KR100651813B1 - Strobo control apparatus, and strobo control method - Google Patents

Abstract

An object of the present invention is to provide a stroboscopic control apparatus and a strobe control method capable of performing imaging without the use of a photometric sensor and without giving a sense of discomfort due to the emission of strobe light. A strobe control device used for an image pickup apparatus that emits strobe light and picks up a subject by an image pickup means, the color temperature being detected based on the image pickup result picked up by the image pickup means, and based on the detected color temperature, the amount of light emitted from the strobe light or Provided is a strobe control device for correcting color temperature of strobe light.

Description

Strobo control apparatus, and strobo control method

1 is a schematic block diagram showing a configuration of a digital camera according to a first embodiment of the present invention.

2 is a graph showing an example of data stored in a color temperature / light source data storage unit.

3 is a diagram for explaining a strobe emission color filter switching unit.

4 is a flowchart for explaining the operation of the digital camera in the case of strobe light emission and imaging using the strobe control unit.

Explanation of symbols on the main parts of the drawings

21: AWB detection circuit 31: RGB integrated value generator

33: R / G / B / G integration value calculation unit 34: Color temperature / light source data storage unit

35: color temperature light source detection unit 37, 41: storage unit

39: strobe light emission amount adjusting unit 43: strobe light emission color filter switching unit

50: strobe control unit

The present invention relates to a strobe control device for correcting strobe light, and a strobe control method.

Conventionally, when a photographing object is dark when imaging in a digital camera, the brightness is supplemented by light-emitting strobe light, and imaging is taken. Here, when only the strobe light is emitted and imaged, there is a problem that the atmosphere of the ambient light source does not survive by the strobe light, resulting in an unnatural color.

Thus, for example, as described in Japanese Patent Laid-Open No. Hei 6-308586, even when strobe light is emitted in a digital camera, a stroboscopic device for photographing utilizing the surrounding atmosphere is proposed. In this stroboscope, the ambient color temperature is measured using a photometric sensor, and the color temperature of the strobe light is corrected based on the measurement result, thereby alleviating unnatural colors caused by the strobe light.

However, in the above-described strobe apparatus of Japanese Patent Laid-Open No. 6-308586, since the photometric sensor is used, a problem arises in that the number of parts increases and the cost increases. In addition, it is preferable that the digital camera is lighter in consideration of the user carrying it, but the weight of the stroboscopic device is increased by using the photometric sensor.

SUMMARY OF THE INVENTION The present invention has been made to solve various problems including the above problems, and an object of the present invention is to provide a strobe control apparatus and a strobe control method capable of capturing images without giving a sense of discomfort due to the emission of strobe light without using a photometric sensor. do.

In order to achieve the above object, the present invention is a stroboscopic control device used for an image pickup apparatus that emits strobe light and picks up a subject by an image pickup means, and detects a color temperature based on the image pickup result picked up by the image pickup means. And correction means for correcting the light emission amount of the strobe light or the color temperature of the strobe light based on the detected color temperature.

In addition, the present invention provides a strobe control apparatus comprising: a first memory for storing color temperature information of a light source corresponding to a ratio of R and G and a ratio of B and G, and strobe light emission data corresponding to the color temperature for strobe light emission; Means for calculating an integrated value of each of R, G, and B based on RGB data resulting in an image picked up by said imaging means; and said integrated value; Arithmetic means for calculating the integral value data that is the ratio of R and G and the integral value data that is the ratio of B and G among the integrated values of the RGB data generated by the generating means, and the calculation with reference to the first storage means. The strobe light emission amount data is read out based on the integrated value data of the ratio of R and G calculated by the means and the integrated value data of the ratio of B and G, and the strobe is based on the read strobe light emission amount data. And control means for causing the device to emit light.

In addition, the present invention is a strobe control device used in an image pickup device that emits strobe light and picks up a subject, comprising: detecting means for detecting a white balance gain of the subject, and based on a detection result of the detecting means; And a correction means for detecting the color temperature and correcting the amount of light emitted from the strobe light or the color temperature of the strobe light based on the detected color temperature.

In addition, the present invention further includes a second storage means for storing the strobe light emission amount data corresponding to the white balance gain and the color temperature corresponding to the white balance gain in the strobe control apparatus, wherein the correction means is provided. Second control means for reading out strobe light emission amount data corresponding to the white balance gain of the white balance detection means with reference to the second storage means, and causing the strobe device to emit light based on the read strobe light emission amount data; Characterized in having a.

