JP2003209739A - Imaging apparatus, method and program for correcting imbalance among image data, and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus, a method of correcting image data, and a program capable of appropriately and automatically correcting an imbalance in a plurality of image data simultaneously outputted from a plurality of output terminals of an imaging device even if an imaging condition changes. <P>SOLUTION: When a release SW1 is depressed (half-depressed), an ISO sensitivity setting for the main photographing is obtained (step 49). In accordance with the set sensitivity, photographing time in second at calibration photographing is switched so that DC outputs of analog/digital conversion circuits (not shown) which performs A/D conversion for the output of an imaging means will be the constant (step 50) in terms of a direct current. Then calibration photographing is performed (step 51), and the differences in offset/ gain are obtained from the photographed data. When a release SW2 is depressed (fully depressed), main photographing is executed (step 52), and the differences in the gain/offset are corrected by using data calculated in the step 52 (step 55) so as to correct the imbalance in the plurality of image data. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device used in a digital camera or the like, and in the case where the image pickup device has a plurality of output terminals and is configured to read data from a plurality of outputs at the same time, a plurality of output terminals are provided. The present invention relates to a method of correcting an imbalance between image data output from each of them and obtaining a good seamless image when forming one image.

[0002]

2. Description of the Related Art Conventionally, this type of digital still camera has a structure as shown in FIG. In the case of the configuration shown in this figure, the camera operation switch 101
The overall control circuit 100 detects the state change of (the main SW of the camera and the release SW1 and SW2) and starts the power supply to the other circuit blocks.

A subject image within the photographing screen range is formed on the image pickup element 104 through the main photographing optical systems 102 and 103, and an electric signal from the image pickup element 104 is transferred to the CDS / A.
Through the GC circuit 105, the A / D conversion unit 106 sequentially converts each pixel into a predetermined digital signal.

Here, the image pickup device 104 is driven by the output of the driver circuit 107 for horizontal drive and vertical drive for each pixel based on the signal from the timing generator 108 which determines the overall drive timing. Generate an image signal output.

Similarly, a CD which processes the output from the image pickup element 104 in an analog manner and converts it into a predetermined signal level.
The S / AGC circuit 105 and the A / D conversion circuit 106 also operate based on the timing from the timing generator 108.

The output from the A / D conversion circuit 106 is input to a memory controller 115 via a selector 109 that selects a signal based on the signal from the overall control CPU 100, and here all the signals are output to the frame memory 116. To transfer. Therefore, in this case, all the pixel data for each shooting frame is temporarily stored in the frame memory 116, so that in the case of continuous shooting, all of the frame memory 116.
It becomes a write operation to.

After the photographing operation is completed, the memory controller 1
Under the control of 15, the contents of the frame memory 116 storing the shooting data are transferred to the camera DSP 110 via the selector 109. The camera DSP 110 generates RGB color signals based on the pixel data of the shooting data stored in the frame memory 116.

Normally, in the state before photographing, this result is periodically (for each frame) transferred to the video memory 111 to display a finder or the like via the monitor display means 112.

On the other hand, when the photographer performs the photographing operation by operating the camera operation switch 101, each pixel data for one frame is read from the frame memory 116 by a control signal from the overall control CPU 100,
After the image processing is performed by the camera DSP 110, the image is temporarily stored in the work memory 113.

Subsequently, the data in the work memory 113 is compressed by the compression / expansion means 114 according to a predetermined compression format, and the result is stored in the external non-volatile memory 117.
(Normally, a non-volatile memory such as a flash memory is used).

On the other hand, when observing image data that has already been photographed, the data compressed and stored in the external memory is decompressed through the compression / decompression means 114 into ordinary data for each photographed pixel, and the result is obtained. By transferring to the video memory 111, it can be performed through the monitor display means 112.

As described above, in a general digital camera, the output from the image pickup device 104 is converted into actual image data through the process processing circuit in almost real time, and the result is output to the memory or the monitor circuit. There is.

On the other hand, in the digital camera system as described above, the capability of continuous shooting etc. is improved (for example, 10
In order to obtain an ability close to frames / second), it is necessary to improve the system including the image sensor such as increasing the reading speed from the image sensor and writing the image sensor data to the frame memory. is there.

