JP3227178B2 - Imaging device and shooting mode control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus such as a video camera and a method for controlling a photographing mode.

[0002]

2. Description of the Related Art In recent years, the development of video equipment such as video cameras has been remarkable, and various functions have been automated and operability has been improved. For example, automation of zoom lens equipment, automatic focus control, automatic exposure control, etc. Is essential, and for example, when it comes to automatic exposure control, it is an important factor that determines the quality of a captured image, and in any shooting environment, stable and good automatic exposure control must always be possible. The importance of the automatic exposure control function is extremely high.

FIG. 35 is a block diagram showing a basic configuration of an exposure control system of a general video camera. Reference numeral 101 denotes a photographing lens optical system, 102 denotes an iris for adjusting the amount of incident light, and 103 denotes a photographing lens optical system. An image sensor, such as a CCD, which photoelectrically converts an image formed and whose light amount is adjusted by an iris and converts the image into an image signal, 104 standardizes the image signal output from the image sensor by performing predetermined signal processing on the image signal. Camera signal processing circuit for converting into a converted video signal, 10
5 is a video signal output terminal, 106 is a motor that drives the iris 102 to vary the aperture, 107 is an aperture drive circuit that drives and controls the motor 106, 108 controls the accumulation, readout, and reset timing of the image sensor 103. A CCD drive circuit for variably controlling the accumulation time (exposure time) to set a desired shutter speed; 109, evaluates the exposure state based on the level of the luminance signal output from the camera signal processing circuit, and drives the aperture. An automatic exposure control circuit (AE circuit) 110 for controlling the circuit 107 and the CCD driving circuit 108 to optimally control the exposure, and 110 is a switch panel for receiving an input of a key operation.

The exposure control by the AE circuit 109 will be described. The luminance signal output from the camera signal processing circuit 104 is integrated, and the aperture driving circuit 107 is controlled so that the level falls within a predetermined range. A closed loop for iris control is formed to control the output drive current to vary the iris opening amount, and the drive pulse is switched by controlling the CCD drive circuit 108 in accordance with the key operation of the switch panel 110. And a control system for controlling the exposure time, that is, the shutter speed, by varying the accumulation time of the image sensor 103 to obtain an appropriate exposure state.

This storage time control is what is called an electronic shutter. For example, in the case of NTSC, in addition to the usual exposure time of 1/60 second for each screen, a control of about 1/100 to 1/10000 second is performed. The light accumulation time can be selected in a plurality of stages up to the above.

In the system configured as described above,
When a high-speed electronic shutter is used, there is an automatic exposure control mode for controlling the aperture mechanism (iris) of the imaging optical system based on each arbitrarily selected set exposure time, that is, for each shutter speed. This is a so-called shutter priority mode. FIG. 36 shows the shutter priority mode, in which the shutter speed on the horizontal axis is selected, the shutter speed is fixed, and the aperture value on the vertical axis is varied.

[0007]

However, in the iris control based on the brightness level of the image pickup signal and the shutter priority mode as in the above-mentioned video camera apparatus, appropriate exposure control is always realized in various photographing environments and photographing conditions. Cannot be performed, and proper exposure control cannot be performed in many cases.

[0008] In particular, in a camera such as a silver halide camera which captures a still image for a moment, exposure control at the moment of photography may be appropriately performed. However, as in a video camera, a moving image is captured for a long time. In such a case, a video that satisfies these conditions must always naturally follow the changing shooting conditions and shooting environment during shooting, and always perform stable and optimal exposure control. Realization of an exposure control device for a camera is strongly desired.

Therefore, in order to always perform an optimal photographing operation corresponding to all photographing environments, it is conceivable to facilitate photographing modes according to various photographing situations and to select the photographing modes according to photographing situations.

However, when a plurality of photographing modes can be switched, the characteristics and set values of the control parameters suddenly change when the modes are switched, which may cause an unnatural change in the image. In a video camera performing the above, there is a danger that the quality of the image is reduced.

[0011]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above-mentioned problems, and according to the first aspect of the present invention, each of them is individually controlled in accordance with a photographing condition. An image pickup apparatus having a plurality of photographing modes in which characteristics are set, a mode selecting means capable of selecting an arbitrary photographing mode from the plurality of photographing modes, and switching of the photographing mode by the mode selecting means. And a control unit that shifts the shooting mode via a specific mode in a case where the shooting mode is selected. According to the invention described in claim 2 of the present application, in the invention described in claim 1, the imaging apparatus is characterized in that the specific mode has an intermediate control characteristic among the control characteristics of the respective shooting modes. I do. According to the invention described in claim 3 of the present application, in the invention described in claim 1, the control characteristic defines a change in an aperture value, a shutter speed, and a gain with respect to a subject luminance. It is characterized by. According to a fourth aspect of the present invention, there is provided a shooting mode control method capable of switching between a plurality of shooting modes each having a control characteristic individually set according to a shooting condition. Wherein the shooting mode is switched via a specific mode when the shooting mode is switched. According to the invention described in claim 5 of the present application, in the invention described in claim 4, the specific mode has an intermediate control characteristic of the control characteristics of each of the photographing modes. A shooting mode control method is characterized. Further, according to the invention described in claim 6 of the present application, in the invention described in claim 4, the control characteristics are:
It is characterized by a shooting mode control method that defines changes in shutter speed and gain.

[0012]

According to the present invention, when the photographing mode is switched, it is possible to prevent a sudden change in the characteristics and set values of the control parameters, thereby disturbing the screen due to the switching, causing unnatural changes, and excessive control. Can prevent instability,
It is possible to always perform optimal photographing regardless of the photographing situation and photographing environment.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an image pickup apparatus according to the present invention.

FIG. 1 is a block diagram showing the configuration of an embodiment in which the image pickup apparatus of the present invention is applied to a video camera. In FIG. 1, reference numeral 1 denotes a photographic lens optical system, 2 denotes an iris for adjusting the amount of incident light, and 3 denotes An image pickup device such as a CCD, which photoelectrically converts an image formed on the image pickup surface of the image pickup surface by a photographic lens optical system and whose light amount is adjusted by an iris to convert the image into an image pickup signal;
Is a double correlation sampling circuit (CDS) for reducing the noise of the charge accumulated in the image sensor, 5 is an AGC circuit for automatically adjusting the gain of the image signal, and 6 is a predetermined signal processing for the image signal output from the AGC circuit 5. A camera signal processing circuit for converting the video signal output from the camera signal processing circuit into a signal suitable for recording on a video tape recorder or the like; Reference numeral 8 denotes a video tape recorder using a magnetic tape as a recording medium.

On the other hand, reference numeral 9 denotes an AGC for dividing an imaged screen into a plurality of screens and extracting an image signal corresponding to an arbitrary area.
A gate circuit 10 for gating a signal output from the circuit 5; an integrator 10 for integrating an image signal corresponding to a designated area in the image screen selected by the gate circuit 9 to obtain an average light amount; An A / D converter converts a signal output from the integrator into a digital signal that can be processed by a system control circuit described later. The area designating operation by the gate circuit 9 and the integration operation of the integrator 10 relate to the designation of the photometric region and the setting of the weight in accordance with the photographing mode. It can be arbitrarily set by controlling the pulse and the integral reset pulse. The detailed processing will be described later.

Reference numeral 12 denotes a CCD drive circuit for controlling the accumulation operation, readout operation, reset operation, etc. of the image pickup device 3, reference numeral 13 denotes an iris motor for driving the iris 2, reference numeral 14 denotes an iris drive circuit for driving the iris motor, and reference numeral 15 A D / A converter for converting a digital iris control signal output from a system control circuit into an analog signal,
Reference numeral 6 denotes an iris encoder constituted by a Hall element or the like for detecting the opening amount of the iris, that is, the aperture value. Reference numeral 17 denotes an amplifier for amplifying the output of the iris encoder 16, and reference numeral 18 denotes an iris encoder amplified to a predetermined level by the amplifier 17. The A / D converter converts the output into a digital signal that can be processed by a system control circuit described later.

19a, 19b, 19c,... Are data reference tables (LUTs) storing various data for exposure control.
In the present embodiment, three tables are illustrated so that a plurality of settings are made according to the shooting conditions in the Look up table). However, actually, three tables are provided for each of the prepared shooting modes, which will be further described later. In the full auto shooting mode, two data tables are selectively used in the same mode. By the way, in this embodiment, as will be described later, “indoor shooting mode”, “sport shooting mode”, “landscape shooting mode”, “portrait shooting mode”, “full auto shooting mode”, “spot light shooting mode” , "Surf & snow shooting mode",
The “manual shooting mode” is described.

Specifically, information on control characteristics of exposure control parameters such as iris, shutter speed, gain, etc. corresponding to each of a plurality of photographing modes is stored, and according to the set photographing mode. Necessary data is read out.

Reference numeral 20 denotes an operation unit including a plurality of operation keys for performing various operations. Reference numeral 21 denotes a D / D which converts a digital gain control signal output from a system control circuit into an analog control signal and supplies the analog control signal to an AGC circuit. The A converters 22 and 23 convert a digital control signal output from the system control circuit into an analog control signal in order to change or correct various characteristics in camera signal processing and image signal processing according to shooting conditions, respectively. It is a D / A converter to be supplied to the camera signal processing circuit 6 and the image processing circuit 7.

Reference numeral 25 denotes a system control circuit configured by a micro computer, which comprehensively controls the entire video camera system in this embodiment.

The system control circuit 25 sends control signals for controlling the characteristics of the camera signal processing circuit 6 and the image signal processing circuit 7 in accordance with the photographing mode operated by the operation section 20, to D / A converters 22, 23. , And controls the gate pulse supplied to the gate circuit 9 in accordance with the photographing mode, and sets a photometric region for detecting the amount of light on the imaging screen. Further, it controls the integration reset pulse supplied to the integrator 10 to control the selection characteristic of the integration operation.

For example, FIG. 2 shows an example in which a photometric area is set on an image-capturing screen. FIG. 2 shows an example in which a photometric area is set in the center of the image-capturing screen, and signals in this area are mainly exposed. FIG. 9 shows an area setting state of “center-weighted metering” used for control calculation.

This is based on an empirical rule that the probability that the main subject is located substantially at the center of the screen is high. In the exposure calculation, the signal inside the central area indicated by the solid line is larger than the signal outside the central area. Exposure control is performed by assigning coefficients to increase the weight at the center.

Then, the integrated value corresponding to the shooting mode of the image signal in the photometry area taken in through the gate circuit 9 is taken, and the iris control according to the shooting condition is performed by referring to the data of the LUTs 19a, 19b, 19c. The signal is calculated and supplied to the iris drive circuit 14 via the D / A converter 15 and the D / A signal is supplied to the AGC circuit 5.
A gain control signal is supplied via the converter 21 to control the gain of the AGC circuit 5 in accordance with the photographing mode and the photographing state. Further, a control signal is also supplied to the CCD drive circuit 12 to perform photographing mode and photographing. Depending on the situation, the control of the storage time (electronic shutter), readout timing, reset timing, etc. of the image sensor is performed.

These various controls are performed by referring to the output of the iris encoder 16 in the photographing mode, various control parameters are calculated and set, and the above-described controls are selectively, simultaneously, or simultaneously. They are executed in appropriate combinations.

As described above, the system control circuit 25
Operates the iris control, the gain control, the drive control of the image sensor (for example, the electronic shutter by the accumulation time control) based on the integral value, or the like, simultaneously or appropriately in combination based on the photographic mode and the iris drive state. By doing so, optimal exposure control is performed for all shooting situations.

Reference numeral 26 denotes an electronic view finder (EVF) for displaying a photographed image, an image reproduced by the recorder section 8, data on various operation modes, and the like.

Display of these various data will be described later.

The imaging apparatus according to the present invention has the above-described configuration, and its specific operation will be described below step by step.

First, various control parameters used for exposure control in the apparatus of the present invention will be described. (1) Iris Aperture (Parameter P1) The iris control signal output from the system control circuit is converted into an analog signal by the D / A converter 15, and then supplied to the iris drive circuit 14 for current amplification. Then, it is supplied to the iris motor 13 to drive it. Thus, the iris motor 13 controls the aperture state of the iris 2.

Integrator 1 supplied from A / D converter 11
The integrated value of 0 corresponds to the LUT 19 corresponding to the shooting mode.
If the control value is larger than the control values defined by a, 19b, 19bc, etc., it means that the exposure is over. Therefore, the iris drive circuit 14 is controlled to drive the iris motor 13 in the direction to narrow down the iris 2, and the incident light amount To reduce the output level of the integrator 10 as a result.

On the other hand, when the integrated value supplied from the A / D converter 11 is smaller than the control value specified by the LUT 19, the iris motor 13 is driven in the opposite direction, and the iris 2 is driven. It is controlled to open to increase the amount of incident light and consequently to increase the integral value. (2) shear ivy speed (parameter 2) (see Figure 3) accumulation time setting signal D _t of the imaging device is output in the form of a digital signal from the system control circuit 25, CCD driving circuit 12 receives this as a CCD A pulse for determining various timings is generated to control the accumulation time.

Since the setting method and the setting range of the accumulation time are greatly different depending on the structure of the CCD which is the image pickup device, in the present embodiment, a CCD having a structure in which unnecessary charges are discarded to the OFD (overflow drain) during the H blanking period is taken as an example. This will be explained.

FIG. 3A is a diagram for explaining the operation of the CCD. The range that can be set is the range permitted in terms of image quality such as the amount of imaged light and smear if it is within H blanking on the high-speed side. Can be set with. Substantially 1 / 10,000 seconds. The low speed side is H until 1/60 second in the case of NTSC.
It can be set in steps of the blanking cycle (about 63.5 μsec).