In addition, the present invention provides a strobe control device, comprising: a color filter unit for storing a plurality of color filters for correcting the color of the strobe light, wherein the control device is configured to detect the color filter stored in the color filter unit; The color filter corresponding to the color temperature is set as the light emitting path of the strobe device.

In addition, the present invention is a strobe control method used in a stroboscopic control device used in an image pickup device that emits strobe light and picks up a subject by the image pickup means, the color temperature being detected based on the image pickup result picked up by the image pickup means. The light emission amount of the strobe light or the color temperature of the strobe light is corrected based on the detected color temperature.

In addition, the present invention is a strobe control method used in a strobe control device used for an image pickup device that emits strobe light and picks up a subject, wherein the white balance gain of the subject is detected, and the color temperature is based on the detected white balance gain. And correcting the amount of emitted light of the strobe light or the color temperature of the strobe light based on the detected color temperature.

Hereinafter, an image capturing apparatus using a stroboscopic control apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a digital camera is described as an example of the imaging apparatus according to the present invention. 1 is a schematic block diagram showing a configuration of a digital camera according to a first embodiment of the present invention. The digital camera of this embodiment has an image pickup device (CCD) 4 and an amplifier (AMP) circuit 9 as image pickup means for picking up a subject. A lens is disposed in front of the image pickup device 4, and the object image light that has passed through the lens is imaged on the light receiving surface of the image pickup device 4. The imaging device 4 photoelectrically converts the subject image light formed on the light receiving surface. As the imaging device 4, a CCD (Charge Coupled Device) imaging device, a CMOS (Complementary MOS) imaging device, or the like is used. The imaging device 4 is driven based on an instruction from the CPU 19 described later.

The AMP circuit 9 has a gain variable portion that varies the amplification degree with respect to the output of the image pickup device 4 that outputs the image pickup means. This AMP circuit 9 constitutes exposure changing means for changing the exposure state of the imaging means.

In addition, the digital camera according to the embodiment of the present invention includes an A / D converter 10, an image signal processing circuit 12, an image compression processing circuit 13, a video encoder 14, an image display device 15, and a CPU. (19), AF detection circuit 20, AWB detection circuit 21, memory 22, VRAM 23, media controller 24, recording medium 25, and AE detection circuit 26.

The CPU 19 controls the entire digital camera. The AWB (Automatic White Balance) detection circuit 21 detects an image signal level for white balance. The AE (Automatic Exposure) detection circuit 26 detects an image signal level for performing exposure. The exposure control signal and the white balance control signal are formed in the AWB detection circuit 21 and the AE detection circuit 26, and the exposure control signal and the white balance control signal are supplied to the CPU 19. As a result, the CPU 19, the AWB detection circuit 21, and the AE detection circuit 26 automatically control to variably control the state of the exposure changing means (AMP circuit 9) based on the output of the imaging device 4. Configure the control means.

The output signal of the imaging device 4 is supplied to the A / D converter 10 via the AMP circuit 9. The A / D converter 10 converts the image signal output from the AMP circuit 9 into a digital signal. The output signal of the A / D converter 10 is introduced into the CPU 19. The CPU 19 also performs focus control AF.

The AF (Automatic Focus) detection circuit 20 is for performing AF based on the output of the imaging device 4. The AF detection circuit 20 detects the high frequency component level of the image signal in order to perform the focus control. Based on the detected high frequency component level, the CPU 19 controls the lens to be the focus position.

In addition, the CPU 19 controls the opening degree of the aperture with respect to the aperture mechanism provided in the lens according to the exposure control signal output from the AE detection circuit 26, and the AWB detection circuit ( In accordance with the white balance control signal from 21, the image signal processing circuit 12 controls the gain of the three primary color signals. In addition, the CPU 19 supplies a gain control signal to the AMP circuit 9 and controls the gain of the AMP circuit 9 so as to reach a predetermined signal level.

The shutter switch (not shown) is a switch pressed when photographing an image. When the shutter switch is pressed, a shutter signal is sent to the CPU 19, and the image at that time is introduced into the imaging device 4. The image signal for one screen at this time is accumulated in the memory 22.

The image signal for one screen introduced into the memory 22 is supplied to the image compression circuit 13 after the image processing is performed in the image signal processing circuit 12. The image compression circuit 13 compresses and encodes image data. As a compression method of image data, JPEG (Joint Photographic Experts Group) is used, for example. JPEG is a standard for compressing images using DCT (Discrete Cosine Transform). In addition, the compression method of image data is not limited to JPEG.