(Related Art of the Present Invention) FIG. 4 briefly shows a two-output type device structure in which a horizontal CCD is divided into two by an image pickup device such as a CCD as one of the techniques for improving the above-mentioned conventional technique. It is a thing.

In the CCD of FIG. 4, the photodiode portion 9
The charges generated in each pixel are simultaneously transferred to the vertical CCD unit 10 at a predetermined timing, and the charges of the vertical CCD unit 10 are transferred to the horizontal CCDs 7 and 8 line by line at the next timing.

Here, the horizontal CCD 7 transfers the electric charge to the amplifier 5 on the left side for each transfer clock, and the horizontal CCD 8 transfers the electric charge to the amplifier 6 on the right side for each transfer clock. The photographed image data of this CCD is divided into two right and left and read out with the center of the screen as a boundary.

FIG. 5 is a block diagram showing a circuit for processing a signal output from an image sensor of the type shown in FIG.

The picked-up image data of the CCD 11 is divided into two left and right CDS / AGC circuits 14 and 15 and an A / D.
The data is input to the conversion circuits 16 and 17, converted into digital data, and then stored in the frame memories 26 and 27.
This digital data corresponds to the circuit characteristics of the amplifiers 5 and 6,
Due to the gain variations of the CDS / AGC circuits 3 and 6, unbalance mainly occurs in the offset component and the gain component between the two image data. In order to correct this imbalance, calibration shooting is performed separately from the main shooting.

FIG. 6 is a flow chart showing the processing at the time of photographing in the circuit of FIG. The operation will be described with reference to FIGS. The following processing is performed by the overall control CPU 30.
Is in charge of control.

SW1 of release switch 50 (half-press)
At the time when is detected (see step 38, abbreviated as S38 in the figure, the same applies hereinafter), the camera performs photometry / distance measurement, and simultaneously illuminates the left and right boundary portions of the CCD 11 by the illumination device 33. In this state, calibration photographing is performed (step 39), and the gain / offset calculation circuits 34 and 35 calculate the gain correction value / offset correction value so that the left and right boundary portions of the obtained photographed image are continuous (step 40). . After that, when the release switch SW2 (push off) is input to perform the main photographing (steps 41 and 42), the offset correction value / gain correction value is set in advance in the offset correction circuits 18 and 19 and the gain correction circuits 20 and 21, respectively. The gain component and the offset component of the main captured image are corrected so that the boundary between the two left and right images is inconspicuous (step 43).

The signals thus processed separately on the left and right sides are
The images are combined by the image combining circuit 28 (step 44), and color processing such as color interpolation processing and gamma conversion processing is performed by the color processing circuit 29 (step 45) to obtain one image.

[0022]

As described above, as an image pickup device capable of realizing high-speed reading, a technique for simultaneously reading signals from two or more outputs is to make a digital camera in the future closer to a silver salt camera. Is an essential technology. However, although having a plurality of outputs is advantageous in terms of speed, it is obviously disadvantageous in comparison with the output having only one output in terms of matching of output levels.

In an image pickup apparatus such as a digital camera, a correction coefficient is calculated by performing calibration shooting for correcting unbalance between a plurality of outputs before and after shooting.
The correction coefficient is used to correct the imbalance between a plurality of outputs of the main captured image, or the plurality of output signals are converted into digital image data using an analog / digital converter, and then the unbalance is calculated by the correlation between the plurality of outputs. It is proposed to perform balance correction.

However, a high-spec digital camera such as a single-lens reflex type camera is ISO100 to ISO64.
There is one that can set sensitivity equivalent to 00, and one that supports shooting at a long time of more than 10 seconds, etc. Since various shooting conditions can be set, one can be set when correcting the imbalance between multiple outputs. There is a problem that the correction accuracy is not sufficient and the correction accuracy is poor, or stable correction accuracy cannot be obtained, only by the correction method.

The present invention has been made under such a circumstance, and the imbalance between a plurality of image data simultaneously output from a plurality of output terminals of an image pickup device can be favorably maintained even if the photographing conditions are changed. An object of the present invention is to provide an imaging device, a correction method, and a program that can be automatically corrected.

[0026]

In order to achieve the above object, according to the present invention, when an imbalance between a plurality of image data respectively output from a plurality of outputs from an image pickup device is corrected, it is possible to adjust the unbalance according to a shooting condition. Switch the correction method.

