JP6465705B2 - Motion vector detection device, moving object angular velocity calculation device, imaging device, and lens device - Google Patents

Description

  The present invention relates to a motion vector detection device, a moving object angular velocity calculation device, an imaging device, and a lens device.

  Patent Document 1 discloses a method of correcting a difference between a moving speed and a panning speed of a subject by an image blur correction lens in order to prevent a main subject from being shaken due to a difference between the moving speed and the panning speed of the subject in panning. is suggesting.

JP 2006-317848 A

  In order to apply the method of Patent Document 1, it is necessary to obtain the amount of movement of the main subject on the image plane using a motion vector between arbitrary frames. However, the ratio of the main subject area where the panning is performed is often small in the entire screen, and it is difficult to specify the motion vector. In particular, when the main subject is near or fast, that is, when the panning angular velocity is high, this problem becomes significant. This problem applies not only to panning that shakes the camera left and right, but also to tilting that shakes the camera up and down.

  Accordingly, an object of the present invention is to provide a motion vector detection device, a moving object angular velocity calculation device, an imaging device, and a lens device that can easily detect a motion vector of a main subject.

  The motion vector detection device of the present invention is based on information on motion vectors of a plurality of regions in a frame image, a histogram creation means for creating a histogram showing the relationship between the magnitude of the motion vector and the frequency, and the histogram creation means Setting means for setting a frequency threshold in the created histogram, and detecting a motion vector of the moving object based on information on the magnitude of the motion vector having a frequency equal to or higher than the threshold set by the setting means in the histogram Detecting means, and the setting means has a second value that is higher than the first angular velocity than the threshold when the imaging device is rotated at the first angular velocity when obtaining the frame image. The threshold value when rotating at an angular velocity is set low.

  According to the present invention, it is possible to provide a motion vector detection device, a moving object angular velocity calculation device, an imaging device, and a lens device that can easily detect a motion vector of a main subject.

1 is an overall configuration diagram of an imaging apparatus according to an embodiment of the present invention. (Examples 1 and 2) It is a flowchart explaining the panning assist control which the imaging device shown in FIG. 1 performs. (Examples 1 and 2) It is a figure for demonstrating the calculation method of the main object angular velocity of S203 shown in FIG. (Examples 1 and 2) It is a flowchart explaining the detail of S203 shown in FIG. (Example 1) It is a figure which shows the example of the vector detection area | region in the motion vector detection part shown in FIG. (Examples 1 and 2) It is a figure which shows the histogram of the vector detected by the vector detection frame shown in FIG. (Example 1) It is a flowchart explaining the detail of S203 shown in FIG. (Example 2) It is an example of the histogram of S701 shown in FIG. (Example 2) It is an example of the histogram of S701 shown in FIG. (Example 2)

  FIG. 1 is a diagram illustrating a configuration example of an imaging apparatus according to the present embodiment. The imaging apparatus of the present invention is a non-flex single-lens reflex camera (mirrorless camera), but may be a single-lens reflex camera. Further, the imaging apparatus is not limited to an interchangeable lens type in which a lens apparatus (an interchangeable lens) having an optical system is attached to and detached from the imaging apparatus main body, and may be an integrated lens type imaging apparatus. The imaging apparatus can also be applied to a digital video camera, a digital still camera, a mobile phone, and the like.

  The imaging apparatus according to the present embodiment includes an interchangeable lens (lens apparatus) 100 and a camera body 120.

  The interchangeable lens 100 includes an imaging optical system 101 that is interchangeably attached to the camera body 120 and forms a subject image. The imaging optical system 101 includes a fixed lens 102, a zoom lens (magnification lens) 103, a focus lens, a shift lens (image blur correction lens) 104, a diaphragm, and the like. The focus lens is moved in the optical axis direction to adjust the focus. The zoom lens (magnification lens) is moved in the optical axis direction to change the focal length. The shift lens 104 is moved in a direction orthogonal to the optical axis to optically correct image blur. The “perpendicular direction” only needs to have a component orthogonal to the optical axis, and may be moved obliquely with respect to the optical axis. The stop is disposed at the exit pupil position of the imaging optical system 101 and adjusts the amount of light. FIG. 1 shows each lens of the imaging optical system 101 as a single lens for convenience of drawing, but in actuality, it is composed of one or a plurality of lens groups.