As a specific time control method, D _t
Is output from the system control circuit 25, the shutter speed T is determined by the following calculation. . T _NTSC ≒ (262.5-D _t ) * 63.5 μsec. T _PAL ≒ (312.5−D _t ) * 64.0 μsec The CCD driving circuit 12 thus instructed further adds ΔV _sub to V _sub (vertical substrate applied voltage) in order to realize the electronic shutter operation. Is added to change the potential distribution of the charge storage portion by photoelectric conversion, and unnecessary charges are discarded in the direction of the substrate. In this way, an arbitrary shutter speed can be set. FIG. 3B shows this operation.

The system control circuit 25
Current shear ivy speed the D _t in order to slow down the Hayakere if shear ivy speed than the control value defined in LUT19 corresponding to the integral value from the A / D converter 11 to the current less than the value change, change the current value larger than the value of said D _t in order to increase the shear ivy speed as late than the control value defined in LUT19 reversed. (3) Gain (Parameter P3) The D / A converter 21 outputs a gain setting signal for determining the amplification factor of the video signal, and supplies it to the AGC circuit 5.

The AGC gain is set by the AGCC amplifier
The output signal of the DS4 is provided so that appropriate signal processing is performed in the camera signal processing circuit 6 in the next stage.
Conventionally, it has been treated as a part of a component of an AE loop by an iris, and is not intended to be arbitrarily controlled.

In recent years, even if the S / N of the CCD has been improved and the gain of the AGC has been increased to increase the gain, the noise of the imaging system has become less noticeable, and the settable range as a control parameter has been expanded.

Since the gain is a parameter having a fast control response in the image pickup system, the gain is a parameter suitable for AE control in a situation where a quick response is required.

If the current AGC gain is larger than the control value specified in the LUT 19 corresponding to the integrated value from the A / D converter 11, the system control circuit 25
Updates the gain set value to reduce the AGC gain.

Conversely, if the current AGC gain is the A / D converter 2
If the control value is smaller than the control value defined by the LUT 25 corresponding to the integrated value from 5, the gain setting is updated to increase the gain of the AGC.

According to the present invention, by using the above three parameters, it is possible to maintain an appropriate exposure state of the image pickup system according to the photographing situation and the photographing mode. The exposure control used will be described. First, the setting of the photometry area on the imaging screen that changes according to each exposure control mode will be described.

The subject photographed by the video camera is a place,
It changes variously depending on the environment and shooting conditions at that time. Therefore, in order to always perform the optimum automatic exposure control in these shooting situations, the setting position of the photometry area in the image pickup screen and the weighting control of the photometry area are appropriately changed to perform control suitable for the situation. There is a need.

In view of the above, the luminance distribution in the screen is assumed in consideration of the light ray condition corresponding to the set representative scene, and the area in the screen which provides effective information for determining the exposure amount is set to A.
It is necessary to have an automatic photographing mode in which an E (automatic exposure control) operation coefficient is assigned to a large value and a photometric region is set so that the weighting is increased.

According to this embodiment, as shown in FIG. 4, an example is shown in which the imaging screen is divided vertically into four parts and horizontally into six parts, and the entire screen is divided into 24 small areas. Each region is numbered from 1 to 24).

These division operations are controlled by the system control circuit 25. The gate circuit 9 is controlled to open and close by a gate pulse output from the system control circuit 25, and the output of the AGC circuit 5 is controlled. The signal is extracted for each of the regions 1 to 24 and is integrated as an independent value by the integrator 10 for each region.
After being converted into a digital signal by the D converter 11, the digital signal is taken into the system control circuit 25. In the system control circuit 25, a process is performed in which a weighting coefficient set in advance according to the shooting mode is added to the integrated value in each of these areas. Note that these processes can be performed by time division processing corresponding to 24 divisions.

FIG. 5 and FIG. 6 show examples of the imaging screens after the weighting coefficient processing.

FIG. 5 shows the above-mentioned "center-weighted metering" realized by the 24-split AE system of the present invention.
The weighting calculation coefficients in the areas 8 to 11 and 14 to 17 corresponding to the center of the screen are set to 1.0, and the weighting calculation coefficients in the surrounding areas are set to 0.5, so that AE control is performed with emphasis on the center. . Specifically, if the iris, shutter speed, and gain are controlled based on a value obtained by adding the integrated values of these weighted areas, the above-mentioned weights can be reflected in these controls.

FIG. 6 shows an example of a photometry area suitable for "landscape photography" or the like. In general, when performing landscape photography, both the ground and the sky are often simultaneously projected on a screen. In addition, the sky portion often has very high brightness even in a slightly cloudy sky compared to the ground portion. For this reason, when photographing is performed using the conventional AE control that does not consider the photometric area, a person or the like against the ground or the sky often becomes black due to insufficient light quantity.

In order to eliminate these inconveniences, the weighting coefficients of the areas 1 to 6 at the top of the screen corresponding to the sky are set to 0.0 and substantially ignored, and the coefficients above the center of the screen are set to 0.5.
, And the lower half coefficient of the screen is set to 1.0. By allocating the calculation coefficients in this manner, the AE calculation processing can be performed with a weight placed on the lower part of the screen corresponding to the ground.

In addition to the above two examples, various AE characteristics can be set by setting a photographing mode according to a photographing situation and appropriately selecting a photometric area setting and a photographing program according to a photographing situation described later. Is possible.

Next, the actual AE control according to the photographing situation using the above three parameters will be described. As described above, conventional iris control alone is not enough to perform shooting adapted to various shooting situations.
In the present invention, more parameters are prepared, and these can be optimally controlled.

That is, in the present invention, a photographing control called a "program mode" in which photographing can be performed while automatically adjusting each of the photographing conditions under an optimum condition under the assumption of some typical photographing conditions. Invented the scheme. These program modes can be arbitrarily selected and set by operating the keys of the operation unit 20.

In order to always perform good shooting in various places of video shooting and in various situations, a typical scene is set according to the shooting situation, and a plurality of scenes are set in order to optimize the scene. It is necessary to have an automatic shooting (exposure control) mode.

In order to solve this problem, a plurality of lookup tables (LUTs) storing control functions for controlling a plurality of parameters are set, and as shown in FIG.
A plurality of tables 19a, LUT 19b, LUT 19c,... Are prepared by a memory such as a ROM, and are configured to be selectively readable by a system control circuit 25. Performed.

7 and 8 show examples of control characteristics of each parameter controlled by data read from the LUTs 19a, 19b, 19c,...

FIG. 7 shows that the shutter speed of the parameter (2) can be set to 1/100 second as much as possible, and the iris of the parameter (1) or the parameter ( 3) A
FIG. 9 is a program diagram showing a program control operation for performing appropriate exposure control by changing a GC gain, and is stored in, for example, the LUT 19a.

In this program mode, when the power supply frequency is 5
This is for suppressing the flicker of the fluorescent lamp which occurs when using the NTSC video camera in the area of 0 Hz, and can be called an "indoor shooting mode".

In the figure, the horizontal axis is the subject illuminance as an input parameter, and the vertical axis is the set value of each parameter. As is clear from the figure, the setting range of each parameter is A, B, C3 according to the input parameter, that is, the illuminance of the subject.
It is divided into two areas, and exposure control is performed by combining three parameters in each area.

That is, looking at the area A, the shutter speed (P2) is fixed to 1/100 second and the gain (P3) is also fixed, and the iris (P1) is controlled according to the brightness. Exposure control is performed. It is possible to adapt to most subjects in this area A.

On the other hand, in the area B, the illuminance is low, indicating that the iris has been opened, and the iris is constant at the open value as shown in the figure. Therefore, the exposure control is performed by changing the shutter speed to 1/60 second. That is, in the NTSC system, accumulation and reading are originally performed at a period of 1/60 second, so 1/60 second indicates an original operation timing.

When the illuminance further decreases, as shown in area 3, the iris and the shutter have reached their limits. Therefore, exposure control is performed by increasing the gain (P3).

As described above, by changing the control parameters P1 to P3 according to the change of the input parameter indicating the illuminance of the subject, it is possible to perform the optimal exposure control according to the photographing situation.

FIG. 8 shows another program mode. For example, a program diagram stored in the LUT 19b sets the shutter speed (P2) to a high-speed shutter as short as 1/500 sec. This is a program mode prepared to suppress blurring of a fast-moving subject and to clearly capture a screen. In the present invention, the program mode is referred to as a "sport shooting mode".

As can be seen from the drawing, the shutter speed in area A and area B is reduced to 1/500 as much as possible.
Seconds, and the iris (P
Exposure control is performed based on 1) and the gain (P3), and an operation is performed such that the illuminance of the subject is reduced and the shutter speed cannot be maintained for the first time in the area C where the shutter speed is gradually changed to 1/60 second.

As described above, a plurality of program modes are prepared in accordance with the shooting conditions, and by appropriately selecting the program modes by operating the keys of the operation unit 20, the optimum exposure mode can be obtained for any shooting conditions. Control can be performed.

When the photographing program mode is switched by the operation unit 20, the setting of the photometric area on the image-capturing screen is simultaneously switched as described above. For example, FIG.
In the indoor photographing mode of FIG. 8 and the sport photographing mode of FIG. 8, a subject such as a normal person, which is usually located at the center of the screen, is often photographed. Also, in a landscape photographing mode of FIG. 18 described later, the photometry area on the imaging screen is switched to the “landscape photography mode” photometry area shown in FIG. 6 in conjunction with the operation of switching to this photography mode.

By the way, the control of each parameter in each program diagram described above has the following features.

That is, as is apparent from FIGS. 7 and 8 and the like, each control parameter is divided into a plurality of areas (three areas A, B, and C in this embodiment), and the input parameters, that is, the change in the illuminance of the subject. Each area is selected in accordance with each area.
Only one variable parameter used for control is designated, and the other two are fixed (FIX). This is shown in the table below the program diagram.

That is, in FIG. 7, in area A, the parameter (P1) is variable and the others are fixed, that is, when the iris control is being performed, the shutter speed and the gain are fixed.

In the area B, the parameter (P2), that is, the shutter speed is variable and the others are fixed.
In this case, the parameter (P3), that is, the gain is variable, and the others are fixed.

As a result, although the control is performed by changing the three control parameters, the number of variable parameters is always one in each area unit, and the calculation processing of the fixed parameters becomes unnecessary. The processing is the same as that of the conventional single parameter processing.

That is, according to the present invention, the complicated calculation process naturally caused by increasing the control parameters in order to cope with various photographing situations is performed by dividing the parameter setting region into a plurality of regions and changing each region. By setting one parameter to be performed and fixing the other parameters, it is possible to simplify the handling of a variety of complicated imaging conditions and a plurality of parameters to be controlled, and realize optimal AE control without using a large-scale logic or a large-scale computer. Is what you can do.

The present invention has another feature in the above-described control parameter switching operation.

That is, in the present invention, although the number of parameters to be changed is always set to one and the other is fixed, the arithmetic processing is reduced.
The normal imaging target is a moving image, and the imaging conditions are constantly changing.

When each control parameter is set corresponding to an input parameter, the value of the input parameter may move between a plurality of divided areas due to a change in imaging conditions. At this time, a controlled parameter switching operation occurs, but the manner of change on the screen may vary greatly depending on the parameter. If this change occurs frequently, the screen is expected to be difficult to see. You.

As a countermeasure, it is conceivable to provide a hysteresis at the time of area transition and to reduce the frequency of area transition, but there is no effect when switching occurs, and it cannot be a fundamental countermeasure. .

Therefore, in the present invention, as a countermeasure against this, as shown in FIGS. 7 and 8, two parameters of the adjacent area are controlled so as to be simultaneously changed only in the areas B1 and B2 near the boundary of the area. are doing.

In FIG. 7, a boundary portion B sandwiched between broken lines
1 is a boundary region where the parameters P1 and P2 operate simultaneously, and similarly, in the boundary portion B2, the parameters P2 and P3
And are operating at the same time.

By simultaneously changing the two parameters in this way, an image change specific to each parameter occurs simultaneously and gradually, so that even when a parameter moves between areas, the screen changes. Can be visually visually uncomfortable.

The method of controlling the exposure by a plurality of photographing program modes has been described above. According to the present invention, the D / A is controlled by the command of the system control circuit 25 in accordance with the above-mentioned photographing mode switching. Control signals for changing various characteristics of various types of image processing and camera signal processing from the standard position according to the respective shooting conditions can be supplied via the converters 22 and 23.

In other words, in order to always optimally represent each scene in various places and situations where photographing is performed, a camera signal processing circuit shown in FIG. 6. Control of the image signal processing circuit 7 is also effective.

Therefore, taking into account the image pickup screen corresponding to the set representative scene, FIG.
In the camera signal processing circuit 6, the non-linear conversion characteristics (knee characteristics and γ characteristics) of the video signal level
It is not possible to control the characteristics of the aperture correction circuit for changing the sharpness of the image or the like as shown by b and c, and the image signal processing circuit 7 shown in FIG. As the processing, for example, it is conceivable to give a “fade effect” or “afterimage effect” to a captured video signal.

FIG. 11 shows a configuration example of the image signal processing circuit 6 having a function of providing such an additional effect, and the configuration and operation will be described below.

The color signal processing circuit 30 generates a color signal specified by a control signal * 1 from the system control circuit 25 (for example, a blue background or a white background), and outputs the color signal and the video output. Is delayed by one screen by the field memory circuit 32, and 3
It is supplied to a selection switch 31 for making an alternative selection.

From the selection switch 31, information of one of the three selected by the instruction * 2 of the system control circuit 25 is supplied to the input terminal of the multiplier 33. The multiplier 33 executes a multiplication process using the coefficient output from the multiplication coefficient generator 34 according to the instruction * 3 of the system control circuit 25. The result of the multiplication is added by an adder 35 to a signal obtained by performing similar coefficient multiplication processing by a multiplier 38 to a video input signal input from an input terminal 36, and supplied to an output terminal 37. You.

