from the nearest base station via the antenna 51 from the frequency axis with a duplexer, and is output from a PLL synthesizer. The frequency is converted into an IF signal by mixing with the local oscillation signal of the frequency, and only the reception frequency channel is extracted by the broadband BPF, and the signal level of the desired reception wave is made constant by the AGC amplifier, and then to the modulation / demodulation unit 62 in the next stage. Output.

  On the other hand, the RF unit 61 performs transmission power control on an OQPSK (Offset Quadri-Phase Shift Keying) modulation signal sent from the modulation / demodulation unit 62 by an AGC amplifier based on control from the control unit 65 described later during transmission. The signal is mixed with a local oscillation signal of a predetermined frequency output from the PLL synthesizer, frequency-converted to an RF band, amplified to a large power by a PA (Power Amplifier), and radiated from the antenna 51 via the duplexer.

  The modulation / demodulation unit 62 separates the IF signal from the RF unit 61 into a baseband IQ (In-phase / Quadrature-phase) signal by a quadrature detector at the time of reception, digitizes it, and outputs it to the CDMA unit 63. In addition, the modem unit 62 converts the digital I / Q signal sent from the CDMA unit 63 into an analog signal during transmission, performs OQPSK modulation with a quadrature modulator, and sends the result to the RF unit 61.

  The CDMA unit 63 inputs a digital signal from the modulation / demodulation unit 62 at the time of reception to a PN (Pseudo Noise) timing extraction circuit and a plurality of demodulation circuits that perform despreading / demodulation according to instructions of the timing circuit. A plurality of demodulated symbols output from the above are synchronized, synthesized by a synthesizer, and output to the audio processing unit 64. Further, at the time of transmission, the CDMA unit 63 spreads the output symbol from the voice processing unit 64 and then limits the band with a digital filter to form an I / Q signal, which is sent to the modulation / demodulation unit 62.

  The voice processing unit 64 deinterleaves the output symbols from the CDMA unit 63 at the time of reception, and after performing error correction processing by a Viterbi demodulator, the digital signal is compressed from a digital signal compressed by a voice processing DSP (Digital Signal Processor). This is expanded into a digital audio signal, converted into an analog signal, and the speaker (SP) 44 is driven to speak out. The voice processing unit 64 digitizes an analog voice signal input from the microphone (MIC) 47 at the time of transmission, compresses the data amount by a voice processing DSP, and then performs error correction coding by a convolutional encoder. Are interleaved and the output symbols are sent to the CDMA unit 63.

  The RF unit 61, the modem unit 62, the CDMA unit 63, and the audio processing unit 64 are connected to a control unit 65. The control unit 65 further includes an image photographing unit 67, an image processing unit 68, and the main display unit. 45, the sub display unit 50, the memory card 69, the vibrator unit 70, and the LED driving unit 71 are connected.

  Here, the control unit 65 includes a CPU, a ROM storing an operation program necessary for controlling each unit by the CPU, a RAM used as a work memory, and the like, and controls the entire operation of the mobile phone 40. . The ROM causes the CPU to perform processing according to the operation of the AE control, the AWB control, and the shutter key 7 during the shooting operation in the camera mode, which will be described later, thereby allowing the CPU to perform the control value acquisition unit and the imaging condition control unit of the present invention. A program for functioning as history information acquisition means, determination means, and control means is also stored.

  The image photographing unit 67 controls the photographing operation by the CCD 75 disposed behind the photographing optical axis of the optical lens 74 provided in the camera unit 48, and digital data (imaging image) for each RGB primary color component with respect to the output signal of the CCD 75. Signal), color process processing including pixel interpolation processing and γ correction processing for the converted image signal is performed, and finally a digital luminance signal Y and color difference signals Cb and Cr are generated and output.

  The image processing unit 68 compresses the luminance signal Y and the color difference signals Cb and Cr obtained from the image photographing unit 67 based on, for example, the JPEG system, while decompressing the received image data by decompressing the original data. Bitmap image data is obtained.

  The memory card 69 is detachably attached to the cellular phone 40, and stores image data taken by the own device, image data obtained by reception, and the like. The vibrator unit 70 vibrates with a vibration pattern and vibration intensity set in advance when an incoming call is received. The LED driving unit 71 is a driving circuit for a high-intensity white LED that constitutes the photographing light 49, and emits auxiliary light toward the subject that is to be photographed by the camera unit 48 as necessary.