  The zoom encoder 105 detects the position of the zoom lens 103 and outputs a detection signal to a lens system control microcomputer (hereinafter referred to as “lens control means”) 113. The lens control unit 113 can obtain the focal length of the imaging optical system 101 based on the detection signal of the zoom encoder 105.

  An angular velocity sensor (imaging device angular velocity detection means) 111 detects a shake of the entire imaging device and outputs a shake detection signal to the amplifier 112. The amplifier 112 amplifies the shake detection signal and outputs it to the lens control unit 113. It is sufficient that the angular velocity sensor 111 is provided on one of the interchangeable lens 100 and the camera body 120.

  In addition, the lens control unit 113 performs focus lens control, aperture control, and the like. The first driver 114 drives the shift lens 104 in accordance with a control signal from the lens control unit 113. The first driver 114 constitutes an image blur correction unit together with the drive mechanism unit of the shift lens 104. The amplifier 115 amplifies the output of the position sensor 106 of the shift lens 104 and outputs it to the lens control unit 113.

  The lens control unit 113 includes an image blur correction control unit 113a that performs image blur correction control, and a panning assist control unit 113b that performs control for panning assist.

  While panning shots at a slower shutter speed than usual while following the main subject (moving object) that is the subject of the panning shot, it is difficult to match the main subject angular velocity and the panning angular velocity during the exposure period because of long-time shooting. . The panning assist control unit 113b corrects the shake of the main subject based on the difference between the main subject angular velocity and the panning angular velocity, and controls the driving of the shift lens 104 so that an image in which the main subject is stationary can be obtained. In the present invention, only panning of the rotational movement of the camera will be described, but this is also applicable to tilting. For image blur correction, for example, detection and correction are performed for two orthogonal axes such as a horizontal direction and a vertical direction, but since the same configuration is used, only one axis will be described below.

  The camera body 120 includes a shutter 121, an image sensor 122, an analog signal processing circuit (AFE) 123, a camera signal processing circuit 124, a timing generator (TG) 125, an operation unit 131, a camera control unit 132, a second driver 133, and a motor 134. Etc.

  The shutter 121 is driven to open and close to perform exposure. The image sensor 122 includes a CCD image sensor, a CMOS image sensor, and the like, and photoelectrically converts the subject image formed by the imaging optical system 101. The analog signal processing circuit 123 processes the image signal output from the image sensor 122 and outputs the processed image signal to the AFE 123. The TG 125 sets the operation timing of the image sensor 122 and the AFE 123.

  The operation means 131 is an input means such as a switch, button, dial, touch panel or the like. The operation means 131 is for turning on / off the power, switching the S1 and S2 switches, setting the panning assist mode, setting the shutter speed, setting the automatic focus adjustment (AF), manual focus adjustment (MF), and detecting the focus in AF. It is possible to set a focus detection frame that determines the target of the image.

  A camera system control microcomputer (hereinafter referred to as “camera control means”) 132 controls the entire imaging apparatus. For example, the camera control unit 132 outputs a control signal to the second driver 133 for shutter, and drives and controls the motor 134 for driving the shutter.

  In response to the release button being pressed halfway (the S1 switch is turned on), the camera control unit 132 calculates the aperture driving amount corresponding to the photometric result of the photometric sensor or the aperture value set by the photographer, and drives the aperture. Further, in response to half-pressing of the release button, the camera control unit 132 releases the lock of the shift lens 104 so that it can be driven, and performs focus detection. The camera control unit 132 drives the shutter 121 in response to full pressing of the release button (ON of the S2 switch), guides the light beam from the imaging optical system 101 to the imaging element 122, performs exposure (shooting), and shift lens. 104 is driven. The camera control unit 132 controls the camera signal processing circuit 124 based on the output from the image sensor 122 to generate image data (moving image or still image), and records it in the memory card (storage medium) 171.