In the process of processing such a signal, when the non-signal OFF terminal is selected by the selection switch, the adder 35 is selected.
Is input only to the video signal from the input terminal 36, and this video input signal is output (through) to the video signal output terminal 37 as it is. At this time, the coefficient of the multiplier 38 is 1.0, which is a through value.

Next, when the output of the color signal generator 30 is selected by the selection switch 31, the multiplication coefficient generator 34 is controlled in accordance with an instruction from the system control circuit 25 (start / end timing or direct coefficient setting). An operation with the output is performed, and one of them appears as 0 → 1 and the other disappears as 1 → 0 in the inverse operation (1's complement relationship with the coefficient) to the input video signal from the video input terminal 36, and as a result, the color The signal and input signal are switched. Visually, the screen changes so as to gradually change from a blue screen to a moving image.

Also, when the output of the field memory is selected, the relationship between the coefficients of the multiplier 38 is a one's complement as described above. The difference is that the operation is performed at a fixed value of, for example, 0.5 without a temporal change.

In this case, the result of the addition and output is cyclically added at a predetermined rate with a delay of one screen, so that the input image is expressed as trailing in the time axis direction.

By operating such signal processing in, for example, a so-called portrait photographing mode in which a person is photographed with emphasis, the aperture characteristics and the like are changed in the above-described camera signal processing circuit. Image quality can be adjusted by lowering the frequency response in the vicinity of the sharpness of the human visual characteristic and the frequency response in the vicinity of 2-3 MHz in the case of a television signal so that the image can be given a soft feeling. it can.

By operating the circuit as shown in FIG. 11, a color fade can be applied to an image.
The effect of the special image processing can be automatically given.

According to the image pickup apparatus of the present invention, a plurality of program photographing modes are prepared so that optimum control can always be performed in various photographing situations. The setting of the photometric area according to the photographing mode and the switching of the characteristics of the signal processing system according to the photographing mode will be described later, and the setting of each control parameter such as the iris, shutter speed, and gain described above. The operation procedure will be described.

FIG. 9 is a flowchart showing a parameter setting operation including the above-described parameter processing of the area boundary portion in a program photographing mode using the program diagram of FIG. 7, for example.

In the figure, when control is started, S
1 to monitor the power-on, and when the power is turned on, proceed to S2, confirm the photographing program mode (M) selected by the operation unit 20, proceed to S3, and proceed to S3. Reference program LUT 19a or 19b, 19c corresponding to mode (M), and set the specified program characteristics. The details of each shooting mode will be described later.

In S4, the data relating to the weighting of each of the 24 divisions set on the imaging screen is read out from the specified LUT, weighting is performed according to the selected photographing mode as described above, and the flow advances to S5. .

In S5, according to the designated photographing mode,
The contents and characteristics of image processing are read out from the LUT, and image quality adjustment by aperture control or image processing by color fade or the like is set in the above example, which is adapted to the shooting mode.

In S6, the current area on the reference parameter axis, that is, the current area is confirmed from the illuminance of the object corresponding to the input parameter.

Subsequently, the flow proceeds to S7, where the branch destination is determined according to the current area.

If the area is determined as A, the process proceeds to S8, where the iris control parameter P1 is calculated.
In step 9, the inside and outside of the area B1 is determined.
If it is outside 1, the process proceeds to S10, where the shutter speed control parameter P2 is pre-held and fixed, and if it is within B1, it is S1.
The process proceeds to 1 to calculate and update the shutter speed control P2, and then proceeds to S21, where the gain control parameter P3 is held and fixed beforehand, and the process proceeds to S24.

If the area B is determined in S6,
In step S12, the shutter speed control parameter P2 is calculated, and the process proceeds to step S13, where the inside and outside of each of the boundary areas B1 and B2 are determined.
To calculate the iris control parameter P1 and proceed to S21, hold and fix the gain control parameter P3 in advance, and proceed to S24.

If it is within B2, the flow advances to S16 to calculate the gain control parameter P3, and the flow advances to S23. After the iris control parameter P1 is held beforehand and fixed, the flow advances to S24.

If neither B1 nor B2 belongs,
In S15, the iris control parameter P1 is pre-held and fixed, and in S22, the gain control parameter P3 is fixed. Then, the process proceeds to S24.

If it is determined in step S7 that the area is the area C, the process proceeds to step S17, where the gain control parameter P3
Then, in S18, the inside and outside of the area boundary area B2 is determined. If the area is outside the boundary B2, the process proceeds to S20, where the shutter speed control parameter P2 is pre-held and fixed, and if it is within B2. For example, the process proceeds to S19, in which the shutter speed control P2 is calculated and updated, and the process proceeds to S23.
Proceed to.

In S24, the values P1, P2, and P3 of the respective parameters set by the above-described processing, that is, the iris,
The control values of shutter speed and gain are output from the system control circuit 25 to control the iris 2, the image sensor 3, and the AGC circuit 5 according to their program modes, and the next processing time unit comes in S25. (In this embodiment, one operation is used as one basic unit per frame). In step S26, the power-off is confirmed. If the power-on is continued, the process returns to step S1 to repeat the above processing.
If the power-off is instructed, the process ends.

As a result, various parameters can be controlled in accordance with each of the selected program modes, and exposure control is performed based on these parameters.

Further, in conjunction with the switching of the photographing program mode, the characteristics or additional functions of the photometry area and the image signal processing system on the photographing screen are switched to those suitable for the photographing situation. , The optimal automatic exposure control and photographing can be always performed.

Further, even if the photographing situation changes, the photographing state of the camera does not unnaturally change, and the optimum control mode can be switched.

Each of the above-described photographing modes is an automatic photographing mode in each photographing situation. When a photographing mode is selected, various control information is read from a data table LUT corresponding to the photographing mode, and control parameters are read out. Is automatically set and controlled.

The above is the processing procedure from the reading of the characteristics of each parameter from the data reference table LUT to the calculation of AE control data. Next, each program shooting mode and the LUT corresponding to each of these shooting modes are stored in the LUT. Each stored parameter and its definition, characteristics, actual AE
The control characteristics will be described.

FIG. 12 shows the above “full auto shooting mode”.
13 shows an internal structure of an LUT storing data for determining control characteristics in FIG. 13. FIG. 13 is a transition diagram of control parameters corresponding to subject illuminance, that is, photographing luminance, performed based on the LUT in FIG. This is similar to the program diagram as shown in FIG.

The "full auto shooting mode" is an automatic shooting mode in which shooting can be properly performed under almost normal shooting conditions. For this purpose, as described later, a plurality of data tables are provided according to the shooting conditions, and the data tables are configured to be able to cope with various shooting conditions widely.

FIG. 14 also shows the internal structure of the LUT storing data for determining another control characteristic, which is referred to in a shooting situation different from the LUT of FIG. 12 in the “full auto shooting mode”. Is the LUT in FIG.
FIG. 7 is a transition diagram of control parameters corresponding to the subject illuminance, that is, the photographing luminance, which is performed based on the program diagram, and is similar to the program diagram shown in FIGS.

FIGS. 12 and 13 show an indoor shooting mode suitable for use in indoor shooting with flicker, for example.
4, FIG. 15 shows a photographing mode suitable for use when there is no flicker.

In the transition diagram of the control parameters shown in FIG. 13, according to the value of the input luminance level, the area is divided into six areas by five threshold values y1 to y5. Each control parameter of is set,
As shown on the right side of the figure, the iris is variable between CLOSE, a predetermined value F1, and OPEN, and the shutter is a high-speed T.
1, T of 1/100 second (NTSC) for flicker countermeasures
2. The gain is varied between the standard 1/60 second STANDARD, the gain is THROUGH of ± 0 dB, the predetermined value G1,
It changes between the larger G2. In the figure,
I, S, and G are variable areas of the corresponding parameters.

Although the concept of the transition diagram of the control parameters in FIG. 15 is the same as that in FIG. 13, the area division according to the value of the input luminance level is performed by four threshold values y3 to y8. Each control parameter is set for each of the divided areas.

That is, in the present invention, if the full auto mode is set by the operation unit 20, the flicker in the image pickup signal is detected by the system control circuit 25, and the LUT is automatically changed according to the presence or absence of the flicker. 14 is switched to the optimum one shown in FIG. 14, so that these LUTs are appropriately switched in accordance with the photographing conditions in a single program photographing mode, and any photographing conditions are always performed. It is also possible to respond to. In addition, different LUTs can be used according to other shooting conditions as well as flicker.
Needless to say, it can be prepared.

The individual parameters in each figure will be described below in order. (P1: Iris control parameter) The iris control parameter changes according to the input parameter Y, that is, the luminance level, and a function f (y) is defined as an attribute thereof.

The input luminance level is the threshold value y shown in FIG.
If it is higher than 1, the calculation (calcul) is displayed as “→ CAL”, as is apparent from the data column on the right side of FIG.
ation) is required.

In this case, the premise is that the luminance is extremely high,
In order to suppress a decrease in resolution due to the light diffraction phenomenon due to the small aperture of the iris, the shutter speed is set slightly higher so that the iris does not become too small, and a turn-back component in the time axis direction (so-called flickering)
Is set so as to be inconspicuous, the AGC gain is set to ± 0 dB (THROUGH), and the S / N is not deteriorated.

When the input luminance level is between y1 and y2, the iris is fixed at the aperture value F1, and it is set by the data column "F1" in FIG. 12 that no calculation is necessary. I have. It is desirable that the value of F1 be an aperture value that does not cause the diffraction phenomenon.

Further, when the input luminance level is between y2 and y3, it is shown that the calculation is necessary, as is apparent from the display of “→ CAL”. This range is the area having the widest range of controlling the exposure by the iris.

As another parameter, the AGC gain is ±
At 0 dB, the shutter speed is 1/100 second for NTSC and 1 for PAL when the fluorescent lamp flicker of FIG. 13 is present.
/ 60 sec. And set to cancel the fluctuation of the irradiation energy of the fluorescent lamp due to the AC power supply. When there is no flicker (FIGS. 14 and 15), the standard television is used to secure the exposure time. 1/60 second of rate (NT
SC) or 1/50 second (PAL).

In FIGS. 12 and 13, when the input luminance level is equal to or less than y3, it is possible to set the iris to open.
PEN ". Under this condition, since the luminance has started to decrease, the AGC gain is first raised to such an extent that the S / N deterioration is not conspicuous, and if the shutter speed is higher than the standard rate, then the shutter speed is reduced to the minimum speed of the standard rate. To gradually drop.

As described above, with regard to the iris, the entire range from high luminance to low luminance is divided into four by the three threshold values y1, y2, and y3 with respect to the value of the input parameter. Is defined. (P2: shutter control parameter) As the shutter control parameter, a function f (Y) of the luminance of the input parameter is defined by threshold values y1 to y5.

When the input luminance level is higher than y1, “→ T1” is defined, and the shutter speed is set to a high speed T1.
It is set to be fixed to. In this case, no operation is required.

Here, as described above, T1 is set slightly higher in order to cope with a small aperture, for example, 1/1.
It is selected within the range of 25 to 1/500 second.

When the input luminance level is between y1 and y2,
“→ CAL” is set, which indicates that it is necessary to calculate an optimum shutter speed according to the input luminance level and set a parameter value.

In this case, the iris is once fixed at an aperture value at which no diffraction phenomenon occurs in order to cope with a small aperture. Therefore, it is necessary to set the shutter speed as fast as the increase in the amount of light. For this purpose, the above operation is performed.

When the input luminance level is between y2 and y4, the shutter speed is fixed at T2. In this case, no calculation is required.

This T2 corresponds to the light accumulation time for preventing flickering of the fluorescent lamp.
In PAL, it is set to 1/60 second. However, when shooting under the condition where no flickering of the fluorescent light occurs, the light accumulation time is adjusted so as to be extended toward the standard value of the television signal, and the shooting is executed under a condition with better S / N. To control.

Therefore, in consideration of the case where there is no flicker, a control characteristic such that the shutter speed does not stop once at T2 is defined as another LUT and used under the condition where there is no fluorescent lamp flicker. This is the LUT shown in FIG. 14, and FIG. 15 shows a transition of each of the three parameters with respect to the luminance level which is an input parameter in that case. These figures are shown in FIGS.
Since it can be understood from the same viewpoint as described above, detailed description is omitted.

[0133] Regarding the determination of the presence or absence of the fluorescent lamp flicker, the system control circuit 25 monitors the brightness level for each field, and when a periodic level fluctuation is detected, there is flicker, and the brightness level of each field is almost equal. If it is stable, it can be determined that there is no flicker.

Then, the system control circuit 25
Depending on the presence or absence of flicker, two types of LUTs are selectively used in the same program mode called a full auto shooting mode, and an operation is performed so as to perform optimal control suited to a shooting situation.

In the area where the input luminance level is between y4 and y5, "→ CAL" is set, so that the optimum shutter speed is obtained by calculation and the parameters are set.

That is, as a measure for preventing flicker,
Although the shutter speed is set higher than the standard television rate, it is more important to reduce the shutter speed so that the shooting itself can be performed in low light conditions. The above calculation is performed to set the speed.

In this area, since one step of the shutter speed can be set finely, even if the shutter speed is continuously changed, the image does not feel strange.

When the input luminance level is equal to or less than y5, it is specified by "→ standard value" that the shutter speed should be set to the standard value of the TV signal.
It is 1/60 second in NTSC and 1/50 second in PAL.

In this state, only the AGC gain remains as a controllable parameter, and the gain is increased within the allowable range of the S / N deterioration, and the exposure control is executed. (P3: AGC gain) Even when the AGC gain is used as a parameter to be processed, a function f (Y) of the input luminance is defined by a plurality of thresholds. When the input luminance level is higher than y3, “ ± 0dB ”is specified and AG
The C gain is fixed at ± 0 dB, and a gain is set so as not to have an amplifying effect. That is, when exposure control can be performed by the iris and the shutter, the AGC gain is fixed and S
/ N is prevented from deteriorating. In this case, no calculation is required.

