JP2008219128A - Photographing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photographing device capable of adjusting to appropriate white balance quickly. <P>SOLUTION: The photographing device has a color sensor 21 measuring the average color of an atmosphere in which the digital camera 1 is placed, and a white balance control means 40. The white balance control means 40 controls the white balance of an image signal obtained by a CCD 102 according to the difference between a first average color in the atmosphere measured by the color sensor 21 and a second average color in an object measured from the image signal. When the difference is not less than a prescribed value, the white balance is controlled based on the first color. When the difference is less than the prescribed value, the white balance is controlled based on the second color. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photographing apparatus that forms an image signal by imaging subject light on an image sensor.

  2. Description of the Related Art Conventionally, in a digital camera which is one of photographing apparatuses, subject light is imaged on an image sensor such as a CCD image sensor to generate R, G, B signals which are three primary colors, and the generated R, G, B White balance (WB) adjustment is performed to adjust the gain so that the levels of the B signals are the same. For example, Patent Document 1 proposes a technique for adjusting white balance by increasing or decreasing digital values of R, G, and B signals generated by a CCD image sensor based on a gain value corresponding to weather information. ing. Patent Document 2 proposes a technique for preventing a sense of incongruity due to a difference in color temperature change by controlling the white balance of an image signal obtained by a CCD image sensor so as to shift in a certain direction.

  In such WB adjustment using a so-called CCD image sensor, the integral value of the entire image is attempted to approach an achromatic color. Therefore, when a subject of a specific color is occupied and the proportion of the subject is large, there is a problem that the photograph is taken in an achromatic manner (grayish).

  Here, conventionally, a colorimetric sensor that measures the color included in the ambient light of the digital camera is provided, and when photographing, the white balance is adjusted based on the colorimetric value obtained by the colorimetric sensor. It is done. For example, in Patent Document 3, color components of R, G, and B detected by a colorimetric sensor (AWB sensor) are calorimetrically calculated to obtain a WB correction coefficient, and the obtained WB correction coefficient is used for sunset (or sunrise). ) To obtain a new WB correction coefficient by correcting with a different correction coefficient depending on whether or not the image data read out from the CCD image sensor using the new WB correction coefficient. A technique for performing the above has been proposed.

  Further, in Patent Document 4, in order to suppress a color fog phenomenon due to an error after white balance adjustment by a colorimetric sensor (external sensor), white balance fine adjustment is performed based on R and B signals of image data after white balance adjustment. A technique has been proposed in which gain is calculated and fine adjustment of white balance is performed using the calculated white balance fine adjustment gain.

Further, in Patent Document 5, in order to suppress a color cast phenomenon due to an error after white balance adjustment by an external sensor, after white balance adjustment in an area selected from a plurality of predetermined image areas in a shooting screen. A technique has been proposed in which a white balance fine adjustment coefficient is calculated based on image data, and the white balance is finely adjusted based on the coefficient.
JP 2003-244709 A JP-A-5-191687 JP 2001-39739 A JP 2000-23184 A JP 2000-69488 A

  However, in the technique proposed in Patent Document 3 described above, it is necessary to obtain a coefficient for adjusting the white balance in two stages. In the techniques proposed in Patent Documents 4 and 5, it is necessary to finely adjust the white balance once it has been adjusted. Therefore, the techniques proposed in Patent Documents 3, 4, and 5 have a problem that a long time is required to adjust to an appropriate white balance.

  In view of the above circumstances, an object of the present invention is to provide a photographing apparatus capable of adjusting an appropriate white balance in a short time.

The imaging device of the present invention that achieves the above object is an imaging device that forms an image signal by imaging subject light on an imaging device.
A first color sensor for measuring an average color of the atmosphere in which the photographing apparatus is placed;
And white balance control means for controlling the white balance of the image signal obtained by the imaging device based on an average color of the atmosphere measured by the first color sensor.