  Each of the main display unit 45 and the sub display unit 50 is composed of a reflective / transmissive color liquid crystal panel with a backlight and its driving circuit, and can display as a transmissive liquid crystal by turning on the backlight. On the other hand, it is possible to display as a reflective liquid crystal using external light with the backlight turned off, although the visibility is somewhat reduced.

  Although not shown, the hinge portion 41 has a mechanism for detecting the expanded state and the folded state of the upper housing 42 and the lower housing 43. Based on the information from the detection mechanism, the main display unit 45 causes the upper casing 42 and the lower casing 43 to be moved as shown in FIG. In the unfolded state in which the mobile phone 40 is opened, it is determined that the user of the mobile phone 40 is going to “shoot the other party” to capture the other person, and the display on the sub display unit 50 is stopped and the main display is stopped. The monitor image on the camera unit 48 is displayed on the display unit 45. At this time, an image is taken regardless of which one of the set key 46b and the shutter key 46c of the various keys 46 is operated.

  On the other hand, in the folded state in which the upper housing 42 and the lower housing 43 are closed as shown in FIG. 6B, the user of the mobile phone 40 performs “selfie” for photographing himself / herself. The display on the main display unit 45 is stopped, and the monitor image on the camera unit 48 is displayed on the sub display unit 50. At this time, an image is taken by operating the shutter key 46c.

  Note that this mobile phone 40 can record and play back not only still images but also moving images, as well as the still image data obtained by shooting, as with the digital still camera 1 of the first embodiment described above. While all the moving image data is stored in the memory card 69, the content stored in the memory card 69 can be arbitrarily reproduced and output on the main display unit 45 by a selection instruction in the reproduction mode, and an e-mail can be appropriately transmitted. By selecting and setting as an attached file, it is possible to transmit to a communication partner.

  Next, an operation according to the present invention in the mobile phone 40 having the above configuration will be described. FIG. 8 and FIG. 9 are flowcharts showing the processing contents according to the present invention of the control unit 65 at the time of still image shooting in a state where the user operates the camera key 46a of the various keys 46 to set the camera mode.

  In the AWB control in the following processing, the Cb value and Cr value of a certain pixel constituting the image are included in a predetermined white detection range based on the values of the color difference signals Cb and Cr separated in the image photographing unit 67. In this case, while determining that the color of the pixel is white, the Cb value and the Cr value of all the pixels determined to be white are individually integrated, and the integrated value of Cb and the integrated value of Cr are “0”. (Cb = Cr = 0) so that the gain of the R component and the gain of the B component of the image signal are adjusted.

  When the camera mode is set, the control unit 65 first initializes the number of exposure convergence (En) and the number of white balance convergence (Wn) used in the processing described later (step SB1), and each of AE and AWB Control is started (step SB2). The exposure convergence count (En) and the white balance convergence count (Wn) are data stored in the work memory of the control unit 65. Thereafter, imaging processing (image capture) is performed at a fixed period, for example, a frame rate of 30 frames / second (step SB3), and a through image is displayed on the main display unit 45 or the sub display unit 50 (step SB4).

  Subsequently, the same processing as in steps SA5 to SA14 in FIG. 3 described in the first embodiment is performed (steps SB5 to SB14). In this case, the criteria for determining the exposure state and the white balance state are the same as those in the first embodiment. Thereafter, until the photographing operation is performed by the set key 46b of the various keys 46 or the shutter key 46c (NO in step SB15), the above-described processing from step SB3 to SB14 is repeatedly executed. In other words, every time imaging is performed by the CCD 75 while adjusting the in-focus position, the exposure time, the R component gain, and the B component gain values at the next imaging are adjusted based on the captured image, while the work memory The exposure convergence count (En) and the white balance convergence count (Wn) are updated.

  For example, when the shutter key 46c is operated (YES in step SB15), as shown in FIG. 9, both the exposure convergence number (En) stored in the work memory and the white balance convergence number (Wn) are both stored. It is determined whether or not the number of times is equal to or greater than a predetermined number of times determined in advance (step SB16).