When the input luminance level is between y3 and y4, “→
CAL ”is specified, and the optimum AGC
A gain control parameter is set based on the gain.

When the input luminance level is between y4 and y5, the AGC gain is specified to be fixed at a predetermined value G1. In this case, no calculation is required.

When the input luminance level is equal to or less than y5, "→ CAL" is designated so that the optimum AGC gain is calculated and the gain control parameter is set.

The relationship between these threshold definitions and the three parameters is clear from FIG. 13 or FIG. 15. If there is no flicker in FIG.
The area is divided into six areas by 1 to y5, and the parameters to be calculated are, as shown in FIGS.
Each area is distributed so that it is always one,
The iris (I), the shutter (S), the iris (I), the gain (G), the shutter (S), and the gain (G) are arranged from the high luminance side.

Also in the case where there is no flicker in FIG. 15, the whole is divided into four areas by y6 to y8, and the parameters to be calculated are distributed and arranged so that each area has one parameter. The values are I, S, I, and G from the luminance side. (P4: AE weighting parameter = photometry area weight setting) As shown in FIG. 5 and FIG. 6, this is a parameter for setting the photometry area distribution in the imaging screen and their weighting. As is clear from FIG. It is stored in the MAP format, and the attributes are fixed. In other words, it differs for each LUT according to the shooting mode, but is fixed in one shooting mode and does not change according to the luminance signal level.

In the present embodiment, the image is divided into 24 divided areas on the image-capturing screen directly like a map. In the full auto mode, 1.0 is set in the central 2 × 4 area.
A lighter coefficient than the central part of 0.5 is assigned to each of the 16 peripheral areas, which is a photometric area designation of “central part weighted photometry” shown in FIG. (P5: AE reference value parameter) The parameter of the AE reference value indicates a luminance level that is a reference for exposure control, and is stored in a numerical definition. It is determined whether the exposure is excessive or insufficient based on the reference value. In this embodiment, the exposure is set to 50 IRE. This parameter is also constant in the shooting mode regardless of the input luminance level. (P6: image quality adjustment parameter) A parameter for specifying image quality adjustment processing by aperture control or the like described above. The processing content is defined by a code, the attributes are fixed, and are set according to the shooting mode. It does not change depending on the luminance level.

In this full auto mode, the "NORMA
L ", indicating that the basic image quality is set to a standard value and no special processing is performed. (P7: image effect processing parameter) As described with reference to FIG. 11, this is a parameter for designating image processing such as fade, and the processing content is defined by a code.

In this full auto mode, the "NORMA
L ", indicating that the basic image quality is set to a standard value and no special processing is performed.

The attributes are fixed and set according to the shooting mode, and do not change depending on the input luminance level.

As described above, the data table LUT provided for each photographing mode according to the present invention stores the definitions and characteristics of various parameters necessary for control. Such a LUT is stored in accordance with the photographing mode. Since a plurality of cameras can be selected according to the designated shooting mode, optimal control can always be performed for any shooting situation and shooting environment.

Next, the setting and control of the “portrait photographing mode” mainly for photographing a person will be described in detail.

The “portrait photographing mode” is the operation unit 2
0, and is a shooting mode based on center-weighted metering in which the metering areas as shown in FIG. 5 are basically weighted as shown in FIG. 5, and are referred to when this mode is selected. FIG. 16 shows the internal structure of a data table LUT storing the definitions and characteristics of various control parameters required for the control.

A program diagram showing the operation of various control parameters defined and set by the LUT is shown in FIG.
It looks like 7. This figure shows the transition of each control parameter corresponding to the program diagram with respect to the luminance level of the input parameter. The actual program diagram is drawn as shown in FIGS. 7 and 8, but for simplicity, FIG.
2, similarly to FIG. 13, the operation range is shown sequentially from the top in the order of iris, shutter speed, and gain.

That is, in FIG. 17, two thresholds y1 and y2 are provided for the illuminance of the object on the horizontal axis which is an input parameter, the whole area is divided into three areas, and I is an iris control parameter ( P1) and S indicate the shutter speed control parameter (P2), and G indicates the gain control parameter (P3). As shown on the right side of the figure, the iris control parameter (P1) is CLOSE and O
It operates during PEN, and the shutter speed control parameter (P2) is set to the high speed (T1) and 1/60 of the standard.
And the gain control parameter (P3) is ±
0 dB amplification factor 1 (Since the input signal is output as it is, T
HROUGH) to a predetermined value G1.

However, as with the program diagrams of FIGS. 7 and 8, the value of each parameter is changed by calculation in accordance with the luminance level as an input parameter in the variable region.

In the portrait mode, it is assumed that the subject is a person, and therefore, it is important to take a picture with a small depth of field.

The individual parameters in each figure will be described below in order. (P1: Iris control parameter) The iris control parameter changes according to the input parameter Y, that is, the luminance level, and a function f (y) is defined as an attribute thereof.

The input luminance level is the threshold value y shown in FIG.
When the value is higher than 1, the calculation (calcul) is displayed as “→ CAL”, as is apparent from the data column on the right side of FIG.
ation) is required.

To secure S / N with high brightness, AGC
With the gain kept at ± 0 dB (THRUGH), control is performed so that the iris can be first opened to the open value in consideration of a small aperture countermeasure such as a reduction in resolution caused by a light diffraction phenomenon caused by a small aperture of the iris.

When the input luminance level is equal to or lower than y1, the control for setting the iris to open is indicated by "→ OPEN".

By performing such control, the setting is such that the depth of field becomes the shallowest, and the subject such as the person being photographed can be complemented with respect to the background. This state is the basic state of the control characteristics in the portrait shooting mode.

As described above, the control characteristic of the iris is defined by dividing the entire region from high luminance to low luminance into two by one threshold value y1. (P2: shutter control parameter) As the shutter control parameter, a function f (Y) of the luminance of the input parameter is defined by threshold values y1 and y2.

When the input luminance level is higher than y1, "→ T1" is designated, and the shutter speed is set to the high speed T1.
It is set to be fixed to. In this case, no operation is required.

Here, as described above, T1 is set to a somewhat higher shutter speed in order to set a shallower depth of field in addition to the countermeasure against the small aperture.

In practice, the selection is made within a range of about 1/250 to 1/4000 second.

At this stage, to gain S / N,
Even when the brightness becomes low, the control is performed without increasing the AGC gain as much as possible.

When the input luminance level is between y1 and y2,
“→ CAL” is set, which indicates that control is performed so as to obtain the optimum shutter speed according to the input luminance level by calculation and to set the control parameter value.

The variable control width here is between T1 and the standard screen frequency (standard value) of the television.

When the input luminance level is equal to or less than y2, "→ standard value" indicates that the shutter speed should be set to the standard value of the television signal.

Here, the standard value of the television signal means 1/60 second in NTSC and 1/50 second in PAL.

In this state, since only the AGC gain remains as a controllable parameter, the gain is increased within an allowable range in terms of S / N deterioration, and exposure control is performed. (P3: AGC gain) Even when the AGC gain is used as a parameter to be processed, a function f (Y) of the input luminance is defined by a plurality of thresholds, and when the input luminance level is higher than y2, “ → ± 0dB ”is specified and A
The gain is set so that the GC gain is fixed to ± 0 dB and no amplifying action is given. That is, when the exposure control can be performed by the iris and the shutter, the AGC gain is fixed to prevent the S / N from deteriorating. In this case, the calculation is unnecessary.

Since this section is set so as to occupy most of the range of the subject illuminance, S / S is applied over the entire area.
N good imaging is possible.

When the input luminance level is equal to or less than y2, "→ CAL" is designated so that the optimum AGC gain is calculated and the gain control parameter is set.

Since the other parameters have already been set to the maximum for the low illuminance measure, the only controllable parameter left in this state is the AGC gain, and consideration is given to the balance with S / N deterioration. Meanwhile, the exposure control is executed by setting the gain up within an allowable range.

The relationship between the area divided into three by these threshold values y1 and y2 and the three control parameters is as follows.
As is clear from FIG. 17, the parameters to be calculated are distributed and arranged so that one parameter is always set in each of the three areas, and the calculation is simplified.
The arrangement is I, S, G from the area on the high luminance side. (P4: AE weighting parameter = photometry area weight setting) As shown in FIG. 5 and FIG. 6, these are parameters for setting the photometry area distribution in the imaging screen and their weights. As is clear from FIG. It is stored in the MAP format, and the attributes are fixed. That is, the set value differs for each LUT corresponding to the shooting mode, but is fixed in one shooting mode and does not change depending on the luminance signal level.

In the present embodiment, areas are divided directly into 24 areas like a map. In the portrait photographing mode, a lighter coefficient than the central portion of 1.0 is assigned to the central 2 × 4 8 regions and 0.5 to the 16 peripheral regions. Partially weighted metering "is specified. (P5: AE reference value parameter) The parameter of the AE reference value indicates a luminance level that is a reference for exposure control, and is stored in a numerical definition. It is determined whether the exposure is excessive or insufficient based on the reference value. In this embodiment, the exposure is set to 50 IRE. This parameter is also constant in the shooting mode regardless of the input luminance level. (P6: image quality adjustment parameter) A parameter for specifying image quality adjustment processing by aperture control or the like described above. The processing content is defined by a code, the attributes are fixed, and are set according to the shooting mode. It does not change depending on the luminance level.

In the case of "NORMAL", the basic image quality is set as a standard value, and no special image processing is performed. In the case of "SOFT", the frequency characteristic is changed from the standard value of the basic image quality.

The setting in the portrait photographing mode is "SOFT". Specifically, as described above, the frequency related to the sharpness of the human visual characteristic, that is, about 2 MHz to 3 MHz in the television signal. By setting the frequency characteristic with reduced response, the setting is such that a soft image quality can be obtained. (P7: image effect processing parameter) As described with reference to FIG. 11, this is a parameter for designating image processing such as fade, and the processing content is defined by a code.

If "NORMAL" is specified, the basic image quality is set to a standard value, indicating that no special processing is performed.

In the portrait photographing mode, “WHI
TE-FADE "is an effect of gradually whitening the entire screen by activating a white fade circuit which is usually used at the time of scene change. Specifically, in the circuit shown in FIG. 11, the system control circuit 25 instructs the color signal generator 30 to generate white (* 1), switches the switch to the 30 side (* 2), and mixes white. The operation can be performed by setting the multiplication coefficient to about 0.1 to 0.5 (* 3) so that the ratio is about 30%, for example.

The attribute of this parameter is also fixed and set according to the photographing mode, and does not change depending on the input luminance level.

As described above, in the portrait photographing mode, the image is photographed by center-weighted metering, and it is possible to create a screen in which the background is blurred at a shallow depth of field with priority given to the open aperture. The main subject can be complemented with respect to the background, and automatic shooting optimal for portrait shooting can be performed. It is extremely effective to use the above-described image quality adjustment and image processing together.

As described above, the data table LU in the present invention
T stores definitions and characteristics of various parameters required for control, and a plurality of such LUTs are provided according to the shooting mode, and can be selected according to the specified shooting mode. Optimal control can always be performed for the shooting environment.

The above-described portrait photographing mode is taken as an example.
A data table LUT defining the control parameters,
The operating characteristics of the control parameters set thereby have been described.

Next, regarding the “sport shooting mode”,
The control of the control parameters by the internal structure of the data table LUT and its setting will be described.

As described above, the “sports photographing mode” is a photographing mode suitable for photographing a moving subject or a fast-moving subject, and is selected by operating the operation unit 20.
Basically, it is a shooting mode using center-weighted photometry in which a photometry area as shown in FIG. 5 is weighted as shown in FIG.
FIG. 18 shows the internal structure of a data table LUT which is referred to when this mode is selected and stores the definitions and characteristics of various control parameters necessary for the control.

A program diagram showing transition of various control parameters defined and set by the LUT with respect to the luminance level of the input parameter is as shown in FIG. 8, but in the following description, Data table L
In order to clarify the correspondence with the UT, as shown in FIG.
A control parameter transition diagram showing an operation range with respect to input luminance as an input parameter of each control parameter will be used.

In other words, in FIG. 19, five threshold values y1 are set for the illuminance of the object on the horizontal axis, which is an input parameter.
To y6, the whole area is divided into six areas from high luminance to low luminance, and I: iris control parameter (P1), S: shutter speed control parameter (P2), G: gain control parameter (P
Each control parameter of 3) is set, and as shown on the right side of the figure, the iris is variable between CLOSE and OPEN, and the shutter is T1 for high speed, T2 for medium speed, and 1 for standard.
/ 60 seconds (NTSC) STANDARD, gain is ± 0 dB THROUGH, predetermined value G1,
It changes between the larger G2. In the figure,
I, S, and G are variable areas of the corresponding parameters.

Hereinafter, each of the control parameters set in the data table for the landscape photographing mode will be sequentially described. (P1: Iris control parameter) The iris control parameter changes depending on the input parameter Y, that is, the luminance level, and a function f (y) of the luminance level Y is defined as an attribute thereof.

The input luminance level is equal to the threshold value y shown in FIG.
When the value is higher than 1, as is apparent from the data column on the right side of FIG.
ation) is required.

To secure S / N with high brightness, AGC
With the gain kept at ± 0 dB (THROUGH), the iris is fully opened from the minimum aperture to the open value first, taking into account small aperture measures to prevent a reduction in resolution caused by the light diffraction phenomenon due to the small aperture of the iris. Is controlled as follows.

When the input luminance level is equal to or lower than y1, the control for setting the iris to open is designated by "→ OPEN".

In this state, the light quantity becomes insufficient with respect to the currently set shutter speed.
The C gain is raised to such a degree that the S / N deterioration is not so noticeable, the shutter speed is maintained as high as possible, and the shutter speed is set as high as possible to control a fast-moving subject. .