  The display unit 172 is configured by a liquid crystal panel (LCD) or the like that monitors an image that the photographer intends to capture with the camera and displays the captured image. The camera body 120 includes a focus detection unit (not shown). For example, the focus detection unit performs focus detection in a focus detection frame set in an image (frame image) displayed on the display unit 172. The focus detection method is not limited, and for example, a phase difference detection method or a contrast detection method can be used. In the phase difference detection method, focus detection is performed by detecting a phase difference between image signals of a pair of subject images. In the contrast detection method, focus detection is performed by detecting the peak position of the contrast of the subject image formed by the image sensor 122 while changing the relative position between the focus position formed by the imaging optical system 101 and the image sensor 122.

  The camera body 120 includes a mount contact portion 161 with the interchangeable lens 100. The lens control unit 113 and the camera control unit 132 perform serial communication at a predetermined timing via the mount contact portions 116 and 161.

  The camera signal processing circuit 124 performs image processing such as development and color tone adjustment (white balance, γ processing, etc.) on the image data from the AFE 123 according to the shooting mode. The camera signal processing circuit (signal processing means) 124 includes a motion vector detection means 124a. The motion vector detection means 124a receives at least two frame images and detects each motion vector of a plurality of regions set in the input two frame images. The detection signal of the motion vector detection unit 124 a is output to the camera control unit 132.

  The camera control unit 132 includes a setting unit 132a, a histogram creation unit 132b, a subject angular velocity calculation unit 132c, and a subject detection unit 132d.

  The histogram creating unit 132b creates a histogram indicating the relationship between the magnitude of the motion vector and the frequency based on the information on the motion vector detected by the motion vector detecting unit 124a. The setting means 132a sets a frequency threshold in the histogram created by the histogram creation means 132b. The subject detection unit 132d detects the motion vector of the moving object based on the information on the magnitude of the motion vector having a frequency equal to or higher than the threshold set by the setting unit 132a in the histogram, and thereby on the screen where the main subject exists. Select the area. The camera control means 132 functions as a motion vector detection device by the setting means 132a, the histogram creation means 132b, and the subject detection means 132d.

  Further, the main subject angular velocity calculating unit 132c is based on the motion vector of the main subject detected by the subject detecting unit 132d and the information on the focal length and panning angular velocity of the imaging device when obtaining the frame image. ) Is calculated. For this reason, the camera control means 132 also functions as a moving object angular velocity calculation device.

  In the camera of FIG. 1, when the photographer turns on the camera using the operation unit 131, the camera control unit 132 detects the change in state, and the camera control unit 132 supplies power to each circuit of the camera body 120. And execute the initial setting process. The camera control unit 132 supplies power to the interchangeable lens 100, and the lens control unit 113 executes initial settings in the interchangeable lens 100. Communication starts between the lens control unit 113 and the camera control unit 132 at a predetermined timing. From the camera body 120 to the interchangeable lens 100, the camera state, shooting settings, and the like are transmitted, and from the interchangeable lens 100 to the camera body 120, focal length data, angular velocity data, and the like of the interchangeable lens are transmitted.

  During the panning assist mode, the camera body 120 transmits information about the setting of the panning assist mode and the main subject angular velocity calculated by the main subject angular velocity calculating unit 132c to the interchangeable lens 100. If the panning assist mode is set, the lens control unit 113 sets the shift lens driving control as the control of the panning control unit 113b. If the panning assist mode is not set, the lens control unit 113 sets the shift lens driving control to the image blur correction control. The control of the means 113a is assumed.

  Although the “panning assist mode” is set in the present embodiment, the setting of the mode is not essential in the present invention. In addition, the photographer can set the shutter speed in panning shots, but can also use a predetermined shutter speed.

  FIG. 2 is a flowchart relating to the panning assist control when the panning assist mode is selected by the operation unit 131. 2, S201 to S206 are flowcharts executed by the camera control unit 132, S211 to S218 are flowcharts executed by the lens control unit 113, and “S” represents a step (process). The flowchart shown in FIG. 2 and other figures can be embodied as a program for causing a computer to execute each step, and such a program may be stored in a non-transitory computer-readable medium.

