JP2005303400A - Imaging apparatus, image processing apparatus, illumination light source, and illumination apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus, an image processing apparatus, an illumination light source, and an illumination apparatus by accurately grasping a characteristic of a light source, so as to be capable of easily and accurately adjusting white balance. <P>SOLUTION: An imaging element comprising a CCD image sensor 102 photographs an optical image of an object formed by light made incident through a photographing optical system 101. The imaging apparatus such as a digital still camera includes first and second correction modes. In the second correction mode, a reader/writer 109 of a wireless tag (proximity wireless communication element) receiving an instruction from a system controller 108 transmits a signal of requesting individual information of the light source (e.g., spectral distribution) and receives a reply from the illumination light source. A coefficient arithmetic section 110 determines a correction coefficient on the basis of the individual information of the light source (e.g., chromaticity information, color temperature information, and spectral characteristic information) and a white balance circuit 105 corrects the white balance. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an imaging device, an image processing device, an illumination light source, and an illumination device, and more particularly, to an illumination light source or an illumination device in an imaging device having a communication means with an illumination light source or a wireless communication element installed in the illumination device. The present invention relates to a technique for performing white balance correction using solid-state information such as spectral characteristics and color correction coefficients stored in an installed wireless communication element.

  Imaging apparatuses such as a video camera and a digital still camera that record an image obtained by capturing (capturing) a subject image with an image sensor such as an imaging tube or a CCD are known. In such an imaging apparatus, since photographing is performed under various illumination lights having different spectral characteristics such as light from a tungsten lamp, light from a fluorescent lamp, daylight, etc., a mechanism for adjusting the white balance is provided. Yes.

  The white balance adjustment is to set R, G, and B gains so that when a white object illuminated by an arbitrary light source is photographed, the object becomes achromatic. For example, in a digital still camera currently on the market, the type of light source such as a tungsten lamp, a fluorescent lamp, or daylight is estimated from an image signal obtained by photographing a subject with an image sensor, and the type of the estimated light source The white balance is adjusted automatically by setting the gain according to the. In addition, there is a type in which a gain corresponding to the type of light source is set by manually selecting the type of light source. Furthermore, there is also known a method of adjusting white balance by inputting a season, weather, time, etc., and setting a gain according to the season, weather, time, etc. (for example, Patent Document 1). ).

  Also known is a digital still camera that can obtain an appropriate white balance by measuring the spectral distribution of illumination light at the time of shooting and obtaining a correction coefficient for correcting the color balance based on the measurement result. (For example, Patent Documents 2 to 4).

On the other hand, as disclosed in Non-Patent Document 1, ID element (RFID: Radio Frequency Identification) technology that electronically retains individual information and transmits information in a non-contact manner by electromagnetic induction has been developed, and object identification management is performed. Has begun to be applied for. An individual recognition method using an ID element has attracted attention as a technique that replaces a barcode in the distribution field. Note that there are RFID elements, ID tags, wireless communication elements, wireless tags, IC tags, wireless IC tags, proximity wireless communication elements, and the like as names for ID elements.
JP 2000-278707 A Japanese Patent Laid-Open No. 5-122708 Japanese Patent Laid-Open No. 2002-320231 JP 2003-153288 A IPSJ Journal Vol.40, No.8 (August 1999), p846-850, “RFID tags for applying information to objects and their applications”

  By the way, in each method disclosed in the above document, gain values for each type of light source, season, weather, time, and the like are experimentally determined, and an estimated light source, a selected light source, In accordance with the season, weather, time, etc., one set is selected from the combinations of gains prepared in advance. However, there are a wide variety of light sources at the time of imaging. Even if the light sources are classified into the same type, and even in the same season, weather, and time, they are completely the same as the light source when the spectral characteristics determine the gain. There was almost no coincidence, and the white balance was not adjusted accurately.

  In addition, in the method of automatically adjusting white balance based on the imaging signal obtained from the image sensor (white balance correction by the TTL method), for example, when the ratio of the specific color to the shooting screen is extremely high, etc. Depending on the shooting conditions, there is a problem that the type of the light source is erroneously estimated and the white balance becomes inappropriate.

  Furthermore, in the method of obtaining the correction coefficient based on the measured spectral distribution of the illumination light and adjusting the white balance, the spectral distribution measuring device is expensive, and the white balance is adjusted by measuring the spectral distribution and obtaining the correction coefficient. It takes a long time to complete the process, and it is easy to miss a photo opportunity, and there are cases where correction is inappropriate due to erroneous measurement.