As described above, the control characteristic of the iris is defined by dividing the entire region from high luminance to low luminance into two by the threshold value y1. (P2: shutter control parameter) The shutter control parameter is a function f relating to input luminance by a plurality of threshold values.
(y) is defined.

When the input luminance level is y2 or more, "→ T
1 "is set, and setting is made so that the shutter speed is fixed to a predetermined high-speed shutter speed T1.
Therefore, in this area, there is no need to calculate the shutter speed for the input luminance.

Here, as described above, T1 is set to a slightly higher shutter speed in order to cope with a small aperture. However, in many cases, a realistic value of T1 is 1/250 second to 1/250.
/ 1000 seconds will be selectable.

At this stage, the shutter speed is fixed to T1, and the reduction in brightness is compensated by opening the iris to the open value, but the iris is fully opened to the open at y1, so y
In the areas 1 to y2, the amount of light is becoming insufficient. However, in order to maintain the shutter speed as high as possible, the A / D ratio should be kept within the allowable range of the S / N degradation.
This is dealt with by increasing the GC gain.

Between the input luminance level gauges y2 and y3, “→
CAL ", indicating that it is necessary to set the control parameters in order to obtain the optimum shutter speed by calculation. The control variable width here is T
It is between 1 and T2.

As a guide for setting T2, a shutter speed at which a moving subject can be clearly imaged to some extent is set.

In the area between y3 and y4, an instruction is issued to fix the shutter speed to T2. This area requires no calculation. AGC here
The processing of the gain is the same as the above-mentioned y1 and y2 areas.

When the input luminance level is between y4 and y5,
This indicates that “→ CAL” is specified, and control is performed to calculate the optimum shutter speed in accordance with the input luminance and set the value of the control parameter in a range of T2 or less.

That is, since the luminance level has already been considerably reduced in this area, it is not preferable to further increase the AGC gain from the viewpoint of the S / N ratio of the image. This is because they have to shift to the side.

However, since one step of the shutter speed can be set finely in the area on this side, even if the shutter speed is continuously changed, the image does not feel strange.

When the input luminance level is equal to or less than y5, the control to set the shutter speed to the standard value of the television signal is designated by "→ standard value".

The standard value of the television signal here means 1/60 second in NTSC and 1/50 second in PAL.

In this state, since only the AGC gain remains as a controllable parameter, the gain is increased within an allowable range in terms of S / N deterioration, and exposure control is performed. (P3: AGC gain) Looking at the case where the AGC gain is used as a parameter to be processed, a function f (Y) of the input luminance is defined by a plurality of threshold values y, and when the input luminance level is higher than y1, "→ ± 0dB" is specified,
The AGC gain is fixed at ± 0 dB, and the gain is set so that the AGC circuit has no amplifying action. That is, if exposure control is possible with the iris and shutter, the AG
This is for preventing the deterioration of S / N by fixing the C gain, and in this case, the calculation is unnecessary.

When the input luminance level is between y1 and y2, the optimum AGC gain for the input luminance is calculated.
Set “→ C” so that the gain control parameter is set.
AL ”is specified.

When the input luminance level is between y2 and y3, it is specified that the AGC gain is fixed to the predetermined value G1, and no calculation is required.

When the input luminance level is between y3 and y4, the optimum AGC gain for the input luminance is calculated.
Set “→ C” so that the gain control parameter is set.
AL ”is specified.

When the input luminance level is between y4 and y5, it is specified that the AGC gain is fixed at a predetermined value G2 higher than G1, and no calculation is required.

When the input luminance is y5 or less, “→ CAL” is designated so that the optimum AGC gain for the input luminance is calculated and the gain control parameter is set.

In FIG. 19, the relationship between the above three parameters is shown with luminance as the horizontal axis.
Although the area is divided into six areas by five threshold values of 5, the control parameters to be calculated are distributed and distributed so as to be one in any area.
For this reason, the calculation is simplified, and even if the control parameters increase, the expansion of the calculation scale can be suppressed, and the calculation speed can be improved. The parameters to be calculated are I, G, S, G, and S in order from the high-luminance side, and the "G, S" portion is increased in the number of repetitions as necessary to make more precise settings. It is possible.

As described above, the overall operation is a sequence in which after performing the iris control on the high luminance side, the gain and the shutter are sequentially and alternately controlled in an area divided by an appropriate variable width. I have.

The following is a specific example of each parameter when the entire area is further divided into ten areas.

Area: Iris: Shutter: Gain (Maximum brightness: CLOSE: 1/1000: ± 0 dB) 1: CLOSE to OPEN: 1/1000: ± 0 dB No. 2: OPEN: 1/1000: ~ No. 3: OPEN: ~: + 3dB No. 4: OPEN: 1/500:-No. 5: OPEN: ~: + 6dB No. 6: OPEN: 1/250: ~ No. 7: OPEN: ~: + 9dB No. 8: OPEN: 1/125: ~ No. 9: OPEN:: +12 dB No10: OPEN: 1/60: 最低 (minimum illuminance: OPEN: 1/60: +15 dB) (P4: AE weighting parameter = weighting setting of photometry area) As shown in FIG. These are parameters for setting the photometric area distribution in the screen and their weighting. As is clear from FIG. 18, the parameters are stored in the MAP format and the attributes are fixed. That is, L according to the shooting mode
Although different for each UT, it is fixed in one shooting mode and does not change depending on the input luminance signal level.

In this embodiment, 24 operation coefficients are directly allocated to the 24 divided areas like a map.

In the “sport shooting mode”, 1.0 is set in the central 2 × 4 8 areas, and 0.5 is set in the 16 surrounding areas.
A lighter coefficient than that in the center is assigned, which is the setting of "center-weighted photometry" in FIG. (P5: AE reference value parameter) The parameter of the AE reference value indicates a luminance level that is a reference for exposure control, and is stored in a numerical definition. It is determined whether the exposure is excessive or insufficient based on the reference value. In this embodiment, the exposure is set to 50 IRE. The attribute of this parameter is also fixed, and is constant in the shooting mode regardless of the input luminance level. (P6: image quality adjustment parameter) A parameter for specifying image quality adjustment processing by aperture control or the like described above. The processing content is defined by a code, the attributes are fixed, and are set according to the shooting mode. It does not change depending on the luminance level.

In this landscape shooting mode, “NORMAL”
In this case, the basic image quality is set as a standard value, and no special image processing for changing the image quality using the above-described aperture control is performed. (P7: image effect processing parameter) As described with reference to FIG. 11, this is a parameter for designating image processing such as fade, and the processing content is defined by a code.

"NORMAL" is specified.
The basic image quality is set to a standard value, indicating that no special processing is performed.

The attributes of these parameters are fixed and set according to the photographing mode, and do not change depending on the input luminance level.

As described above, according to the "sports photographing mode", automatic exposure control can be realized with priority on the high-speed shutter, and clear and favorable photographing can be performed on a moving subject or a fast moving subject without blurring. be able to.

The data table LUT defining the control parameters for the sports shooting mode and the operating characteristics of the control parameters set thereby have been described above.

Next, the internal structure of the data table LUT in the “landscape photographing mode” and the control of the control parameters by its setting will be described.

In this landscape photographing mode, it is assumed that the subject is a landscape. Therefore, as described above, it is unlikely that a flicker, a fast-moving subject, or the like exists, but is described in FIG. As described above, there is often a high luminance portion such as the sky in the screen information, and as shown in the figure, the setting of the photometry area is changed to reduce the weighting coefficient at the top of the screen and increase the weighting coefficient at the bottom, It is necessary to set control parameters suitable for the subject.

The landscape photographing mode is set by the operation of the operation unit 20, and FIG. 20 shows the internal structure of a data table LUT storing definitions and characteristics of various control parameters required for the control.

A program showing transitions of various control parameters defined and set by the LUT with respect to the luminance level of input parameters is as shown in FIG. 22, and actual program diagrams are shown in FIGS. However, for the sake of simplicity, FIG. 22 shows the operating range in the order of iris, shutter speed, and gain from the top.

That is, in the figure, I indicates an iris control parameter (P1), S indicates a shutter speed control parameter (P2), and G indicates a gain control parameter (P3). As shown on the right side of FIG. The iris control parameter (P1) operates between CLOSE and OPEN, and S
Is the shutter speed control parameter (P2) is constant, G
Means that the gain control parameter (P3) changes from an amplification factor 1 of ± 0 dB (THROUGH because an input signal is output as it is) to a predetermined value G1. However, in the variable region, the value of each parameter changes in accordance with the luminance level as an input parameter, as in the program diagrams of FIGS.

In the landscape photographing mode, there are many cases where there is no flicker, fast-moving subject, or the like. Therefore, the shutter speed (P2) is fixed at 1/60 second of the standard, and the control is centered on the iris (P1). Is released, the gain (P3) is controlled.

That is, as shown in the figure, the control range of the parameter is divided into two areas at the boundary of the threshold value y in accordance with the subject luminance value of the input parameter. The shutter speed (P2) is fixed at 1/60 second regardless of the value of the subject brightness of the input parameter, the AGC gain (P3) is fixed at ± 0 dB until the brightness decreases to y, and the iris (P1) Only control is performed. After the brightness becomes y or less and the iris is opened, the AGC gain is changed to perform the optimal exposure control.

As described above, a plurality of program modes are prepared according to the shooting conditions, and by appropriately selecting the program modes by operating the keys of the operation unit 20, the optimum exposure mode can be obtained for any shooting conditions. Control can be performed.

When the photographing program mode is switched by the operation unit 20, the setting of the photometry area on the image pickup screen is simultaneously and simultaneously switched as described above.

The individual control parameters set in the data table for the landscape photographing mode will be described below in order. (P1: Iris control parameter) The iris control parameter changes according to the input parameter Y, that is, the luminance level, and a function f (y) is defined as an attribute thereof.

The input luminance level is the threshold value y shown in FIG.
If the value is higher than 1, the calculation (calcul) is displayed as "→ CAL", as is apparent from the data column on the right side of FIG.
ation) is required.

To secure S / N with high brightness, AGC
With the gain kept at ± 0 dB (THROUGH), the control range is from the minimum aperture of the iris to the open value.

When the input luminance level is equal to or less than y, the control for setting the iris to open is designated by “→ OPEN”.

In this state, it can be considered that the illuminance is fairly low. If priority is given to continuing photographing even if the S / N of the image is degraded, the area is increased by increasing the AGC gain.

As described above, the control characteristic of the iris is defined by dividing the entire area from high luminance to low luminance into two parts by the threshold value y1. Thus, the control characteristics of the iris are defined. (P2: Shutter control parameter) The shutter control parameter has a fixed attribute and a low input brightness level because it is unlikely that a flicker or a fast-moving subject is present, and it is not necessary to reduce the degree of advance of the field. It is shown that the value is always fixed to a constant value regardless of the content, and the content is set to “→ standard value” so as to be set to the standard value of the television standard, and no calculation is required.

The standard value of the television signal here means 1/60 second in NTSC and 1/50 second in PAL. (P3: AGC gain) When looking at the case where the AGC gain is a parameter to be processed, a function f (Y) of the input luminance is defined by the threshold value y, and the input luminance level is y1.
If higher, “→ ± 0 dB” is specified and AGC
The gain is fixed at ± 0 dB so that the AGC circuit does not have an amplifying function. That is, when the exposure control can be performed by the iris and the shutter, the AGC gain is fixed to prevent the S / N from deteriorating. In this case, the calculation is unnecessary.

Also, since this section is set so as to occupy most of the range of the illuminance of the subject, S / S
N good imaging is possible.

When the input luminance level is equal to or less than y1, "→ CAL" is designated so that the optimum AGC gain is calculated and the gain control parameter is set.

In this state, the illuminance is extremely low, and the S
This is an area corresponding to increasing the AGC gain when photographing is desired to be continued even if / N is deteriorated.

Since the other parameters have already been set to the maximum for the low illuminance measure, the only controllable parameter left in this state is the AGC gain, and consideration is given to the balance with S / N deterioration. Meanwhile, the exposure control is executed by setting the gain up within an allowable range.

The relationship between the area divided into two by the threshold value y1 and the three control parameters is clear from FIG. 22, and here, the parameters to be calculated are always one in each of the two areas. The operation is simplified and the operation is simplified, and the arrangement is I, G from the area on the high luminance side. (P4: AE weighting parameter = photometric area weight setting) As shown in FIG. 5 and FIG. 6, this is a parameter for setting the photometric area distribution in the imaging screen and their weighting. It is stored in MAP format, and the attributes are fixed.

That is, although it differs for each LUT according to the shooting mode, it is fixed in one shooting mode and does not change according to the luminance signal level.

In this embodiment, 24 operation coefficients are directly allocated to the 24 divided areas like a map.
In this “landscape shooting mode”, the 1 × 6 6
A coefficient of 0.0 is assigned to the area, a coefficient of 0.5 is assigned to the next 1 × 6 area, and a coefficient of 1.0 is assigned to the lower half of the 2 × 6 area. As shown, the photometry area is designated as "lower partial weighted photometry".

As a result, it is possible to prevent the subject from being blackened by the influence of high luminance such as the sky.