  The flowchart shown in FIG. 2 operates on a frame rate basis. The frame rate is the number of frames (the number of still images and the number of frames) processed per unit time (for example, 1 second), and is expressed in units of fps. S221 represents an interruption process of angular velocity data acquired by the lens control unit 113 from the angular velocity sensor 111.

  First, the operation of the camera control means 132 will be described. In S <b> 201, the lens information is acquired, and angular velocity data, focal length data, and the like are acquired through communication with the lens control unit 113. In S202, vector data is acquired from the motion vector detection means 124a of the camera signal processing circuit 124. The camera control unit 132 may have the function of the motion vector detection unit 124a. In S203, the main subject angular velocity is calculated based on the angular velocity data and focal length data acquired in S201, and the vector data acquired in S202. When the main subject cannot be detected, 0 is set as the main subject angular velocity calculation result. In S <b> 204, the main subject angular velocity calculated in S <b> 203 is transmitted to the lens control unit 113. In S205, the operations in S201 to S204 are repeated until S2 is pressed. When the S2 switch is turned on, the information is notified to the lens control unit 113. In S206, vector data, main subject angular velocity, and other data are initialized, and the process returns to S201.

  Next, the operation of the lens control unit 113 will be described. The angular velocity data is transmitted to the camera control means 132 in S211 and the focal length data is transmitted in S212. In step S213, the main subject angular velocity is received from the camera control unit 132. In S214, the lens control unit 113 repeats the above processing until the S2 switch is turned on. When the S2 switch is turned on, the lens control unit 113 controls the shift lens 104 in and after S215. In S215, it is determined whether or not the main subject angular velocity is detected. Since the main subject is not detected when the main subject angular velocity is 0, normal image stabilization control is performed in S216. If the main subject angular velocity is detected, a difference between the current angular velocity data and the main subject angular velocity received in S213 is calculated in S217, and a driving instruction for the shift lens 104 is output from the difference data calculated in S217 in S218. . In S219, the operation of S216 or S217 and S218 is repeated until the end of exposure is detected. When the exposure is completed, a drive command for returning the shift lens 104 to the center position (initial position) is output in S220.

  FIG. 3 is a diagram for explaining a method of calculating the main subject angular velocity. Specifically, FIG. 3 shows that the main subject has moved from point A to point B during t seconds, and the subject image formed on the image sensor 122 has moved from point C to point D accordingly. FIG. When the distance (image plane movement amount) between point C and point D is ν [pixel], the focal length is f [mm], and the pixel pitch of the image sensor 122 is p [μm / pixel], the main subject on the image plane The angular velocity ω [rad / sec] is expressed by the following equation.

When panning an imaging apparatus, the main object of the angular velocity omega in the image plane, as shown in the following equation, and minus the panning angular velocity omega _p from main object angular velocity omega _s is the angular velocity of the main subject itself.

From Equation (2), the main subject angular velocity ω _s is calculated as follows.

Information on the panning angular velocity ω _p is obtained from the angular velocity sensor 111, and the angular velocity ω of the main subject on the image plane is obtained from the motion vector detection device described above. As a result, the subject angular velocity calculation unit 132c can obtain the main subject angular velocity ω _s from Equation 3. In S204 and S213, this information is transmitted and received. Note that the method of calculating the main subject angular velocity is not limited to this, and a value designated in advance may be used. In S217, ω is calculated from Equation (2). At this time, the latest information detected by the angular velocity sensor 111 during exposure is used as the panning angular velocity ω _p . In S218, the amount of movement of the shift lens 104 is calculated by integrating the angular velocity of the difference.

  The panning assist function is realized by the above operations of the camera control unit 132 and the lens control unit 113.

  FIG. 4 is a flowchart illustrating details of S203 according to the first embodiment. First, in S401, the histogram creation unit 132b creates a histogram based on the detection result by the motion vector detection unit 124a.