  The present invention has been made in order to solve the above-described problems of the prior art, and by accurately grasping the characteristics of the light source, an imaging device capable of easily and accurately adjusting the white balance in a preferable form, An object is to provide an image processing device, an illumination light source, and an illumination device.

  According to a first aspect of the present invention, there is provided an image pickup apparatus for picking up an optical image of a subject formed by light incident through a photographing optical system using an image pickup element, a wireless communication means for performing wireless communication with a close proximity wireless communication element, an illumination light source or an illumination Means for receiving a signal from a proximity wireless communication element installed in an illumination device including a light source, obtaining individual information of the illumination light source, and correcting means for performing color correction on a photographed image using the individual information of the illumination light source An imaging device comprising:

  According to a second aspect of the present invention, there is provided the image pickup apparatus according to the first aspect, wherein switching means for switching whether or not to perform color correction using individual information of the illumination light source acquired through wireless communication with the proximity wireless communication element. It is characterized by having.

  According to a third aspect of the present invention, in the imaging apparatus according to the first aspect, the individual information of the illumination light source is added to the photographed image and stored.

  According to a fourth aspect of the present invention, there is provided the imaging apparatus according to the first aspect, further comprising storage means for storing spectral characteristics or color correction coefficients corresponding to the individual information of the illumination light source.

  According to a fifth aspect of the present invention, in the imaging device according to the first aspect, when a signal from the illumination light source or the illumination device including the illumination light source cannot be received, a proximity wireless communication device other than the proximity wireless communication element installed in the illumination light source is provided. Means for receiving a signal from a communication element and acquiring information on a plurality of objects existing around the imaging environment; imaging environment determining means for determining the imaging environment from information on objects existing around the imaging environment; and the illumination A measuring unit that measures light, an illumination light source determining unit that determines the illumination light source from the determination result of the shooting environment and the measurement result of the illumination light, and a correction unit that performs color correction from the determination result of the illumination light source. Features.

  According to a sixth aspect of the present invention, in an image processing apparatus of an image pickup apparatus that picks up an optical image of a subject formed by light incident through a photographing optical system with an image pickup device, the environment in which the image is taken as input image information When the spectral characteristic or chromaticity information of the illumination light source is added, color correction is performed using the spectral characteristic information or chromaticity information of the illumination light source.

  According to a seventh aspect of the present invention, in the image processing apparatus according to the sixth aspect, the color correction is a white balance correction.

  According to an eighth aspect of the present invention, in the illumination light source in which the proximity wireless communication element is installed, the proximity wireless communication element includes chromaticity information, color temperature information, or spectral characteristic information of the light source, or the light source of the light source. Information for acquiring chromaticity information, color temperature information, or spectral characteristic information is stored.

  According to a ninth aspect of the present invention, in the illumination device that performs illumination by turning on the illumination light source, the illumination light source stores solid information of the illumination light source, and content of a signal that responds to a transmission request for the solid information of the illumination light source Is different between when the illumination light source is turned on and when the illumination light source is turned off.

  A tenth aspect of the present invention is the illumination device according to the ninth aspect, wherein an acquisition unit that acquires individual information of the light source stored in the illumination light source, and a proximity wireless communication in which the individual information of the illumination light source is installed in the illumination device Storage means for storing in the communication element.

  The invention of claim 11 is the illumination device according to claim 9 or 10, characterized in that the information acquired from the illumination light source is stored in the storage means when the illumination light source is turned on, and the information stored when the illumination light source is turned off is erased. To do.

  According to a twelfth aspect of the present invention, in the illumination device according to any one of the ninth to eleventh aspects, the acquisition unit that acquires the individual information of the illumination light source stored in the illumination light source is a proximity wireless device installed in the illumination light source. A communicable distance of a proximity wireless communication element installed in the illumination device that communicates with a communication element is larger than a communicable distance of a proximity wireless communication element installed in the illumination light source.

  According to the first aspect of the present invention, the solid-state information of the illumination light source in the shooting environment is acquired through communication with a proximity wireless communication element (hereinafter referred to as a wireless tag), and color correction is performed using this information. Since solid information such as measurement of the color temperature of the light source can be color-corrected using accurate solid-state information of the illumination light source without depending on an inaccurate measurement result, appropriate color correction can be performed.

  According to the second aspect of the present invention, since it is selected whether or not to use the color correction method for acquiring the individual information of the light source using the wireless tag of the first aspect, the light source in which the wireless tag is not installed Under the lighting environment, general color correction processing can be executed, and the application range as a camera can be expanded.

  According to the invention of claim 3, since the individual information of the light source acquired by using the wireless tag is added to the captured image and stored, in the image processing apparatus after the image capturing, various information is obtained using the individual information of the light source. Color correction can be performed.