  In the photographing apparatus of the present invention, because of the above configuration, when the subject represented by the image signal obtained by the image sensor is a subject of a specific color, and the proportion of the subject is large, the first color sensor The white balance can be adjusted using the average color of the atmosphere measured in (1). On the other hand, when the proportion of the subject is small, the white balance can be adjusted based on the image signal obtained by the image sensor. Therefore, it is possible to solve the problem of being photographed in an achromatic manner (grayish) that occurs in WB adjustment by a so-called CCD image pickup device, and in comparison with the techniques proposed in Patent Documents 3, 4, and 5. It is possible to adjust to an appropriate white balance in a short time.

  Here, the white balance control means measures the white balance of the image signal obtained by the image sensor from the average first color of the atmosphere measured by the first color sensor and the image signal. When the difference is greater than or equal to a predetermined value, based on the difference from the average second color of the subject being photographed, the second color is determined based on the first color and when the difference is less than the predetermined value. Control based on this is preferable.

  When the difference between the first color and the second color is greater than or equal to a predetermined value, the subject is a subject with a high saturation (or low saturation) of a specific color and the subject occupies a large proportion Therefore, the white balance is adjusted using the average color of the atmosphere measured by the first color sensor. On the other hand, when the difference between the first color and the second color is less than a predetermined value, the white balance is adjusted using the average second color of the subject measured from the image signal. In this way, the white balance can be adjusted more appropriately.

  Further, a correspondence table between the color and the color temperature measured by the first color sensor is provided, and the white balance control means refers to the correspondence table, and the white balance of the image signal obtained by the imaging device is referred to. It is also a preferable aspect that the image capturing device is controlled so as to leave the atmosphere of the color of the environment placed at the time of shooting in the image represented by the image signal after white balance adjustment.

  For example, when photographing under the light source of an incandescent light bulb, controlling the white balance based on the color of the incandescent light bulb measured by the first color sensor allows the white balance itself to be adjusted appropriately, but the incandescent light bulb The color atmosphere will be lost. Therefore, referring to the above correspondence table, correcting the color temperature of the incandescent light bulb so as to leave the atmosphere of the incandescent light bulb color, and controlling the white balance based on the color corresponding to the corrected color temperature, the color of the incandescent light bulb The white balance can be adjusted while leaving the atmosphere.

Furthermore, it comprises sunset time estimation means for estimating a sunset time zone based on at least time information,
The white balance control means is obtained by the imaging device when a color corresponding to sunset is measured by the first color sensor within the sunset time zone estimated by the sunset time estimation means. It is also preferable to control the white balance of the obtained image signal so as to enhance redness.

  In this way, if the color corresponding to the sunset is measured by the first color sensor within the sunset time zone, it is determined that the sunset has occurred, and the white balance of the image signal obtained by the image sensor is reduced to red. By controlling to emphasize, it is possible to shoot an impressive evening scene with a stronger redness.

In addition, the night estimation means for estimating the night time zone based on at least time information,
The white balance control means is an image obtained by the image sensor when brightness corresponding to a night view is detected by the first color sensor in the night time zone estimated by the night time estimation means. It is also preferable that the white balance of the signal is controlled so as to emphasize blueness.

  In this way, if a color corresponding to a night view is detected by the first color sensor within the night time zone, it is determined as a night view, and the white balance of the image signal obtained by the image sensor is emphasized for blueness. By controlling so as to be able to shoot, it is possible to shoot a cool and impressive night view with a stronger blue.

Further, in addition to the first color sensor that measures the average color of the atmosphere in which the photographing apparatus is placed, a second color sensor that measures the average color of the atmosphere in front of the photographing apparatus is further provided. Prepared,
The white balance control means is configured to determine a white balance of an image signal obtained by the imaging element by using a first color measured by the first color sensor and a second color measured by the second color sensor. Based on the first color when there is no more than a predetermined difference, and based on the second color when there is a more than a predetermined difference. It is also preferable to control them.

  In this case, for example, when photographing the outdoor from the room with the photographing apparatus, the white balance is controlled based on the second color that is the average color of the outdoor atmosphere measured by the second color sensor. can do. Therefore, the white balance can be adjusted properly even when shooting outdoors from indoors.

  According to the present invention, it is possible to provide a photographing apparatus capable of adjusting to an appropriate white balance in a short time.

  Embodiments of the present invention will be described below.