  FIG. 5 is a diagram showing an example of a vector detection area in the motion vector detection means 124a. In the figure, reference numeral 501 denotes an image (frame image) obtained by the image sensor 122, the display unit 172 can display the image 501, and a focus detection frame (not shown) is set here by the operation means 131. Can do. A frame drawn with a broken line is a vector detection frame 502. Reference numeral 503 denotes a main subject.

  In FIG. 5, 40 vector detection frames are set on the imaging screen, and a correlation result between at least two frame images is output from the motion vector detection unit 124a as vector data of each region. A known method such as template matching can be used to detect the motion vector.

  FIG. 6 is a diagram showing a histogram created based on the magnitudes of motion vectors detected in the entire region. In general, a histogram is a statistical graph with frequency on the vertical axis and class on the horizontal axis. The horizontal axis of the present embodiment is a diagram in which the magnitudes of motion vectors are arranged for each pixel.

  FIG. 6A shows a histogram in the normal image blur correction mode. The main purpose of the normal image stabilization mode is to stop background blur.In motion vector detection, the number of vector detection frames corresponding to the background is large, so the frequency peak of the histogram is high, and the size of the background vector is large. It concentrates around 0. 6A and 601 are threshold values for determining reliability with respect to the frequency set in the normal image blur correction mode, and are set by the setting unit 132a. In order to remove the moving body vector indicated by 503 as noise, the threshold value is set high.

  FIG. 6B shows a histogram when the main subject moves slowly during panning. Here, it is necessary to determine the moving object indicated by 503 as the main subject. However, since the number of vector detection frames for the main subject is small, the setting means 132a sets the reliability determination threshold value low as indicated by 602. . Since the background is also detected when the main subject moves slowly, a peak appears in the portion corresponding to the main subject and the background, but since the main subject is trying to obtain a still image, the vector for the main subject is near zero. Value. Since the value obtained by converting the output of the angular velocity sensor 111 into the amount of movement on the image plane is equal to the background vector, it is possible to separate the background vector by using this and select only the vector for the main subject. Become.

  FIG. 6C shows a histogram when the main subject moves quickly during panning. When the speed of the subject is fast and the panning angular speed of the camera that follows it is fast, the vector for the background is not detected beyond the detection range. Also, because of the low contrast due to the flow, vectors other than the main subject do not form a peak. Further, since the variation in the vector detected as the main subject increases, the frequency peak for the main subject becomes low. Therefore, the setting unit 132a sets a low value as shown by the threshold value 603 for reliability determination. As a result, vectors other than the main subject are not erroneously detected, and the main subject can be detected.

  Returning to FIG. 4, in S <b> 402, the setting unit 132 a sets the reliability determination threshold for the panning assist mode, but here sets the threshold 602 shown in FIG. 6B.

  In S403, the setting unit 132a resets the reliability determination threshold according to the panning angular velocity. When the panning angular velocity is high, a threshold 603 shown in FIG. 6C is set. The higher the panning angular velocity, the lower the threshold may be proportionally. However, the threshold need not be changed proportionally, and may be changed stepwise or exponentially. In other words, the setting unit 132a has a second threshold value of the second panning angular velocity that is higher than the first threshold value of the first panning angular velocity (for example, the threshold value 602 shown in FIG. 6B). It is sufficient that the threshold value 603) shown in FIG. More generally, the setting means 132a has a threshold value when the imaging device is rotated at a second angular velocity higher than the first angular velocity than a threshold value when the imaging device is rotated at the first angular velocity when obtaining a frame image. It is sufficient to set low.

  In S404, using the changed threshold value, the subject detection unit 132d determines whether a vector serving as the main subject is detected from the histogram. Since the main subject can be easily determined by changing the threshold value, the main subject can be detected here with high probability.

  When a vector corresponding to the main subject is detected, in step S405, the subject detection unit 132d calculates a final motion vector for the main subject using vector data constituting the frequency of the histogram corresponding to the main subject. For example, in S405, the final motion vector for the main subject is calculated by taking the average of the corresponding motion vector values detected by the motion vector detection means 124a.

  In step S406, the subject angular velocity calculation unit 132c calculates the main subject angular velocity from the final motion vector calculated in step S405 and the current angular velocity data received from the lens control unit 113.