  When the number of times (En, Wn) is equal to or greater than the specified number (YES in step SB16), that is, the change in the control result of AE or AWB immediately before the photographing operation does not cause a large change in the brightness of the subject. The degree that the brightness (exposure value) of the captured image has been continuously within the permissible range (100 to 110) since the last time the brightness (exposure value) was within the allowable range (90 to 120) In addition, there is no significant variation in color balance, and the degree of color deviation that has been continuously within the appropriate white balance range (± 5) since the last time within the specified tolerance (± 10) is more than specified. If there is, that is, if the photographing operation is performed within a period in which the change of the subject is extremely small, the following processing is executed. In other words, an image to be recorded is captured in the control state by the AE control and AWB control that have been performed until the photographing operation is performed, and the captured image data is filed by the image processing unit 68 and recorded in the memory card 69. (Step SB21).

  On the other hand, the determination result in step SB16 is NO, and either one of the exposure convergence number (En) and the white balance convergence number (Wn) stored in the work memory is set to a predetermined number of times determined in advance. If not, that is, if the shooting operation is at least within the period when the brightness of the subject has changed significantly or the color balance has changed significantly, the following processing is performed. Execute.

  That is, when the imaging with the CCD 75 is performed once at that time (step SB17), the exposure convergence count (En) has not reached the specified count (the brightness of the subject has changed significantly) ( In step SB18, YES), AE processing and AWB processing based on the image signal during the imaging operation are performed (steps SB19 and SB20). Further, even when the exposure convergence number (En) is equal to or greater than the prescribed number, the white balance convergence number (Wn) has not reached the prescribed number (the color balance has changed significantly) (step SB18). NO), only the AWB process is performed (step SB20). After that, based on the new AE processing and AWB processing, or the shooting conditions of the AWB processing, the image to be recorded is captured, and the captured image data is filed by the image processing unit 68 and stored in the memory card 69. (Step SB21).

  Thereafter, the process returns to step SB1, and the above-described processing is repeated until the camera mode is ended or the power is turned off.

  As described above, in the mobile phone 40 according to the present embodiment, when a shooting operation using the shutter key 46c or the like is performed during a period in which the change of the subject is extremely small during still image shooting in the camera mode, prior to the main shooting. The series of imaging condition control processes such as the imaging process, the AE process, and / or the AWB process (steps SB17 to SB20) are omitted, so that the time lag from the shooting operation to the actual shooting is minimized and promptly responded. Therefore, it is possible to perform imaging condition control with emphasis on performance. Therefore, the probability of missing a photo opportunity can be reduced when shooting under a situation where there is very little change in the subject.

  In addition, when the shooting operation is performed during a period in which the brightness and color balance of the subject are remarkably changed, the above-described series of processing can be performed to ensure accurate exposure and white balance according to the shooting result. it can. Therefore, when shooting under conditions where the brightness or color balance of the subject has changed significantly, for example, immediately after the camera mode is set, the shutter key is immediately operated before the mobile phone 40 is stably held at the subject. In such a case, it is possible to reduce the probability that the photographing result will be a white or black image or an image of an inappropriate color.

  That is, in this embodiment as well, as in the first embodiment, appropriate imaging condition control is performed by selectively executing imaging condition control operations with different characteristics according to the shooting situation at that time. Can do.

  Also in the present embodiment, the change state of the control result of the AE or AWB immediately before the shooting operation is performed by the same method as in the first embodiment, the exposure convergence number (En) and the white balance convergence number. Since it is acquired as a numerical value by (Wn), it is possible to more accurately determine the shooting situation based on this, and extremely appropriate imaging condition control can be performed.

  In the present embodiment, the case where the camera unit 48 has the pan focus specification has been described. However, the present invention is effective even when the camera unit 48 has a configuration having an AF function.

It is a perspective view which shows the digital still camera in the 1st Embodiment of this invention. It is a block diagram which shows the electric constitution of the digital still camera. It is a flowchart which shows the processing content at the time of still image photography. It is a flowchart following FIG. (A) is a diagram showing the criteria for determining the exposure state, and (b) is a diagram showing the criteria for determining the white balance state. It is a perspective view which shows the mobile telephone with a camera in the 2nd Embodiment of this invention. It is a block diagram which shows the electric constitution of the mobile phone. It is a flowchart which shows the processing content at the time of still image photography. It is a flowchart following FIG.