  FIG. 1 is a perspective view of a digital camera which is a first embodiment of the photographing apparatus of the present invention as viewed obliquely from the upper right, FIG. 2 is a top view of the digital camera shown in FIG. 1 as viewed from above, and FIG. FIG. 2 is a rear view of the digital camera shown in FIG.

  The digital camera 1 is a photographing device that forms an image signal by forming an image of subject light on a CCD image sensor (hereinafter referred to as a CCD) that is one of the image sensors. As shown in FIG. 1, the digital camera 1 is provided with a lens barrel 10 in the center of a camera body 1a. Further, a power button 11 is provided on the upper surface of the camera body 1a. When the power button 11 is operated, the lens barrel 10 is extended as shown in FIGS. It is like that.

  Further, on the upper surface of the camera body 1a, in addition to the power button 11 for turning on the power, a release button 12 and a shooting mode dial 12_1 are provided around the release button 12, and the shooting mode dial 12_1 is AUTO ( When shooting is performed by pressing the release button 12 when switching to FIG. 2), shooting conditions are automatically set in the digital camera 1 and shooting is performed. When the shooting mode dial 12_1 is switched to manual (reference M), manual shooting is performed. When the shooting mode dial 12_1 is further switched to moving image shooting mode, moving picture shooting is performed and the scene position (reference SP) is set. When the camera is switched to the) side, shooting conditions corresponding to the shooting scene are automatically set in the digital camera 1 and shooting is performed. In the manual, the white balance mode can be changed. White balance modes include “AUTO mode” in which the white balance is automatically adjusted, “Sunny mode” for shooting outdoors in sunny conditions, “Cloudy mode” for shooting in shade, etc., shooting under fluorescent lighting There is a “fluorescent lamp mode” for performing the shooting, and a “bulb mode” for shooting with the incandescent bulb.

  Also, as shown in FIG. 3, a liquid crystal monitor 13 is provided on the back side of the camera body 1a, and a subject is displayed on the liquid crystal monitor 13 or a menu is displayed in the photographing mode. When the playback button 14 on the side of the LCD monitor 13 is pressed once in this shooting mode, the mode is switched to the playback mode and the already shot image is displayed on the LCD monitor 13, and when the playback button 14 is pressed again, the shooting is performed. The mode is switched and a through image is displayed on the liquid crystal monitor 13. In addition, an F (photo mode) button 15 is provided next to the playback mode button 14, and a frequently used mode such as a pixel setting mode or a sensitivity setting mode can be easily switched by operating the F button 15. You can also do it.

  A cross key 16 and an OK / menu button 17 are provided below the F button 15, and a zoom switch 18 is provided above the F button 15. By operating the cross key 16 or the OK / menu button 17, the setup menu is switched to set the date and time, whether or not to display images, and the shooting menu is switched to select continuous shooting, self-timer, etc. You can do it.

  Further, below the cross key 16, a DSP / BACK button 19 used for switching the display of the liquid crystal monitor 13 or stopping the operation is provided.

  Further, on the upper surface of the camera body 1a shown in FIG. 1, a color sensor 21 for measuring the average color of the atmosphere in which the digital camera 1 is placed (see FIG. 4; an example of the first color sensor according to the present invention). A color measuring unit 20 provided with a corresponding color).

  1 is provided with a xenon tube at the upper right of the front surface of the camera body 1a, and a flash light emitting unit 30 that emits flash light from the xenon tube toward the subject at the time of flash photography is provided.

  FIG. 4 is a diagram showing an internal configuration of the digital camera shown in FIG.

  The digital camera 1 shown in FIG. 4 includes a photographing lens 101 and a CCD 102 arranged in the lens barrel 10 shown in FIG. The CCD 102 is a solid-state image sensor that captures subject light that has passed through the photographing lens 101. The CCD 102 includes a large number of photoelectric conversion elements such as photodiodes that convert incident subject light into image signals that are electrical signals.

  Further, the digital camera 1 is subjected to a CDS & color separation unit 103 that performs a process of reducing noise of the analog image signal output from the CCD 102 and a color separation process of a color represented by the analog image signal, and the processes. An A / D unit 104 that performs analog / digital conversion of an analog image signal into a digital image signal, and performs white balance adjustment and γ processing based on RGB image data that has been converted into a digital image signal by the A / D unit 104 And a WB adjustment / γ processing unit 105.