  According to the fourth aspect of the present invention, the imaging apparatus stores in advance even when only individual identification information such as an ID number for identifying a light source type is obtained as individual information of an illumination light source, not physical characteristics such as a spectral distribution. Optimal color correction can be performed using physical characteristics such as spectral distribution associated with the identification information being used, or correction coefficients used for white balance correction.

  According to the invention of claim 5, when the individual information of the illumination light source cannot be obtained at the time of shooting, it communicates with the wireless tag installed on the object existing around the shooting environment, and the shooting environment is determined from the type of the object existing around the shooting environment. Since the type of light source is determined from measurement information such as the shooting environment and the color temperature of the illumination light, the light source type is determined more accurately than when color correction is performed only from the color temperature characteristics. Can be performed, and appropriate color correction is possible.

  According to the sixth aspect of the present invention, the image processing apparatus can know accurate spectral characteristics, chromaticity points, or color temperature information of the light source in the photographing environment, and can perform highly accurate color correction.

  According to the seventh aspect of the present invention, the accurate spectral characteristics, chromaticity point, or color temperature of the light source can be known, so that accurate white balance correction can be performed.

  According to the invention of claim 8, since the spectral characteristic, color temperature characteristic or chromaticity point of the light source is recorded on the wireless tag as the individual information recorded on the light source, than when measuring the characteristic, Accurate light source characteristics can be acquired.

  According to the ninth aspect of the present invention, the content of the response to the transmission request for the individual information of the light source is different between when the light source is turned on and when the light source is turned off. Or not. In addition, it is possible to prevent the imaging apparatus from performing white balance correction using the characteristics of the illumination light source even though the light source is turned off.

  According to the invention of claim 10, since the lighting device transmits the individual information of the illumination light source in response to the transmission request of the individual information of the light source from the imaging device, the transmission content is changed depending on whether or not the illumination light source is turned on. Therefore, it is possible to reduce the cost of the apparatus.

  According to the invention of claim 11, since the individual information of the illumination light source is stored only when the illumination light source is turned on, only when the illumination light source is turned on in response to a request from the imaging device, Even when the illumination light source characteristic information is transmitted and the imaging apparatus performs white balance correction using the individual information of the illumination light source, it can be easily determined that the illumination light source is not turned on.

  According to the invention of claim 12, since the transmittable distance of the wireless tag attached to the illumination light source is set shorter than the communication distance of the wireless tag attached to the lighting device, the imaging device turns off the illumination light source. In this case, it is possible to avoid acquiring information directly from the wireless tag of the illumination light source and performing color correction by mistake.

The present invention relates to an image pickup apparatus having a communication means with an illumination light source or a wireless communication element installed in the illumination apparatus, and characteristics (for example, chromaticity) of the light source stored in the illumination light source or the wireless communication element installed in the illumination apparatus. By accurately grasping information, color temperature information, spectral characteristic information), it is possible to provide an imaging device that can easily and accurately adjust the white balance. The configuration for this is based on the light incident through the imaging optical system. In an imaging apparatus that captures an optical image of a subject to be formed using an imaging element, wireless communication means that performs wireless communication with a proximity wireless communication element, and an illumination light source or a proximity wireless communication element installed in an illumination device that includes the illumination light source Means for acquiring individual information of the illumination light source, and correction means for performing color correction on the photographed image using the individual information of the illumination light source It is characterized in.
Examples of the present invention will be described below.

A digital still camera according to a first embodiment in which the present invention is implemented will be described.
1A and 1B are perspective views showing an external appearance of a digital still camera according to the first embodiment. FIG. 1A is a front perspective view and FIG. 1B is a rear perspective view.
On the front surface of the camera body 2 of the digital still camera 1, a lens barrel 4 incorporating a photographing lens 3, an objective window 5 a of an optical viewfinder 5, a release button 6, and a measurement window 7 for measuring the color temperature of illumination light. Is arranged. Further, an eyepiece side window 5b of the finder 5, an LCD (Liquid Crystal Display) 8, and an operation unit 9 are provided on the back surface.

By operating this, the operation unit 9 can turn on / off the power, switch between the shooting mode and the playback mode, select a correction mode under the shooting mode, select an image to be played back, erase image data, and the like. it can.
As the correction mode, the first or second correction mode can be selected. The first correction mode is a mode in which the color temperature of the illumination light that illuminates the subject is measured, and the white balance is adjusted based on the color temperature. The second correction mode is a mode in which a spectral distribution is acquired from an illumination light source or an illumination device using wireless communication, and white balance is adjusted based on the obtained spectral distribution.

