JPH04343582A - Still image fetching device - Google Patents

Abstract

PURPOSE:To improve an SN ratio and a dynamic range without deteriorating resolution. CONSTITUTION:An image signal picked up at first by a CCD 18 by rapid shutter operation is temporarily stored in a frame memory 40, a moving vector is detected by a moving vector detecting part 48 based upon the temporarily stored image signal and an image signal picked up in the 2nd operations and following operation, and only image signals obtained when the size of the moving vector is almost '0' are mutually accumulatively added and stored in a frame memory 44. When the peak value of the image signal stored in the frame memory 44 which is detected by a peak detecting part 50 is saturated, a system controller 10 ends the accumulative addition by the frame memory 44 and outputs the image signal from the frame memory 44 to a multimedium filing system 56.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image capture system that captures still images without image blur.

0002

2. Description of the Related Art Conventionally, various techniques have been developed in order to capture still images without image blur. For example, Japanese Patent Laid-Open No. 1-125064 discloses that a motion vector is obtained from the image output of a video camera, image shake is detected from the result, and the readout area of the memory is controlled according to the amount of shake. Furthermore, a technique has been disclosed in which image blur is corrected while minimizing deterioration in image quality by interpolating the signal read from the memory according to the readout area.

0003

The technique disclosed in the above-mentioned publication can display or record a captured image signal 100% effectively when there is no image blur. however,
When image shake occurs, the effective screen size becomes narrower, and even if the image is displayed to fill the entire screen through interpolation processing, there is a problem in that image quality, such as resolution, deteriorates.

The present invention has been made in view of the above points, and aims to further improve the S/N and dynamic range without causing deterioration of resolution by making full use of the characteristics of still images. An object of the present invention is to provide an image capture device that is free from image blur.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the still image capture device of the present invention has an image sensor that captures an image using a high-speed shutter operation, and a device that starts capturing an image in synchronization with a trigger signal indicating the start of capturing. After that, a first image signal for temporarily storing an image signal imaged first among image signals output from the image sensor for a plurality of times in a plurality of consecutive image captures.
storage means, a motion vector detection means for detecting a motion vector from an image signal captured from a second consecutive time among the plurality of image signals, and an image signal read from the first storage means. and a second storage means for cumulatively adding and storing only the image signals when the magnitude of the motion vector detected by the motion vector detection means is almost “0”, and storing the image signals in the second storage means. a peak detection means for detecting a peak value of the cumulatively added image signal; a saturation determination means for determining whether the peak value detected by the peak detection means is at a saturation level; and a saturation determination means for recording the image signal. an image recording means; and a control means for terminating the cumulative addition by the second storage means based on the saturation signal from the saturation determining means and outputting the image signal from the second storage means to the image recording means. We are prepared.

[0006] The invention further includes motion vector recording means for recording the motion vector detected by the motion vector detection means, and the control means continuously detects almost the same motion based on the recording result by the motion vector recording means. When the vector is detected, it is determined that the subject has shifted in position due to an external factor, and the first recording means is caused to store a new image signal.

Alternatively, a motion vector recording means for recording the motion vector detected by the motion vector detection means after storing it in the first storage means, and a motion vector recording means for recording the motion vector detected by the motion vector detection means; and a third storage means for temporarily storing an image signal captured by the motion vector recording means, and the control means is configured to detect the first motion vector 0 by the motion vector detection means based on the recording result by the motion vector recording means. When a motion vector with a high frequency of appearance is detected before being detected, the image signal stored in the third storage means is stored in the first storage means.

[0008]

[Operation] That is, according to the still image capture device of the present invention, after the image sensor that captures images by high-speed shutter operation starts capturing images in synchronization with a trigger signal indicating the start of capturing images, in a plurality of consecutive image captures. Among the plurality of image signals output from the image sensor, the image signal captured first is temporarily stored in the first storage means, and the image signal captured after that and the image read out from the first storage means A motion vector is detected from the signal by the motion vector detection means, and only the image signals when the magnitude of the detected motion vector is almost 0 are cumulatively added and stored in the second storage means. Then, the peak value of the cumulatively added image signal stored in the second storage means is detected by the peak detection means, and the saturation determination means determines whether or not this peak value is at the saturation level. At times, the control means terminates the cumulative addition by the second storage means and outputs the image signal from the second storage means to the image recording means.