For example, in the case of a system such as a digital camera which performs a calibration photographing for correcting an imbalance between a plurality of image data separately from the photographed main image, the exposure for the calibration photographing is set according to the photographing sensitivity setting. By changing the time, there is a method for favorably performing the imbalance correction even if the shooting sensitivity setting changes.

In consideration of operability, it is desirable that the calibration photographing is performed before the main photographing.
When shooting at a long time such as over 0 seconds, in order to make the image reading timing of the calibration shooting and the image reading timing of the main shooting close in time, the calibration shooting is performed after the main shooting at the long shooting time. There is a method of preventing the deterioration of the correction accuracy by performing the above.

More specifically, according to the present invention, an image pickup device is provided with the following (1) to (7), (11) to (13) and (1).
6) to (21), and the unbalance correction method is the following (8), (9), (14), (22),
Configure as in (23) and program as follows (1
0), (15), and (24), and the storage medium is configured as (25) below.

(1) Between a plurality of image areas output from each of the plurality of image pickup areas and an image pickup means for outputting a signal from each of the plurality of image pickup areas. Correction means for correcting the unbalance of the image capturing means using the image capturing data of the calibration image capturing, and control means for controlling the calibration image capturing method to be switched according to the image capturing conditions of the image capturing means in the main image capturing. Imaging device.

(2) In the image pickup device according to (1), the calibration image pickup is an image pickup performed by uniformly illuminating a plurality of image pickup areas in the image pickup means by illumination means.

(3) In the image pickup apparatus described in (2) above, the control means switches the image pickup time of the calibration image pickup.

(4) In the image pickup apparatus described in (2), the control means performs the calibration photographing,
An imaging device that switches between before and after actual shooting.

(5) In the image pickup apparatus described in (2), the control means switches the brightness of the illumination means in the calibration photographing.

(6) In the image pickup apparatus described in (1), the control means sets the shooting condition of the calibration shooting to a direct current output of an A / D conversion circuit for A / D converting the output of the image pickup means. An image pickup device which is switched so as to be constant.

(7) In the image pickup device according to any one of (1) to (6), the image pickup condition of the image pickup means is at least one of photographing time, temperature and photographing sensitivity.

(8) An unbalance correction method between image data for correcting unbalance between image data in an image pickup device which outputs a plurality of image data by data obtained by calibration shooting, An imbalance correction method between image data that sets the shooting time in calibration shooting according to the second.

(9) An unbalance correction method between image data for correcting the unbalance between the image data in the image pickup device which outputs a plurality of image data by the data obtained by the calibration shooting, An imbalance correction method between image data that determines whether to perform calibration shooting before or after actual shooting according to at least one of time, temperature, and shooting sensitivity.

(10) A program for realizing the unbalance correction method according to (8) or (9).

(11) Between an image pickup means for dividing a subject image into a plurality of image pickup areas, and outputting a signal from each of the plurality of image pickup areas, and a plurality of image data output from each of the image pickup areas. An image pickup apparatus comprising: a correction unit that corrects the unbalance of the image using the shooting data of the calibration shooting; and a control unit that operates the correction unit when a change in a predetermined shooting condition is detected.

(12) In the image pickup apparatus described in (11), the control means performs the calibration by the correction means again when a predetermined time has elapsed since the previous calibration photographing by the correction means was performed. An imaging device that operates shooting.

(13) In the image pickup apparatus described in (11), the control means corrects the correction value again when a predetermined temperature difference occurs with respect to the temperature at the time of the previous calibration photographing by the correction means. An imaging device that operates calibration imaging by means.

(14) An unbalance correction method between image data for correcting the unbalance between the image data in the image pickup device which outputs a plurality of image data by the data obtained by the calibration photographing, An imbalance correction method between image data in which calibration photographing is again performed when a change in a predetermined photographing condition is detected after photographing is performed.

(15) A program for realizing the unbalance correction method described in (14) above.

(16) Between the image pickup means for dividing a subject image into a plurality of image pickup areas and picking up an image, and outputting a signal from each of the plurality of image pickup areas, and a plurality of image data output from each of the image pickup areas. And a control unit that controls the operation of the calibration shooting according to the shooting conditions in the main shooting. Image pickup device.