  By looking through the optical viewfinder 5, the shooting range can be observed. The LCD 8 constitutes a so-called electronic viewfinder that displays a subject image photographed through the photographing lens 3 in real time and is used for image reproduction and the like.

  When the release button 6 is pressed halfway, the photographing lens 3 is focused. The CCD image sensor (imaging device) 102 (see FIG. 2) arranged in the back of the photographing lens 3 captures an image for one frame during photographing (imaging), and records image data in the memory card 11 attached. Is done. In the first and second correction modes, when the release button 6 is fully pressed, image data after completion of the correction coefficient calculation process performed in response to the half-press immediately before the release button 6 is recorded in the memory card 11. The Thereby, the image data in which the white balance is adjusted based on the color temperature or spectral distribution acquired immediately before is recorded in the memory card 11.

  A lid 10 is provided on the side surface of the camera body 2 so as to be freely opened and closed, and the memory card 11 can be inserted and removed. An optical sensor of a color temperature measuring device 201 (see FIG. 2) that measures the color temperature of the illumination light that illuminates the subject is disposed behind the measurement window 7.

FIG. 2 is a block diagram illustrating a main configuration of the digital still camera according to the first embodiment. The digital still camera is provided with a mechanism for focusing the photographing lens 3, a circuit for reading out image data from the memory card 11, and the like, which are not shown.
The system controller 108 controls each part of the digital still camera according to the input of the operation signal from the release button 6 and the operation part 9. A CCD image sensor (imaging device) 102 is disposed behind the photographing lens 3. The CCD image sensor 102 is driven by a driver 106 to convert an optical subject image into an electrical imaging signal and output it. Micro light filters of R, G, and B are arranged in a matrix on the light receiving surface of the CCD image sensor 102, and an imaging signal including each color component of R, G, and B is amplified to an appropriate level by an amplifier 103. Thereafter, the A / D converter 104 converts the image data into red, green, and blue images.

The white balance circuit 105 adjusts the white balance by correcting the signal levels of one of the three colors R, G, and B, for example, the other two colors based on green. In this example, the white balance is adjusted by multiplying the red image data of the three color image data obtained by digitally converting the imaging signal by the red correction coefficient krg and the blue image data by the blue correction coefficient kbg. In this example, the red correction coefficient krg and the blue correction coefficient kbg are white balance adjustment values.
Note that the signal level of the analog signal may be corrected instead of the image data. In this case, R, G, and B analog signals are generated from the imaging signal, and gains when amplifying two color analog signals among these analog signals may be increased or decreased as an adjustment value.

In the first correction mode, the correction coefficient calculated by the coefficient calculation unit 110 based on the measurement result of the color temperature measuring device 201 is set in the white balance circuit 105.
The first correction mode may be a so-called external sensor method or a TTL method.

In the external sensor system, a white balance sensor having a white diffusion plate is attached to a camera, and white balance is set using each color signal detected from the white balance sensor through the diffusion plate.
The TTL method specifies a photographic light source that illuminates a subject using programmed color temperature information such as sunlight and illumination light and a video signal from an image sensor, and sets a white balance that matches the photographic light source. Is what you do.
In any method, since white balance setting is not performed based on the spectral distribution of the light source, white balance correction errors due to measurement errors of illumination light are likely to occur.

  In the ROM 111, correction factors corresponding to general light source types such as a tungsten lamp, a fluorescent lamp, and daylight are written. The correction coefficient written in the ROM 111 is experimentally determined in advance based on, for example, the spectral distribution of a typical light source.

  The white balance circuit 105 outputs green image data, red image data multiplied by a red correction coefficient, and blue image data multiplied by a blue correction coefficient, and these are output via an γ conversion circuit 112 as an output image storage unit 113. Sent to. The γ conversion circuit 112 performs γ conversion on each image data so that an image is displayed on the LCD 8 with an appropriate gradation.

  The output image storage unit 113 includes a recording circuit that records image data in the memory card 11, an LCD 8, and an LCD drive circuit that drives the LCD 8 based on the image data. Under the shooting mode, the image data from the γ conversion circuit 112 is sent to the LCD drive circuit, so that the subject image being shot is displayed on the LCD 8 as a moving image. Further, when the release button 6 is fully pressed under the shooting mode, image data for one frame is written to the memory card 11 by the recording circuit.

FIG. 3 is a flowchart showing processing in the second correction mode.
In the second correction mode, in response to an instruction from the system controller 108, a signal requesting individual information (for example, spectral distribution) of the light source is transmitted from the reader / writer 109 of the wireless tag (step 1). Next, a response from the light source or the illumination device is received (step 2). The coefficient calculation unit 110 determines a correction coefficient based on the individual information (for example, spectral distribution) of the light source, and performs correction using the white balance circuit 105 (step 3).
Hereinafter, a method for determining the correction coefficient when the spectral distribution P (λ) is acquired as the individual information of the light source will be described.

