JP2006203493A - Image movement correction device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a further highly accurate and natural image movement correction device without variance in camera shake correction after the end of panning by updating a correction reference value, which is different from that of during normal time, from immediately after the end of the panning by reducing drift of a correction reference value in a movement detection circuit after the panning being an intended photographing operation, in order to provide natural operational feelings in the camera shake correction in a camcorder or a DSC. <P>SOLUTION: A difference and a code of an A/D conversion means 103 and a correction reference value deciding means 104 are calculated by a calculation means 105. An update method for a correction reference value is switched by determination conditions 112 immediately after the end of the panning determined by update method determination conditions 111 for a correction reference value. Consequently, correction capability after the end of the panning can be enhanced by reducing the drift of the correction reference value. <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 and lighter, and optical zooms have been increased in magnification. As a result, video movies and DSCs have become one of the most common home appliances for the general consumer. However, on the other hand, downsizing, weight reduction, high zooming of optical zoom, and the spread of video movies and DSC to consumers who are not proficient in shooting, destabilize the screen due to camera shake during shooting. The problem also occurred. 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-described system is configured by a coil and a magnet based on motion information in the two directions of pitching and yawing obtained from an 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 attitude of the imaging unit by the actuated 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 movement information of the image pickup device in the pitching and yawing directions obtained from the sensor, the optical axis of the incident light is bent by tilting the two glass plates of the variable apex prism in the horizontal and vertical directions, respectively. This stabilizes the movement of the captured 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 on the movement of the imaging device in the pitching and yawing two directions obtained from the angular velocity sensor as the focus of the photographing lens Based on the distance, it is converted into the amount of movement of the image on the solid-state image sensor, and the drive timing of the solid-state image sensor is controlled based on this conversion result, and the image readout position from the solid-state image sensor according to the movement of the captured image By changing the (frame), the movement of the captured image is stabilized.
Japanese Patent Application Laid-Open No. 2002-99013 (shake detection device and shake correction optical instrument)

  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. One of them is panning, which is an intended shooting operation in the horizontal direction, and tilting, which is an intended shooting operation in the vertical direction (hereinafter, only panning will be described as an example for ease of explanation. The same is true of the remaining correction when the intended photographing operation is performed.

  The camera shake correction has a correction reference value and a target value of the correction reference value, and the target value is calculated as an average value of a certain section of the input value. The correction reference value changes over time to this target value, which is to suppress discontinuous movement of the corrected image due to a sudden change in the reference value. However, as shown in FIG. 2, the output signal 204 of the angular velocity sensor at the time of panning has a larger input than that at the time of normal hand-held when a series of operations of stationary-panning-stationary shown by 201, 202, 203 is performed. A value is entered (202 interval). For this reason, the correction reference target value 205 calculated as the average value of the input value in a certain interval deviates from the output value of the angular velocity sensor, and the actual correction reference value 206 also changes accordingly. In some cases, the period during which the correction capability is reduced may occur for a long time (indicated by 207 in FIG. 2). FIG. 3 shows the flow of conventional control. In step 302, the correction reference value is updated. In step 303, the correction reference value and the input value are subtracted. If a large input is generated by panning or the like in the angular velocity sensor because it has been used, the correction reference value may be updated to a value that does not exhibit a sufficient correction effect in 302.

  The present invention has been made in view of the above problems, and an object thereof is to provide an image motion correction device capable of improving the correction effect after the end of panning and performing shooting with a natural operation feeling during normal shooting. To do.

  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, a correction reference value determination means calculated from the difference between the digital signal output by the A / D conversion means and the reference value for correction at the previous timing, An arithmetic unit that calculates a difference and a sign between an output of the A / D conversion unit and an output of the correction reference value determination unit, an output from the output of the A / D conversion unit and an output of the correction reference value determination unit Correction signal determining means for determining a signal for correcting the movement of the apparatus, correction signal generating means for generating a signal for correcting the movement of the apparatus based on the determined correction signal, and an output of the reference value determining means for correction Special A first correction reference value updating unit generating unit that changes the output and a second correction reference value updating unit generating unit that changes the output characteristics of the correction reference value determining unit with characteristics different from the first correction condition. A switching means capable of selecting output of the first correction condition and the second correction condition, a correction reference value update method determination condition calculated by a panning operation intended by the imaging apparatus, and the calculation means Switching condition determining means for switching the switching means based on the calculated difference in the output of the correction reference value determining means and the output of the correction reference value update method determining condition. This is an image motion correction device.

