JP3697983B2 - Imaging apparatus and imaging method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an imaging apparatus and an imaging method using a solid-state imaging element.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, so-called digital cameras are known in which a subject image is formed on a charge-coupled device (CCD) by an imaging lens and the image is recorded in a memory. Also in this digital camera, a control circuit that automatically controls the shutter speed of the electronic shutter according to the brightness at the time of imaging is provided, as with a general camera, and is not affected by the brightness at the time of imaging. A clear image can be recorded.
[0003]
[Problems to be solved by the invention]
However, in such a digital camera provided with an automatic shutter speed control circuit, the shutter speed decreases as the imaging environment becomes darker. For this reason, when imaging is performed under a dark imaging environment, so-called camera shake is likely to occur, and a clear image may not be recorded.
[0004]
The present invention has been made in view of such conventional problems, and an object of the present invention is to provide an imaging apparatus and an imaging method that prevent the occurrence of camera shake.
[0005]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided an imaging unit that captures a subject image, a first imaging control unit that causes the imaging unit to capture an image at a first shutter speed that is faster than a predetermined shutter speed, and the predetermined imaging unit. A second imaging control unit that causes the imaging unit to capture an image at a second shutter speed that is a shutter speed, and a contour extraction unit that extracts a contour from the subject image captured by the imaging control of the first imaging control unit; The image pickup apparatus includes an image synthesizing unit that synthesizes the contour extracted image extracted by the contour extracting unit and the subject image captured by the imaging control of the second imaging control unit. .
[0006]
Thus, according to the first aspect of the present invention , the first subject image and the second subject image are captured at different shutter speeds, and the contour extraction image is created from the first subject image.
Then, the contour extraction image and the second subject image are combined.
At this time, for example, if the first shutter speed is faster than the second shutter speed, the first subject image captured at the first shutter speed is the second subject image captured at the second shutter speed. Although the probability of camera shake occurring is lower than that of an image, and at least the contour of the subject image can be considered to be better , the color and brightness of the image are not necessarily good . On the other hand, the second subject image captured at a slower second shutter speed, on the other hand, may improve the color and brightness of the image, but has a high probability of camera shake.
[0007]
Therefore, although the probability that camera shake has occurred is low, the color and brightness of the image are not necessarily appropriate, and the color and brightness of the image may be appropriate, but camera shake has occurred. By synthesizing the second subject image with a high probability, it is possible to obtain an image in which camera shake is prevented and the image color and brightness are appropriate.
[0008]
Therefore, by extracting the contour from the subject image and synthesizing it with the image captured at the second shutter speed, an image in which the contour is clear and the color and brightness of the image are ensured is prevented. can get.
[0009]
The invention according to claim 2 has a judging means for judging whether the predetermined shutter speed is slower than a predetermined speed, the imaging by the imaging means, the imaging control by the first imaging control means, 2. The imaging apparatus according to claim 1, wherein the contour extraction by the contour extraction unit and the image synthesis by the image synthesis unit are executed when the determination unit determines that the speed is slower than a predetermined speed. There is.
Thus, according to the second aspect of the present invention, the camera shake shooting mode may be automatically set.
The invention according to claim 3 is characterized in that the predetermined shutter speed is an appropriate speed for appropriately capturing the color and brightness of the image, and is determined before the first image capturing. 2 is assumed.
Thus, according to the third aspect of the present invention, the predetermined shutter speed is an appropriate speed for properly capturing the color and brightness of the image, and is determined before the first image capturing.
According to a fourth aspect of the present invention, the imaging by the first imaging control means is executed before the imaging by the second imaging control means . The imaging according to claim 1, 2, or 3 It is said to be a device.
As described above, according to the fourth aspect of the present invention, the imaging by the first imaging control means is executed before the imaging by the second imaging control means .
According to a fifth aspect of the present invention, the imaging by the second imaging control means is executed before the imaging by the first imaging control means . The imaging according to claim 1, 2, or 3 It is said to be a device.