(17) In the image pickup apparatus described in (16), the calibration image pickup is an image pickup in which a plurality of image pickup areas in the image pickup means are uniformly illuminated by illumination means. apparatus.

(18) The image pickup device according to the above (17), wherein the control means switches the image pickup time of the calibration image pickup.

(19) In the image pickup apparatus according to the item (17), the control means performs the calibration photographing after the main photographing.

(20) In the image pickup device according to the item (17), the control means switches the brightness of the illumination means in the calibration photographing.

(21) In the image pickup apparatus described in (16), the image pickup conditions of the image pickup means are temperature, image pickup sensitivity,
An imaging device, which is at least one of the time from calibration shooting to actual shooting.

(22) An unbalance correction method between image data for correcting the unbalance between the image data in the image pickup device outputting a plurality of image data by the data obtained by the calibration shooting, which is a shooting condition in the main shooting. An unbalance correction method between image data, characterized in that the operation of the calibration photographing is controlled according to the above.

(23) The imbalance correction method between image data according to claim (22), characterized in that the photographing time of the calibration photographing is shortened as the exposure sensitivity in the main photographing increases.

(24) Claims (15), (22), (2)
A program for realizing the unbalance correction method according to any one of 3).

(25) Claims (10), (15), (2)
A storage medium storing the program of 3).

[0055]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to examples of an image pickup apparatus. The present invention is not limited to the form of the image pickup apparatus, and can be implemented in the form of a method, in the form of a program for realizing this method, supported by the description of the embodiment.

(First Embodiment) FIG. 1 is a flow chart showing the processing at the time of shooting in the "imaging device" according to the first embodiment. The hardware configuration of this embodiment is the same as that of FIG. 5, so this embodiment will be described with reference to FIGS. 1 and 5.

In FIG. 5, the CCD 11, which is an image sensor having two outputs (CH1 and CH2), operates at a predetermined frequency when driven by the driver 12,
The entire screen is vertically divided into two parts, and the left and right image data are separately output. The subject is imaged on the CCD 11 by a main optical system (not shown), photoelectrically converted by a photodiode in the CCD 11, and then vertically CCD (hereinafter referred to as VC).
It is vertically transferred through a CD to a horizontal CCD section (hereinafter referred to as HCCD), further transferred horizontally by the HCCD, and output by an output amplifier section. TG / SSG1
A timing generating circuit 3 outputs a vertical synchronizing signal VD and a horizontal synchronizing signal HD, and simultaneously supplies a timing signal to each circuit block. The output of the right half surface of the CCD 11 is input to the CDS / AGC circuit 6 via the CH1 output, reset noise and the like are removed by a method such as correlated double sampling, and converted into digital data by the A / D conversion circuit 17. . Similarly, the output of the left half surface of the CCD 11 is input to the CDS / AGC circuit 3 via the CH2 output, reset noise and the like are removed by a method such as correlated double sampling, and converted into digital data by the A / D conversion circuit 16. To be done.

The left and right image data converted into digital data are input to the image processing circuit 100, and the image synthesizing circuit 28
Then, after being finally combined into one image, color processing is performed by the color processing circuit 29. However, if the images are combined without special processing, the left and right screen imbalances lead to the understanding of the boundary between the left and right screens. Therefore, before the main shooting, the left and right output imbalance amounts are obtained from the image data obtained by the calibration shooting, and the unbalance is corrected during the main shooting.

In the calibration photographing, the light receiving surface of the CCD 11 is evenly illuminated by the illuminating device 33,
This is a shooting method for shooting with an appropriate exposure. The imaging data at that time is calculated by the gain / offset calculation circuits 34 and 35, and the unbalance amount is obtained by calculating the gain shift amount and the offset shift amount of the left and right screens. It is considered that the calculated unbalance amount gradually shifts due to changes over time / temperature changes, etc., but it is considered that there is no discernible shift during a certain period of time. Unbalance correction can be performed using the gain / offset deviation amount. Therefore, it is desirable to carry out the calibration photographing regularly before the end of this period. It should be noted that, for convenience of explanation, “the imbalance correction is performed using the deviation amount”, but in short, the data for correcting the deviation may be calculated and the correction may be performed using this data.