  The spectral distribution P (λ) is once written in the memory 110 a in the coefficient calculation unit 110. When the writing of the spectral distribution P (λ) data is completed, the coefficient calculation unit 110 reads the spectral distribution P (λ) data from the memory 110a. The coefficient calculation unit 110 is preset with the red, green, and blue spectral sensitivities r (λ), g (λ), and b (λ) of the CCD image sensor 102. Strictly speaking, the spectral sensitivities r (λ), g (λ), and b (λ) are measured on the front surface of the CCD image sensor 102 and the imaging lens 3 arranged on the optical path of the imaging light incident on the CCD image sensor 102. This is in consideration of spectral transmittance such as an attached infrared cut filter and an optical low pass filter (LPF) for removing a high frequency component of an optical image.

  The coefficient calculation unit 110 calculates the spectral distribution P (λ) obtained by measurement and the red, green, and blue spectral sensitivities r (λ), g (λ), and b (λ) of the CCD image sensor 102 as follows ( The red, green, and blue signal levels R1, G1, and B1 are calculated by applying the formulas (1) to (3).

[Equation 1]
R1 = ∫P (λ) r (λ) dλ (1)
G1 = ∫P (λ) g (λ) dλ (2)
B1 = ∫P (λ) b (λ) dλ (3)

  The coefficient calculation unit 110 applies matrix calculation by applying the signal levels R1, G1, and B1 calculated by the equations (1) to (3) to the following equation (4), and thereby the individual difference for each digital camera and the like. To calculate signal levels R2, G2, and B2 that are fine-tuned in color. It should be noted that the values m11 to m33 in the equation (4) are determined according to the level of fine color adjustment in consideration of individual differences for each digital camera.

  In the second correction mode, the coefficient calculation unit 110 applies the signal levels R2, G2, and B2 obtained from Equation (4) to the following Equations (5) and (6), and uses white as a reference for green. A red correction coefficient krg and a blue correction coefficient kbg for adjusting the balance are calculated.

[Equation 3]
kbg = G2 / B2 (5)
krg = G2 / R2 (6)

  As in the case of the first correction mode, the data after white balance correction is sent to the output image storage unit 113 via the γ conversion circuit 112. Regardless of the correction mode, the stored image data may also be stored with the individual information of the light source or the light source acquired from the illumination device. Even in the first correction mode, the individual information of the light source may be acquired by the procedure described in the second correction mode, and this may be attached to the captured image data.

  In this case, if the white balance correction performed using the first correction mode has failed or needs to be corrected, correction is performed using individual information (for example, spectral distribution) of the attached light source. It becomes possible.

In the above description, the individual information of the light source has been described as a spectral distribution. However, the present invention does not limit the individual information of the light source, such as an ID number indicating the type of the light source. It may be. In this case, the spectral distribution or the correction coefficient for color correction corresponding to the ID number acquired through the wireless tag is stored in, for example, the ROM 111, so that the same effect as the case of acquiring the spectral distribution directly from the light source is obtained. Can be obtained.
As described above, according to the present invention, it is not necessary to mount an expensive apparatus for measuring spectral characteristics in a camera, and no white balance correction error due to subsequent measurement does not occur.

  In addition, the present invention does not limit the timing at which the camera requests the individual information of the light source. However, the point in time when the release button is half-pressed is preferable, so that a sufficient speed for response from the wireless tag cannot be obtained. In such a case, an inquiry may be made at predetermined intervals after the camera is turned on, and the latest light source information may be used at the time of shooting, thereby shortening the time from button pressing to shooting. be able to.

FIG. 4 is a block diagram showing the configuration of a wireless tag, which is a close proximity wireless communication element used in the present invention, and a reader / writer that performs wireless communication with the wireless tag to read and write data.
The wireless tag and the reader / writer communicate signals through a transmission / reception antenna. A typical wireless tag and reader / writer according to the present invention have the following configuration.

  In the wireless tag shown in FIG. 4, reference numeral 21 denotes a memory that stores a wireless tag identification number, wireless tag content, and the like. A data processing circuit 22 performs various data processing. A modulation circuit 23 modulates transmission data. A transmission driver 24 performs transmission processing. Reference numeral 25 denotes an antenna input circuit which controls the transmitting / receiving antenna. A power generation circuit 26 rectifies and smoothes the received power wave to generate a stable DC voltage and supplies it to each circuit as an operating voltage. Reference numeral 27 denotes a demodulation circuit that performs demodulation processing on the received signal.