The compression-encoded image signal is supplied to the recording medium 25 through the media controller 24 and recorded on the recording medium 25. As the recording medium 25, for example, a card-type removable free memory using a flash memory is used. As the recording medium 25, a nonvolatile memory, a magnetic tape, a magnetic disk, an optical disk, or the like built in a digital camera may be used.

Next, the strobe control unit 50 will be described. The strobe controller 50 controls to correct the amount of strobe light emitted by the strobe light emitting part (not shown) that emits strobe light or the color temperature of the strobe light. The RGB integrated value generator 31 is output from the A / D converter 10. The integrated value is calculated based on the RGB data resulting from the image picked up by the image pickup device 4. This integrated value is calculated for each of R, G, and B. This integration may be integrated for all the pixels, or all pixels may be divided into a plurality of pixels to be integrated for the pixels in the divided region.

The R / G, B / G integrated value calculating section 33 is the integrated value data which becomes the ratio (R / G) of R and G among the integrated values of the RGB data generated by the RGB integrated value generating section, and B and G. Calculate the integrated value data which is the ratio (B / G) of.

The color temperature / light source data storage unit 34 stores the light source corresponding to the ratio of R and G and the ratio of B and G, and the color temperature information of the light source. An example of data stored in this color temperature / light source data storage 34 is shown in FIG. 2. In Fig. 2, the vertical axis is the ratio (B / G) of the integrated values of B and G, and the horizontal axis is the ratio (R / G) of R and G, and the light source and color temperature corresponding thereto are stored. For example, here, there are five types of shades of shading and shading (shade / clouding (symbol a) in FIG. 2), sunlight (symbol b), fluorescent lamp (symbol c), incandescent lamp (symbol d) and tungsten (symbol e). It is classified by light source, and color temperature information is stored such as shading and clouding at 10000 ° C, sunlight at 5000 to 6000 ° C, fluorescent lamp at 4000 ° C, incandescent lamp at 3000 ° C, and tungsten at 2000 ° C.

The data stored in the color temperature / light source data storage unit 34 stores, in advance, the distance between the coordinates of the center coordinates, the vertical axis, and the horizontal axis as coordinate values for each light source, so as to enter the coordinate range of which light source. It becomes possible to detect. Moreover, although this light source was illustrated about the case classified into five types, four or less types may be sufficient and six or more types may be sufficient as it.

The color temperature and light source detection unit 35 refers to the color temperature and light source data storage unit 34 to calculate the integrated value of the R / G and the integrated value of the B / G output from the R / G and B / G integrated value calculation unit 33. Detects the light source and color temperature corresponding to the combination of.

The storage unit 37 stores the light emission amount for strobe light emission corresponding to the color temperature in correspondence with the color temperature as strobe light emission amount data. In this case, the strobe light emission amount is stored as the color temperature is lowered, and the strobe light emission amount is increased as the color temperature is increased. The strobe light emission amount data may be stored in correspondence with the color temperature or in correspondence with the light source.

The strobe light emission amount adjusting unit 39 reads the strobe light emission amount data corresponding to the color temperature detected by the color temperature and light source detection unit 35 with reference to the storage unit 37, and the strobe light emission unit data is read based on the read strobe light emission amount data. The amount of light to strobe light is controlled.

The storage unit 41 stores color temperature information of the light source corresponding to the ratio of R and G and the ratio of B and G, and color filter information for designating a color filter to be used according to the color temperature. The strobe light emission color filter switching unit 43 has a color filter unit for storing a plurality of color filters according to the color temperature of the object to be photographed, and the color temperature / light source detection unit among the plurality of color filters stored in the color filter unit with reference to the storage unit 41. A color filter corresponding to the color filter information detected by 35 is set on the light emitting path of the stroboscope.

Here, the strobe emission color filter switching section 43 will be described in more detail with reference to FIG. 3. The color filter 200 is set between the light emitting glass surface 100 provided in the strobe light source and the light source (on the light emission path) in the strobe light emitting unit which emits strobe light of the imaging device. Here, the color filter 200 is stored in plural sheets in the color filter unit, and the color filter corresponding to the color filter information is driven from the color filter unit by the driving means of the strobe light emission color filter switching unit 43 from the light emitting glass surface 100. It sets by moving between and a light source. On the basis of the color filter information, this color filter is set to orange when the light source is tungsten, a yellow filter when the light source is a fluorescent lamp, a yellow filter when the light source is incandescent lamp, and a blue filter when the shade is shaded. This color filter may be set by polymerizing a plurality of sheets.