At this time, it is preferable that the calibration photographing is always performed with stable exposure in order to always obtain the amount of imbalance accurately, but the ISO sensitivity setting of the camera is changed, that is, the CDS / AGC circuits 3 and 6 are changed. If the gain is changed, the exposure will change if the shooting seconds (also referred to as exposure time and exposure time) of the calibration shooting are always shot under the same conditions. Therefore, the A / D conversion circuit 16 may be changed in some cases. There is a problem that the range of 17 and 17 is exceeded.

Therefore, in the present embodiment, as shown in FIG. 1, the setting information of the ISO sensitivity (corresponding to the photographing sensitivity of the claims) is acquired before the calibration photographing (step 4).
9), the shooting conditions of the calibration shooting are changed according to the ISO sensitivity so that the outputs of the A / D conversion circuits 16 and 17 are almost constant in terms of direct current (step 5).
0). In step 50, for example, when the ISO sensitivity is high, the exposure time of the calibration photographing is shortened to
When the SO sensitivity is low, the exposure time is lengthened to change the shutter control time to change the A / D conversion circuit 116,
The output level of the image output from 117 is kept constant. In step 50, the exposure is kept constant by changing the photographing time of the calibration photographing, but as a method of keeping the image output level constant, a control operation such as changing the brightness of the illumination device 33 is also used. I don't care. However, in this case, the ISO sensitivity setting is not changed between the calibration shooting and the actual shooting.
In this way, by changing the method of unbalance correction according to the ISO sensitivity setting, good unbalance correction accuracy can be obtained in all ISO sensitivity settings.

Next, after performing the calibration photographing, the main photographing is performed at the same ISO sensitivity setting (step 54), and the offset deviation amount and the gain deviation amount obtained by the calibration imaging are adjusted to the offset correction circuits 18 and 1.
9. The gain correction circuits 20 and 21 are respectively set to correct the imbalance between the left and right screens of the main captured image (step 55). By this processing, the signal is such that the boundary is not known when the left and right images are combined. After that, OB clamping is performed by the OB clamp circuits 22 and 23. However, if the OB clamping processing is separately performed on the left and right outputs, the unbalance removed by the effort will occur again. Clamp both outputs with the same value. Next, the memory controller 24, 25
The image data is temporarily stored in the frame memories 26 and 27 via (step 56). High-speed continuous shooting performance can be obtained by performing the processes from shooting to temporary storage in memory in parallel on the left and right screens at high speed.

At a timing after a series of continuous shooting or when the frame memories 26 and 27 are full, the frame memories 26 and 27 are moved to the memory controller 24,
Images are called one by one through the image synthesis circuit 2
The image data divided into right and left by 8 is combined into one image (step 57). Further color processing circuit 29
Then, predetermined color processing (color interpolation processing, gamma conversion, etc.) is performed (step 58).

As described above, according to the present embodiment, since the photographing time in the calibration photographing is switched in accordance with the ISO sensitivity setting, a plurality of image data output simultaneously from a plurality of output terminals of the image pickup device are selected. The unbalance can be automatically corrected well even if the shooting conditions change, and a good image without an unnatural level difference can be obtained.

(Second Embodiment) FIG. 2 is a flow chart showing the processing at the time of shooting by the "imaging device" according to the second embodiment. The hardware configuration of the present embodiment is similar to that of FIG. 5, so the operation will be described with reference to FIGS. 2 and 5.

It is considered that the amount of unbalance of signals obtained by simultaneously reading out signals from a plurality of output terminals of the image sensor changes with time and temperature. Therefore, the imbalance correction between a plurality of outputs by the calibration shooting as in the first embodiment may not be properly corrected if the time interval or the temperature difference between the calibration shooting and the main shooting is large. Until the main shooting is performed, calibration shooting can be performed regularly to keep the time interval between the main shooting short, but with a high-performance digital camera such as a digital SLR camera, It is also necessary to assume long-time shooting such that the shooting time during the main shooting exceeds 10 seconds. In such a case, if the calibration shooting is performed before the main shooting, the time interval between the calibration shooting and the exposure start of the main shooting can be kept short, but the image is actually transferred. The time interval until the end may be extended by the exposure time, and the unbalance amount obtained by the calibration shooting may change during that time. Considering the shooting response of the camera and the simplicity of image processing during continuous shooting,
Performing the calibration shooting before the main shooting is more advantageous than performing the calibration shooting afterward because the unbalance correction amount is determined during the main shooting, but the calculated unbalance amount changes. If the correction accuracy is lowered due to this, there is a clear disadvantage in terms of image quality. As described above, it may be considered that the correction accuracy needs to be prioritized even if the shooting response is sacrificed.