[0009]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of an image capture device according to a first embodiment of the present invention. Each configuration in the figure is controlled by a system controller 10 and driven by a timing clock from an SSG (sync signal generator) 12.

A lens system 16 including an aperture 14 is used to guide a subject image to an image pickup device (CCD) 18, and is driven by a lens and aperture driver 20. This lens and aperture driver 20 includes a sensor (not shown) for detecting the positional state of the lens system 16, and outputs a position sensor information signal from the sensor to the system controller 10, and receives a signal from the system controller 10 based on this. The lens system 16 is driven in response to the lens system control signal.

An image pickup device (CCD) 18 captures an image of the subject guided by the lens system 16. This CCD1
8 is a CCD drive clock from the CCD driver 22 (
CK), the captured image signal is sent to a subsequent sample-and-hold (S/H) circuit 24. CCD
The driver 22 generates the CCD drive CK based on the CCD drive reference CK from the SSG 12 in response to a control signal from the system controller 10 .

The S/H circuit 24 includes, for example, a CDS (correlation 2
It samples and holds the image signal from the CCD 18 at the timing CK from the SSG 12. The preamplifier 26 amplifies the image signal sampled and held by the S/H circuit 24 and then supplies it to an analog-to-digital (A/D) converter 28 . The A/D converter 28 converts the supplied image signal into a digital signal and supplies it to the digital video processing unit 30. The digital video processing unit 30 performs color separation, conversion processing, correction processing (γ correction, WB
, gain control, aperture correction, etc.) is output onto the data bus 32.

Digital to analog (D/A) converter 34
converts the image data on the data bus 32 into an analog signal, and then passes it through a low-pass filter (LPF) 36,
It is supplied to the monitor 38 and displayed.

Frame memory “I” 40, frame memory “II” 42, and frame memory “III” 44
are for storing one frame of image data, and store the image data on the data bus 32 in response to a control signal from the memory controller 46. The memory controller 46 generates a control signal to each frame memory based on a memory operation command signal from the system controller 10.

The motion vector detection section 48 detects a motion vector from the image data stored in the frame memory "I" 40 and the frame memory "II" 42 in response to a control signal from the system controller 10, and detects the motion vector from the image data stored in the frame memory "I" 40 and the frame memory "II" 42. A determination signal indicating this is output to the memory controller 46.

The peak detection section 50 performs peak detection of the image data stored in the frame memory "III" 44 in response to a peak detection section control signal from the system controller 10, and outputs a peak value output signal indicating the result. is output to the system controller 10. Further, the image data stored in the frame memory "III" 44 is supplied to the switch SW1. This switch SW1 is activated by a switching control signal from the system controller 10.
The supplied image data is selectively supplied to the data bus 32 or the adder 52. The adder 52 is connected to the data bus 3
2 and the image data from switch SW1 are added and output to frame memory "III" 44. An interface (I/F) 54 supplies image data on the data bus 32 to a multimedia filing system 56 .

In the image capture device having such a configuration, when the power (not shown) is turned on, the CCD 18 first operates in the movie mode, and the CCD driving standard C of the SSG is activated.
Under the control of the CCD driver 22 in accordance with K, sequential exposure and readout are performed at a normal television rate.

The read signal is sent to the digital video processing unit 30 via the S/H circuit 24, preamplifier 26, and A/D converter 28. The digital video processing unit 30 performs color separation, conversion processing, and correction processing (
γ correction, WB, gain control, aperture correction,
etc.), the read image data is supplied to the D/A converter 34 via the data bus 32, and the LPF
36 and the like on the monitor 38. This monitor 3
While looking at the image displayed in 8, align the subject,
Focus adjustment, magnification setting (zooming), etc. are performed.

When preparations for image capture (imaging) are thus completed, a button (not shown) or the like is pressed to provide a trigger signal for starting imaging to the system controller 10. The imaging operation for capturing an image will be described below with reference to the flowchart of FIG. 2, which is an operation flowchart of the system controller 10. First, in synchronization with a trigger signal indicating the start of imaging, the system controller 10 drives the CCD 18 with a high-speed shutter operation to capture an image (step S10).