  As described above, according to the present invention, after detecting panning as a photographing operation, the correction reference value update unit is changed according to time, and the correction reference value is invalid due to a large input to the angular acceleration sensor during panning. By preventing such update, it is possible to eliminate the malfunction of the camera shake correction effect limitation during normal shooting and to provide an excellent effect of supplying image motion correction performance with a natural feeling of operation.

  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, and a correction reference value determination means calculated from the difference between the digital signal output by the A / D conversion means and the correction reference value at the previous timing; Imaging from the output of the output of the A / D conversion means and the output of the correction reference value determination means and the sign, and the output of the A / D conversion means and the output of the correction reference value determination means A correction signal determining means for determining a signal for correcting the movement of the apparatus, a correction signal generating means for generating a signal for correcting the movement of the apparatus based on the determined correction signal, and a reference value determining means for correction. Output characteristics A first correction reference value updating unit generating unit that changes, and a second correction reference value updating unit generating unit that changes the output characteristics of the correction reference value determining unit with characteristics different from the first correction condition; , A switching means capable of selecting output of the first correction condition and the second correction condition, a correction reference value update method determination condition calculated by a panning operation intended by the imaging apparatus, and a calculation by the calculation means A switching condition determining means for switching the switching means based on the output difference of the corrected reference value determining means and the output of the correction reference value updating method determining condition, and the correction reference value updating The first correction reference value update unit and the second correction reference value update unit are switched according to the method determination condition, and the correction reference value is determined. The natural value is not natural even after panning. Has the effect of shooting with a work feeling can be.

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

(Embodiment 1)
FIG. 1 is a block diagram of an image motion correction apparatus according to the present invention. FIG. 4 is an output example of an output signal 401, a correction reference value target value 402, and a correction reference value 403 in the present embodiment. FIG. FIG. 5 shows a flow of a series of processes according to the present invention.

  In FIG. 1, 101 is a motion detecting means for detecting the physical motion of the apparatus, and 102 is an input signal amplifying circuit for amplifying the motion detected by the motion detecting means 101 in an analog manner. 103 converts the analog signal of the motion detected by the A / D conversion means into a digital signal. Reference numeral 104 denotes a correction reference value determination unit, which is calculated from the motion signal obtained up to the previous time digitized by the A / D conversion unit 103. Reference numeral 105 denotes arithmetic means for calculating a difference and a sign between the motion signal digitized by the A / D conversion means 3 and the signal averaged by the correction reference value determination means 104, and 106 denotes digital data by the A / D conversion means 103. Correction signal determining means for determining a signal for correcting the motion of the image from the converted motion signal and the signal calculated by the correction reference value determining means 104, and 107 for actually correcting the motion of the imaging device from the determined correction signal Correction signal generating means for generating a signal to be corrected. In this description, it is assumed that a microcomputer is used after the A / D conversion means 103, 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.

  In step 501, a physical shake of the apparatus detected by the motion detection unit 101 is detected, amplified by the input signal amplification circuit 102, and then converted into a digital signal by the A / D conversion unit 103.

  In step 502, the difference between the correction reference value determined by the correction reference value determination means 104 and the A / D conversion means 103 is calculated using the calculation means 105, and the sign and difference at that time are obtained.

  In step 503, it is determined whether panning is being performed using the difference value obtained in step 502.

  Step 504 is processing for detecting whether or not the panning determined in step 503 is in progress. If panning has not ended, the process proceeds to step 506 as it is, and if panning has ended, the process proceeds to step 505. This initializes the panning end timer and starts counting.