  Further, the digital camera 1 includes a CPU 106 that controls the entire digital camera 1, and the CCD 102, the CDS & color separation unit 103, the A / D unit 104, WB adjustment / γ processing at a predetermined timing according to an instruction from the CPU 106. A clock generator 107 that drives the unit 105, a buffer memory 108 that stores image data processed by the WB adjustment / γ processing unit 105, and a data bus 109 that transmits the image data are provided.

  Further, the digital camera 1 is provided with a color measurement unit 20 shown in FIG. The color measurement unit 20 includes the color sensor 21 described above and a diffusion plate 22 provided in front of the color sensor 21. In the color measurement unit 20, the subject light is incident on the color sensor 21 through the diffusion plate 22, so that the average color of the atmosphere in which the digital camera 1 is placed can be measured over a wide range. From the color sensor 21, R, G, B signals carrying R, G, B light obtained by separating subject light incident through the diffusion plate 22 are output to a CPU 106 described later.

  Further, the digital camera 1 is provided with white balance control means 40. The white balance control means 40 controls the white balance of the image signal obtained by the CCD 102 based on the average color of the atmosphere measured by the color sensor 21. Specifically, the white balance control means 40 determines the white balance of the image signal obtained by the CCD 102, the average first color of the atmosphere measured by the color sensor 21, and the subject measured from the image signal. When the error is equal to or greater than a predetermined value, control is performed based on the first color, and when the error is less than the predetermined value, control is performed based on the second color.

  Further, the digital camera 1 converts the RGB signal composed of the image data stored in the power supply unit 110 for supplying the power supply voltage necessary for each block, the above-described flash light emitting unit 30, and the buffer memory 108 into a YC signal. YC processing unit 111 is provided.

  The digital camera 1 further includes a compression / decompression unit 112, an I / F (interface) 113, and a memory card 114. The compression / decompression unit 112 performs compression processing on the YC signal. The compressed image signal is recorded on the memory card 114 via the I / F 113. The compression / decompression unit 112 decompresses the compressed image signal from the memory card 114 via the I / F 113. The decompressed image signal is stored in the buffer memory 108 via the data bus 109.

  The digital camera 1 also includes an EEPROM 115 in which a program necessary for operating as the digital camera 1 is written, the power button 11, the release button 12, the shooting mode dial 12_1, the playback button 14, the F button 15, An operation unit 116 including a cross key 16, an OK / menu button 17, a zoom switch 18, and a DSP / BACK button 19 is provided.

  Further, the digital camera 1 includes a YC → RGB conversion unit 117 that converts the YC signal converted by the YC processing unit 111 described above into an RGB signal again, and a liquid crystal monitor 13 that shows the converted RGB signal as shown in FIG. A driver 118 is provided.

  Here, a schematic operation of the digital camera 1 will be described. The power button 11 in the operation unit 116 is turned on. Then, the CPU 106 detects that the power button 11 has been turned on, and power is supplied from the power supply unit 110 to each block. Here, when the photographing mode dial 12_1 is switched to AUTO, the subject image formed on the CCD 102 via the photographing lens 101 is thinned out at predetermined intervals and output as an image signal. The subject image based on the image signal is displayed on the liquid crystal monitor 13 as a through image. A timing signal is supplied to the CCD 102 from the clock generator 107, and image signals are thinned out and output at predetermined intervals by the timing signal. The clock generator 107 outputs a timing signal based on an instruction from the CPU 106. The timing signal is output from the CCD 102, the subsequent CDS & color separation unit 103, the A / D unit 104, and the WB adjustment / γ processing. Also supplied to the unit 105. Accordingly, the CCD 102, the CDS & color separation unit 103, the A / D unit 104, and the WB adjustment / γ processing unit 105 perform image signal processing in order in synchronization with the timing signal.