Next, the operation of the digital camera of the above-described embodiment will be described with reference to the drawing centering on the operation of the strobe controller 50. 4 is a flowchart for explaining the operation of the digital camera when the strobe light is emitted using the strobe control unit 50 to capture an image. Here, as an example, the case where a light source is a tungsten light source is demonstrated. First, in imaging, it is detected with reference to the user's instruction input through a switch or the like as to whether the image is in the stroboscopic imaging mode (step S11). If it is not in the strobe shooting mode, imaging is terminated without performing strobe light emission.

On the other hand, in the strobe photographing mode, at the time of pre metering, the subject image light is received by the image pickup device 4, amplified by the AMP circuit 9, and digital value by the A / D converter 10. When the RGB data converted into the < Desc / Clms Page number 5 > Next, the RGB integrated value generation unit 31 calculates an integrated value for each of R, G, and B based on the RGB data, and outputs the integrated value to the R / G · B / G integrated value calculation unit 33. When the R / G and B / G integrated value calculating unit 33 obtains the integrated value output from the RGB integrated value generating unit 31 (step S12), the integrated values of R / G and B / G are calculated. The calculation result is output to the color temperature / light source detection unit 35 (step S13).

The color temperature and light source detection unit 35 refers to the color temperature and light source data storage unit 34 to detect a color temperature and a light source corresponding to each integrated value of R / G and B / G. Here, the data shown in FIG. 2 is referred to, and since it is detected that the coordinate of the intersection of the integrated value of R / G and the integrated value of B / G is in the area | region which shows a tungsten light source, it is detected that a light source is a tungsten light source, and a tungsten light source The color temperature according to the present invention is detected as color temperature information (step S14). The strobe light emission amount adjusting unit 39 acquires the color temperature information detected by the color temperature and light source detection unit 35, reads out the strobe light emission amount according to the acquired color temperature information from the storage unit 37, and outputs the light amount of strobe light based on the read out strobe light emission amount. Is instructed to the strobe light emitting unit (step S15).

On the other hand, the strobe light emission color filter switching unit 43 acquires color temperature information detected by the color temperature and light source detection unit 35, reads color filter information according to the acquired color temperature information from the storage unit 41, and reads out the color filter. The color filter corresponding to the information is switched and mounted by moving from the color filter part onto the light emission path of the light source and the light emitting glass surface (step S16). In this case, since the light source is a tungsten light source, it is switched to an orange color filter. When the shutter pressed halfway is pushed in further, the strobe light emission according to the tungsten light source is emitted as the strobe light emission amount according to the instruction of the strobe light emission amount adjusting unit 39, and the image is captured (step S17).

According to the embodiments described above, strobe light emission can be performed at the strobe light emission amount and the color temperature of the strobe light according to the light source. For example, in the case of a tungsten light source, it is possible to darken the overall light at a setting that emphasizes the atmosphere to suppress stroboscopic light and thereby to emit light without using a photometric sensor and without damaging the atmosphere such as the solidity of the tungsten light source. can do. In addition, when the light source is a fluorescent lamp, the sun, or the like, the dark atmosphere does not overlap, so the amount of stroboscopic light emission is increased compared to the tungsten light source to emit light.

In addition, by switching to the color filter according to the color temperature of the light source, the image can be captured while maintaining the atmosphere of the light source that is normally not erased by the strobe light, thereby reducing the gap between the color temperature of the strobe light and the ambient light. Even if strobe light is emitted, an image of an atmosphere that does not feel strobe light can be generated.

Next, a second embodiment will be described. In the above-described embodiment, the case where the value obtained by calculating the integrated value of RGB based on the information acquired from the image pickup device 4 is used when controlling strobe light emission, has been described in the present embodiment. The case where the white balance value is used instead of the information obtained from the above) will be described.

The configuration of the second embodiment is the same as that of Fig. 1, but the functions thereof are different. The difference will be described below. The AWB detection circuit 21 detects the white balance gain and outputs the detection result to the color temperature / light source detection unit 35. The color temperature / light source data storage unit 34 associates the white balance gain with the color temperature corresponding to the white balance gain and stores them as table information. In addition, the color temperature / light source data storage unit 34 associates the color temperature with a light source corresponding to the color temperature and stores the information as table information.

In this configuration, when imaging is performed, if the white balance gain is detected by the AWB detection circuit 21 during pre-photometry, the detection result is output to the color temperature / light source detection unit 35. The color temperature / light source detector 35 acquires a color temperature corresponding to the white balance gain output from the AWB detection circuit 21 with reference to the table information of the color temperature / light source data storage 34. By detecting this color temperature, a light source corresponding to the color temperature is also specified with reference to the table information.