Explanation of symbols

1 Digital Still Camera 2 Shooting Lens 9 Shutter Key 12 Lens Optical System 13 CCD
18 Color process circuit 21 DRAM
22 control unit 30 key input unit 40 mobile phone 45 main display unit 46a camera key 46b set key 46c shutter key 48 camera unit 65 control unit 67 image capturing unit 68 image processing unit 74 optical lens system 75 CCD

Claims (9)

In an electronic camera device that records an image of a subject imaged by an imaging means,
Control value acquisition means for acquiring a predetermined control value based on the image imaged by the imaging means;
Imaging condition control means for controlling imaging conditions based on the control value acquired by the control value acquisition means;
History information acquisition means for acquiring history information indicating a change state of an image quality control result by the image quality adjustment means during shooting standby;
A determination unit that determines whether or not a change state immediately before indicated by the history information acquired by the history information acquisition unit meets a predetermined condition in response to a shooting request;
If it is determined by the determination means that the change state meets a predetermined condition, the imaging condition control means performs imaging condition control of an image to be recorded based on the control value acquired by the acquisition means during shooting standby. On the other hand, if it is determined that the change state does not correspond to a predetermined condition, an imaging operation prior to the imaging operation of the image to be recorded is performed, and the imaging condition control means is used to control the image to be recorded. An electronic camera device, comprising: a control unit that causes the control value acquisition unit to acquire a new control value used by the camera.   The predetermined condition is that the degree of change immediately before the change state indicated by the history information is continuously within a predetermined appropriate range centered on the control target of the control result by the imaging condition control means is not less than a specified level. The electronic camera device according to claim 1, wherein the electronic camera device is an electronic device.   The predetermined condition is that the change state immediately before indicated by the history information continues within a predetermined appropriate range centered on the control target after the control result by the imaging condition control means is finally within the predetermined allowable range. The electronic camera apparatus according to claim 1, wherein the degree of being within the range is not less than a specified level.   The predetermined control value acquired by the control value acquisition means includes a control value required for exposure control, and the imaging condition control means includes an exposure control means for controlling exposure based on the control value. The imaging device according to claim 1, 2 or 3.   The predetermined control value acquired by the control value acquisition means includes a control value required for white balance control, and the imaging condition control means includes a white balance control means for controlling white balance based on the control value. The imaging apparatus according to claim 1, wherein the imaging apparatus is characterized.   The history information acquisition unit acquires information indicating a change state of a control result by the imaging condition control unit during a standby state for shooting until a shooting preview operation is performed prior to a shooting operation. The imaging device according to any one of claims 1 to 5. Pan is a shooting mode that has an autofocus function that automatically controls the focus, and that sets the shooting environment to stop the autofocus function and secure a longer depth of field within a predetermined control range. It has a focus mode,
In the shooting in the pan-focus mode, the control unit sets the control value last acquired by the acquisition unit during shooting standby when the determination unit determines that the change state satisfies a predetermined condition. When the imaging condition control means performs the imaging condition control of the image to be recorded based on the condition, and when it is determined that the change state does not correspond to the predetermined condition, the imaging operation prior to the imaging operation of the image to be recorded is performed. The control value acquisition unit acquires a new control value used by the imaging condition control unit for imaging condition control of an image to be recorded. Imaging device. An imaging condition control method for an electronic camera device that records an image of a subject imaged by an imaging means,
During shooting standby, a control value required for imaging condition control of an image captured by the imaging unit is acquired, and imaging condition control is performed based on the acquired control value, and history information indicating a change state of the control result is acquired. And a process of
A step of determining whether or not a change state immediately before indicated by the history information acquired during shooting standby corresponds to a predetermined condition when there is a shooting request;
When the result of the determination corresponds to the predetermined condition, imaging condition control of an image to be recorded is performed based on the control value acquired during shooting standby, and the result of the determination satisfies the predetermined condition. If not applicable, a new control value is acquired by an imaging operation prior to the imaging operation of the image to be recorded by the imaging means, and the imaging condition control of the image to be recorded is performed based on the acquired new control value. An imaging condition control method comprising the steps of: In a computer of an electronic camera device that records an image of a subject imaged by an imaging means,
During shooting standby, a control value required for imaging condition control of an image captured by the imaging unit is acquired, and imaging condition control is performed based on the acquired control value, and history information indicating a change state of the control result is acquired. Processing to
A process for determining whether or not a change state immediately before indicated by the history information acquired during shooting standby corresponds to a predetermined condition when there is a shooting request;
When the result of the determination corresponds to the predetermined condition, imaging condition control of an image to be recorded is performed based on the control value acquired during shooting standby, and the result of the determination satisfies the predetermined condition. If not applicable, a new control value is acquired by an imaging operation prior to the imaging operation of the image to be recorded by the imaging means, and the imaging condition control of the image to be recorded is performed based on the acquired new control value. A program for executing and processing.

Images