  As described above, the A / D unit 104 converts the digital image signal into a digital image signal in synchronization with the timing signal output from the clock generator 107 in accordance with an instruction from the CPU 106, and the WB adjustment / γ processing unit 105 performs white balance adjustment and γ When correction is performed at predetermined intervals, it is necessary to adjust the flow of the image signals well. Therefore, the image signals are subjected to YC processing at predetermined intervals via the buffer memory 108 provided in the subsequent stage. The timing of transferring to the unit 111 is adjusted. From the buffer memory 108, the image signal stored at the old time is transferred to the YC processing unit 111 first. The image signal transferred to the YC processing unit 111 is converted from an RGB signal to a YC signal by the YC processing unit 111 and then supplied to the YC → RGB conversion unit 117 via the data bus 109. The YC → RGB conversion unit 117 converts the YC signal into an RGB signal again, and the converted RGB signal is supplied to the liquid crystal monitor 13 via the driver 118. Thereby, the subject image is displayed on the liquid crystal monitor 13. The CCD 102, the CDS & color separation unit 103, the A / D unit 104, and the WB adjustment / γ correction unit 105 operate in synchronization with the timing signal output from the clock generator 107 described above, and are generated by the CCD 102 at predetermined intervals. Since the image signal is processed, the subject in the direction in which the photographing lens 101 is directed is always displayed on the liquid crystal monitor 13 as a subject image. When the release button 12 is pressed during a photo opportunity while visually recognizing the object image being displayed, all the image signals imaged on the CCD 102 are passed after a predetermined time from the pressing timing of the release button 12 as a starting point. Are output as RGB signals. The RGB signal is converted into a YC signal by the YC processing unit 111, further compressed by the compression / decompression unit 112, and the compressed image signal is recorded on the memory card 114 via the I / F 113. The compression / decompression unit 112 compresses still images using a compression method compliant with the JPEG standard, and records an image signal on the memory card 114. Compression information, shooting information, etc. are written in the header portion of the file consisting of image signals. When the playback button 14 (see FIG. 3) is pressed, the mode is switched to the playback mode, and the header of the file is read from the memory card 114 first. After the compressed image signal in the file is decompressed and restored based on the compression information in the header, the subject image based on the image signal is displayed on the liquid crystal monitor 13.

  In the digital camera 1 of the first embodiment, when the subject represented by the image signal obtained by the CCD 102 is a subject of a specific color, and the proportion of the subject is large, the atmosphere measured by the color sensor 21 The white balance is adjusted using the average color. On the other hand, when the proportion of the subject is small, the white balance is adjusted based on the image signal obtained by the CCD 102. Therefore, it is possible to adjust to an appropriate white balance in a short time. Hereinafter, this will be described in detail with reference to FIG.

  FIG. 5 is a flowchart for determining the colorimetric values used in the white balance control routine executed by the digital camera shown in FIG.

  First, in step S1, white balance (WB) control is started.

  Next, in step S <b> 2, colorimetry is performed in an AWB (Auto White Balance) control routine by the CCD 102 to obtain a colorimetric value A. That is, a colorimetric value A representing the average color (corresponding to the second color referred to in the present invention) of the subject measured from the image signal obtained by the CCD 102 is obtained.

  In step S3, an average color (corresponding to the first color referred to in the present invention) in the atmosphere where the digital camera 1 is placed is measured by the color sensor 21 to obtain a colorimetric value B.

  Next, in step S4, the colorimetric value A and the colorimetric value B are compared. As a result of the comparison, if it is determined that the colorimetric value A and the colorimetric value B are substantially the same (A≈B), the process proceeds to step S5. In step S5, the colorimetric value A (CCD colorimetric value) is used as it is, and the process proceeds to step S8 to complete the colorimetry.

  In step S4, when the colorimetric value A and the colorimetric value B are compared, and it is determined that the colorimetric value A is larger than the colorimetric value B (A >> B), the subject is a specific object. Since it is highly likely that the subject is a single color with low saturation and the proportion of the subject is large, the process proceeds to step S6. In step S6, the colorimetric value B measured by the color sensor 21 is used, and the process proceeds to step S8 to complete the colorimetry.