  On the other hand, if the main subject cannot be detected even if the threshold value is changed in S404, for example, if the target subject is too small to reach the threshold value for determining the main subject, the main subject is determined in S407. Set the angular velocity to zero.

  By transmitting the information on the main subject angular velocity acquired in this way to the lens control unit 113, the panning assist operation is executed with a high probability.

  As described above, according to the first embodiment, the setting unit 132a sets the threshold for reliability determination according to the panning angular velocity. Specifically, the second panning angular velocity higher than the first panning angular velocity is set lower than the threshold value for determining the reliability of the first panning angular velocity in the histogram. This facilitates the detection of the motion vector of the main subject and facilitates the use of the panning assist function.

  In the second embodiment, the motion vector of the main subject is easily detected by reducing the number of histogram divisions according to the panning angular velocity (widening the bin width and reducing the number of bins). In this embodiment, it is assumed that the threshold value for reliability determination is fixed to the threshold value 602 shown in FIG. In the histogram illustrated in FIG. 6 of the first embodiment, the horizontal axis indicates the magnitude of the motion vector in units of pixels. Reducing the number of histogram divisions (reducing the number of bins) is, for example, a case where the horizontal axis indicates the magnitude of a motion vector in units of several pixels to several tens of pixels. In the present embodiment, the histogram creating means 132b is rotated at a second angular velocity higher than the first angular velocity than the number of bins when the imaging device for obtaining the frame image is rotated at the first angular velocity. When the number of bins can be set small.

  FIG. 7 is a flowchart illustrating details of S203 according to the second embodiment. First, in S601, the number of histogram divisions is set according to the acquired panning angular velocity. In step S602, it is determined whether a main subject has been detected from the histogram created in step S601.

  FIG. 8A shows a histogram when the panning angular velocity is high. FIG. 8A shows a histogram before and after changing the number of divisions. The solid line represents the histogram before the number of divisions is changed, and the wavy line represents the histogram after the number of divisions is changed. This is the same in other figures of FIG. In the histogram before changing the number of divisions, the vector corresponding to the main subject is dispersed and the frequency is low and does not exceed the reliability determination threshold value 801 (or 602). Therefore, the main subject is not detected. On the other hand, by reducing the number of divisions, the frequencies in the same bin are summed, so that the frequency peak exceeds the threshold 701 and the main subject can be detected. A histogram with a reduced number of divisions is rearranged around 0. That is, the histogram creation unit 132b sets bins so as to include a bin centered at a position where the magnitude of the motion vector is zero. This is because the motion vector for the main subject is expected to be close to 0 during the panning because the main subject is being chased.

  FIG. 8B is a diagram showing a different histogram from FIG. 8A when the panning angular velocity is high. In FIG. 8B, a plurality of (here, two types) histograms are created so that the dividing points of the histograms do not match each other (the bin positions are shifted from each other). In the same figure, histograms A and B respectively show histograms before and after changing the number of divisions. By creating two types of histograms with division points set in this way, it is easy to detect the peak of the frequency, and the main subject can be easily detected. In this case, the subject detection unit 132d detects the main subject based on one of the plurality of histograms.

  FIG. 8C shows still another histogram when the panning angular velocity is high. Since the vector of the main subject is expected to be in the vicinity of 0, the number of divisions of the histogram near 0 is reduced, but the number of divisions is not changed in a portion away from 0. Then, the determination as to which range the number of divisions is reduced with respect to 0 is changed according to the panning angular velocity. That is, when the imaging apparatus is rotated at the second angular velocity, the histogram creating unit 132b sets the number of bins in the first range including the position where the magnitude of the motion vector is 0 to be small, and the outside of the first range. Do not set a small number of bins in the second range. By creating such a histogram, even if an unexpected noise component is included in the vector output, the influence of the noise can be ignored, and the main subject can be reliably identified.

  Returning to FIG. 7, if the main subject is detected by the subject detection unit 132d in S703, the process proceeds to S704, and if the main subject is not detected in S703, the process proceeds to S708.