[0020] When the imaging is completed, the image signal is read out from the CCD 18 and sent to the S/H circuit 24, preamplifier 26, A/
After being subjected to predetermined processing by the D converter 28 and the digital video processing section 30, it is output onto the data bus 32. Here, the system controller 10 generates a corresponding control signal to the memory controller 46 by giving a memory operation command signal to the memory controller 46, and transfers the image data on the data bus 32 to the frame memory "I" 40 and the memory controller 46. Frame memory “III” 44
(Step S12).

Then, the memory operation command signal is given to the memory controller 46 to generate a corresponding control signal and output the image data stored in the frame memory "III" 44 to the peak detection section 50 (step S
14). Here, it is determined whether the peak value has reached the saturation level based on the peak value output signal from the peak detection section 50 (step S16). If it is determined that the peak value has not yet reached the saturation level, the CCD 18 is made to perform a second image capture using the same high-speed shutter operation (
Step S18).

[0022] When the imaging is completed, the image signal is read out from the CCD 18 and sent to the S/H circuit 24, preamplifier 26, A/
After being subjected to predetermined processing by the D converter 28 and the digital video processing section 30, it is output onto the data bus 32. Here, the system controller 10 generates a corresponding control signal to the memory controller 46 by giving a memory operation command signal to the memory controller 46, and transfers the image data on the data bus 32 to the frame memory "II" 42. It is stored (step S20).

Next, a memory operation command signal is given to the memory controller 46 to generate a corresponding control signal,
A motion vector is detected by outputting the image data stored in the frame memory "I" 40 and the image data stored in the frame memory "II" 42 to the motion vector detection section 48 (step S22). Then, based on the determination signal from the motion vector detection unit 48, it is determined whether the motion vector is almost "0" (step S
24).

Here, if the image stored in the frame memory "I" 40 and the image stored in the frame memory "II" 42 are images at the same position, the motion vector detection section 48 detects The magnitude of the motion vector becomes "0". In other words, no motion vector is detected. Also,
When the position is changed or the image is displaced due to image blur, a motion vector is detected and becomes a motion vector of a size corresponding to the magnitude of the image blur.

In step S24, if it is determined that the determination signal indicating that the motion vector is almost "0" is output, the image data stored in the frame memory "II" 42 and the image data stored in the frame memory "III" 44 are The result is stored in the frame memory "III" 44 (step S26). That is, first, a memory operation command signal is given to the memory controller 46 to generate a corresponding control signal, and the image data stored in the frame memory "II" 42 is supplied to the adder 52 via the data bus 32. . Next, a memory operation command signal is given to the memory controller 46 to generate a corresponding control signal, and the frame memory "III" is
”44, the peak detection unit 5
0 and the adder 52 via the switch SW1. Then, the addition result of the adder 52 is stored in the frame memory "III" 44. Thereafter, the process returns to step S14 and the above-described operations are repeated.

Here, in step S14, the image data stored in the frame memory "III" 44,
In other words, the peak detection unit 50 detects the peak of the image data resulting from the addition, and as a result, when the peak value reaches the saturation level (step S16), the imaging operation for capturing the image is ended and the normal movie mode is returned to. .

Further, in step S24, if it is determined that the detection result of the motion vector detection section 48 is that there is movement, the image data stored in the frame memory "II" 42 is not added in step S26. In step S18
Returning to , the image data in frame memory "II" 42 is
The data is rewritten to the image data captured by the CCD 18 in the next high-speed shutter operation.

Thereafter, the same operation is repeated, and only the image data at the same position as the image data stored in the frame memory "I" 40 is cumulatively added to the frame memory "III" 44.

It should be noted that the image data output to the monitor 38 is stored in the frame memory "III" at the time of image capture.
The image data is switched to the image data from 44, and after being amplified to an appropriate level, the image is displayed. Of course, at first, S/N
A bad image is displayed, but as the cumulative addition progresses, the S
As the S/N ratio continues to improve, random noise will eventually be reduced compared to the original signal, and an image with a good S/N ratio and no image blur will be displayed. Therefore, the viewer can observe the image without being bothered by image shake.

In this embodiment, the captured image signal with good S/N and no shake is displayed on the monitor 38, and
The data is transferred to the multimedia filing system 56 via the I/F 54, where it is processed, recorded, and the like.

