JP2002354338A - Imaging device and imaging method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device and an imaging method by which burdens are placed on a user with posterior image processing by himself because of acquisition of only one image with wrong white balance correction can be reduced. SOLUTION: The imaging device has a mode of acquiring two or more images with a single photographing. When this mode is selected (S202, YES), two images are acquired using different white balance correction values with a single photographing (S207 and S211), so that the user can perform image processing by using one of the two images.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a white balance between information obtained from a colorimetric sensor for detecting the color temperature of ambient light (hereinafter also referred to as an external sensor) and information obtained from an image signal output from an image sensor. The present invention relates to an imaging device and an imaging method used for correction.

[0002]

2. Description of the Related Art Conventionally, as an automatic white balance method in an image pickup apparatus such as a digital still camera, an external sensor method, TTL (Through The Le) is used.
ns) system and its hybrid system. The external measurement sensor method performs white balance correction using information obtained by measuring the color of the external light, and the TTL method calculates the color of the external light from an output signal of the image sensor and uses the information to calculate white balance. This is to correct white balance. The hybrid system is a system that uses information of both the external sensor system and the TTL system.

[0003]

A) In the hybrid system, two color temperature information can be obtained by the TTL system and the external sensor system. However, if the color temperature information obtained from the TTL method is different from the color temperature information obtained from the external sensor method, at least one of them indicates that incorrect color temperature information has been detected. Which is correct to some extent can be predicted from the luminance information of the subject or the like, but it cannot always be said that it is correct. JPEG
If a captured image is stored in a format other than the RAW data, such as the format, and image processing is performed with incorrect color temperature information, it is very difficult to correct the image to the correct color afterwards. .

B. In the hybrid system, in addition to the method of selecting and using color temperature information obtained from two systems, the TTL system and the external sensor system, the color temperature information obtained by the external sensor system is used. Therefore, a method of changing the color temperature detection range by the TTL method is also used. In this case, there are several methods for changing the color temperature detection range. For example, based on rough color temperature information obtained from an external sensor, a method of detecting all color temperatures that can be predicted from the color temperature from an image by a TTL method,
In this method, only a certain light source (for example, whether it is a fluorescent lamp or the like) is determined from the external measurement sensor, and TTL color temperature detection is performed within a color temperature range that can be taken by a predetermined light source.

In the above method, the former is TTL
While the color temperature is detected by giving priority to the method, the latter gives priority to the external measurement sensor over the TTL method. Here, in the latter case where the external measurement sensor is prioritized, if the color temperature of the light illuminating the subject and the color temperature of the light illuminating the external measurement sensor are different, there is a disadvantage that incorrect color temperature information is detected. When the color temperature of the light illuminating the subject and the external measurement sensor is the same, the color temperature can be detected with high accuracy. In the case of the former TTL system priority, even if the color temperature of the light illuminating the subject and the color temperature of the light illuminating the external measurement sensor are different, it is rare that an erroneous color temperature is detected. In many cases, the correct color temperature cannot be detected due to the influence of the color. Therefore, when the color temperature of the light illuminating the subject and the external sensor is the same, it is desirable to give priority to the external sensor, and if the color temperature is different, it is desirable to give priority to TTL, but in practice it is very difficult to distinguish between them. is there.

The present invention has been made under such a situation, and reduces the burden of acquiring an image on which erroneous white balance correction has been performed and imposing a subsequent user on image processing. It is an object of the present invention to provide an imaging device and an imaging method capable of performing the above.

[0007]

In order to achieve the above object, the present invention provides an image pickup apparatus having the following (1) to (5).
And the imaging method is configured as in the following (6) to (9).

(1) In an image pickup apparatus having a mode for acquiring two or more images in one photographing, when the above mode is selected, white balance correction is performed by different numerical values in one photographing. An imaging apparatus including a control unit that controls so as to acquire more than one image.

