JP2006098655A - Image movement correction device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image movement correction device designed so that fluctuations in blur correction after the completion of panning is prevented by ignoring the component of the rocking back of an angular velocity sensor caused by the high pass filter circuit of a movement detection circuit and computation after panning, as an intended photographing operation, in order to provide the natural feeling of an operation in shake correction of a movie or DSC, thereby restraining an erroneous determination between the component of rocking back and panning, and performing panning determination with high accuracy. <P>SOLUTION: A computing means 5 calculates a difference between an A/D converting means 3 and an averaging means 4 and signs. After the completion of panning determined by a first panning determination condition 11, the condition for the determination is switched by a second panning determination condition 12. This prevents erroneous determination of panning, which results from rocking back caused by the circuit or computation, thus performing panning determination with high accuracy, leading to photographing in which a defect in a photographic image is restricted. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image motion correction apparatus used for camera shake correction or the like of an image pickup apparatus, and more particularly to improve its performance.

  In recent years, consumer video cameras (hereinafter referred to as “video movies”) and digital still cameras (hereinafter referred to as “DSCs”) have become smaller, lighter, and optical zooms have become more powerful. For ordinary consumers, video movies and DSCs are one of the ordinary home appliances. On the other hand, however, the downsizing, weight reduction, high optical zoom magnification, and the spread of video movies and DSCs to consumers who are not proficient in shooting have caused problems such as screen instability due to camera shake during shooting. I let you. Therefore, in order to solve this problem, many video movies and DSCs equipped with an image motion correction device have been developed and commercialized.

  As an image motion correction device of an imaging device, for example, an imaging unit including an imaging optical system and a solid-state imaging device is supported by a gimbal mechanism, and this is driven and controlled based on motion information of the imaging device itself obtained from an angular velocity sensor. There is a method of correcting the movement of an image ("Development of image blur prevention technology of a video camera" Television Society Technical Report Vol. 11, No. 28, pp 19-24 (1987)).

  The above-mentioned system is configured by a coil and a magnet based on the motion information in the pitching and yawing two directions obtained from the angular velocity sensor by rotatably supporting the imaging unit of the imaging device at the center of gravity by a gimbal mechanism. The captured image is stabilized by controlling the posture of the imaging unit by an actuator.

  As another example, a system that includes a variable apex prism in the front part of the image pickup optical system and that controls the movement of the image by information from the angular velocity sensor (“optical image stabilization system”). “The Institute of Television Engineers Technical Report Vol. 17, No. 5, pp 15-20 (1993)).

  In the above method, two glass plates are connected with a bellows made of a special film, and a variable apex prism filled with a high refractive index liquid is provided in front of the solid-state image sensor. Based on the information on the movement of the imaging device in the two directions of pitching and yawing obtained from the sensor, the two glass plates of this variable apex angle prism are tilted in the horizontal and vertical directions, respectively, and the optical axis of the incident light is bent and photographed. It stabilizes the movement of the image.

  As another example, a frame for reading out only a part of the image on the solid-state image sensor as an output image is provided, and this frame is moved by changing the drive timing of the solid-state image sensor. There is a method for correcting movement.

The above-mentioned method uses a solid-state image sensor having a larger number of pixels than a standard solid-state image sensor conforming to the broadcasting system, and uses information about the movement of the imaging device in the pitching and yawing two directions obtained from the angular velocity sensor as the focal length of the photographing lens. Based on the result of the conversion, the drive timing of the solid-state image sensor is controlled based on the conversion result, and the readout position (frame) of the image from the solid-state image sensor according to the movement of the captured image is converted. ) To stabilize the movement of the captured image.
Japanese Patent Laid-Open No. 11-231367 (blur detection device and blur correction camera)

  As described above, it is well known that various methods have been proposed and put to practical use for the image motion correction apparatus, but there are still some problems to be solved.