  In S704, the camera control unit 132 determines whether or not the number of divisions set in S701 is equal to or greater than a predetermined value. If the number of divisions does not satisfy the predetermined value, the process proceeds to S705. If the number of divisions satisfies the predetermined value, the process proceeds to S706. move on.

  In S705, the camera control unit 132 calculates a motion vector of the main subject according to the number of division settings. When the number of divisions of the histogram is reduced in order to detect the main subject, an error is likely to occur if the motion vector of the main subject is calculated using all vectors that make a peak. Therefore, the final method for calculating the motion vector of the main subject when the number of divisions of the histogram is reduced is changed from that when the number of divisions of the histogram is not reduced.

  For example, when the focus detection frame is set on the display unit 172 by the photographer, the vector detected in the vector detection frame near the focus detection frame is weighted. More specifically, the subject detection unit 132d weights motion vectors within a predetermined range from the focus detection frame, adds the motion vectors outside the predetermined range, and averages them to detect the motion vector of the main subject. . The present invention is not limited to this example, and the motion vector of the main subject may be detected by averaging motion vectors within a predetermined range from the focus detection frame (without using a motion vector outside the predetermined range). Thereby, the most effective vector can be selected and the motion vector of the main subject can be detected more accurately. In S707, as described above, the main subject angular velocity is calculated using the angular velocity data, the focal length data, and the like.

  FIG. 9 is a diagram showing a histogram when the panning angular velocity is slow (main subject angular velocity is slow), where the solid line represents the histogram before the division number is changed, and the wavy line represents the histogram after the division number is changed. Yes. When the panning angular velocity is low, both the background and main subject motion vectors are detected. In FIG. 9, 901 is a vector corresponding to the background, and 902 is a vector corresponding to the main subject. When the panning angular velocity is low in this way, if the number of histogram divisions is reduced, the background and the main subject are integrated as shown at 903. On the other hand, reference numeral 904 indicates a reliability determination threshold value, but when the panning angular velocity is low, the motion vectors for the main subject are concentrated, so that there is a high possibility that the threshold level will be reached, and there is no need to reduce the number of histogram divisions.

  Therefore, when the panning angular velocity is low, the number of histogram divisions is equal to or greater than a predetermined value in S701. In this case, since the result of the histogram represents the motion of the main subject sufficiently accurately, in S706, the subject detection means 132d simply averages the corresponding motion vectors without weighting based on the focus detection frame. Thus, the motion vector of the main subject is detected. In S707, the main subject angular velocity is calculated using angular velocity data, focal length data, and the like.

  In S708, the main subject angular velocity is set to zero. In this case, image blur correction is not performed.

  As described above, according to the second embodiment, the histogram creating unit 132b changes the division number of the histogram according to the panning angular velocity. Specifically, the second panning angular velocity higher than the first panning angular velocity is less than the number of divisions of the first panning angular velocity in the histogram. This facilitates the detection of the motion vector of the main subject and facilitates the use of the panning assist function. Further, according to the second embodiment, the method for calculating the motion vector of the main subject is changed according to the panning angular velocity. Specifically, in the calculation method at the first panning angular velocity, the motion vector of the main subject is detected using the motion vector corresponding to the frequency equal to or higher than the threshold value as it is (for example, by simple averaging). On the other hand, in the calculation method for the second panning angular velocity, only the motion vectors in the vicinity of the focus detection frame among the motion vectors corresponding to the frequency equal to or higher than the threshold value are used, or weighted and added to the motion vector away from the focus detection frame. And take the average. As a result, the data is converted into data representing the result of the region where the motion vector of the main subject is more likely to exist, and the motion vector of the main subject is detected from the data.

  The methods of Examples 1 and 2 may be applied simultaneously.

  Although the embodiments of the present invention have been described above, the present invention can be variously modified and changed within the scope of the gist thereof.

  The imaging device of the present invention can be applied to the use of an imaging device such as a digital camera, a digital video camera, and a mobile phone.