(2) A colorimetric sensor for detecting information relating to the color temperature of ambient light, and color information detecting means for detecting information relating to the color temperature of light illuminating the subject from an image signal output from the image sensor. A first numerical value deriving unit that derives a numerical value of white balance correction based on information detected by the colorimetric sensor, and a numerical value of white balance correction based on information detected by the color information detecting unit. The second numerical value deriving means, and the difference between the numerical value derived by the first numerical value deriving means and the numerical value derived by the second numerical value deriving means is not within a predetermined range. Two images, an image subjected to white balance correction by the numerical value derived by the deriving means and an image subjected to white balance correction by the numerical value derived by the second numerical value deriving means, An image pickup apparatus having a control means for controlling to acquire.

(3) A colorimetric sensor for detecting information on the color temperature of ambient light, and color information detecting means for detecting information on the color temperature of light illuminating the subject from an image signal output from the image sensor. A first numerical value deriving means for deriving a numerical value of a white balance correction giving priority to the colorimetric sensor based on information detected by the colorimetric sensor and information detected by the color information detecting means, and A second numerical value deriving means for deriving a numerical value of white balance correction giving priority to the color information detecting means based on the information detected by the color information detecting means and the information detected by the color information detecting means; and a numerical value derived by the first numerical value deriving means. When the difference between the numerical value derived by the second numerical value deriving means and the numerical value derived by the second numerical value deriving means is not within a predetermined range, the white value is derived from the numerical value derived by the first numerical value deriving means. An image pickup apparatus having a control means for controlling to acquire two images with the image subjected to Balance correction and the second numerical derivation means image subjected to white balance correction by a value obtained by derivation with.

(4) In the image pickup apparatus according to any one of (1) to (3), when the photographing data format is a RAW format, the control means controls two or more images in one photographing. An imaging device that controls so as to acquire only one image without acquiring the image.

(5) In the image pickup apparatus according to any one of (1) to (3), when the control unit obtains two or more images by one photographing, the control unit transmits each image to be obtained. An imaging device that controls display on a display.

(6) An image pickup method in an image pickup apparatus having a mode for acquiring two or more images in one photographing, wherein step A for selecting the mode, and a case where the mode is selected in step A A step B of acquiring two or more images using different white balance correction values in one photographing.

(7) A colorimetric sensor for detecting information relating to the color temperature of ambient light, and color information detecting means for detecting information relating to the color temperature of light illuminating the subject from an image signal output from the image sensor. An imaging method in an imaging device, comprising: a step A of deriving a numerical value of white balance correction based on information detected by the colorimetric sensor; and a numerical value of white balance correction based on information detected by the color information detecting unit. Deriving step B, and step C of determining whether a difference between the numerical value derived in step A and the numerical value derived in step B is within a predetermined range.
And when an image cannot be determined to be within the predetermined range in step C, an image subjected to white balance by the numerical value derived in step A and an image subjected to white balance correction by the numerical value derived in step B An imaging method, comprising: acquiring D images.

(8) A colorimetric sensor for detecting information relating to the color temperature of ambient light, and color information detecting means for detecting information relating to the color temperature of light illuminating the subject from the image signal output from the image sensor. An imaging method in an imaging apparatus, comprising: a step A of deriving a numerical value of a white balance correction with priority on a colorimetric sensor based on information detected by the colorimetric sensor and information detected by the color information detecting means; Step B of deriving a numerical value of the white balance correction giving priority to the color information detecting means based on the information detected by the sensor and the information detected by the color information detecting means, and the numerical value derived in the step A and the numerical value derived in the step B Step C for determining whether the difference from the numerical value is within a predetermined range; In this case, there is provided a step D of acquiring two images, an image subjected to white balance correction by the numerical value derived in step A and an image subjected to white balance correction by the numerical value derived in step B. Imaging method.

(9) The imaging method according to any one of (6) to (8), further comprising the step of displaying each image on a display when acquiring two or more images. Method.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to embodiments of a digital still camera. In addition,
The present invention is not limited to the form of an apparatus, but can be implemented in the form of a method supported by the description of the embodiments.