  For example, in an image motion correction device that detects the movement of a device using an external sensor such as an angular velocity sensor, a high correction effect is required when the device is supported by a hand, and the lateral direction is used. Intended for panning, which is the intended shooting operation, and tilting, which is the intended shooting operation in the vertical direction (hereinafter, only panning will be described as an example for ease of explanation, but the same applies to tilting). When shooting, a natural feeling of operation is realized by limiting the camera shake correction effect to reduce the catch of the corrected image that occurs when the correction reaches the maximum correction range. As shown in FIG. 6, the output signal 204 of the angular velocity sensor during panning includes “stationary 201 -panning 202 -stationary 2” as indicated by 201-203. When performing the series of operations of 3 ", actually device 203 periods unwag occurs in the opposite direction after the end of panning period 202 despite stationary.

  This drift is not caused by the angular velocity sensor but by the high-pass filter circuit or calculation in the motion detection circuit, and it takes a certain amount of time to settle to the level before the start of panning. As described above, in order to limit the camera shake correction effect, the output signal 204 of the angular velocity sensor is monitored, and it is determined that there is panning when motion is detected in the same direction for a certain period or longer. In the method, when the angular velocity sensor output is shaken back, the period may be misidentified as panning (indicated by 207 in FIG. 6).

  FIG. 7 shows the flow of conventional control. When the horizontal axis in FIG. 6 is the moving average value of the motion detection input, the average value and the sign of the input value are discriminated in step 304. In this case, when the same code continues for a threshold time or more as a criterion for panning determination, if the input is shaken back for a long time, the panning may be erroneously detected again at 304 and 305.

  The present invention has been made in view of the above problems, and has a natural operation feeling by performing high-precision panning determination and eliminating the malfunction of camera shake correction effect restriction due to erroneous panning determination during normal shooting. An object of the present invention is to provide an image motion correction apparatus capable of photographing.

  In order to solve this problem, the present invention provides a motion detection means for detecting the physical motion of the apparatus, an input signal amplification circuit for electrically amplifying the output signal of the motion detection means, and an input signal amplification circuit. A / D conversion means for converting the analog signal into a digital signal, averaging means for averaging the input digital signal, and the difference and sign of the output of the A / D conversion means and the output of the averaging means are calculated. An arithmetic means, a correction signal determining means for determining a signal for correcting the movement of the imaging apparatus from the output of the A / D conversion means and the output of the averaging means, and correcting the movement of the apparatus based on the determined correction signal Correction signal generating means for generating a signal for generating a signal, a first correction condition generator for changing the output characteristic of the correction signal determining means, and the first correction condition for the output characteristic of the correction signal determining means Different A second correction condition generation unit that changes according to the nature, a switching unit that can select the output of the first correction condition and the second correction condition, and a first for detecting a panning operation intended by the imaging apparatus Calculated by the computing means, a second panning determination condition having characteristics different from the first panning determination condition for removing signal undulation during repeated panning of the imaging device A switching condition determining means for switching the switching means based on the difference and sign of the output of the averaging means, the output of the first panning condition, and the output of the second panning condition. This is a featured image motion correction apparatus.

  As described above, according to the present invention, it is possible to perform image motion correction that provides a natural feeling of operation even during panning.

  That is, in the movement of the imaging device detected by the motion detection means, after detecting panning as a photographing operation, the second panning determination condition is changed according to time, and the angular velocity signal obtained by the high-pass filter circuit or calculation in the motion detection circuit By eliminating the erroneous panning judgment caused by the back-fluctuating component of the camera, it is possible to eliminate the malfunction of the camera shake correction effect restriction during normal shooting and to provide an excellent effect of supplying image motion correction performance with a natural feeling of operation. Is.

  According to a first aspect of the present invention, there is provided a motion detecting means for detecting a physical motion of the apparatus, an input signal amplifying circuit for electrically amplifying an output signal of the motion detecting means, and an amplification by the input signal amplifying circuit. A / D conversion means for converting the analog signal thus converted into a digital signal, averaging means for averaging the input digital signal, and the difference and sign between the output of the A / D conversion means and the output of the averaging means Calculating means for determining, a correction signal determining means for determining a signal for correcting the movement of the imaging apparatus from the output of the A / D conversion means and the output of the averaging means, and the movement of the apparatus based on the determined correction signal. A correction signal generating means for generating a signal for correction; a first correction condition generating section for changing an output characteristic of the correction signal determining means; and an output characteristic of the correction signal determining means as the first correction condition. Has different characteristics A second correction condition generating unit that is changed in the above, a switching means that can select the output of the first correction condition and the second correction condition, and a first for detecting a panning operation intended by the imaging apparatus. A panning determination condition, a second panning determination condition having characteristics different from the first panning determination condition for removing the signal swingback during repeated panning of the imaging device, and the calculation unit A switching condition determining means for switching the switching means based on the difference and sign of the output of the averaging means, the output of the first panning condition, and the output of the second panning condition, and the first The first correction condition and the second correction condition are switched according to the panning determination condition and the condition determined by the second panning determination condition, and the correction signal determining means Is intended to limit the power, it has the effect that it is taken with a natural operation feel no discomfort.