  In the reader / writer shown in FIG. 4, reference numeral 31 denotes a data processing circuit which performs various data processing and transfers the received information to the memory 110a of the coefficient calculation unit 110 in FIG. A modulation circuit 32 modulates transmission data. Reference numeral 33 denotes a transmission driver, which performs transmission processing. Reference numeral 34 denotes an antenna input circuit, which controls a transmission / reception antenna. Reference numeral 35 denotes a demodulation circuit, which performs demodulation processing on the received signal.

A digital still camera according to Embodiment 2 will be described.
FIG. 5 is a block diagram illustrating a main configuration of the digital still camera according to the second embodiment.
The digital still camera according to the second embodiment relates to a case where a response from the light source cannot be obtained as a result of transmitting a signal requesting the spectral distribution of the light source through the reader / writer 109 in the digital still camera according to the first embodiment. is there. That is, it corresponds to the case where there is no light source with a wireless tag installed in the shooting environment or when shooting outdoors.

  In the present embodiment, when a response from the light source cannot be obtained, a response from a wireless tag installed other than the light source is detected, and the detected signal is input to the environment determination unit 200. The environment determination unit 200 analyzes signals from a plurality of detected peripheral objects and identifies a plurality of objects existing in the vicinity. Then, it is determined whether the observation environment is indoor or outdoor based on the content of the specified object.

In the determination method, for example, the memory 200a in the environment determination unit 200 stores various objects and the probability of the objects being installed indoors or the probability of being installed outdoors, and this is detected first. The shooting environment is judged by comparing with surrounding objects.
In the above description, the expressions “probability of being installed indoors” and “probability of being installed outdoors” are used. However, the probabilities are not necessarily probabilities, and of course, scores such as scores corresponding to the probabilities may be used.

6A and 6B are conceptual diagrams for determining the shooting environment. FIG. 6A shows a case where the image is taken indoors, and FIG. 6B shows a case where the image is taken outdoors.
As shown in FIG. 6A, if the detected object is a refrigerator, a television set, a personal computer or the like, the probability of being indoors is high, so the score is set high. Conversely, if there is a high probability of being outdoors, such as cars, traffic lights, traffic signs, or when no signal is obtained, the score is set low. The shooting environment is determined from the total probability (or total score) for all detected objects.

Next, the light source discriminating unit 202 determines the light source type that seems to be optimal based on the photographing environment and the measurement result by the optical sensor of the color temperature measuring device 201. At this time, even if it is determined that the color temperature is low and the illumination light is reddish, it is determined whether the shooting environment is indoors or outdoors, whether it is due to sunset or a light source such as an incandescent lamp. Therefore, white balance correction corresponding to each can be performed. Thereby, the precision with respect to an auto white balance can be improved.
As a result, even in a situation where the same color temperature is used indoors and outdoors, the assumed light source type can be accurately determined, so that appropriate white balance correction can be performed.

FIG. 7 is a diagram illustrating a situation in which a subject is photographed by the digital still cameras according to the first and second embodiments.
The subject 41 is illuminated by an illuminating device 42. The illuminating device 42 is provided with a wireless tag (not shown) in which the spectral distribution of the light source is recorded. The digital still camera 1 is provided with a wireless tag reader / writer, which is used to read the spectral distribution of the light source from the wireless tag of the illumination device 42. The digital still camera 1 corrects the white balance of the photographed image using the read spectral distribution, performs γ conversion, and stores the image.

The illumination light source of Example 3 will be described.
FIG. 8 is a diagram illustrating an illumination light source according to the third embodiment.
The illumination light source according to the third embodiment includes, for example, a fluorescent lamp 51, and a wireless tag 52 is attached to the base portion of the fluorescent lamp 51. Individual information of the light source is recorded in the wireless tag 52 attached to the illumination light source. The individual information of the light source records information for acquiring the spectral distribution, color temperature, or characteristics of the light source. As information for acquiring the characteristics, for example, a URL on the network where the characteristics are stored, a URL of a database in which the URL of the storage location is recorded, and the like are conceivable, but the present invention is not limited to this.