  In step 506, it is confirmed whether the panning end timer started from the end of panning is counting. If this timer is counting, the process proceeds to step 507. At this time, if this timer is not counting, the first correction reference value update performed in step 509, which is the same process as in the conventional example, as shown in 404 section (T1 section) of FIG. Processing is performed. Note that the update at this time is performed by the update means indicated by the first correction reference value update means generation unit 108. The first correction reference value updating means is an update method for changing the reference value for correction to the target value over time with respect to the target value calculated as the addition average value of a certain section of the input value. This is a correction reference value update method having characteristics suitable for the case where it is necessary to suppress discontinuous movement of the correction image due to a sudden change in the reference value, such as when the apparatus is held by hand.

  In step 507, it is confirmed whether the panning end timer satisfies the correction reference value update processing condition indicated by the correction reference value update method determination condition 111. At this time, if this condition is satisfied, the second correction reference value updating process performed in step 508 as shown in the 405 section (T2 section) of FIG. 4 is performed. Note that the update at this time is performed by the update means indicated by the second correction reference value update means generation unit 109. The second correction reference value updating means resets the target value calculated as the addition average value of a certain section of the input value, and performs recalculation of the correction reference value and the target value of the correction reference value. This is a correction reference value updating method having characteristics suitable for reducing drift of a correction reference value that occurs immediately after intentionally moving the apparatus.

  If this condition is not satisfied, a first correction reference value update process performed in step 509, which is the same process as in the conventional example, as shown in section 406 (T1 section) in FIG. Is implemented. Note that the update at this time is performed by the update means indicated by the first correction reference value update means generation unit 108.

  In step 510, the correction reference value update process determined in step 508 or step 509 is performed, and the correction reference value is updated as indicated by the correction reference value determination unit 104.

  Based on the above processing, the correction signal is determined by the correction signal determination means 106 based on the outputs from the A / D conversion means 103 and the correction reference value determination means 104 in step 511, and the correction signal generation means 107 is determined. Based on the output, the motion correction of the image pickup apparatus is realized in step 512.

  The image motion correction apparatus according to the present invention can perform blur correction with high accuracy even at the end of panning by reducing a large drift of the correction reference value after the intended panning operation from the detected motion signal. 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 for demonstrating the subject in a conventional apparatus. Flow chart for explaining processing that has been a problem in the past Explanatory drawing for demonstrating the effect at the time of applying this invention Flow chart for explaining the whole of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Motion detection means 102 Input signal amplifier circuit 103 A / D conversion means 104 Correction reference value determination means 105 Calculation means 106 Correction signal determination means 107 Correction signal generation means 108 First correction reference value update means generation section 109 Second Correction reference value update means generation unit 110 switching means 111 correction reference value update method determination condition 112 switching condition determination means

Claims (5)

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;
A correction reference value determining means calculated from the difference between the digital signal output by the A / D conversion means and the correction reference value at the previous timing;
An arithmetic means for calculating a difference and a sign of an output of the A / D conversion means and an output of the correction reference value determining 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 correction reference value determining means;
Correction signal generating means for generating a signal for correcting the movement of the apparatus based on the determined correction signal, and a first correction reference value updating means generating section for changing the output characteristics of the correction reference value determining means And a second correction reference value updating unit generating unit that changes the output characteristic of the correction reference value determining unit 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 correction reference value update method determination condition calculated by a panning operation intended by the imaging apparatus, a difference between the output of the correction reference value determination unit calculated by the calculation unit, and the correction reference value update method determination Switching condition determining means for switching the switching means based on the output of the condition;
Have
An image motion correction apparatus characterized in that a characteristic of the correction reference value determination means is changed by output of the correction reference value update method determination condition. 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 the 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 corrects a camera shake component of the photographed image by changing an output position of the photographed image by driving the image sensor and controlling the image memory. . The first correction reference value update condition is a condition having characteristics suitable for cases where it is necessary to suppress discontinuous movement of the corrected image due to a sudden change in the reference value, such as when the apparatus is held by hand. The image motion correction apparatus according to claim 1, which occurs. The second correction reference value update condition is generated immediately after the apparatus is intentionally moved largely, or the like, and a condition having characteristics suitable for the case where it is necessary to reduce the drift of the correction reference value. The image motion correction apparatus described.

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