Further, even when the shooting time during the main shooting is short, the temperature difference between the calibration shooting and the main shooting may become large when continuous shooting is continued. In such a case as well, the unbalance correction accuracy due to the calibration shooting may be deteriorated, which may be disadvantageous in terms of image quality.

As described above, when long-time shooting is performed, or when the temperature difference between the main shooting and the calibration shooting is large, the calibration shooting is performed after the main shooting to perform the main shooting. The read timing of the image and the read timing of the calibration photographing can be temporally close to each other, and the change in the unbalance amount due to the passage of time or the temperature change can be suppressed to improve the unbalance correction accuracy.

The present embodiment is an example in which the method of unbalance correction is changed according to the photographing time and the temperature change during the main photographing.

Similar to the first embodiment, first, when the release switch 50SW1ON (half-pressed state) is detected, calibration photographing is performed and the gain / offset deviation amount is calculated (steps 61 to 63). Further, the release switch 50SW2ON (fully pressed state) is detected (step S64). When the fully-pressed state is detected, a main shooting (shooting for recording the shot image data) operation is performed (step S65). Then, the process proceeds to steps S66 and S67 to check the time from the calibration photographing to the main photographing and the temperature difference between the calibration photographing and the main photographing. The time from the calibration shooting to the main shooting is less than 10 seconds, and the temperature difference between the calibration shooting and the main shooting is 5
If the temperature is lower than 0 ° C. (“No” in both steps 66 and 67), the gain / offset deviation amount obtained by the calibration photographing before the main photographing is the offset correcting circuits 18 and 19, the gain correcting circuit 20. , 21
, And the main captured image data is offset-corrected by the offset correction circuits 18 and 19, and gain-corrected by the gain correction circuits 20 and 21 (step 68). As a result, in the case of a device in which the image pickup device is divided into right and left and read out as in the CCD 11 of FIG. Corrected (steps 69, 7)
0).

If the second time from the calibration photographing by the switch SW1ON to the main photographing determined by SW2ON is 10 seconds or more (step 6).
6, "Yes"), or the temperature of the CCD 11 is measured by the temperature sensor 36 during the calibration photographing and the main photographing, and the temperature difference is 5 ° C or more (1 ° C or more, 3 ° C or more depending on the system). In the case where there is a temperature difference other than the above (step 67, “Yes”), the gain / offset deviation amount obtained by the calibration shooting before the main shooting is ignored, and the offset correction circuits 18, 19 and the gain correction are performed. Initial values of the offset shift amount and the gain shift amount are set in the circuits 20 and 21, respectively. These initial values are preferably selected such that the offset deviation amount is zero and the gain deviation amount is 1, so that the data is not corrected. Step 66
Then, the processing flow is switched when the time until the actual shooting is 10 seconds, but depending on the system, it may be 5 seconds, 1 second, or any other time. The captured main image data is offset-corrected and gain-corrected by the offset correction circuits 18 and 19 and the gain correction circuits 20 and 21 with initial values, and then the frame memories 26 and 27 are passed through the memory controllers 24 and 25. Is temporarily stored in (step 73). Then, the calibration photographing is operated again with a time interval as short as possible from the main photographing operation of step 65 (step 74). In the calibration shooting, the brightness of the lighting device and the exposure time are appropriately selected, and the shooting is performed at an exposure time that is sufficiently shorter than the main shooting time.Therefore, the data read timing and the calibration shooting during the main shooting are performed. Since the time interval of the data read timing is short, sufficient unbalance correction accuracy can be obtained. After the gain / offset deviation amount (step 75) calculated by this calibration photographing is set in the offset correction circuits 18 and 19 and the gain correction circuits 20 and 21, the frame memory 2
The image data temporarily stored in 6 and 27 are again input to the offset correction circuits 18 and 19 via the memory controllers 24 and 25, respectively. The offset correction circuits 18 and 19 perform the offset deviation correction, and the gain correction circuits 20 and 21 perform the gain deviation correction, so that the boundary is not recognized when the left and right images are combined (step 76). After that, OB clamping is performed by the OB clamp circuits 22 and 23. However, if the OB clamping processing is separately performed on the left and right outputs, the unbalance removed by the effort will occur again. Both outputs are clamped with the same value (step 77). Next, it is input to the image synthesizing circuit 28 via the memory controllers 24 and 25,
Combine the left and right image data into one image
(Step 78). Further, the color processing circuit 47 performs predetermined color processing (color interpolation processing, gamma conversion, etc.) (step 79).