Of course, recording media (HD, MO, FD,
It may be configured to record directly to a memory card, hard copy, etc., or it may be configured to record directly to an ISDN, ISDB, INS, RAN.
Image data may be transferred to a remote location using a communication line such as

In addition, in this embodiment, a data compression section (AD
CT, ADPCM, AVQ, etc.) are not specified, but
In response to a request from the receiving side or recording side, the image data compressed by the data compression unit at an appropriate compression rate and format is sent to the receiving side or recording side at a desired transfer rate.

FIG. 3 is a block diagram of a second embodiment of the present invention. In this figure, the illustration of the same parts as in FIG. 1 is omitted, and therefore the explanation of the parts common to the first embodiment is omitted. The feature of the second embodiment is that the frame memory "III" 44, the adder 52, and the peak detection section 50 have a word length of, for example, 12 bits.

Therefore, the saturation level of cumulative addition and its storage is increased by a factor of 16. Furthermore, frame memory “III”
44 and a display section such as a monitor 38 or a recording section such as a multimedia filing system 56, that is, a frame memory "III" 44 and a data bus 32.
A bit slice section 58, a 12-bit to 8-bit conversion section 60, and a switch SW2 are provided between the two. Then, by a switching signal from an observer (not shown), 12
Bit-to-8 bit converted 8-bit output, 5-step bit slice output such as 8 bits from the high brightness side and 8 bits from the low brightness side (see Figure 4), or upper 4 bits divided into lower 8 bits. All 12-bit outputs are selected and displayed on the monitor 38 or data is transferred or recorded. In the second embodiment, as a result of cumulative addition,
Images with high S/N and no image blur can be obtained with a dynamic range wider than that of the CCD 18.

FIG. 5 is a block diagram of a third embodiment of the present invention, and FIG. 6 is an operational flowchart thereof. Note that in FIG. 5, illustration of the same parts as in FIG. 1 is omitted. In addition, the flowchart in Figure 6 is similar to Figure 2.
Flowchart and steps S10 to S26
are the same. In the third embodiment, a motion vector information recorder 62 for tracking changes in motion vectors is added.

In operation, the motion vector information recorder 6
2, changes in the motion vector are tracked, and if the same motion vector occurs, for example, N times in a row, it is determined that the subject is stationary after its position has shifted due to some external factor, and the image capture operation currently being performed is determined. This will stop the process and start capturing the image again.

That is, in the flowchart of FIG. 6, if it is determined in step S24 that the motion vector is not "0", that is, the detection result of the motion vector detection section 48 indicates that there is motion, then the same motion vector is It is determined whether the process has continued N times (step S28), and if it has not continued N times, the process returns to step S18.

However, if the same motion vector continues N times, the image data in the frame memory "II" 42 is stored in the frame memory "I" 40 (step S3).
0), after clearing the image data in the frame memory "III" 44 (step S32), the above step S18
Return to Therefore, in the third embodiment, even if the position of the subject shifts due to an external factor unintended by the observer, the image is quickly re-captured.

Of course, after stopping, the observer may decide whether or not to capture images again, and the image data captured until the stopping may be displayed or recorded as is. FIG. 7 is an operation flowchart of the fourth embodiment of the present invention.

In the fourth embodiment, frame memory “I”
If a motion vector with a high frequency of appearance is detected as a result of tracking changes in the motion vector by the motion vector information recorder 62 until the motion vector first outputs "0" after being stored in the frame memory " frame memory "II" with its motion vector than the position of the image stored in "II"40;
It is determined that the image position stored in frame memory "II" 42 appears more frequently, and the image information stored in frame memory "II" 42 is newly stored in frame memory "I" 40, and imaging is continued. be.

That is, in step S24, if it is determined that a determination signal indicating that the motion vector is almost "0" is output, the image data stored in the frame memory "II" 42 and the image data stored in the frame memory "III" 44 are The result is stored in the frame memory "III" 44, and k=1 is set in a register (not shown) configured inside the system controller 10 (step S34). After that, step S1
Return to 8.

Further, in step S24, if it is determined that the motion vector is not "0", that is, the detection result of the motion vector detecting section 48 is that there is motion, then the contents of the register are determined to be k=1. Determine whether or not there is (step S3
6) If k=1, it is determined whether the same motion vector has continued N times (step S28), and if it has not continued N times, the process returns to step S18.

However, if the same motion vector continues N times, the image data in the frame memory "II" 42 is stored in the frame memory "I" 40 (step S3).
0), after clearing the image data in the frame memory "III" 44 (step S32), the above step S18
Return to

On the other hand, in step S36, k=
If it is determined that the motion vector is not 1, it is determined whether the same motion vector has appeared a predetermined number of times, for example, M times (step S3
8). If it has not appeared a predetermined number of times, the process returns to step S18. However, if the motion vector appears a predetermined number of times, the position of the image stored in the frame memory "I" 40 is
It is determined that the image position stored in
Proceeding to step S30 above, the frame memory "II"
42 image data are stored in frame memory "I" 40. After clearing the image data in the frame memory "III" 44 (step S32), the process returns to step S18. As a result, the frame memory “I” is initially
"Compared to the case where the image information stored in 40 is used, image capture is completed much faster.

[0045]

[Effects of the Invention] As detailed above, according to the present invention,
It is possible to provide an image capture device free from image blur that can further improve S/N and dynamic range without causing deterioration of resolution by making full use of the feature of still images.

In other words, according to the present invention, high-quality image data without image blur can be obtained by reducing the effective screen size or It can be recorded or viewed without sacrificing image quality such as deterioration of resolution. moreover,
An image with a higher S/N than the original image can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an image capture device according to a first embodiment of the present invention.

FIG. 2 is an operational flowchart of an imaging operation for capturing an image in the first embodiment.

FIG. 3 is a block diagram of a second embodiment of the present invention.

FIG. 4 is a diagram showing an example of a bit slicing operation of the bit slicing section in FIG. 3;

FIG. 5 is a block diagram of a third embodiment of the present invention.

FIG. 6 is a flowchart for explaining the operation of the third embodiment of the present invention.

FIG. 7 is a flowchart for explaining the operation of the fourth embodiment of the present invention.

[Explanation of symbols] 10...System controller 10, 12...Sink signal generator (SSG), 32...Data bus, 38...
Monitor, 40...Frame memory "I", 42...Frame memory "II", 44...Frame memory "III",
46...Memory controller, 48...Movement vector detection unit,
50...Peak detector, 52...Adder, 56...Multimedia filing system, 58...Bit slice unit,
60...12-bit to 8-bit converter, 62...Movement vector information recorder, SW1, SW2...Switch.

Claims (3)

[Claims] 1. An image sensor that captures an image using a high-speed shutter operation, and a plurality of images outputted from the image sensor during a plurality of consecutive images after the image capture is started in synchronization with a trigger signal indicating the start of image capture. a first storage means for temporarily storing an image signal imaged first among the image signals; an image signal imaged continuously from the second time onward among the plurality of image signals; and the first storage means. a motion vector detection means for detecting a motion vector from an image signal read from the means; and cumulative addition of only the image signal when the magnitude of the motion vector detected by the motion vector detection means is almost "0". a second storage means for storing the second
peak detection means for detecting the peak value of the cumulatively added image signal stored in the storage means; saturation determination means for determining whether the peak value detected by the peak detection means is at a saturation level; an image recording means for recording, and a saturation signal from the saturation determining means to terminate the cumulative addition by the second storage means, and output the image signal from the second storage means to the image recording means. 1. A still image capturing device, comprising: a control means for controlling a still image. 2. Further comprising motion vector recording means for recording the motion vector detected by the motion vector detection means, wherein the control means continuously records almost the same motion vector based on the recording result by the motion vector recording means. 2. The still image according to claim 1, wherein when a motion vector is detected, it is determined that the position of the subject has shifted due to an external factor, and the first recording means is caused to store a new image signal. Capture device. 3. Motion vector recording means for recording the motion vector detected by the motion vector detection means after storing it in the first storage means; further comprising a third storage means for temporarily storing an image signal captured by the motion vector recording means, and the control means detects the first motion vector by the motion vector detection means based on the recording result by the motion vector recording means. The image signal stored in the third storage means is stored in the first storage means when a motion vector with a high appearance frequency is detected before 0 is detected. A still image capture device according to claim 1.