  In step S4, when the colorimetric value A and the colorimetric value B are compared, and it is determined that the colorimetric value A is smaller than the colorimetric value B (A ≦ B), the subject is a specific object. Since it is highly possible that the subject is a single color with high saturation and the proportion of the subject is large, the process proceeds to step S7. In step S7, the colorimetric value B measured by the color sensor 21 is used, and the process proceeds to step S8 to complete the colorimetry.

  FIG. 6 is a diagram showing an internal configuration of a digital camera which is the second embodiment of the photographing apparatus of the present invention.

  The external view (perspective view, top view, and back view) of the digital camera 2 shown in FIG. 6 is the same as the external view of the digital camera 1 shown in FIGS. Omitted. Further, the same components as those of the digital camera 1 shown in FIG. 4 described above are denoted by the same reference numerals as those shown in FIG. 4, and differences will be mainly described.

  The digital camera 2 shown in FIG. 6 includes a reference table 51 (corresponding to an example of a correspondence table in the present invention) described later. In addition, the digital camera 2 refers to the reference table 51, and the digital camera 2 captures the white balance of the image signal obtained by the CCD 102 in the image represented by the image signal after white balance adjustment. A white balance control means 50 is provided for controlling to leave an atmosphere of the color of the environment that is sometimes placed.

  FIG. 7 is a diagram showing the reference table shown in FIG.

  In the reference table 51 shown in FIG. 7, the color temperature (K: Kelvin) in the atmosphere (environment) where the digital camera 2 is placed, and the ratio of R / G signals from the color sensor 21 at these color temperatures. The value of B / G, which is the ratio of G, B, and G signals, is shown.

  For example, when photographing is performed in the indoor (tungsten) environment shown in FIG. 7, that is, under the light source of an incandescent bulb, based on the incandescent bulb color temperature 3486 representing the average color of the atmosphere measured by the color sensor 21. When the white balance is controlled, the color atmosphere of the incandescent light bulb is lost. Therefore, when this color temperature 3486 is corrected by R / G (2.7183) and B / G (0.7465) and the white balance is controlled based on the corrected color temperature, the atmosphere of the incandescent light bulb color remains. The white balance can be adjusted as it is.

  FIG. 8 is a diagram showing an internal configuration of a digital camera which is the third embodiment of the photographing apparatus of the present invention.

  The external view of the digital camera 3 shown in FIG. 8 is also the same as the external view of the digital camera 1 shown in FIGS. Further, the same components as those of the digital camera 1 shown in FIG. 4 described above are denoted by the same reference numerals as those shown in FIG. 4, and differences will be mainly described.

  The digital camera 3 shown in FIG. 8 includes a GPS information conversion unit 60 that plays the role of sunset time estimation means and nighttime estimation means according to the present invention. The GPS information conversion unit 60 receives GPS signals from GPS (Global Positioning System) satellites, acquires GPS position (longitude, latitude) information and current time information, and sets the sunset time based on the information. Estimate the time zone and night time zone.

  The digital camera 3 is provided with white balance control means 70. This white balance control means 70 is used for the image signal obtained by the CCD 102 when the color sensor 21 measures the color corresponding to the sunset within the sunset time zone estimated by the GPS information conversion unit 60. White balance is controlled to emphasize redness. Further, the white balance control means 70 is an image signal obtained by the CCD 102 when the color sensor 21 detects the brightness corresponding to the night view in the night time zone estimated by the GPS information converter 60. The white balance is controlled to emphasize the blueness. Here, in detecting the brightness corresponding to the night view, an example in which the brightness corresponding to the night view is detected by the color sensor 21 will be described. However, the present invention is not limited to this, and the digital camera 3 is placed. The brightness corresponding to the night view may be detected by a visible light sensor that detects the brightness of the atmosphere.

  FIG. 9 is a flowchart regarding sunset in the white balance control routine executed by the digital camera shown in FIG.

  First, in step S11, white balance (WB) control is started. Next, in step S12, the color sensor 21 obtains a colorimetric value.

  Next, in step S13, it is determined whether or not the color temperature corresponding to the colorimetric value is around 3000K. If it is determined that the color temperature is not around 3000K, the process proceeds to step S15, and jumps to a normal WB processing routine in step S15. On the other hand, if it is determined that the color temperature is around 3000K, the process proceeds to step S14.