The photometric area distribution is not limited to the pattern shown in FIG. 6; 1
-No. 12, the weighting coefficients of the upper two stages are 0.0,
13-No. 24, the photometric distribution with the weighting coefficient of the lower two stages being 1.0, 1 to No. 6, the weighting coefficient of the first row is 0.0, 7-No. 18, the weighting coefficient of the middle two stages is 0.5, 19-No. No. 24, the photometry distribution in which the lower one-stage weighting coefficient is set to 1.0; 1 to
No. 12, the weighting coefficients of the upper two stages are 0.0, 1
4-No. The weighting coefficient at the lower center of 17 is 1.0,
No. on the side and below. 13, No. 18, No. 1
9-No. A photometric distribution in which 24 is set to 0.5 is also conceivable. In particular, the last photometric distribution is effective when a high-luminance subject exists also on the near side of the screen. If these are stored in the data table and are appropriately selected, the range of photographing can be expanded. (P5: AE reference value parameter) The parameter of the AE reference value indicates a luminance level that is a reference for exposure control, and is stored in a numerical definition. It is determined whether the exposure is excessive or insufficient based on the reference value. In this embodiment, the exposure is set to 50 IRE. The attribute of this parameter is also fixed, and is constant in the shooting mode regardless of the input luminance level. (P6: image quality adjustment parameter) A parameter for specifying image quality adjustment processing by aperture control or the like described above. The processing content is defined by a code, the attributes are fixed, and are set according to the shooting mode. It does not change depending on the luminance level.

[0247] In this landscape photography mode, "NORMAL"
In this case, the basic image quality is set as a standard value, and no special image processing for changing the image quality using the above-described aperture control is performed. (P7: image effect processing parameter) As described with reference to FIG. 11, this is a parameter for designating image processing such as fade, and the processing content is defined by a code.

"NORMAL" is specified, and
The basic image quality is set to a standard value, indicating that no special processing is performed.

The attributes of these parameters are fixed and set according to the photographing mode, and do not change depending on the input luminance level.

As described above, the data table LUT according to the present invention stores the definitions and characteristics of various parameters required for control. A plurality of such LUTs are provided according to the photographing mode, and the designated photographing is performed. Because it can be selected according to the mode, for every shooting situation and shooting environment,
Optimal control can always be performed.

The data table LUT in which the control parameters are defined and the operation characteristics of the control parameters set thereby have been described above using the landscape shooting mode as an example.

Next, a description will be given of a “spot light shooting mode” which is still another program shooting mode of the present invention. The setting and control of various shooting modes and the data table LUT will be described by taking the “spot light shooting mode” as an example. The control of the control parameters by the internal structure and its setting will be described in detail.

The spotlight photographing mode assumes a photographing situation in which a high-luminance subject usually exists at one point in a dark background in a spot.
This shooting mode is suitable for shooting a subject such as a spotlight hitting a spot in a dark room by a party or the like, and can be selected by operating the operation unit 20.

In general, when photographing an object in which a spotlight hits a part of the dark background,
As in the past, when the entire image was taken, the low-brightness portion occupied the majority of the screen when the average photometry was performed.Therefore, the low-brightness portion led to the overexposure and overexposure occurred in the main subject portion where the spotlight was hit. I will.

Even if the center-weighted photometry is used, the spot portion is not always located at the center, and even if the weight of the central portion is large, if the area of the high-luminance portion is small, Similarly, accurate exposure control cannot be performed.

The "spot light photographing mode" of the present invention is a program photographing mode in which good exposure control can be performed even in such a photographing situation, and will be described in detail below.

FIG. 21 shows the internal structure of a data table, that is, an LUT storing definitions and characteristics of various control parameters required for control corresponding to the spotlight photographing mode. The LUT is defined and set by this LUT. The program diagram showing the transition of the input parameters of the various control parameters to the brightness level is the same as the “landscape shooting mode” shown in FIG. Therefore, the control parameters will be described below with reference to FIG.
The values of 1, y2 are different in each mode.

That is, in FIG. 22, a threshold value y1 'is provided for the subject illuminance on the horizontal axis, which is an input parameter, the whole area is divided into two areas, and exposure control is performed by iris and gain. , Shutter speed is fixed.

The individual control parameters set in the data table LUT for the spotlight photographing mode will be described below in order. (P1: Iris control parameter) The iris control parameter changes according to the input parameter Y, that is, the luminance level, and a function f (y) of the input luminance is defined as an attribute thereof.

The input luminance level is the threshold value y shown in FIG.
If the value is higher than 1 ', as is apparent from the data column on the right side of FIG.
) is required.

Since it is desired to secure S / N with high brightness, AGC
With the gain kept at ± 0 dB (THROUGH), the control range is from the minimum aperture of the iris to the open value.

When the input luminance level is equal to or less than y1 ', the control for setting the iris to open is designated by "→ OPEN".

In this state, it can be considered that the illuminance is fairly low. If priority is given to continuation of photographing even if the S / N ratio of the image is deteriorated, this area is raised by increasing the AGC gain.

As described above, the control characteristic of the iris is defined by dividing the entire region from high luminance to low luminance into two by the threshold value y1 '. Thus, the control characteristics of the iris are defined. (P2: Shutter control parameter) It is shown that the shutter control parameter has a fixed attribute and is always fixed to a constant value regardless of the input luminance level, and the content is set to the standard value of the television standard. “→ Standard value” is set, and no calculation is required.

The standard value of the television signal here means 1/60 second in NTSC and 1/50 second in PAL. (P3: AGC gain) When looking at the case where the AGC gain is a parameter to be processed, a function f (Y) of the input luminance is defined by the threshold value y, and the input luminance level is y.
If it is higher than 1 ', “→ ± 0 dB” is specified and A
The gain is fixed such that the GC gain is fixed to ± 0 dB and the AGC circuit does not have an amplifying function. That is, when the exposure control can be performed by the iris, the AGC gain is fixed to prevent the deterioration of the S / N. In this case, the calculation is unnecessary.

Since this section is set so as to occupy most of the range of the subject illuminance, S / S is applied over the entire area.
N good imaging is possible.

When the input luminance level is equal to or less than y1 ', "→ CAL" is designated so that the optimum AGC gain is calculated and the gain control parameter is set.

In this state, the illuminance is extremely low, and the S
This is an area corresponding to increasing the AGC gain when photographing is desired to be continued even if / N is deteriorated.

Since the other parameters have already been set to the maximum for the low illuminance measure, the only controllable parameter left in this state is the AGC gain, so that consideration is given to the balance with S / N deterioration. Meanwhile, the exposure control is executed by setting the gain up within an allowable range.

The relationship between the area divided into two by the threshold value y1 and the three control parameters is clear from FIG. 22, and the parameter to be calculated is always one in each of the two areas. The operation is simplified and the operation is simplified, and the arrangement is I, G from the area on the high luminance side. (P4: AE weighting parameter = weighting setting of photometry area) This is a parameter for setting the photometry area distribution in the imaging screen and their weighting. As is clear from FIG. 21, the attribute is f (Y) and the input luminance is It is shown to be a function. Specifically, it is defined by a histogram created according to the input luminance signal,
An input luminance signal level in each of the four divided areas is detected, and a histogram of the luminance level is created. Thereby, a portion of the imaging screen where a high-intensity spotlight is hit is accurately detected, and that area is detected. Control such as weighted metering is performed.

In this embodiment, the luminance levels are detected for the 24 divided areas, and the upper N (= 2) areas are extracted from the luminance histogram created from them, and the AE control is performed using only these N areas. Is executed.

Therefore, even in the case of illumination such as a spotlight which is biased to a part of the imaging screen, an appropriate exposure value can be determined without being affected by a dark portion having no main subject.

FIG. 23 shows such a histogram. The upper part of the figure shows the luminance histogram, the horizontal axis indicates the level of the IRE, the level increases from left to right, and 0 to 6 on the vertical axis indicate the number of areas corresponding to each IRE level.

The lower part is a cumulative histogram of the upper part of the luminance histogram. The vertical axis represents the number of regions divided into 24.

[0275] In the figure, the upper two areas (,) are extracted from the 24 areas of the cumulative histogram.

In this manner, a high-luminance portion in the imaging screen can be detected, AE photometric characteristics can be set with emphasis on that portion, and AE control excluding the effect of a portion where a main subject does not exist can be realized. . Valid when present. If these are stored in the data table and are appropriately selected, the range of photographing can be expanded. (P5: AE reference value parameter) The parameter of the AE reference value indicates a luminance level that is a reference for exposure control, and is stored in a numerical definition. It is determined whether the exposure is excessive or insufficient based on the reference value. In this embodiment, the exposure is set to 50 IRE. The attribute of this parameter is also fixed, and is constant in the shooting mode regardless of the input luminance level. (P6: image quality adjustment parameter) A parameter for specifying image quality adjustment processing by aperture control or the like described above. The processing content is defined by a code, the attributes are fixed, and are set according to the shooting mode. It does not change depending on the luminance level.

In this landscape shooting mode, “NORMAL”
In this case, the basic image quality is set as a standard value, and no special image processing for changing the image quality using the above-described aperture control is performed. (P7: image effect processing parameter) As described with reference to FIG. 11, this is a parameter for designating image processing such as fade, and the processing content is defined by a code.

"NORMAL" is specified.
The basic image quality is set to a standard value, indicating that no special processing is performed.

The attribute of this parameter is also fixed and set according to the photographing mode, and does not change depending on the input luminance level.

As described above, the data table LUT according to the present invention stores the definitions and characteristics of various parameters necessary for control. A plurality of such LUTs are provided according to the photographing mode, and the designated photographing is performed. Because it can be selected according to the mode, for every shooting situation and shooting environment,
Optimal control can always be performed.

The spotlight photographing mode is taken as an example, and the data table LU defining the control parameters is described.
The operating characteristics of T and the control parameters set thereby have been described.

Next, the setting and control operation of each control parameter in the “surf & snow shooting mode” will be described in detail.

The "surf & snow shooting mode" is set by operating the operation unit 20, is referred to when this mode is selected, and stores a definition and characteristics of various control parameters necessary for the control and a data table. FIG. 24 shows the internal structure of the LUT.

A program diagram showing the operation of various control parameters defined and set by the LUT, that is, the transition of each control parameter with respect to the input luminance level, is shown in FIG. Is the same as Therefore, in the present application, setting of control parameters in the surf & snow photographing mode is performed using FIG.

However, the two threshold values, shutter speed and gain control value are set separately between these photographing modes only with the same design.
To distinguish them, the two thresholds are each set to y
1 ', y2', the high-speed shutter speed is T1 ', and the gain control value is G1'.

The individual parameters in each figure will be described below in order. (P1: Iris control parameter) The iris control parameter changes according to the input parameter Y, that is, the luminance level, and a function f (y) is defined as an attribute thereof.

The input luminance level is the threshold value y shown in FIG.
If the value is higher than 1 ', as is clear from the data column on the right side of FIG.
) is required.

To secure S / N with high luminance, AGC
With the gain kept at ± 0 dB (THRUGH), control is performed so that the iris can be first opened to the open value in consideration of a small aperture countermeasure such as a reduction in resolution caused by a light diffraction phenomenon caused by a small aperture of the iris.

When the input luminance level is equal to or lower than y1 ', control for setting the iris to open is indicated by "→ OPEN".

As described above, the control characteristic of the iris is defined by dividing the entire region from high luminance to low luminance into two by one threshold value y1. (P2: shutter control parameter) As the shutter control parameter, a function f (Y) of the luminance of the input parameter is defined by threshold values y1 'and y2'.

If the input luminance level is higher than y1 ', "→ T1'" is designated, and the shutter speed is set to a high speed T1. In this case, no operation is required.

Here, as described above, the shutter speed is set to a somewhat higher shutter speed in order to cope with a small aperture.

Actually, the selection is made within a range of about 1/125 to 1/500 second.

At this stage, to gain S / N,
Even when the brightness becomes low, the control is performed without increasing the AGC gain as much as possible.

[0295] Between the input luminance levels y1 'and y2', "→ CAL" is set. The optimum shutter speed according to the input luminance level is obtained by calculation, and the control parameter value is set. This indicates that the control is performed.

The variable control width here is between T1 'and the standard screen frequency (standard value) of the television.

When the input luminance level is y2 'or less, "→ standard value" indicates that the shutter speed should be set to the standard value of the television signal.

The standard value of the television signal here means 1/60 second in NTSC and 1/50 second in PAL.

In this state, since only the AGC gain remains as a controllable parameter, the gain is increased within an allowable range in terms of S / N deterioration, and the exposure is controlled to be controlled. (P3: AGC gain) Even when the AGC gain is used as a parameter to be processed, a function f (Y) of the input luminance is defined by a plurality of thresholds, and when the input luminance level is higher than y2 ′, "→ ± 0dB" is specified,
The AGC gain is fixed at ± 0 dB, and the gain is set so as not to have an amplification effect. That is, when the exposure control can be performed by the iris and the shutter, the AGC gain is fixed to prevent the S / N from deteriorating. In this case, the calculation is unnecessary.

Since this section is set so as to occupy most of the range of the illuminance of the subject, S / S is applied over the entire area.
N good imaging is possible.

When the input luminance level is equal to or less than y2 ', "→ CAL" is designated so that the optimum AGC gain is calculated and the gain control parameter is set.

The other parameters have already reached their limits, and the remaining controllable parameters in this state are A
Since only the GC gain is used, the exposure control is executed by taking the gain up within an allowable range while considering the balance with the S / N deterioration.

The relationship between the area divided into three by these threshold values y1 'and y2' and the three control parameters is clear from FIG. 17, and the parameters to be calculated here are also three areas. Each of them is arranged in a dispersed manner so as to always be one, and the calculation is simplified, and the arrangement is I, S, G from the area on the high luminance side. (P4: AE weighting parameter = photometric area weight setting) This is a parameter for setting the photometric area distribution in the imaging screen and their weighting. As is clear from FIG. 24, the attribute is f (Y) and the input luminance is It is shown to be a function.

[0304] More specifically, it is defined by a histogram created in accordance with the input luminance signal.
An input luminance signal level in each of the divided areas is detected, and a luminance level histogram is created, thereby accurately detecting a distribution state of a high luminance part and a low luminance part on an imaging screen, and determining a weighted photometry area. decide.

In this embodiment, the luminance levels are detected for each of the 24 divided areas, and the upper 50% (that is, 24 ^ 2 = 12) areas are extracted from the luminance histogram created from these luminance areas. Exposure control is performed using only luminance information.