  According to a second aspect of the present invention, the output of the correction signal generating means controls the lens and changes the optical axis incident on the imaging imaging surface, thereby correcting the camera shake component of the captured image.

  According to a third aspect of the present invention, the output of the correction signal generating means corrects the camera shake component of the photographed image by changing the output position of the photographed image by driving the image sensor and controlling the image memory. .

  In the invention according to claim 4, the first correction condition generates a condition having characteristics suitable for a case where a high correction effect is required, such as when the apparatus is held by hand.

  In the invention described in claim 5, the second correction condition generates a condition having a characteristic suitable when the correction effect needs to be limited when the apparatus is intentionally moved largely. .

  According to a sixth aspect of the present invention, the first panning determination condition includes a time measuring means, and the same sign as the sign of the difference between the output of the A / D conversion means calculated by the computing means and the output of the averaging means Is determined to be panning from a continuous time.

  According to a seventh aspect of the present invention, the second panning determination condition includes a time measuring means, and the amount of motion detection and the detection time can be arbitrarily changed from the end of the first panning determination condition. is there.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a block diagram of an image motion correction apparatus of the present invention, and FIG. 5 shows a flow of a series of processes of the present invention.

  In FIG. 1, reference numeral 1 denotes motion detection means for detecting the physical motion of the apparatus, and 2 denotes an input signal amplification circuit, which amplifies the motion detected by the motion detection means 1 in an analog manner. Reference numeral 3 denotes analog / digital conversion means (hereinafter referred to as A / D conversion means), which converts an analog signal of detected motion into a digital signal. Reference numeral 4 denotes averaging means for obtaining a moving average of the motion signal digitized by the A / D conversion means 3. 5 is a computing means for computing the difference and sign between the motion signal digitized by the A / D converting means 3 and the signal averaged by the averaging means 4, and 6 is digitized by the A / D converting means 3. This is a correction signal determining means for determining a signal for correcting the motion of the image from the motion signal and the signal averaged by the averaging means 4.

  Reference numeral 7 denotes a correction signal generating means for generating a signal for actually correcting the movement of the image pickup device from the determined correction signal. Based on the output signal of the correction signal generating means 7, camera shake correction control is performed. As a specific correction operation, the lens is controlled to change the optical axis incident on the imaging imaging surface to correct the camera shake component of the photographed image, and the output of the correction signal generating means is the driving of the imaging device, the image There is one that corrects a shake component of a captured image by changing an output position of the captured image by memory control.

  Reference numeral 8 denotes a first correction condition generation unit which generates a condition for determining the output characteristics of the correction signal generation means 6. Reference numeral 9 denotes a second correction condition generation unit that generates conditions having characteristics different from those of the first correction condition generation unit 8. In the present embodiment, the correction condition generated by the first correction condition generation unit 8 is “correction condition A”, the correction condition generated by the second correction condition generation unit 9 is “correction condition B”, and the correction condition A has a normal high camera shake correction effect, and the correction condition B has a camera shake correction effect smaller than the correction condition A. The correction condition A is a condition suitable for a case where a high correction effect is required when the camera shake is relatively large, such as when the user holds the apparatus by hand. The correction condition B is a condition suitable when it is necessary to limit the correction effect when the user intentionally moves the apparatus (such as panning or tilting).

  Reference numeral 10 denotes switching means for switching between the output of the first correction condition generation unit 8 and the output of the second correction condition generation unit 9, which is constituted by a switch, for example. Specific switching control will be described later.