  In step S14, it is determined whether it is evening time. If it is determined that it is not the evening time, the process proceeds to step S15 described above. On the other hand, if it is determined that it is evening time, the process proceeds to step S16.

  In step S16, the white balance (WB) is set to “cloudy mode”, and the process proceeds to step S17 to complete the setting of WB. In this “cloudy mode”, the color temperature is set to a higher color temperature. That is, the color temperature is set in the blue direction. In this way, by deliberately shifting the white balance in the blue direction, it is possible to emphasize the redness of the sunset that is lost as a result of normal white balance adjustment. Therefore, it is possible to photograph an impressive evening scene with a stronger redness.

  FIG. 10 is a flowchart regarding the night view in the white balance control routine executed by the digital camera shown in FIG.

  First, in step S21, white balance (WB) control is started. Next, in step S22, using the color sensor 21 as a visible light sensor, the brightness of the atmosphere in which the digital camera 3 is placed is detected to obtain a photometric value.

  Next, in step S23, it is determined whether or not the photometric value is a brightness value corresponding to a night scene. If it is determined that the brightness value does not correspond to the night view, the process proceeds to step S25, and jumps to a normal WB processing routine in step S25. On the other hand, if it is determined that the brightness corresponds to the night view, the process proceeds to step S24.

  In step S24, it is determined whether it is a night view time. If it is determined that it is not the night view time, the process proceeds to step S25 described above. On the other hand, if it is determined that the night view time is reached, the process proceeds to step S26.

  In step S26, the white balance (WB) is set to “bulb mode”, and the process proceeds to step S27 to complete the setting of WB. In this “bulb mode”, the color temperature is set to a lower color temperature. In this way, by deliberately shifting the white balance in the direction of eliminating redness, it is possible to shoot a cool and impressive night view with stronger bluishness.

  FIG. 11 is a perspective view of a digital camera, which is a fourth embodiment of the photographing apparatus of the present invention, seen obliquely from the upper right, and FIG. 12 is a diagram showing an internal configuration of the digital camera shown in FIG.

  The same constituent elements as those of the digital camera 1 shown in FIGS. 1 and 4 are denoted by the same reference numerals as those shown in FIGS. 1 and 4, and the differences will be mainly described. To do.

  In addition to the color sensor 21 that measures the average color of the atmosphere in which the digital camera 4 is placed, the digital camera 4 shown in FIG. 11 further measures the average color of the atmosphere in front of the digital camera 4. And a colorimetric unit 600 provided with a color sensor 601 (see FIG. 12; corresponding to an example of the second color sensor in the present invention). The color measurement unit 600 is also provided with a diffusion plate 602 provided on the front surface of the color sensor 21.

  Further, the digital camera 4 is provided with a white balance control means 80 shown in FIG. The white balance control unit 80 sets the white balance of the image signal obtained by the CCD 102 to a predetermined value or more between the first color measured by the color sensor 21 and the second color measured by the color sensor 601. Depending on whether or not there is a difference, control is performed based on the first color when there is no difference greater than a predetermined value, and based on the second color when there is a difference greater than or equal to a predetermined value.

  For example, when the digital camera 4 is used to take an image of the outside from the room, the average first color of the indoor atmosphere measured by the color sensor 21 and the average first of the outdoor atmosphere measured by the color sensor 601 are used. There is a predetermined difference or more between the two colors. Therefore, in this digital camera 4, the white balance is controlled based on the second color that is the average color of the outdoor atmosphere measured by the color sensor 601. For this reason, even when photographing the outdoors from the room, it is possible to adjust to an appropriate white balance.

  In the above-described embodiment, the example of the CCD has been described as the imaging device according to the present invention. However, the present invention is not limited to this, and the imaging device according to the present invention may be a CMOS sensor or an organic semiconductor. .

  In the above-described embodiment, the digital camera is described as an example of the photographing apparatus according to the present invention. However, the present invention is not limited thereto, and the photographing apparatus according to the present invention may be a camera mounted on a mobile phone, It may be a video camera or the like.