When expressed in terms of coefficients, each of the extraction regions has 1.
The AE control calculation is performed by assigning 0 to 0.0 and 0.0 to each of the non-extraction areas.

FIG. 25 shows such a histogram. The upper part of the figure shows the luminance histogram, the horizontal axis indicates the level of the IRE, the level increases from left to right, and 0 to 6 on the vertical axis indicate the number of areas corresponding to each IRE level.

The lower part is a cumulative histogram of the upper part of the luminance histogram. The vertical axis represents the number of regions divided into 24.

[0309] In the same figure, the top 12 areas (1 to 12) corresponding to 50% of the 24 areas of the cumulative histogram are shown.
Is extracted.

[0310] In this manner, the AE photometric characteristic can be set by selecting half of the twelve of the higher luminances in the imaging screen and emphasizing the selected parts. Therefore, even in shooting situations where there are many high-brightness areas, such as snow scenes and sandy beaches, the result of performing exposure compensation to prevent blackening of the main subject and blackening of a part of the screen is reduced. It is possible to prevent poor-quality shooting in which an image in a high-brightness portion becomes overnatural due to overexposure and obtain a natural shot image over the entire screen. (P5: AE reference value parameter) The parameter of the AE reference value indicates a luminance level that is a reference for exposure control, and is stored in a numerical definition. It is determined whether the exposure is excessive or deficient based on the reference value. In the present embodiment, it is assumed that a high-luminance portion occupies a large proportion in the imaging screen, such as a snow scene or a sandy beach. Since the photographing mode is set, the AE reference value is set to 80 IRE, which is slightly higher than a general 50 IRE, so as to suppress the occurrence of overexposure so that a high-luminance subject portion can be clearly captured as a whole. This parameter is also independent of the input brightness level,
It is constant in the shooting mode. (P6: image quality adjustment parameter) A parameter for specifying image quality adjustment processing by aperture control or the like described above. The processing content is defined by a code, the attributes are fixed, and are set according to the shooting mode. It does not change depending on the luminance level.

In this photographing mode, "NORMAL" is set, and the basic image quality is set to a standard value. (P7: image effect processing parameter) As described with reference to FIG. 11, this is a parameter for designating image processing such as fade, and the processing content is defined by a code.

[0312] "NORMAL" is specified.
The special effect of the image is set not to be performed.

As described above, in the "surf & snow photographing mode", a reference setting higher than a normal AE reference value is performed, and a photometric area of a high luminance portion (upper 50%) is set by a luminance histogram. As a result, it is possible to suppress the occurrence of overexposure, and to capture images with whiter whites and reduced black spots on people, etc., even on high-brightness screens over a wide area, such as in snow scenes at ski resorts. It is possible.

Next, the internal structure of the data table LUT in the “manual photographing mode” and the setting of control parameters based on the data will be described in detail.

The manual shooting mode is set by the operation of the operation unit 20, and is basically a center-weighted metering mode in which a photometric area is weighted as shown in FIG. FIG. 26 shows the internal structure of a data table LUT which is referred to when this mode is selected and stores the definitions and characteristics of various control parameters necessary for the control.

FIG. 27 shows a program showing transition of various control parameters defined and set by the LUT with respect to a luminance level as an input parameter.

That is, in FIG. 27, a threshold value y1 is provided for the subject illuminance on the horizontal axis, which is an input parameter, and the entire area is divided into two areas.

The manual photographing mode is based on the AE control of the shutter priority mode. When the shutter speed is manually specified, the iris control value or the AGC gain is optimized accordingly. It is an automatic mode with.

[0319] Therefore, A
The feature is that the variable range of the GC gain is set wide. This is because, in the normal automatic shooting mode, the intention of the operator is not reflected as it is, so that the S / N is deteriorated.
Although the increase in the GC gain can be suppressed as much as possible, in the manual shooting mode, the operator constantly monitors the shooting state, so that the variable range of the AGC gain is made wider than in the automatic shooting mode, so that the shootingable range is increased. It is set to enlarge.

The individual control parameters set in the data table LUT for the manual shooting mode will be described below in order. (P1: Iris control parameter) The iris control parameter changes according to the input parameter Y, that is, the luminance level, and a function f (y) is defined as an attribute thereof.

When the input luminance level is equal to the threshold value y shown in FIG.
If it is higher than 1, the calculation (calcul) is displayed with "→ CAL" as is apparent from the data column on the right side of FIG.
ation) is required.

Since it is desired to secure S / N with high luminance, AGC
With the gain kept at ± 0 dB (THROUGH), the control range is from the minimum aperture of the iris to the open value. This area covers almost the entire area of the subject illuminance.

When the input luminance level is equal to or lower than y1, the control for setting the iris to open is designated by "→ OPEN".

In this state, it can be considered that the illuminance is fairly low. If priority is given to continuing photographing even if the S / N ratio of the image is degraded, the AGC gain is increased and this area is used.

As described above, the control characteristic of the iris is defined by dividing the entire region from high luminance to low luminance into two by the threshold value y1. (P2: Shutter control parameter) The shutter speed control parameter is a manually set parameter, and the attribute is manually set without being changed depending on the input luminance level, but set manually.

The high-speed side is from 1/10000 to the low-speed side according to the standard television standard rate (1/60 second in NTSC,
The variable range is up to 1/50 second in PAL), and can be manually changed within this variable range. (P3: AGC gain) When looking at the case where the AGC gain is a parameter to be processed, a function f (Y) of the input luminance is defined by the threshold value y1, and the input luminance level is y.
If it is higher than 1, “→ ± 0 dB” is specified and AG
The C gain is fixed at ± 0 dB, and the gain is set so that the AGC circuit does not have an amplifying function. That is, when the exposure control can be performed by the iris and the shutter, the AGC gain is fixed to prevent the S / N from deteriorating. In this case, the calculation is unnecessary.

Also, since this section is set so as to occupy most of the range of the illuminance of the subject, S / S
N good imaging is possible.

When the input luminance level is equal to or lower than y1, "→ CAL" is designated so that the optimum AGC gain is calculated and the gain control parameter is set.

In this state, the illuminance is extremely low, and the S
This is an area corresponding to increasing the AGC gain when photographing is desired to be continued even if / N is deteriorated.

Since the other parameters have already been set to the maximum for low illuminance measures, the only controllable parameter left in this state is the AGC gain, so that consideration is given to the balance with S / N deterioration. Meanwhile, the exposure control is executed by setting the gain up within an allowable range.

Under these conditions, this mode sets a wider variable range as compared with the other automatic photographing modes.

The relationship between the area divided into two by these threshold values y1 and the three control parameters is shown in FIG.
It is clearer, again that the parameters to be calculated are
The two areas are distributed so as to be always one, and the calculation is simplified, and the arrangement is I and G from the area on the high luminance side.

A feature of the manual shooting mode is that the variable range of the AGC is set wider than the other shooting modes, and as shown in FIG. 27, other shooting modes (for example, as shown in FIG. 17). In the portrait shooting mode), the upper limit of the AGC gain up is G1, whereas in the manual mode, it can be set up to G2. The difference ΔG between G1 and G2 = G2−G1
Since the noise characteristics of an image pickup device such as a CCD have been improved at present, it is possible to set +3 dB to 6 dB. The control of the expansion of the variable range may be performed automatically, or a gain-up switch may be provided and turned on to be operated consciously. (P4: AE weighting parameter = photometric area weight setting) As shown in FIG. 5 and FIG. 6, this is a parameter for setting the photometric area distribution in the image pickup screen and their weighting. It is stored in MAP format, and the attributes are fixed.

That is, although it differs for each LUT according to the shooting mode, it is fixed in one shooting mode and does not change according to the luminance signal level.

In this embodiment, 24 operation coefficients are directly allocated to the 24 divided areas like a map.
In the “manual shooting mode”, as shown in FIG. 5, a calculation coefficient of 1.0 is assigned to the central 2 × 4 area, and a lighter operation coefficient of 0.5 is assigned to the surrounding 16 areas, which is 0.5. In this case, the photometry area is designated in the so-called "center-weighted photometry", which emphasizes the center of the imaging screen. (P5: AE reference value parameter) The parameter of the AE reference value indicates a luminance level that is a reference for exposure control, and is stored in a numerical definition. It is determined whether the exposure is excessive or insufficient based on the reference value. In this embodiment, the exposure is set to 50 IRE. The attribute of this parameter is also fixed, and is constant in the shooting mode regardless of the input luminance level. (P6: image quality adjustment parameter) A parameter for specifying image quality adjustment processing by aperture control or the like described above. The processing content is defined by a code, the attributes are fixed, and are set according to the shooting mode. It does not change depending on the luminance level.

In this landscape photography mode, “NORMAL”
In this case, the basic image quality is set as a standard value, and no special image processing for changing the image quality using the above-described aperture control is performed. (P7: image effect processing parameter) As described with reference to FIG. 11, this is a parameter for designating image processing such as fade, and the processing content is defined by a code.

[0337] "NORMAL" is specified.
The basic image quality is set to a standard value, indicating that no special processing is performed.

The attribute of this parameter is also fixed and set according to the photographing mode, and does not change depending on the input luminance level.

The data table LUT defining the control parameters in the "manual photographing mode" and the operation characteristics of the control parameters set thereby have been described. According to the manual photographing mode, the degree of freedom in photographing is greatly increased by manual operation such as arbitrary setting of shutter speed and positive / negative exposure correction. In particular, since the variable range of the control parameters is expanded from that in the automatic shooting mode, shooting in a darker situation is also possible.

As described above, the data table LUT according to the present invention stores the definitions and characteristics of various parameters required for control, and a plurality of such LUTs are provided according to the shooting mode. Because it can be selected according to the mode, for every shooting situation and shooting environment,
Optimal control can always be performed.

Here, L corresponding to each shooting mode described above
The operation of reading data from the UT to the system control circuit, calculating control parameters, and setting control parameters will be described in detail with reference to the flowchart of FIG.

These processing operations are basically from the confirmation processing of the program photographing mode in S2 in the flowchart of FIG. 9 to the output of iris, shutter and gain control data based on each control parameter in S24. It takes place inside.

FIG. 28 is an operation flowchart showing a data set procedure for setting control characteristics according to the photographing program mode.
This routine is executed in parallel in the processing of steps S24 to S24. After this routine is completed, the process returns to step S25 in FIG.

When the control is started, the photographing mode is selected by the operation unit 20 in FIG. 1 in S101, and the result of the selection is taken into the system control circuit 25. In S102, the photographing mode is selected according to the selected photographing mode. The LUT is selected from the LUTs 19a to 19b.

In S103, a parameter counter n for designating a parameter is initialized to n = 01, and
In S104, the data of the parameter Pn specified in S103 is read.

The parameter specification will be described.
From each data table LUT, when n = 01, data relating to iris, when n = 02, data relating to shutter speed, when n = 03, data relating to AGC gain, and when n = 04, AE weighting (photometry) Data relating to the area weighting coefficient), n = 05 for data relating to the AE evaluation reference value, that is, a level serving as a reference for keeping the brightness level constant, n = 06 for image quality adjustment, n = 7 for special effects Data relating to typical image processing and the like are read into the system control circuit 25, respectively.

In step S105, the attribute of the read parameter is confirmed, and it is determined whether the data depends on the input parameter (f (Y)) or is fixed data corresponding to the mode without depending on the input parameter. Done.

That is, as shown in the data table LUT, the attribute means whether it changes according to a predetermined function f (Y) with respect to the input parameter, that is, the illuminance of the subject in this embodiment, or whether the attribute changes. Indicates that the attribute of the parameter is f (Y) in step S105 and depends on the input parameter, the flow proceeds to step S1.
The process proceeds to step S07, and if it is fixed, the process proceeds to step S106, and the value of the parameter is set assuming that the attribute of the data is fixed regardless of the luminance level.

At S107, 1 is set to the parameter counter n.
Is added to obtain n + 1. In S108, it is checked whether or not n has become larger than the maximum value in the LUT. Until n reaches the maximum value, the operations in S104 to S107 described above are repeated to read parameters. Are repeated, and if n exceeds the maximum value, the flow shifts to the data output processing of S109 and thereafter.

[0350] After S109, the LU is executed in S101 to S108.
This processing indicates output processing of control data based on parameters read from T. In S109, the parameter counter is reset to n = 01.

In S110, the attribute of the parameter is confirmed, and it is determined whether the parameter is dependent on the input parameter (f (Y)) or is a fixed one corresponding to the mode without depending on the input parameter. S11 if f (Y)
1 if fixed, skip S111 and S112 and skip to S113
Proceed to.

At S111, the output of the integrator 10 is sampled by the A / D converter 11 every unit processing time (for example, one field period), and the luminance signal level as an input parameter is taken into the system control circuit 25. In accordance with the value of this input signal, the data definition of the LUT is referred to, and it is determined whether data operation is necessary or not. If the calculation conditions are satisfied, the process proceeds to S112, in which only the parameter specified in the current state is changed, the AE is controlled, and the optimum value of the parameter for adjusting to the proper exposure is calculated.

If it is determined in S111 that the calculation is unnecessary, the process of calculating the control output in S112 is skipped, and the process proceeds to S113.

In S113, 1 is added to the parameter counter n, and the process proceeds to S114 as n + 1, and returns to step S110 until the parameter counter n exceeds the maximum value of the parameter number of the LUT. Is repeated, and when the parameter counter n exceeds the maximum value of the parameter number of the LUT, the process proceeds to the next S115, and returns to the process of S25 in the flowchart of FIG.

The above is the processing procedure from the reading of the characteristics of each parameter from the data reference table LUT to the calculation of the AE control data. In this way, the LUT corresponding to the set photographing mode changes the photographing situation. By reading out suitable control data and performing control, it is possible to execute optimal photographing.

Next, various displays in the EVF for allowing the operator to recognize various program shooting modes in the present invention will be described.