An imaging apparatus according to Embodiment 4 will be described.
FIG. 9 is a schematic block diagram illustrating the imaging apparatus according to the fourth embodiment.
When a wireless tag is attached to the light source itself, the wireless tag responds if there is a request for individual information on the light source, whether it is on or off, so the light source itself is turned off Nevertheless, white balance correction may be performed based on the spectral distribution of the light source at the time of lighting, but the image pickup apparatus of Embodiment 4 prevents such a malfunction.
Individual information (for example, spectral distribution and color temperature) of the light source is recorded in the first wireless tag 61 installed in the light source. This is the same as the light source shown in the third embodiment. The light source lighting device has a first reader / writer 62 for reading the first wireless tag 61 of the light source, and writes individual information of the light source read by the first reader / writer 62 via the system controller 63. The second wireless tag 65 and the second reader / writer 64 for writing data to the second wireless tag 65 are provided. The second wireless tag 65 is read by a reader / writer 66 provided in the camera and used for white balance correction.

FIG. 10 is a flowchart illustrating an operation process of the imaging apparatus according to the fourth embodiment.
It is determined whether or not the switch has been switched in the lighting circuit 67 (step 11).
When it is detected that the switch in the lighting circuit 67 is switched from OFF to ON, the system controller 63 uses the first reader / writer 62 to transmit the individual information of the light source to the first wireless tag 61 attached to the light source. An inquiry is made (step 12), individual information of the light source is read from the first wireless tag 61 of the light source (step 13), and the second reader / writer 64 is used to store the light source information in the memory of the second wireless tag 65 of the lighting device. Individual information is written (step 14).
When it is detected that the switch in the lighting circuit 67 has been turned from ON to OFF, the system controller 63 uses the second reader / writer 64 to obtain the individual information in the memory of the second wireless tag 65 of the lighting device. Erase (step 15).

  In the imaging device of Example 4, by setting the communication distance between the light source and the lighting device to be shorter than the communication distance between the lighting device and the camera, in the state where the light source is turned off, Information can be acquired from the wireless tag of the light source, and erroneous determination that the light source is turned on can be prevented. Therefore, the camera can acquire individual information of the light source only when the light source is turned on, and white balance correction according to the characteristics of the light source can be performed.

  In the above description, the first reader / writer 62 and the second reader / writer 64 are described as separate devices, but the same device may be used by switching. In addition, although a method using a wireless tag has been described as a preferred embodiment for obtaining individual information of a light source stored in an illumination light source, the present invention is not limited to this.

FIG. 11 is a schematic block diagram illustrating a modification of the imaging apparatus according to the fourth embodiment.
The imaging device of the modification of the fourth embodiment may acquire the individual information stored in the memory 71 installed in the light source through the connector 72 by mechanical connection between the illumination light source and the lighting device. Of course.

FIG. 12 is a flowchart showing operation processing of the imaging apparatus of the modification shown in FIG.
As shown in FIG. 11, the system controller 73 inquires of the light source about the spectral characteristics via the connector 72 (step 21). If there is no response, the system controller 73 receives a response from an object other than the light source (step 24). A determination is made (step 25). The spectral distribution of the light source is estimated based on the determined photographing environment and side light data from the measuring instrument (step 27), and the white balance is corrected using the obtained spectral characteristics (step 28).

FIG. 1A is a perspective view illustrating an external appearance of a digital still camera according to a first embodiment, and FIG. 1A is a front perspective view and FIG. 1B is a rear perspective view. 1 is a block diagram illustrating a main configuration of a digital still camera according to Embodiment 1. FIG. It is a flowchart which shows the process in 2nd correction mode. 1 is a block diagram illustrating a configuration of a wireless tag that is a close proximity wireless communication element used in the present invention and a reader / writer that performs wireless communication with the wireless tag to read and write data. FIG. FIG. 6 is a block diagram illustrating a main configuration of a digital still camera according to a second embodiment. FIGS. 6A and 6B are conceptual diagrams for determining a shooting environment. FIG. 6A shows a case where the image is taken indoors, and FIG. 6B shows a case where the image is taken outdoors. It is a figure which shows the condition which image | photographs a to-be-photographed object with the digital still camera of Example 1,2. It is a figure which shows the illumination light source of Example 3. FIG. FIG. 10 is a schematic block diagram illustrating an imaging apparatus according to a fourth embodiment. FIG. 10 is a flowchart illustrating an operation process of the imaging apparatus according to the fourth embodiment. FIG. 11 is a schematic block diagram illustrating a modification of the imaging apparatus according to the fourth embodiment. FIG. 10 is a flowchart illustrating an operation process of an imaging apparatus according to a modification example of Example 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Digital still camera, 2 ... Camera body, 3 ... Shooting lens, 4 ... Lens barrel, 5 ... Optical viewfinder, 5a ... Objective window, 5b ... Eyepiece side window, 6 ... Release button, 7 ... Measurement window, 8 ... LCD (Liquid Crystal Display), 9 ... operation unit, 10 ... lid, 11 ... memory card, 21 ... memory, 22 ... data processing circuit, 23 ... modulation circuit, 24 ... transmission driver, 25 ... antenna input circuit, 26 ... power supply Generation circuit 27 ... Demodulation circuit 31 ... Data processing circuit 32 ... Modulation circuit 33 ... Transmission driver 34 ... Antenna input circuit 35 ... Demodulation circuit 41 ... Subject ... 42 ... Illumination device 51 ... Fluorescent lamp 52 ... wireless tag, 61 ... first wireless tag, 62 ... first reader / writer, 63 ... system controller, 64 ... second reader / writer, 65 ... second wireless tag, 66 ... reader, writer , 67 ... lighting circuit, 71 ... memory, 72 ... connector, 73 ... system controller, 74 and 76 ... reader / writer, 75 ... wireless tag, 77 ... lighting circuit, 101 ... imaging optical system, 102 ... CCD image sensor (imaging) Element), 103 ... amplifier, 104 ... A / D converter, 105 ... white balance circuit, 106 ... driver, 108 ... system controller, 109 ... reader / writer, 110 ... coefficient operation unit, 110a ... memory, 111 ... ROM, DESCRIPTION OF SYMBOLS 112 ... (gamma) conversion circuit, 113 ... Output image memory | storage part, 200 ... Environment discrimination | determination part, 200a ... Memory, 201 ... Color temperature measuring device, 202 ... Light source discrimination | determination part.