As described above, during short-time shooting, the unbalance correction amount is calculated by the calibration shooting before the main shooting, and during long shooting, the unbalance correction amount is calculated by the calibration shooting performed after the main shooting. In this way, by changing the method of unbalance correction depending on the shooting time, it is possible to perform good correction without compromising operability during short-time shooting, and good unbalance correction during long-time shooting. It can be carried out. With this method, there are restrictions on operability, such as delaying the shooting of the next frame during long-time shooting, but if the calibration shooting is sufficiently short compared to the exposure seconds of the main shooting, there is no perceptible impact. It is also possible to limit it to.

As described above, when the temperature difference between the calibration shooting before the main shooting and the main shooting is large, the temperature is largely changed by switching the calibration shooting immediately after the main shooting. Even in such a case, good imbalance correction can be performed. The object of the present invention can be achieved by adding the configuration of the present embodiment to the configuration of the first embodiment.

In the present invention, as an example, the program code of software for realizing the functions of the above-described embodiment is
It is supplied to the imaging device via a network such as the Internet, and the computer (or CPU or MP
U) can be achieved by reading and executing the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the function of the CPU 30 of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

A storage medium for supplying the program code is, for example, a floppy (R) disk, a hard disk, an optical disk, a magneto-optical disk, a CD-RO.
M, CD-R, magnetic tape, non-volatile memory card,
A ROM or the like can be used.

Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also the OS (operating system) running on the computer based on the instruction of the program code. ) And the like perform some or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written in the memory provided in the function expansion board inserted into the computer or the function expansion unit connected to the computer, based on the instruction of the program code, A CPU or the like included in the function expansion board or the function expansion unit performs a part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

When the present invention is applied to the above-mentioned storage medium, the storage medium stores the program code corresponding to the above-mentioned flow chart, but in brief description, it is indispensable for the image pickup apparatus of the present invention. Various modules
It will be stored in a storage medium.

[0080]

As described above, according to the present invention,
Since the operation of the calibration shooting is controlled according to the shooting operation in the main shooting, the imbalance between the plurality of image data output simultaneously from the plurality of output terminals of the image sensor can be effectively performed even if the shooting conditions change. A good image can be obtained that can be automatically corrected and has no unnatural level difference.

[Brief description of drawings]

FIG. 1 is a flowchart showing processing at the time of shooting according to a first embodiment.

FIG. 2 is a flowchart showing processing at the time of shooting according to the second embodiment.

FIG. 3 is a block diagram showing a configuration of a conventional digital still camera.

FIG. 4 is a diagram showing a structure of an image sensor in which a horizontal CCD is divided into two.

5 is a block diagram showing a circuit for processing an output of an image sensor of the type shown in FIG.

FIG. 6 is a flowchart showing processing at the time of shooting in the circuit of FIG.

[Explanation of symbols]

11 CCD 18, 19 Offset correction circuit 20,21 Gain correction circuit 34/35 gain / offset calculation circuit

Claims (25)