As described above, according to the fifth aspect of the present invention, the imaging by the second imaging control unit is executed before the imaging by the first imaging control unit .
The invention according to claim 6 is characterized in that the image pickup by the first image pickup control means and the image pickup by the second image pickup control means are automatically executed by pressing the shutter key once. It is assumed that it is an imaging device described in any of the above.
Thus, according to the sixth aspect of the present invention, the image pickup by the first image pickup control unit and the image pickup by the second image pickup control unit are automatically executed by pressing the shutter key once.
[0010]
According to a seventh aspect of the present invention, there is provided an imaging process for imaging a subject image, a first imaging control process for causing the imaging process to image at a first shutter speed that is faster than a predetermined shutter speed, and the predetermined imaging process. A second imaging control step that causes the imaging step to image at a second shutter speed that is a shutter speed; and a contour extraction step that extracts a contour from the subject image captured by the imaging control of the first imaging control step; The imaging method includes an outline synthesis image extracted by the outline extraction process and an image synthesis process for synthesizing a subject image captured by the imaging control of the second imaging control process.
Thus, according to the seventh aspect of the invention, the first subject image and the second subject image are captured at different shutter speeds, and the contour extraction image is created from the first subject image.
Then, the contour extraction image and the second subject image are combined.
At this time, for example, if the first shutter speed is faster than the second shutter speed, the first subject image captured at the first shutter speed is the second subject image captured at the second shutter speed. Although the probability of camera shake occurring is lower than that of an image, and at least the contour of the subject image can be considered to be better, the color and brightness of the image are not necessarily good. On the other hand, the second subject image captured at a slower second shutter speed, on the other hand, may improve the color and brightness of the image, but has a high probability of camera shake.
Therefore, by extracting the contour from the subject image and synthesizing it with the image captured at the second shutter speed, an image in which the contour is clear and the color and brightness of the image are ensured is prevented. can get.
The invention according to claim 8 includes a determination step of determining whether the predetermined shutter speed is slower than a predetermined speed, and includes imaging in the imaging step, imaging control in the first imaging control step, and contour extraction. 8. The imaging method according to claim 7, wherein the contour extraction by the process and the image synthesis by the image synthesis process are executed when it is determined that the determination process is slower than a predetermined speed. .
Thus, according to the eighth aspect of the invention, the camera shake shooting mode may be automatically set.
The invention according to claim 9 is characterized in that the predetermined shutter speed is an appropriate speed for appropriately capturing the color and brightness of the image, and is determined before the first image capturing. The imaging method described in 7 or 8 is assumed.
Thus, according to the ninth aspect of the invention, the predetermined shutter speed is an appropriate speed for appropriately capturing the color and brightness of the image, and is determined before the first image capturing.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1A and 1B are external views of a digital camera according to this embodiment. As shown in the figure, the digital camera has a rectangular parallelepiped main body 1, a display screen 2 is provided on the back of the main body 1, lenses 3 are provided on the front corners, and a shutter key is provided on the upper surface. 4 and a camera shake shooting mode key 5 are provided.
[0012]
FIG. 2 is a block diagram of the digital camera according to the present embodiment. Behind the lens 3, an aperture device 25 for adjusting the amount of light of an incident subject image and an image pickup device 6 comprising a CCD are sequentially arranged. The aperture device 25 can variably set the exposure to F2 to F16, is connected to the aperture control circuit 24, and the image sensor 6 is connected to the signal processing circuit 7.
[0013]
The CPU 8 operates based on a program to control each unit constituting the digital camera and calculate a corrected exposure and an appropriate shutter speed. The CPU 8 is connected to the aperture control circuit 24, the image sensor 6 and the signal processing circuit 7, and also includes a display RAM 10, a key input unit 11, an external I / F control unit 12, a ROM 13, a work RAM 14, and a recording. A memory 15 is connected.
[0014]
The aperture control circuit 24 operates based on the appropriate exposure calculated by the CPU 8, and drives the aperture device 25 to the appropriate exposure. The signal processing circuit 7 processes a signal from the output signal from the image sensor 6 and incorporates an electronic shutter. The shutter speed is a speed according to an instruction from the CPU 8 within a range of 1 to 1/1000 second. Controlled.
[0015]
The key input unit 11 is provided with various keys such as the shutter key 4 and the camera shake shooting mode key 5. The external I / F control unit 12 controls data input / output with an external device such as a personal computer connected to the digital camera. The ROM 13 stores an operation program of the CPU 8 and the like, and the CPU 8 operates based on the operation program and controls each unit. The work RAM 14 is not only used as a work area for the CPU 8, but also stores a plurality of pieces of image data that are captured in response to a single operation of the shutter key 4, as will be described later.
[0016]
In the present embodiment having the above-described configuration, when the shutter key 4 is operated, the CPU 8 executes control according to the flowchart shown in FIG. 3 based on the program stored in the ROM 13. That is, it is determined whether or not the camera shake shooting mode is set (step S1). If the camera shake shooting mode is not set, shooting is performed in the normal shooting mode (step S8). At the time of shooting in the normal shooting mode, the appropriate exposure and the appropriate shutter speed are calculated based on the luminance signal from the image sensor 6 that has been captured by the signal processing circuit 7 in advance. Then, the aperture control circuit 24 is controlled based on the appropriate exposure, and the speed of the electronic shutter in the signal processing circuit 7 is controlled based on the appropriate shutter speed. Then, the image data captured by the signal processing circuit 7 with the operation of the electronic shutter is directly recorded in the recording memory 15.
[0017]
If the camera shake shooting mode key 5 is operated in advance and the camera shake shooting mode is set, it is determined whether or not the appropriate shutter speed is slow (step S2). This determination is made by comparing a predetermined reference shutter speed (for example, 1/60 seconds) with an appropriate shutter speed. Accordingly, if the appropriate shutter speed is 1/120 seconds at this time, the appropriate shutter speed is not slow. Therefore, in this case, image data is recorded in the normal photographing mode in step S8 described above.
[0018]
However, if the appropriate shutter speed is 1/30 seconds, this appropriate shutter speed is slower than the reference shutter speed (1/60 seconds). In this case, shooting is performed at a shutter speed faster than the appropriate shutter speed (1/30 seconds) or faster than the reference shutter speed (1/60 seconds) (step S3). Through the processing in step S3, the image data of the subject photographed at a high shutter speed is stored from the signal processing circuit 7 into the working RAM 14.
[0019]
It should be noted that the aperture device 25 is maintained at an appropriate exposure during photographing in step S3.
[0020]
Next, based on the image data stored in the work RAM 14, it is determined whether or not the contour of the subject can be extracted (step S4). If the contour cannot be extracted, that is, if camera shake occurs even at the fast shutter speed, shooting is performed at a shutter speed at which the contour can be extracted, that is, a shutter speed faster than the fast shutter speed. After that (step S5), the above-mentioned determination of step S4 is performed.
[0021]
Then, by shooting with the shutter speed changed in this way, a subject whose contour can be extracted without camera shake is photographed, and when the contour is extracted, the appropriate shutter, which has a slow shutter speed, continues. Shooting is performed at speed (step S6). Of course, at this time, the aperture device 25 is maintained at an appropriate exposure. As a result of the processing in step S 6, the image data of the subject photographed at the appropriate shutter speed is stored from the signal processing circuit 7 into the work RAM 14.
[0022]
Subsequently, the contour of the subject image extracted in step S4 and the image taken in step S6 are combined in the work RAM 14. At this time, since the subject image shot in step S6 was shot at an appropriate shutter speed (slow shutter speed), the image color and brightness are appropriate even if the camera shake occurs and the outline is unclear. It can be said that Therefore, by synthesizing at least the image having the proper color and brightness and the contour of the extracted subject image, it is possible to synthesize the image having the proper contour, color and brightness. Therefore, by storing the image data of the image synthesized in step S7 in the recording memory 15, a subject image with no camera shake and proper color and brightness is recorded even under a low shutter speed condition. be able to.
[0023]
In this embodiment, shooting is performed first with a fast shutter speed and then with a slow shutter speed. However, the order of shooting may be any. In this embodiment, the camera shake shooting mode is set by key operation. However, if the appropriate shutter speed is slower than a predetermined value without key operation, it is considered that there is a risk of camera shake. The camera shake shooting mode may be automatically set.
[0024]
【The invention's effect】
As described above, the present invention captures a subject image at different first and second shutter speeds and combines the captured subject images, so that an image with a low probability of camera shake is generated. Can be combined with an image having an appropriate color and brightness, so that a clear subject image can be recorded while preventing the occurrence of camera shake even under a low shutter speed condition.
[0025]
In addition, since the contours of the subject image captured at a speed faster than the appropriate shutter speed are extracted and synthesized, the camera shake is prevented, the contour is clear, and the color and brightness of the image are secured. The subject image can be recorded. In addition, since the second shutter speed is set to an appropriate shutter speed, it is possible to record a subject image that is prevented from camera shake, has a clear outline, and has an appropriate color and brightness.
[Brief description of the drawings]
FIG. 1A is a perspective view showing an external appearance of a digital camera according to an embodiment of the present invention, and FIG. 1B is a perspective view of the apparatus from a different direction.
FIG. 2 is a block configuration diagram of the digital camera.
FIG. 3 is a flowchart showing a processing procedure of the CPU according to the embodiment;
[Explanation of symbols]
3 Lens 4 Shutter Key 5 Camera Shake Mode Key 6 Image Sensor 7 Signal Processing Circuit 8 CPU
11 Key input unit 14 Work RAM
15 Recording memory

Claims (9)

An imaging means for imaging a subject image;
First imaging control means for causing the imaging means to image at a first shutter speed that is faster than a predetermined shutter speed;
Second imaging control means for causing the imaging means to image at a second shutter speed which is the predetermined shutter speed;
Contour extracting means for extracting a contour from the subject image captured by the imaging control of the first imaging control means;
An imaging apparatus comprising: an outline extraction image extracted by the outline extraction unit; and an image synthesis unit that synthesizes a subject image captured by imaging control of the second imaging control unit. Having a determination means for determining whether the predetermined shutter speed is slower than a predetermined speed;
An imaging control by the first imaging control means, and the contour extraction by the outline extraction means, the image synthesis by the image synthesis means, to be executed when the determination unit determines that slower than the rate at which a predetermined The imaging apparatus according to claim 1. The imaging apparatus according to claim 1, wherein the predetermined shutter speed is an appropriate speed for appropriately capturing the color and brightness of an image, and is determined before the first imaging. The imaging apparatus according to claim 1, wherein the imaging by the first imaging control unit is executed before the imaging by the second imaging control unit . The imaging apparatus according to claim 1 , wherein imaging by the second imaging control unit is performed before imaging by the first imaging control unit . 6. The image pickup apparatus according to claim 1, wherein the image pickup by the first image pickup control unit and the image pickup by the second image pickup control unit are automatically executed by pressing the shutter key once. . An imaging process for capturing a subject image;
A first imaging control step that causes the imaging step to image at a first shutter speed that is faster than a predetermined shutter speed;
A second imaging control step of causing the imaging step to image at a second shutter speed that is the predetermined shutter speed;
A contour extraction step of extracting a contour from the subject image captured in the imaging control of the first imaging control step;
An imaging method comprising: an outline extraction image extracted by the outline extraction step; and an image synthesis step of synthesizing a subject image captured by the imaging control of the second imaging control step. A determination step of determining whether the predetermined shutter speed is slower than a predetermined speed;
The first image synthesis by the image synthesis step and contour extraction by the outline extraction process and the imaging control by the imaging control step, characterized in that it is executed when the determining step determines that slower than the rate at which a predetermined The imaging method according to claim 7. The imaging method according to claim 7 or 8, wherein the predetermined shutter speed is an appropriate speed for appropriately capturing the color and brightness of an image, and is determined before the first imaging. .

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