Claims (12)

In an imaging apparatus that captures an optical image of a subject formed by light incident through an imaging optical system using an imaging element,
Wireless communication means for performing wireless communication with the proximity wireless communication element, means for receiving a signal from a proximity wireless communication element installed in an illumination light source or an illumination device including the illumination light source, and acquiring individual information of the illumination light source; An image pickup apparatus comprising correction means for performing color correction on a photographed image using individual information of the illumination light source. The imaging device according to claim 1,
An image pickup apparatus comprising: a switching unit that switches whether or not to perform color correction using individual information of the illumination light source acquired through wireless communication with the proximity wireless communication element. The imaging device according to claim 1,
An imaging apparatus, wherein individual information of the illumination light source is added to a captured image and stored. The imaging device according to claim 1,
An imaging apparatus comprising storage means for storing spectral characteristics or color correction coefficients corresponding to individual information of the illumination light source. The imaging device according to claim 1,
When a signal from the illumination light source or the illumination device including the illumination light source cannot be received, a signal is received from a proximity wireless communication element other than the proximity wireless communication element installed in the illumination light source, Means for acquiring object information; imaging environment determining means for determining the imaging environment from information on objects existing around the imaging environment; measuring means for measuring illumination light; results of determining the imaging environment; and the illumination An imaging apparatus comprising: an illumination light source determination unit that determines the illumination light source from a light measurement result; and a correction unit that performs color correction from the determination result of the illumination light source. In an image processing apparatus of an imaging apparatus that captures an optical image of a subject formed by light incident through an imaging optical system with an imaging element,
When spectral characteristics or chromaticity information of the illumination light source in the environment where the image was captured is added to the input image information, color correction is performed using the spectral characteristic information or chromaticity information of the illumination light source. An image processing apparatus that performs the processing. The image processing apparatus according to claim 6.
The image processing apparatus according to claim 1, wherein the color correction is white balance correction. In the illumination light source where the proximity wireless communication element is installed,
The proximity wireless communication element includes light source chromaticity information, color temperature information, or spectral characteristic information, or information for acquiring the light source chromaticity information, color temperature information, or spectral characteristic information. Illumination light source characterized by being made. In an illumination device that performs illumination by turning on an illumination light source,
The illumination light source stores solid-state information of the illumination light source, and the content of a signal responding to a transmission request for the solid-state information of the illumination light source differs between when the illumination light source is turned on and when the illumination light source is turned off. apparatus. The lighting device according to claim 9.
Illumination comprising: acquisition means for acquiring individual information of the light source stored in the illumination light source; and storage means for storing the individual information of the illumination light source in a proximity wireless communication element installed in the illumination device. apparatus. The lighting device according to claim 9 or 10,
Information obtained from the illumination light source when the illumination light source is turned on is stored in a storage unit, and the information stored when the illumination light source is turned off is erased. The lighting device according to any one of claims 9 to 11,
The acquisition means for acquiring the individual information of the illumination light source stored in the illumination light source communicates with the proximity wireless communication element installed in the illumination light source, and can communicate with the proximity wireless communication element installed in the illumination device The distance is larger than the communicable distance of the proximity wireless communication element installed in the illumination light source.