  Reference numeral 11 denotes a first panning determination condition generating unit for generating a first panning determination condition, which is a condition for determining the panning operation intended by the operator. Reference numeral 12 denotes a second panning determination condition generation unit that generates a second panning determination condition, and has a characteristic that is different from the first panning condition from the first panning condition generation unit 11. The first panning determination condition includes a time measuring means (timer), and a time in which the same code as the difference between the output of the A / D conversion means 3 calculated by the calculation means 5 and the output of the averaging means 4 continues. To determine “being panning”. In addition, the second panning determination condition includes a time measuring means (timer), and the motion detection amount and the detection time can be arbitrarily changed from the end of the first panning determination condition.

  Reference numeral 13 denotes a switching condition determination means for switching the switching means 10 based on the calculation means 5 and the panning determination conditions from the first panning determination condition generator 11 and the second panning determination condition generator 12.

  In this description, it is assumed that a microcomputer is used after the A / D conversion means 3, but it is not always necessary that the microcomputer be realized on the microcomputer.

  An example of the operation of the image motion correction apparatus configured as described above will be described with reference to the drawings.

  First, in step 701, the correction condition A is set in the first correction condition generating unit 8. This correction condition A is a condition having a normal high camera shake correction effect.

  In step 702, the physical fluctuation of the apparatus detected by the motion detection means 1 is detected, amplified by the input signal amplification circuit 2, and then converted into a digital signal by the A / D conversion means 3.

  In step 703, a moving average is obtained from the motion signal input digitally converted by the averaging means 4.

  In step 704, the difference between the A / D conversion means 3 and the averaging means 4 obtained by the computing means 5 is taken, and the sign and difference at that time are obtained.

  Step 705 is a process for detecting a change between the previous code and the current code. The process is performed by the switching condition determination unit 13. If the code is reversed, “panning is finished” in step 710. At step 711, the panning end timer is initialized and counting is started. At this time, in addition to the panning determination condition in the conventional example (similar to the first panning determination condition 11), the initial value 401 (here, width H1 and time T1) of the second panning determination condition 12 shown in FIG. Anything that falls within this range is not determined to be panning).

  If there is no sign reversal in step 705, the panning end timer included in the switching condition determination unit 13 is confirmed in step 706. At this time, if the panning end timer is still counting, the second panning determination condition 12 is switched as indicated by the set value 402 and the set value 403 in FIG. Here, the set value 402 is a width H2 and time T2, and the set value 403 is a width H3 and time T3. The width has a relationship of H1> H2> H3, and the time has a relationship of T1> T2> T3. It is not always necessary to set the time in this relationship.

  In addition, as shown in FIG. 2, this switching does not necessarily need to be three steps, and may change continuously. If the previous panning end timer has been counted, the second panning determination condition 12 is invalidated and only the first panning determination condition 11 is set as the panning determination condition.

  In step 713, the panning determination conditions from the first panning determination condition generating unit 11 and the second panning determination condition generating unit 12 are checked based on the output of the computing means 5. At this time, if the second panning determination condition 12 is invalidated, the check is performed only with the first panning determination condition 11. When this condition is not satisfied, it is determined that panning is not performed. When this condition is satisfied, the switching condition determining unit 13 determines panning (step 714), and the switching unit 10 is corrected as a second correction condition. A correction condition B different from the condition A is set. The characteristic of the correction condition B may be fixed, but may change stepwise or continuously. Thereby, as shown in FIG. 3, it becomes possible to perform a correct panning determination for the panning operation. That is, in FIG. 6, there is no erroneous panning determination (207 in FIG. 6), and only regular panning determination (206 in FIG. 3) can be realized.

  FIG. 3 is a schematic diagram showing the operation of this apparatus, in which 201 is a stationary period before panning, 202 is a panning operation period, 203 is a stationary period after the end of the panning operation period 202, 204 is an output signal of the angular velocity sensor, 205 is a panning discrimination signal, and the H period is a discrimination period. As shown in the figure, during the panning operation (period 202), the level of the output signal 204 from the angular velocity sensor is high, and the rest period (periods 201 and 203) is low. In addition, a hand shake signal is a minute signal that is output in a stationary period.