[0018]

FIG. 1 is a block diagram showing a configuration of a white balance control system in a "digital still camera" according to a first embodiment.

In FIG. 1, reference numeral 100 denotes a solid-state image pickup device such as a CCD (Charge Coupled Device) which converts an optical signal s10 from a subject into an electric signal and outputs it as an image signal s11.
This image signal s11 is recorded once in the memory 105.
Reference numeral 101 denotes a white balance gain calculation unit that calculates a white balance gain s12 from the image signal s11 converted by the solid-state imaging device 100. Reference numeral 102 denotes a colorimetric sensor that detects colorimetric sensor data s13 that is R, G, and B (red, green, and blue) information of ambient light. Reference numeral 103 denotes a white balance gain s1 based on the colorimetric sensor data s13.
4 is a white balance gain calculation block for calculating the value No. 4. Reference numeral 104 compares the white balance gain s12 calculated by the TTL method with the white balance gain s14 calculated by the external measurement sensor method.
The image signal processing circuit 10 uses the white balance gain s12 calculated by the L method as a white balance gain s15.
Send to 6. Conversely, if the value is far, the respective white balance gains s12, s12 calculated by the TTL method and the colorimetric sensor are used.
s14 is sent to the image signal processing circuit 106 as a white balance gain s15. An image signal processing circuit 106 performs a white balance correction by multiplying the image signal s11 stored in the memory 105 by a white balance gain s15. Here, when there are two types of white balance gains s15, the image signal processing circuit s106
5, the same image signal is called twice, and images s16 multiplied by the respective white balance gains s15 are sequentially output.

FIG. 2 is a flowchart showing the processing of the white balance control system in the digital still camera according to the present embodiment. A more detailed description will be given based on this flowchart.

First, in step 201 (denoted as S201 in the figure), it is confirmed that the storage format of the captured image is not the RAW mode. If the storage format is the RAW mode, the process proceeds to step 212 of the conventional white balance processing. Next, in step 202, it is determined whether or not a mode for outputting two or more images is selected.
Here, if the mode is not selected, the process proceeds to the conventional white balance processing step 212. Here, step 2 of the conventional white balance processing
Reference numeral 12 denotes a hybrid white balance method combining a TTL method and an external sensor method, and a detailed method is not particularly limited. Next, step 203
Then, the image is read from the memory 105. Then step 2
In step 04, a white balance gain s12 by the TTL method is calculated from the read image data. Next, in step 205, the white balance gain s based on the external measurement sensor system based on the data obtained from the external measurement colorimetric sensor.
14 is calculated. Next, in step 206, white balance correction is performed using the TTL white balance gain s12. Next, in step 207, the image after white balance correction is output. Next, the white balance gain s12 based on the TTL method and the white balance gain s14 based on the external sensor method are compared. If the difference is equal to or more than a certain value α, the process proceeds to step 209; The process ends when one sheet is output.

In step 209, the same image is called from the memory 105 again. Then, in step 210, the image is subjected to white balance gain s1 by the external sensor method.
4 to perform white balance correction. Then, in step 211, the image after the white balance correction is output, and the processing of the white balance control system ends.

As described above, according to this embodiment,
When the possibility of erroneous white balance correction is high, the user can select either one of the two images that he or she considers desirable, so that the work of editing colors after shooting can be reduced as much as possible.

In this way, it is possible to reduce the burden of acquiring only one image on which erroneous white balance correction has been performed and imposing a burden on subsequent image processing by the user.

Embodiment 2 FIG. 3 is a block diagram showing a configuration of a white balance control system in a "digital still camera" according to Embodiment 2.

FIG. 3 differs from the first embodiment in that when calculating the white balance gain, both the image signal s11 obtained from the CCD output and the colorimetric data obtained from the colorimetric sensor are considered. Is a point. Other configurations are the same as those of the digital still camera in FIG.