[Claims] 1. An image pickup unit that divides an image of a subject by a plurality of image pickup areas and outputs a signal from each of the plurality of image pickup areas; and a plurality of image data output from each of the image pickup areas. A correction unit that corrects the imbalance using the shooting data of the calibration shooting and a control unit that controls to switch the calibration shooting method according to the shooting conditions of the imaging unit in the main shooting are provided. An imaging device characterized by the above. 2. The image pickup apparatus according to claim 1, wherein the calibration image pickup is an image pickup performed by uniformly illuminating a plurality of image pickup areas in the image pickup unit by an illumination unit. 3. The image pickup apparatus according to claim 2, wherein the control unit switches a photographing time of the calibration photographing. 4. The image pickup apparatus according to claim 2, wherein the control unit switches the calibration photographing before or after the main photographing. 5. The image pickup apparatus according to claim 2, wherein the control unit switches the brightness of the illumination unit in the calibration photographing. 6. The image pickup apparatus according to claim 1, wherein the control unit sets the shooting condition of the calibration shooting to an output of an A / D conversion circuit for A / D converting the output of the image pickup unit to be constant in DC. An image pickup device, which is switched so that 7. The image pickup device according to claim 1, wherein the image pickup condition of the image pickup means is at least one of photographing time, temperature, and photographing sensitivity. 8. A method for correcting unbalance between image data, wherein an unbalance between image data in an image pickup device that outputs a plurality of image data is corrected by data obtained by calibration shooting. An imbalance correction method between image data, characterized in that a shooting time in calibration shooting is set according to time. 9. A method for correcting unbalance between image data, wherein an unbalance between image data in an image sensor that outputs a plurality of image data is corrected by data obtained by calibration shooting. An unbalance correction method between image data, characterized in that it is determined whether to perform calibration photographing before or after main photographing according to at least one of time, temperature, and photographing sensitivity. 10. A program for realizing the unbalance correction method according to claim 8. 11. An image pickup unit that divides an image of a subject by a plurality of image pickup areas and outputs a signal from each of the plurality of image pickup areas, and between a plurality of image data output from each of the image pickup areas. It is characterized by further comprising: a correction unit that corrects the unbalance by using shooting data of calibration shooting; and a control unit that operates the correction unit when a change in a predetermined shooting condition is detected. Imaging device. 12. The image pickup apparatus according to claim 11, wherein the control unit, when a predetermined time has elapsed since the last calibration photographing by the correcting unit,
An imaging apparatus, wherein calibration imaging by the correction means is operated again. 13. The image pickup apparatus according to claim 11, wherein the control unit performs calibration by the correction unit again when a predetermined temperature difference occurs with respect to a temperature at the time of the previous calibration photographing by the correction unit. An imaging device characterized by operating an option shooting. 14. A method for correcting unbalance between image data, wherein an unbalance between image data in an image sensor that outputs a plurality of image data is corrected by data obtained by the calibration shooting. An imbalance correction method between image data, characterized in that when a change in a predetermined photographing condition is detected after the above-mentioned step, calibration photographing is operated again. 15. A program for realizing the unbalance correction method according to claim 14. 16. An image pickup unit which divides a subject image into a plurality of image pickup areas and picks up an image, and outputs a signal from each of the plurality of image pickup areas, and between a plurality of image data output from each of the image pickup areas. It is characterized by comprising: a correction means for correcting the unbalance using image data obtained by the calibration photography, and a control means for controlling the operation of the calibration photography according to the photography conditions in the main photography. Imaging device. 17. The imaging device according to claim 16, wherein the calibration imaging is imaging performed by uniformly illuminating a plurality of imaging regions in the imaging unit by an illumination unit. 18. The imaging device according to claim 17, wherein the control unit switches a shooting time of the calibration shooting. 19. The image pickup apparatus according to claim 17, wherein the control unit performs the calibration photographing after the main photographing. 20. The image pickup apparatus according to claim 17, wherein the control unit switches the brightness of the illumination unit in the calibration photographing. 21. The image pickup device according to claim 16, wherein
The image pickup apparatus is characterized in that the image pickup condition of the image pickup means is at least one of temperature, photographing sensitivity, and time from calibration photographing to actual photographing. 22. An unbalance correction method between image data for correcting unbalance between image data in an image pickup device which outputs a plurality of image data by data obtained by calibration shooting, which is provided in a shooting condition in main shooting. An unbalance correction method between image data, characterized in that the operation of the calibration photographing is controlled in accordance therewith. 23. The unbalance correction method between image data according to claim 22, wherein the shooting time of the calibration shooting is shortened as the exposure sensitivity in the main shooting becomes higher. 24. A program for realizing the unbalance correction method according to any one of claims 15, 22, and 23. 25. A storage medium storing the program according to claim 10, 15, or 23.