According to the present invention, various photographing modes and the like are displayed on a screen in an electronic view finder (EVF).

FIG. 29 shows an example of a display area distribution in a mode other than the manual shooting mode, and FIG. 30 shows an example of a display area distribution in a manual shooting mode.

Each of these shows an example of the display screen in the EVF 26, and an area d indicated by a double line at the upper left is an area for displaying various shooting mode names and manual parameter setting values. In an automatic shooting mode other than the manual shooting mode, the shooting mode name is displayed, and in the manual shooting mode, the setting parameter value in the manual shooting mode is displayed at the same place.

Other solid lines in the EVF indicate menu screens such as image processing contents and self-timer settings, various warnings such as running out of battery, and various video recorders (VTRs) such as recording and pause. It is a display area of superimposition information such as display of an operation state and insertion recording information to be printed together when recording a VTR. This part is automatic /
Manually common.

In the automatic mode, two shooting modes such as "sports mode" and "portrait mode" are displayed.

In the manual shooting mode, "S: 1
/ 1000 ”and“ +3 dB ”are also displayed over two lines.

As described above, in shooting modes other than the manual shooting mode, for example, iris, shutter, A
Although the GC gain cannot be manually operated, the shutter can be manually operated only in the manual mode.

The program shooting modes have been described above. Next, a description will be given of mode transition control when switching between the plurality of shooting modes by operating the keys of the operation unit 20.

As described above, according to the apparatus of the present invention, a plurality of photographing modes are provided according to the photographing conditions, and by switching these with the operation unit 20, optimal photographing is always possible. However, when the photographing conditions change during the actual photographing and it is necessary to switch the photographing mode, the setting condition of each control parameter greatly differs depending on the mode before and after the switching, so that the image is conspicuous. There is a risk that changes will occur and the image quality will be degraded.

Therefore, according to the present invention, as described below, a neutral mode is provided for each photographing mode, and when the photographing mode is switched, the designated neutral mode is temporarily passed through the neutral mode. It is configured to shift to a shooting mode.

FIG. 31 is a diagram for explaining the concept of the neutral mode. FIG. 31A shows a mode transition without the neutral mode. Here, the total number of combinations of the mode transitions is (number of modes -1) x number of modes ÷ 2, and the mode transition mode that minimizes the shock at the time of the mode transition is similarly expressed by the above equation. In this case, the number of modes is tentatively set to 5 in the case of FIG.

[0368] On the other hand, Fig. 47B shows a mode transition via the neutral mode. In this case, the mode of transition is the same as the number of modes, and there are five modes in the figure, which is about half that in the case of FIG.

By selecting a setting state having characteristics close to each of the above modes as the neutral mode, abrupt and large fluctuations of each control parameter at the time of mode transition are prevented, and unnatural fluctuations on the screen are prevented. A smooth mode transition that does not cause a problem can be realized.

FIG. 32 shows an example of a data table LUT storing various control data in the neutral mode. In the example shown in FIG. 32, it is similar to the "spot light mode" shown in FIG. The setting of the AE weighting in (P4) is different, the attribute is fixed, and is defined in the MAP format based on the luminance signal.

In the example shown in the figure, 24 operation coefficients are directly assigned in a map shape to the 24 divided areas, and 1.0 is assigned to the central 2 × 4 area and 16 to the surrounding area.
The area is assigned a lighter coefficient of 0.5 than the center. In this mode, the AE photometric characteristic emphasizing the central portion can be set, and is constant in this mode regardless of the input luminance signal.

FIG. 33 shows the iris shown in the LUT of FIG.
FIG. 9 is a diagram illustrating parameter transitions in which the relationship and setting of three parameters of a shutter and an AGC gain are shown with an input luminance level as a horizontal axis.

The area is divided into two areas by one threshold value y1, and is distributed and distributed so that one parameter is calculated for each area to be calculated. The parameters to be calculated are I and G in order from the high luminance side.

Next, an algorithm for shifting between a plurality of photographing modes by a key operation of the operation unit 20 will be described with reference to a flowchart of FIG.

The processing in this flowchart is the details of the mode selection and confirmation processing shown in S2 in the flowchart of FIG. 9 described above.

In the figure, when the processing is started, S
In 201, a signal selected and input by a key operation of the operation unit 20 is used for a currently selected shooting mode (first shooting mode).
Is determined, the process proceeds to S202 if they are not the same, and proceeds to S208 if they are the same.

In S202, since an instruction to change the current shooting mode has been issued, a mode transition flag indicating a mode change instruction is set, and the flow advances to the next step S203. In step S202, the reference for comparing whether or not the mode has changed in step S201 in the next execution is set to the changed shooting mode (second mode).

At S203, it is determined whether or not the transition from the first mode before the change to the neutral mode has been completed.
If not completed, the process proceeds to S204 to shift to the neutral mode, and then exits the mode determination routine. If completed, the process advances to step S205 to determine whether the transition from the neutral mode to the second mode has been completed.

If the transition to the second mode has not been completed in S205, the transition from the neutral mode to the second mode is performed, and the process exits the mode discriminating routine.
If the transition to the second mode has been completed at 05,
Proceeding to S207, the mode transition flag is cleared, and the process exits the mode determination routine.

In S208, when the mode change instruction has not been issued in S201, it is determined whether or not the mode shift flag has been set. If the mode shift flag has been set, it means that the mode switching operation has not been completed. Therefore, the process proceeds to S203, and if not set, it means that the mode switching operation has been completed, and the process exits the mode selection routine.

After exiting the mode selection routine, the flow returns to S3 of the flowchart in FIG.

Next, as a simple example, the “spotlight shooting mode” is set as the first mode currently set.
Next, a case will be described in which “landscape shooting mode” is selected as the second mode to be set, and the mode switching operation is actually performed via the neutral mode.

As is clear from FIGS. 21 and 22, FIG. 32 and FIG. 33, the difference between the “spotlight shooting mode” and the “neutral mode” is that 20 and 22 and 32,
As is clear from FIG. 33, the only difference between the “landscape shooting mode” and the “neutral mode” is AE weighting.

In this case, by operating the operation unit 20 to instruct the mode transition, the process of the flowchart in FIG. 32 is executed and the mode switching operation is performed. It is necessary to repeatedly execute S1 to S26 of the flowchart in FIG. 9 three times. This will be described with reference to the flowchart of FIG. (First round) If it is determined in S201 that a request to switch the shooting mode from the "spotlight shooting mode" to the "scenery shooting mode" has been issued, the process proceeds to S202, in which a mode transition flag is set. To S203.

In S203, since the transition to the neutral mode has not been completed, the flow advances to S204 to change the AE-waiting parameter (P04) to the setting in the neutral mode, and exits the mode selection routine. (Second round) As a result of determining the state of the operation unit 20 in S201, the switching operation of the operation unit has been completed, and the operation unit 2
Since the 0 key operation has not been performed, the process proceeds to S108, where it is determined whether or not the mode transition flag has been set. Since the mode transition flag remains set in the first round, the process proceeds to S203. Since the change of the data table LUT to the neutral mode has been completed this time, the process proceeds to S205. In S205, “Landscape shooting mode”
Since the transition to has not been completed, the process proceeds to S206, where the data table LUT is changed from the neutral mode to the “scenery shooting mode”, specifically, the AE weighting parameter is changed to execute the mode selection routine. Exit. (Third round) As a result of determining the state of the operation unit 20 in S201, no key operation has been performed.
Since the mode transition flag is set,
Proceed to 203.

In S203, LUT for neutral mode
Has already been completed, the process proceeds to step S205. Here, since the switching to the next “landscape shooting mode” has already been completed, the process proceeds to step S207 to clear the mode transition flag, and Exit the selection routine.

As described above, when the photographing mode is switched, the photographing mode is always switched to the next photographing mode via the neutral mode. Therefore, the setting of the control parameters and the characteristics are drastically changed and the image is disturbed. In addition, it is possible to smoothly and naturally switch the photographing mode without causing an unnatural change in the image.

In the above example, the case where the spotlight shooting mode is switched to the landscape shooting mode has been described as an example. However, the same applies to other shooting modes, and the same applies when a plurality of control parameters are shifted. It is.

In the above-described embodiment, the neutral mode is provided separately from the other photographing modes. However, another photographing mode can be used as the neutral mode according to the photographing mode in which the switching operation is performed. .

[0390]

As described above, according to the imaging apparatus of the present invention, a plurality of photographing modes are provided according to the photographing conditions, and when the photographing mode is switched, the photographing mode is not suddenly switched to the photographing mode to be switched to. Since the process is performed via the neutral mode in which intermediate control parameter characteristics are set for various shooting modes, the process of shifting to each shooting mode can be simplified, and the control parameter setting and characteristics Can be switched smoothly and naturally without causing an image to be disturbed suddenly and causing an unnatural change in the image.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration in a case where an imaging device according to the present invention is applied to an exposure control device of a video camera.

FIG. 2 is a diagram showing a photometry area in central partial weight photometry.

FIG. 3 is a diagram for explaining the operation of the electronic shutter.

FIG. 4 is a diagram showing an area division state on an imaging screen according to the present invention.

FIG. 5 is a diagram for describing the setting and weighting of a photometry area of “center-weighted photometry” in the present invention.

FIG. 6 is a diagram for explaining setting and weighting of a photometric area in a “landscape shooting mode” according to the present invention.

FIG. 7 is a program diagram for explaining parameter processing according to the “indoor shooting mode” of the present invention.

FIG. 8 is a program diagram for explaining parameter processing according to the “sport shooting mode” of the present invention.

FIG. 9 is a flowchart for explaining processing for explaining parameter setting in FIGS. 7 and 8;

FIG. 10 is a diagram illustrating characteristics of a camera signal processing circuit performed in conjunction with switching of a shooting mode according to the present invention.

FIG. 11 is a diagram illustrating control of an image processing circuit performed in conjunction with switching of a shooting mode according to the present invention.

FIG. 12 is a diagram for explaining a data table according to the “full auto shooting mode” of the present invention.

FIG. 13 is a program diagram for explaining parameter processing based on FIG. 12 according to the “full-auto shooting mode” of the present invention.

FIG. 14 is a diagram showing the “full auto shooting mode” of the present invention;
FIG. 6 is a diagram for explaining a data table referred to in a shooting situation different from that of FIG.

FIG. 15 is a program diagram for explaining parameter processing based on FIG. 14 according to the “full auto shooting mode” of the present invention.

FIG. 16 is a diagram for explaining a data table according to the “portrait shooting mode” of the present invention.

FIG. 17 is a program diagram for explaining parameter processing according to the “portrait shooting mode” and the “surf & snow shooting mode” of the present invention.

FIG. 18 is a diagram for explaining the structure of a data table according to the “sport shooting mode” of the present invention.

FIG. 19 is a program diagram for explaining parameter processing according to the “sport shooting mode” of the present invention.

FIG. 20 is a diagram illustrating the structure of a data table according to the “landscape shooting mode” of the present invention.

FIG. 21 is a diagram for explaining the structure of a data table according to the “spot light shooting mode” of the present invention.

FIG. 22 is a program diagram for explaining parameter processing according to the “landscape shooting mode” and the “spotlight shooting mode” of the present invention.

FIG. 23 is a diagram showing a luminance histogram for determining a photometric area according to the “spot light shooting mode” of the present invention.

FIG. 24 is a diagram for explaining the structure of a data table according to the “surf & snow shooting mode” of the present invention.

FIG. 25 is a diagram showing a luminance histogram for determining a photometry area according to the “surf & snow photography mode” of the present invention.

FIG. 26 is a diagram for explaining the structure of a data table according to the “manual shooting mode” of the present invention.

FIG. 27 is a program diagram for explaining parameter processing according to the “manual shooting mode” of the present invention.

FIG. 28 is a flow chart for explaining the processing of the flow chart of FIG. 10 in more detail;

FIG. 29 is a diagram for describing display of various operation modes and control parameters in the EVF.

FIG. 30 is a diagram for explaining display of various operation modes and control parameters in the EVF.

FIG. 31 is a diagram for explaining a neutral mode.

FIG. 32 is a diagram for explaining the structure of a data table according to the “neutral mode” of the present invention.

FIG. 33 is a program diagram for explaining parameter processing according to the “neutral mode” of the present invention.

FIG. 34 is a flowchart illustrating a mode transition operation.

FIG. 35 is a block diagram showing a configuration when a general imaging device is applied to an exposure control device of a video camera.

FIG. 36 is a diagram for explaining a shutter priority mode.

Continuation of front page (72) Inventor Koji Takahashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-4-70277 (JP, A) JP-A-2-60378 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 5/232-5/243 G03B 7/08 101

Claims (6)

(57) [Claims] 1. An imaging apparatus having a plurality of imaging modes in which control characteristics are individually set according to imaging conditions, comprising: a mode selection unit capable of selecting an arbitrary imaging mode from the plurality of imaging modes. An imaging apparatus, comprising: a control unit that shifts a shooting mode via a specific mode when a shooting mode is switched by the mode selection unit. 2. The imaging apparatus according to claim 1, wherein the specific mode has an intermediate control characteristic of the control characteristics of each of the photographing modes. 3. The imaging apparatus according to claim 1, wherein the control characteristic defines a change in an aperture value, a shutter speed, and a gain with respect to a subject luminance. 4. A photographing mode control method capable of switching among a plurality of photographing modes each having a control characteristic individually set according to a photographing condition, wherein the photographing mode is switched between the plurality of photographing modes. A photographing mode control method wherein the photographing mode is shifted via a specific mode when the photographing mode is changed. 5. The photographing mode control method according to claim 4, wherein the specific mode has an intermediate control characteristic among the control characteristics of the respective photographing modes. 6. The photographing mode control method according to claim 4, wherein the control characteristic defines a change in an aperture value, a shutter speed, and a gain with respect to a subject luminance.