Reference numeral 301 denotes a color temperature sensor information s13 that predicts a possible color temperature of light actually illuminating the subject, and obtains a white balance gain by limiting a color temperature range detected from the image signal s11. (TT
White balance giving priority to the L method). 303
Considers that the colorimetric data s13 obtained from the colorimetric sensor 102 and the colorimetric data of the light illuminating the subject are the same, and determines the color temperature range detected from the image signal s11 with the data obtained from the colorimetric data s13. The white balance gain is determined only for the same color temperature (white balance giving priority to the external sensor method).

FIG. 4 is a flowchart showing the white balance control system processing in the digital still camera of the present embodiment. A more detailed description will be given based on this flowchart.

First, at step 401, the image signal s11 is read from the memory 105. Next, in step 402, the TT is calculated in consideration of the colorimetric sensor data s13 from the image signal s11.
The white balance gain s32 giving priority to the L method is calculated. Next, in step 403, the white balance correction of the image s11 is performed using the white balance gain s32 giving priority to the TTL method. Then, in step 404, the image is output. Next, in step 405, it is confirmed that the storage format of the captured image is not the RAW mode. Here, if the storage format is the RAW mode, the processing of the white balance control system is terminated as it is. Then step 4
At 06, it is determined whether or not the mode for outputting two or more images is selected. Here, if the mode has not been selected, the processing of the white balance control system is terminated. Next, in step 407, the white balance gain detection range is limited to the color temperature calculated from the colorimetric sensor data s13, and the white balance gain s34 giving priority to the external sensor system is calculated.

Next, at step 408, the white balance gain s32 giving priority to the TTL method and the white balance gain s34 giving priority to the external measurement sensor method are compared. If the difference is less than a certain value β, The processing of the white balance control system ends. Only in other cases, the processing of step 409 is performed. In step 409, the image s11 is read from the memory 105 again. In step 410, the white balance correction of the image s11 is performed using the white balance gain s34 giving priority to the external sensor system. Next, in step 411, an image subjected to white balance correction giving priority to the external measurement sensor system is output, and the processing of the white balance control system ends.

As described above, according to the present embodiment,
As in the case of the first embodiment, it is possible to reduce the burden of acquiring only one image on which erroneous white balance correction has been performed and imposing a load on image processing performed by a subsequent user.

In each of the above embodiments, the color temperature is obtained by two types of methods, but any number of types may be used. The color temperature may be obtained by the number of the types, and the image may be acquired by the number of the color temperatures.

In each embodiment, when two or more images are acquired, each image may be displayed on a display so that the user can check the state of the white balance.

[0034]

As described above, according to the present invention,
It is possible to reduce the burden of acquiring only one image on which erroneous white balance correction has been performed and imposing a burden on image processing by a user later.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a white balance control system according to a first embodiment.

FIG. 2 is a flowchart illustrating white balance control processing according to the first embodiment.

FIG. 3 is a block diagram illustrating a configuration of a white balance control system according to a second embodiment.

FIG. 4 is a flowchart illustrating white balance control processing according to a second embodiment.

[Explanation of symbols]

REFERENCE SIGNS LIST 100 CCD 101 TTL white balance gain calculating means 102 TTL colorimetric sensor (external sensor) 103 white balance gain calculating means using external sensor 104 white balance control circuit 106 image signal processing circuit

Claims (9)

[Claims] 1. An image pickup apparatus having a mode for acquiring two or more images in one photographing operation, wherein when the mode is selected, two images in which white balance correction is performed by different numerical values in one photographing operation. An imaging apparatus, comprising: a control unit that controls so as to acquire the above-described image. 2. An image pickup apparatus comprising: a colorimetric sensor for detecting information on a color temperature of ambient light; and a color information detecting means for detecting information on a color temperature of light illuminating a subject from an image signal output from the image pickup device. In the apparatus, first numerical value deriving means for deriving a numerical value of white balance correction based on information detected by the colorimetric sensor; and a numerical value of white balance correction based on information detected by the color information detecting means. A second numerical value deriving unit, wherein when the difference between the numerical value derived by the first numerical value deriving unit and the numerical value derived by the second numerical value deriving unit is not within a predetermined range, the first numerical value deriving unit Two images, an image subjected to white balance correction by the numerical value derived by the means and an image subjected to white balance correction by the numerical value derived by the second numerical value deriving means, An imaging apparatus, comprising: control means for controlling acquisition. 3. An image pickup apparatus comprising: a colorimetric sensor for detecting information on a color temperature of ambient light; and a color information detection unit for detecting information on a color temperature of light illuminating a subject from an image signal output from the image pickup device. In the apparatus, a first numerical value deriving unit that derives a numerical value of white balance correction giving priority to the colorimetric sensor based on the information detected by the colorimetric sensor and the information detected by the color information detecting unit; A second numerical value deriving unit that derives a numerical value of white balance correction giving priority to the color information detecting unit based on the detected information and the information detected by the color information detecting unit; and a numerical value derived by the first numerical value deriving unit. When the difference from the numerical value derived by the second numerical value deriving means is not within a predetermined range, the white value is calculated by the numerical value derived by the first numerical value deriving means. An image pickup apparatus comprising: control means for controlling so as to obtain two images, that is, an image on which balance correction has been performed and an image on which white balance correction has been performed based on numerical values derived by the second numerical value derivation means. apparatus. 4. The imaging device according to claim 1, wherein the control unit does not acquire two or more images in one photographing when the photographing data format is a RAW format. ,
An image pickup apparatus that controls so as to acquire only one image. 5. The imaging device according to claim 1, wherein the control unit displays each of the acquired images on a display when acquiring two or more images in one photographing operation. An imaging apparatus characterized by performing control so as to perform the following operations. 6. An imaging method for an imaging apparatus having a mode for acquiring two or more images in one photographing, comprising: a step A of selecting the mode; and a step of selecting the mode in the step A. A step B of acquiring two or more images using different white balance correction values in one photographing operation. 7. An image pickup apparatus comprising: a colorimetric sensor for detecting information on a color temperature of ambient light; and color information detecting means for detecting information on a color temperature of light illuminating a subject from an image signal output from the image pickup device. An imaging method in an apparatus, comprising: a step A of deriving a numerical value of white balance correction based on information detected by the colorimetric sensor; and deriving a numerical value of white balance correction based on information detected by the color information detecting unit. Step B to perform, Step C to determine whether the difference between the numerical value derived in Step A and the numerical value derived in Step B is within a predetermined range, and it is not possible to determine in Step C that the difference is within a predetermined range. In this case, the image obtained by performing the white balance using the numerical value derived in step A and the white balance Imaging method characterized by comprising the steps D to acquire two images with subjected to correction image. 8. An image pickup apparatus comprising: a colorimetric sensor for detecting information on a color temperature of ambient light; and color information detecting means for detecting information on a color temperature of light illuminating a subject from an image signal output from the image pickup device. An imaging method in an apparatus, wherein a numerical value of a white balance correction prioritizing a colorimetric sensor is derived based on information detected by the colorimetric sensor and information detected by the color information detecting means.
A step B of deriving a numerical value of white balance correction giving priority to color information detection means based on information detected by the colorimetric sensor and information detected by the color information detection means; and the numerical value derived in step A and Step C for determining whether the difference from the numerical value derived in Step B is within a predetermined range; and, if it is not possible to determine in Step C that the difference is within the predetermined range, white balance correction is performed using the numerical value derived in Step A. A step D of acquiring two images: an image subjected to white balance correction and an image subjected to white balance correction based on the numerical value derived in step B. 9. The imaging method according to claim 6, further comprising a step of displaying each image on a display when acquiring two or more images. Imaging method.