132a ... setting means, 132b ... histogram creation means, 132c ... subject speed calculation means, 132d ... subject detection means

Claims (14)

Histogram creation means for creating a histogram indicating the relationship between the magnitude of the motion vector and the frequency based on the information on the motion vector of each of the plurality of regions in the frame image;
Setting means for setting a frequency threshold in the histogram created by the histogram creating means;
Detecting means for detecting a motion vector of a moving object based on information on the magnitude of the motion vector having a frequency equal to or higher than a threshold set by the setting means in the histogram;
Have
The setting means is configured such that when the imaging device is rotated at a second angular velocity higher than the first angular velocity than the threshold value when the imaging device is rotated at the first angular velocity when obtaining the frame image. A motion vector detection apparatus characterized by setting a threshold value low.   The motion vector detection device according to claim 1, wherein the setting unit decreases the threshold as the angular velocity of the imaging device increases. Histogram creation means for creating a histogram showing the relationship between the magnitude of the motion vector and the frequency based on information on motion vectors of a plurality of regions in the frame image;
In the histogram created by the histogram creating means, detecting means for detecting a motion vector of a moving object based on information on the magnitude of the motion vector having a frequency equal to or higher than a threshold value;
Have
The histogram creating means rotates the imaging device at a second angular velocity higher than the first angular velocity than the number of bins in the histogram when the imaging device at the time of obtaining the frame image is rotated at the first angular velocity. A motion vector detection apparatus characterized in that the number of bins when set is small.   The motion vector detection device according to claim 3, wherein the histogram creation unit sets the number of bins to be smaller as the angular velocity of the imaging device is larger.   5. The motion vector detection device according to claim 3, wherein the histogram creation unit sets the bin so as to include a bin centered at a position where the magnitude of the motion vector is zero. The histogram creating means creates a plurality of histograms in which bin positions are shifted from each other,
5. The motion vector detection apparatus according to claim 3, wherein the detection unit detects a motion vector of the moving object based on one of the plurality of histograms.   When the imaging device is rotated at the second angular velocity, the histogram creation means sets the number of the bins in the first range including a position where the magnitude of the motion vector is 0, and sets the first range. The motion vector detection device according to claim 4, wherein the number of bins in the second range outside is not set to be small. The motion vector detection device according to any one of claims 1 to 7,
Based on the motion vector of the moving object detected by the motion vector detecting device, the focal length of the imaging device when obtaining the frame image, and the angular velocity information of the imaging device when obtaining the frame image. A calculation means for calculating an angular velocity;
A moving object angular velocity calculation device comprising:   9. An imaging apparatus comprising the moving object angular velocity calculation device according to claim 8, wherein an angular velocity of the moving object as a main subject is calculated.   The imaging device according to claim 9, wherein the detection unit detects a motion vector of the moving object by averaging motion vectors of the motion vectors having a frequency equal to or greater than the threshold. A focus detection unit that performs focus detection in a focus detection frame set in the frame image;
The detection means weights a motion vector within a predetermined range from the focus detection frame, adds the motion vector outside the predetermined range, and averages the motion vector to detect the motion vector of the moving object. Item 15. The imaging device according to Item 10. A focus detection unit that performs focus detection in a focus detection frame set in the frame image;
The imaging device according to claim 10, wherein the detection unit detects a motion vector of the moving object by averaging motion vectors within a predetermined range from the focus detection frame.   The imaging apparatus according to claim 9, further comprising a correction lens that is moved in a direction orthogonal to the optical axis based on the angular velocity of the moving object detected by the moving object angular velocity calculation device and corrects image blur. A lens device that is replaceably attached to the imaging device according to any one of claims 9 to 11,
One of the lens device and the imaging device has an imaging device angular velocity detection means for detecting an angular velocity of the imaging device to which the lens device is attached,
The lens device is
A correction lens that is moved in a direction perpendicular to the optical axis to correct image blur;
Based on the information on the angular velocity of the moving body detected by the moving body angular velocity calculation device of the imaging device and the angular velocity of the imaging device detected by the imaging device angular velocity detection means, the correction is performed so that an image in which the moving body is stationary is obtained. Control means for controlling the driving of the lens;
A lens device comprising: