JP2002057933A - Image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pickup device that eliminates useless photographing in the case of generating a blur control image. SOLUTION: The image pickup device is provided with an image pickup means and an image pickup control means that makes the image pickup means pick up images whose focal distance is respectively adjusted depending on a distance up to a main subject to be photographed in a blur control processing mode. For example, in the case that one subject or more exists in a foreground of the main subject, the image pickup control means makes the image pickup means pick up images of the main subject, any of the subjects in the foreground and a subject in a background in total three shots while the focus is adjusted to them, and in the case that no subject in the foreground of the main object exists and two or more background objects with different distance exist, the image pickup control means makes the image pickup means pick up images of the main object and two of the objects in the background and in total three shots while the focus is adjusted to each of them. Thus, the image pickup device can efficiently pick up original images required for the blur control processing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an imaging device such as a digital camera.

[0002]

2. Description of the Related Art As a digital camera, for example, a plurality of images having different focal lengths focused on a foreground and a background, respectively, are taken, and from these plurality of images, an all-focus image in which a plurality of subjects are focused on each other, Some have a function of creating a blur control image in which the degree of blur of a subject such as a foreground or a background is adjusted.

For example, Japanese Patent Application Laid-Open No. Hei 10-257369 discloses a technique in which the positions of a plurality of CCD image pickup devices are shifted along the optical axis, and images picked up from the plurality of CCD image pickup devices are processed at the same time. Discloses a configuration for creating an omnifocal image in which all subjects are focused.
Although this publication discloses a case where an omnifocal image is created, there is no description about a case where a blur control image is created.

[0004]

By the way, in order to obtain an all-in-focus image for a specific scene to be photographed, all images focused on a plurality of subjects having different focal lengths are taken, respectively. It is necessary to perform omnifocal image processing using the plurality of acquired images. Also, for the same scene, when obtaining a blur control image in which the degree of blur of a part of the subject such as the foreground or the background is adjusted, similarly to the case of obtaining the omnifocal image, each of the plurality of subjects is All the images focused on are captured, and blur control image processing is performed using a plurality of the obtained images.

[0005] When obtaining a blur control image in this way, it is not efficient to capture all images in which each of a plurality of objects is focused, since useless shooting cannot be avoided.

The present invention has been made in view of the above circumstances, and has as its object to provide an image pickup apparatus capable of eliminating useless image pickup when creating a blur control image.

[0007]

An object of the present invention is to provide an image pickup means, and an image pickup control means for causing the image pickup means to pick up a plurality of images whose focal lengths have been adjusted in accordance with the distance of a main subject in a blur control processing mode. , Is provided.

In this imaging apparatus, in the blur control processing mode, a plurality of images having different focal lengths are captured according to the distance of the main subject, so that an original image required for the blur control processing can be efficiently captured. It is possible to eliminate unnecessary imaging and blur control processing.

Specifically, when one or more foreground subjects are present than the main subject, the imaging control means includes a main subject, one of the foreground subjects, and a background subject. It is preferable to perform three focused imagings. Or, there is no subject in the foreground than the main subject,
When there is one background subject, the imaging control means may perform two imagings focusing on the main subject and at infinity. Alternatively, when there is no foreground subject than the main subject and there are two or more background subjects at different distances, the imaging control unit may control the main subject and the background subject respectively. The imaging may be performed three times with focusing on the image.

In any case, an image necessary for the blur control process can be efficiently obtained.

[0011] The image processing apparatus may further include a combination processing unit that creates a blur control image using the image acquired by the imaging unit. With such a configuration, a single imaging device can obtain not only each captured image but also a composite image obtained by the blur control process.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 are an external perspective view and a rear view, respectively, showing a digital camera to which an image pickup apparatus according to an embodiment of the present invention is applied.

In FIG. 1 and FIG. 2, reference numeral 1 denotes a digital camera, which is provided with a photographing lens 2, a finder window 5, a distance measuring window 101, and the like on the front surface of a camera body 1A. A CCD 3 as an image sensor for photoelectrically converting the obtained optical image is provided on the optical path of the photographing lens 2. Then, the photographing lens 2, CC
The imaging means is configured to include D3. Further, on an upper surface of the camera body 1A, a release (shutter) button 4, a shooting mode setting key 8, a liquid crystal display panel 9, and the like are provided. In the figure, reference numeral 6 denotes a recording medium for storing image data, and reference numeral 7 denotes a recording medium insertion opening formed on a side surface of the camera body 1A.

The photographing mode setting key 8 is used by the photographer to set exposure conditions such as aperture priority and shutter speed priority while switching the macro photography, and further perform zoom setting while looking at the liquid crystal display panel 9. .

As shown in FIG. 2, an image processing mode setting key 102, a liquid crystal monitor 103 as a view finder, and the like are provided on the back of the camera body 1A.
An image processing mode setting key 102 is used when the photographer sets a combined image mode for creating an all-focus image or a blur control image while setting the blur amount while watching the liquid crystal monitor 103.

This digital camera 1 can record image data captured by the CCD 3 on a recording medium 6 in the same manner as a normal camera, and also has a function of creating an all-focus image from a plurality of images having different focal lengths. It has a function to create a blur control image. The function of creating the blur control image is activated by operating the image processing mode setting key 102 to set the blur control mode.

FIG. 3 is a block diagram showing the electrical configuration of the digital camera 1, wherein thin arrows indicate the flow of control data.
Thick arrows indicate the flow of image data.

Reference numeral 40 denotes a CPU which stores the photographing conditions when the release button 4 is pressed, the setting state of the photographing mode setting key 8 and the like, and displays the exposure conditions and the like on the liquid crystal display panel 9. . Furthermore, CPU4
0 drives the photographing lens 2 via the photographing lens driving unit 46 based on the distance measurement result from the distance measuring unit 44 so as to focus on an appropriate subject, while moving the diaphragm 48 via the diaphragm driving unit 47. Control. The CPU 40 controls the entire digital camera 1 as a whole.

An analog image signal from the CCD 3 is converted into digital image data by an A / D converter 41 and temporarily stored in an image memory (RAM) 42. C
The PU 40 stores the image data read from the image memory (RAM) 42 on the recording medium 6.

The synthesizing section 43 creates an image corresponding to the set contents of the image processing mode from the plurality of images having different focal lengths, out of the all-focus image and the blur control image.

Next, the image creation processing in the composite image mode will be described.

FIG. 4 shows a so-called perspective conflict scene in which subjects 10 and 11 are present on the P plane and the Q plane, respectively. For simplicity of description, the subjects 10 and 11 are shown as planar charts. Reference numeral 12 denotes an image focused and imaged on the P surface, in which a circle in the chart 10 as the foreground is clearly shown and a star in the chart 11 as the background is blurred. On the other hand, reference numeral 13 denotes an image obtained by focusing on the Q plane, in which the circle of the chart 10 as the foreground is blurred and the star of the chart 11 as the background is clearly shown.

In the composite image mode, these two images 1
From images 2 and 13, images 14 and 15 are created. The image 14 is a so-called all-in-focus image in which both the subjects 10 and 11 are focused. On the other hand, the image 15 is the chart 11 as the background.
Is a blur control image in which the degree of blur of the chart 10 as the foreground is emphasized more than the image 13 while focusing on.

As described above, in this digital camera 1,
An all-focus image or a blur control image in which the foreground or background blur is arbitrarily changed can be obtained from two or more images of the same scene shot with different focus planes (focus positions). .

The principle of creating an all-focus image is described in Patent
No. 83648 and JP-A-10-108057, and a method of controlling the degree of blur is as follows.
JP-A-9-200508, and further, Kubota and Aizawa: "Registration Considering Rotation of Multi-Focus Image and High-Speed Reconstruction of Arbitrary-Focus Image by Inverse Filtering Method," IEICE-25 / IE99-25 (1999-07). ), Etc., and are well-known, so that the description is omitted here.

Further, in the above description, the distance distribution of the subject is two kinds of foreground and background, and two images are taken. However, the distance distribution may be three foreground, background and middle. It may be the above.

To use the function of creating an omnifocal image or a blur control image, an image processing mode setting key 10 is used.
2 can be set.

When the composite image mode is set by the image processing mode setting key 102 and the blur condition is operated, the amount of blur is displayed on the LCD monitor 103 as “foreground focus, background blur large”, “foreground focus, background blur small”. , "Large foreground blur, focus on background", "small foreground blur, focus on background", and "all focus", so that the photographer can select a desired setting. The composition processing unit 43 creates a predetermined image according to the settings of the photographer.

For example, to obtain the image 14, "all focus" may be set, and to obtain the image 15, "foreground blur large, background in-focus" may be set.

Note that the digital camera 1 may automatically set the blur control mode without the user setting the mode.

Hereinafter, a case will be described in which blur control image processing is performed in three typical scenes commonly seen in FIGS. 5A to 5C.

FIG. 5A shows a scene having a main subject 30 in front of a background 31. In this case, the main subject 30 exists at an appropriate distance, and the background 31 exists at a distance that can be regarded as infinity in focus. When performing the blur control process in this scene, it is appropriate to capture a total of two images: one focused on the main subject 30 and one focused on infinity 31.

FIG. 5B shows a scene in which the main subject 32 exists in front of the background 33 and the third subject 34 exists in the middle of the main subject 32. In other words, the main subject 32 is located at a very short distance, and a plurality of subjects 33 and 34 are present in the background. The distance between the background 33 and the third subject 34 cannot be regarded as infinity in focus. It is when it exists in. In order to perform the blur control process in this scene, it is appropriate to capture three images: an image focused on the main subject 32, an image focused on the background 33, and an image focused on the third subject 34. .

FIG. 5C shows a scene in which a main subject 35 exists in front of a background 36, and a foreground 37 further exists in front of the main subject 35. The main subject 35 exists at an appropriate distance, another subject 38 exists in front of the main subject 35, and the background 36 cannot be regarded as infinity in focus. When performing the blur control process in this scene, it is appropriate to capture three images: an image focused on the main subject 35, an image focused on the background 36, and an image focused on the foreground 37.

As described above, from the distance distribution of the subject, it is possible to determine at which distance a plurality of focused images should be taken when performing the blur control process.

The main subject may be detected and specified as follows, for example. That is, the subject closest to the center of the screen may be specified as the main subject, or a subject having a predetermined color may be specified as the main subject. Whether or not it has a predetermined color is determined, for example, by L *
chromaticity (* a * b) indicating hue and saturation in the a * b * color system
*) For example, a person can be specified as a main subject by determining whether or not the a * b * value is within the skin color area.

Alternatively, a configuration may be adopted in which the subject closest to the center of the screen and conforming to a predetermined a * b * value is specified as the main subject.

Next, the operation of the above configuration will be described with reference to flowcharts shown in FIGS.

In the following description and drawings, steps are abbreviated as S.

If the release button 4 is pressed in S1 (the determination in S1 is YES), the CPU 40 reads and stores the current photographing conditions and image processing mode settings in S2. Then, in S3, the subject distance is measured by the distance measuring unit 44.

Next, in S4, the CPU 40 determines whether or not the composite image mode is set as the image processing mode. If the composite image mode is set (the determination in S4 is YES), the process proceeds to S11 in FIG. move on. If the composite image mode is not set (NO in S4), in S5,
The function of the composition processing unit 43 is set to OFF (image data passes without any processing).

Subsequently, in S6, the CPU 40 drives the photographing lens 2 through the photographing lens driving unit 46 so as to focus on an appropriate subject based on the distance measurement result.
In step S7, the aperture is set to an appropriate value via the aperture drive unit 47.

Then, the CCD 3 is integrated in S8, and the image data is read out in S9. The read image data is converted into digital data by an A / D converter 41 by a pipeline method, and is temporarily stored in a RAM 42. In S10, the CPU 40 reads out the image data in the RAM 42, records it on the recording medium 6, and returns to S1 to move to the next shooting.

If the result of determination in S4 is that the composite image mode is set (YES in S4), S11 in FIG.
First, the main subject distance is detected. The detection of the main subject
The measurement may be performed based on the distance measurement result, or the photometry result may be used together. Next, in S12, the CPU 40 checks whether or not there is a foreground from the main subject based on the distance measurement result. If there is a foreground (YES in S12), the process proceeds to S30 in FIG. On the other hand, if there is no foreground (NO in S12), the CPU 40 checks whether there is one background of the main subject from the distance measurement data in S13. If the number of backgrounds is not one (NO in S13), the process proceeds to S50 in FIG. on the other hand,
If there is one background (YES in S13), S14
Proceed to. In this case, the background is regarded as infinity. In S14, the blur amount is set in the synthesis processing unit 43, and then in S15
The aperture is set to an appropriate value through the aperture drive unit 47.
Then, the photographing lens 2 is driven via the photographing lens driving section 46 in S16 so as to focus on the main subject, and in S17
Then, the CCD 3 is integrated, and the image data is read out in S18.
The read image data is A / D
The data is converted into digital data by the converter 41 and
2 is temporarily stored. Next, in S19, the photographic lens 2 is set via the photographic lens driving unit 46 so as to focus on infinity.
Is driven, the CCD 3 is integrated in S20, and the image data is read out in S21. The read image data is converted into digital data by an A / D converter 41 by a pipeline method, and is temporarily stored in a RAM 42. And CPU
The image data read from the RAM 42 by the RAM 40 is
In step S22, the blur control process is performed in the combining processing unit 43, and the image is recorded on the recording medium 6 in step S23.

If it is determined in S12 that there is a foreground more than the main subject (YES in S12), it is determined that there are three main subjects: a main subject, a foreground, and a distant view. In this case, in S30, the blur amount is first set in the synthesis processing unit 43, and then in S31, the aperture is set to an appropriate value via the aperture drive unit 47. Then, in S32, the photographic lens 2 is driven via the photographic lens driving unit 46 so as to focus on the main subject, the CCD 3 is integrated in S33, and the image data is read out in S34. The read image data is converted into digital data by an A / D converter 41 by a pipeline method, and is temporarily stored in a RAM 42. Next, the photographing lens 2 is driven via the photographing lens drive unit 46 in S35 so as to focus on the foreground, the CCD 3 is integrated in S36, and the image data is read out in S37. The read image data is converted into digital data by an A / D converter 41 by a pipeline method, and is temporarily stored in a RAM 42. Further, the photographing lens 2 is driven via the photographing lens driving section 46 in S38 so as to focus on the distant view, the CCD 3 is integrated in S39, and the image data is read out in S40. The read image data is converted into digital data by an A / D converter 41 by a pipeline method,
Is temporarily stored. Then, the image data in the RAM 42 read by the CPU 40 is subjected to blur control processing by the synthesizing processing unit 43 in S41, is recorded on the recording medium 6 in S42, and returns to S1 to move to the next photographing.

If it is determined in S13 that the number of backgrounds is not one (NO in S13), it is determined that there are three subjects, that is, a main subject, a first background, and a second background. In this case, in S50, the blur amount is first set by the synthesis processing unit 43, and then the aperture is set to an appropriate value via the aperture driving unit 47 in S51. Then, in S52, the photographic lens 2 is driven via the photographic lens drive unit 46 so as to focus on the main subject, the CCD 3 is integrated in S53, and the image data is read out in S54. The read image data is converted into digital data by an A / D converter 41 by a pipeline method, and is temporarily stored in a RAM 42. Next, in S55, the photographing lens driving unit 4 is focused so as to focus on the first background.
The photographing lens 2 is driven via 6, the CCD 3 is integrated in S56, and the image data is read out in S57. The read image data is transferred to the A / D converter 4 by a pipeline method.
The data is converted into digital data by 1 and temporarily stored in the RAM 42. Further, S58 is performed so as to focus on the second background.
Then, the photographing lens 2 is driven via the photographing lens driving section 46, the CCD 3 is integrated in S59, and the image data is read out in S60. The read image data is converted into digital data by an A / D converter 41 by a pipeline method, and is temporarily stored in a RAM 42. And the CPU 40
The image data of the RAM 42 read by
At 1, the blur control process is performed by the combination processing unit 43, and the blur control process is performed at S62. The blur control process is performed at S62.

In the above embodiment, the image to be picked up is determined based on the distance distribution of the subject. However, in the present invention, for example, the focus image of the main subject and the focus at infinity are further simplified. A method of taking a focused image or always taking a focused image in the center area of the screen and a focused image at infinity can also be adopted.

In the above embodiment, the synthesizing unit 43
Is provided in the digital camera 1, and the blur control image is created in the digital camera 1. However, the blur control is performed by using an image processing device such as a computer from a plurality of images captured by the digital camera 1. A configuration for creating an image may be adopted.

[0050]

According to the first aspect of the present invention, in the blur control processing mode, a plurality of images whose focal lengths have been adjusted according to the distance of the main subject are picked up by the image pickup means. The image necessary for the above can be obtained efficiently.

According to the second to fourth aspects of the present invention, it is possible to more efficiently capture an image suitable for the blur control process.

According to the fifth aspect of the present invention, it is possible to provide an image pickup apparatus capable of creating a blur control image using these images as well as photographing the images.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing a digital camera to which an imaging device according to an embodiment of the present invention is applied.

FIG. 2 is a rear view of the digital camera.

FIG. 3 is a block diagram showing an electrical configuration of the digital camera.

FIG. 4 is an explanatory diagram of an image synthesis process.

5A is a scene having one background behind a main subject, FIG. 5B is a scene having two backgrounds behind a main subject, and FIG. Is a scene in which a main subject exists in front of the background, and a foreground further exists in front of the main subject.

FIG. 6 is a flowchart illustrating an operation of the digital camera.

FIG. 7 is a flowchart showing processing subsequent to C in FIG. 6;

FIG. 8 is a flowchart showing processing subsequent to E in FIG. 7;

FIG. 9 is a flowchart showing processing subsequent to F in FIG. 7;

[Explanation of symbols]

 1. Digital camera (imaging device) 2. Photographing lens 3. CCD 40. CPU (imaging control unit) 43: Synthesis processing unit 102: Image processing mode setting key

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Claims (5)

[Claims] 1. An image pickup means, and an image pickup control means for causing the image pickup means to pick up a plurality of images whose focal lengths have been adjusted in accordance with the distance of a main subject in a blur control processing mode. Imaging device. 2. When there is at least one subject in the foreground than the main subject, the imaging control unit focuses on the main subject, one of the foreground subjects, and the background subject. The imaging apparatus according to claim 1, wherein the imaging is performed three times. 3. A foreground subject does not exist than the main subject.
The imaging apparatus according to claim 1, wherein when there is one background subject, the imaging control unit causes the imaging to be performed twice with the main subject focused on infinity. 4. A foreground subject is not present than the main subject.
When there are two or more subjects with different backgrounds, the imaging control unit causes the main subject and two of the background subjects to be imaged three times by focusing on the respective subjects. 2. The imaging device according to 1. 5. The imaging apparatus according to claim 1, further comprising a synthesis processing unit that creates a blur control image using the image acquired by the imaging unit.