It is the perspective view which looked at the digital camera which is 1st Embodiment of the imaging device of this invention from diagonally upper right. FIG. 2 is a top view of the digital camera shown in FIG. 1 as viewed from above. It is the rear view which looked at the digital camera shown in FIG. 1 from the back. It is a figure which shows the internal structure of the digital camera shown in FIG. 6 is a flowchart for determining colorimetric values used in a white balance control routine executed by the digital camera shown in FIG. It is a figure which shows the internal structure of the digital camera which is 2nd Embodiment of the imaging device of this invention. It is a figure which shows the reference table shown in FIG. It is a figure which shows the internal structure of the digital camera which is 3rd Embodiment of the imaging device of this invention. FIG. 9 is a flowchart regarding sunset in a white balance control routine executed by the digital camera shown in FIG. 8. It is a flowchart regarding a night view of the white balance control routine executed by the digital camera shown in FIG. It is the perspective view which looked at the digital camera which is 4th Embodiment of the imaging device of this invention from diagonally upper right. It is a figure which shows the internal structure of the digital camera shown in FIG.

Explanation of symbols

1, 2, 3, 4 Digital camera 1a Camera body 10 Lens barrel 11 Power button 12 Release button 12_1 Shooting mode dial 13 LCD monitor 14 Playback button 15 F button 16 Four-way controller 17 OK / menu button 18 Zoom switch 19 DSP / BACK Button 20,600 Color measurement unit 21,601 Color sensor 22,602 Diffuser 30 Flash light emitting unit 40, 50, 70, 80 White balance control means 51 Reference table 60 GPS information conversion unit 101 Shooting lens 102 CCD
103 CDS & Color Separation Unit 104 A / D Unit 105 WB Adjustment / γ Processing Unit 106 CPU
107 clock generator 108 buffer memory 109 data bus 110 power supply unit 111 YC processing unit 112 compression / decompression unit 113 I / F
114 Memory card 115 EEPROM
116 Operation unit 117 YC → RGB conversion unit 118 Driver

Claims (6)

In an imaging device that forms an image signal by imaging subject light on an image sensor,
A first color sensor for measuring an average color of the atmosphere in which the photographing apparatus is placed;
An imaging apparatus comprising: white balance control means for controlling white balance of an image signal obtained by the imaging element based on an average color of the atmosphere measured by the first color sensor. .   The white balance control means determines the white balance of the image signal obtained by the image sensor, the average first color of the atmosphere measured by the first color sensor, and the subject measured from the image signal. When the difference is greater than or equal to a predetermined value, control is performed based on the first color and when the difference is less than the predetermined value, control is performed based on the second color. The imaging apparatus according to claim 1, wherein   A correspondence table of colors and color temperatures measured by the first color sensor is provided, and the white balance control means refers to the correspondence table to determine the white balance of the image signal obtained by the image sensor, 3. The photographing according to claim 1, wherein the photographing device is controlled so as to leave an atmosphere of an environmental color placed at the time of photographing in the image represented by the image signal after white balance adjustment. apparatus. A sunset time estimating means for estimating a sunset time zone based on at least time information;
The white balance control means is obtained by the imaging device when a color corresponding to a sunset is measured by the first color sensor within the sunset time zone estimated by the sunset time estimation means. 2. The photographing apparatus according to claim 1, wherein the white balance of the obtained image signal is controlled so as to enhance redness. A night estimation means for estimating a night time zone based on at least time information,
The white balance control means is an image obtained by the image sensor when brightness corresponding to a night view is detected by the first color sensor in the night time zone estimated by the night estimation means. 2. The photographing apparatus according to claim 1, wherein the white balance of the signal is controlled so as to emphasize blueness. In addition to the first color sensor that measures the average color of the atmosphere in which the photographing apparatus is placed, the apparatus further includes a second color sensor that measures the average color of the atmosphere in front of the photographing apparatus,
The white balance control means is configured to measure a white balance of an image signal obtained by the imaging device by using a first color measured by the first color sensor and a second color measured by the second color sensor. Depending on whether or not there is a predetermined difference or more based on the first color when there is no predetermined difference or based on the second color when there is a predetermined difference or more. 3. The photographing apparatus according to claim 1, wherein the photographing apparatus is controlled.

Images