  Based on the above processing, the correction signal determination means 6 determines the correction signal based on the outputs from the A / D conversion means 3 and the averaging means 4 in step 716, and the output of the correction signal generation means 7 is output. Originally, in step 717, motion correction of the imaging apparatus is realized.

  In addition, in these processes, if there is a movement that satisfies the second panning determination condition 12 during the swingback period as shown in FIG. 4, the process is interrupted after the end of the panning, and the panning end counter Initialize and resume processing.

  An image motion correction apparatus according to the present invention performs high-precision panning determination by ignoring a high-pass filter circuit in a motion detection circuit after a panning operation intended from a detected motion signal or a back-fluctuation component by calculation. It can be applied to applications that provide a natural feeling of operation in various shooting situations.

1 is a block diagram showing an image motion correction apparatus according to Embodiment 1 of the present invention. Explanatory drawing of the 2nd panning determination condition in this invention Explanatory drawing for demonstrating the effect at the time of applying this invention Explanatory drawing for demonstrating interruption and resumption of the 2nd panning determination condition in this invention Flow chart for explaining the whole of the present invention Explanatory drawing for demonstrating the subject in a conventional apparatus. Flow chart for explaining processing that has been a problem in the past

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motion detection means 2 Input signal amplifier circuit 3 A / D conversion means 4 Averaging means 5 Calculation means 6 Correction signal determination means 7 Correction signal generation means 8 1st correction condition generation part 9 2nd correction condition generation part 10 Switching Means 11 Switching condition judgment means 12 First panning judgment condition 13 Second panning judgment condition

Claims (7)

Motion detection means for detecting the physical motion of the device;
An input signal amplification circuit for electrically amplifying the output signal of the motion detection means;
A / D conversion means for converting the analog signal amplified by the input signal amplifier circuit into a digital signal;
Averaging means for averaging the input digital signal;
An arithmetic means for calculating a difference and a sign of an output of the A / D conversion means and an output of the averaging means;
Correction signal determining means for determining a signal for correcting the movement of the imaging device from the output of the A / D conversion means and the output of the averaging means;
Correction signal generating means for generating a signal for correcting the movement of the apparatus based on the determined correction signal;
A first correction condition generator for changing the output characteristics of the correction signal determination means;
A second correction condition generator for changing the output characteristic of the correction signal determining means with a characteristic different from the first correction condition;
Switching means capable of selecting output of the first correction condition and the second correction condition;
A first panning determination condition for detecting a panning operation intended by the imaging apparatus;
A second panning determination condition having a characteristic different from that of the first panning determination condition for removing signal swingback during repeated panning of the imaging device;
Switching condition determining means for switching the switching means based on the difference and sign of the output of the averaging means calculated by the computing means, the output of the first panning condition, and the output of the second panning condition; ,
Have
An image motion correction apparatus, wherein the output of the motion correction amount determination means is limited by the output of the switching condition determination means. 2. The image motion correction apparatus according to claim 1, wherein the output of the correction signal generation signal corrects a camera shake component of the photographed image by controlling a lens and changing an optical axis incident on the imaging imaging surface. 2. The image motion correction apparatus according to claim 1, wherein the output of the correction signal generation signal is to correct a shake component of the photographed image by changing the output position of the photographed image by driving the image sensor and controlling the image memory. . The image motion correction apparatus according to claim 1, wherein the first correction condition generates a condition having characteristics suitable when a high correction effect is required, such as when the apparatus is held by hand. 2. The image motion correction apparatus according to claim 1, wherein the second correction condition generates a condition having a characteristic suitable when the correction effect needs to be limited when the apparatus is intentionally moved largely. The first panning determination condition includes a timing unit, and determines that panning is performed from a time when the same code as the difference between the output of the A / D conversion unit calculated by the calculation unit and the output of the averaging unit is continuous. The image motion correction apparatus according to claim 1, wherein: 2. The image motion correction apparatus according to claim 1, wherein the second panning determination condition includes a time measuring unit, and the motion detection amount and the detection time can be arbitrarily changed from the end of the first panning determination condition. .

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