Then, the color temperature and the light source are specified by the color temperature and light source detection unit 35, whereby the strobe light emission amount adjusting unit 39 controls the strobe light emission amount, and the strobe light emission color filter switching unit 43 switches the color filter. Is done.

According to this embodiment, since the color temperature is specified according to the value of the white balance gain, it is possible to directly specify the color temperature in comparison with the first embodiment, and it is also possible to improve the accuracy of the color temperature specification.

In addition, in the above-described embodiment, the exposure may be darkened or brightened according to the detected color temperature to capture the image.

In addition, the RGB integrated value generating unit 31, the R / G and B / G integrated value calculating unit 33, the color temperature and light source detecting unit 35, the strobe emission amount adjusting unit 39, and the AWB detecting circuit 21 shown in FIG. The strobe light emission may be controlled by recording a program for realizing the function on a computer-readable recording medium, and executing the program recorded on the recording medium to be read by the imaging device. The recording medium referred to here is a memory card that can be read by a camera, a magnetic disk, an optical disk, a memory built into the camera, or the like. This program may be downloaded from the Internet in addition to being executed through a recording medium.

In this case, the color filter switching may be implemented by separately purchasing the color filter unit, mounting it in the imaging device, and reading out the program in the imaging device.

As described above, according to the present invention, the color temperature is specified based on the detection result (for example, RGB data) or the white balance gain of the imaging means, instead of merely referring to the ambient brightness, and according to the color temperature Since the emission amount and the strobe emission color are controlled, natural color taste can be reproduced in the atmosphere of the ambient light source without causing discomfort without using the photometric sensor.

In addition, according to the present invention, in the case of strobe light emission, the color filter according to the color temperature is switched so that the color taste of the photograph is prevented from becoming the dominant color of the strobe light, so that the strobe light emission is felt without affecting the strobe light emission color. You can complete it with a picture of nature's color.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and any person skilled in the art to which the present invention pertains may have various modifications and equivalent other embodiments. Will understand. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (7)

A strobe control device used for an imaging device which emits strobe light and picks up a subject by an imaging means, And a correction means for detecting a color temperature based on the imaging result picked up by the imaging means, and correcting the amount of light emitted from the strobe light or the color temperature of the strobe light based on the detected color temperature. The method of claim 1, First storage means for storing color temperature information of the light source corresponding to the ratio of R and G and the ratio of B and G, and stroboscopic emission amount data for strobe light emission corresponding to the color temperature; The correction means is: Integrated value generating means for calculating respective integrated values of R, G, and B based on RGB data resulting in the image picked up by said image pickup means; Calculating means for calculating integrated value data that is a ratio of R and G and integrated value data that is a ratio of B and G among the integrated values of the RGB data generated by the integration value generating means; The strobe light emission amount data is read out based on the integrated value data of the ratio of R and G and the integrated value data of the ratio of B and G calculated by the calculation means with reference to the first storage means, and based on the read strobe light emission amount data. And a control means for emitting light to the strobe device. A strobe control device used for an imaging device that emits strobe light and picks up a subject, Detection means for detecting a white balance gain of the subject; And a correction means for detecting a color temperature based on a detection result of said detection means, and correcting a light emission amount of strobe light or a color temperature of said strobe light based on the detected color temperature. The method of claim 3, wherein And second storage means for correspondingly storing the white balance gain and the stroboscopic light emission data corresponding to the color temperature corresponding to the white balance gain, The correction means, And second control means for reading strobe light emission amount data corresponding to the white balance gain of the white balance detection means and emitting light to the strobe apparatus based on the read strobe light emission amount data with reference to the second storage means. Strobe control device. The method according to any one of claims 1 to 4, Further comprising a color filter unit for storing a plurality of color filters for correcting the color of the strobe light, And the control device sets a color filter corresponding to the detected color temperature among the color filters stored in the filter unit in the light emitting path of the strobe device. A strobe control method used in a strobe control device used for an imaging device which emits strobe light and picks up a subject by an imaging means, And a color temperature is detected based on the imaging result picked up by the imaging means, and corrects the light emission amount of the strobe light or the color temperature of the strobe light based on the detected color temperature. A strobe control method used in a strobe control device used for an imaging device which emits strobe light and picks up a subject, Detect the white balance gain of the subject, And detecting a color temperature based on the detected white balance gain, and correcting the light emission amount of the strobe light or the color temperature of the strobe light based on the detected color temperature.

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