JP6071173B2 - Imaging apparatus, control method thereof, and program - Google Patents

Description

  The present invention relates to an imaging apparatus such as a video camera and a digital camera, and a control method and program thereof, and is applied to autofocus, automatic exposure control, and the like in in-vehicle shooting mounted on a vehicle or a moving body.

  An in-vehicle video camera installed in the vicinity of the driver's seat of a vehicle always captures and records on the recording medium the image that can be seen from the driver's seat during driving, and records it until a predetermined short time has elapsed when an accident occurs. After that, the recording is stopped. Thereby, it is possible to reproduce the captured video immediately before and immediately after the accident and to verify the cause of the accident.

  It is desirable that a video camera having a function capable of photographing such a drive state is mounted not only on a commercial vehicle but also on all private passenger cars. However, such a video camera is actually mounted only on some commercial vehicles such as taxis. Since this type of video camera is a dedicated device, it is expensive and difficult to install in personal passenger cars.

  On the other hand, consumer video cameras are becoming cheaper year by year, and are widely used in most homes mainly for home use. Patent Document 1 discloses a video station, a video camera, and a video station that can easily capture and record a wide range of scenes in front of the vehicle while driving the vehicle, using a video camera equipped with a popular hand shake detection sensor. An in-vehicle video camera device and a vehicle are disclosed.

  2. Description of the Related Art Conventionally, video cameras have widely employed autofocus in order to reliably perform shooting in an optimally focused state where a shooting target, that is, a subject is in focus. In auto-focusing, the imaging object is positioned in the distance measuring area at the center of the screen, thereby detecting the in-focus state with respect to the imaging object and automatically adjusting the focusing mechanism of the imaging optical system. As a method for detecting the in-focus state with respect to the subject, a method for detecting the in-focus state using the fact that the sharpness information included in the imaging output at the in-focus position is maximized is known.

  In recent years, studies for detecting a motion vector from an image signal have been actively conducted for image shake correction and the like. Development of an automatic focusing function of a subject tracking method that detects the movement of a subject using this motion vector and tracks the subject for automatic focusing is also becoming popular.

JP 2006-261865 A U.S. Pat. No. 3,890,462 Japanese Examined Patent Publication No. 60-46878

B.K.P.Horn, Artificial Intelligence 17, p.185〜203 (1981) Morio Onoe, Information Processing Vol. 17, No. 7, p.634-640 July 1976

  However, the video camera described in the above conventional example does not have a function specialized for in-vehicle shooting or the like, and may cause inconvenience in in-vehicle shooting. For example, in the case of shooting while traveling, unlike the normal shooting, the photographer does not always aim at the subject but may be fixed to a part of the vehicle body. When fixed to the vehicle body, the main subject is not always present at the center of the screen depending on the angle of the camera with respect to the traveling direction and the curve of the road. In such shooting, when focus adjustment is performed by setting a distance measurement area in the center portion of the screen, a subject different from the user's intention may be focused and the main subject may be blurred.

  In the case of shooting while traveling, a flow occurs in the image on the screen in accordance with the traveling direction and speed. When the image in the distance measurement area flows, the fluctuation of the distance measurement value changes drastically, the correct distance measurement value cannot be obtained, the autofocus is not stable, and the image may be fluffed. is there.

  Furthermore, in the case of in-vehicle shooting, a state in which a part of the vehicle body or a part of the vehicle is reflected in the screen is likely to occur. However, since there is a large change in the brightness of the inside and outside of the vehicle, if the evaluation frame for adjusting the exposure is set incorrectly, there is a possibility that an underexposed or overexposed video is recorded without proper exposure.

  The present invention has been made in view of the above-described problems, and in on-vehicle shooting, an evaluation area for autofocus and exposure control is automatically set to always enable shooting with stable focus and stable exposure. For the purpose.

An imaging apparatus according to the present invention includes an imaging unit that converts an optical image formed by an imaging optical system into a video signal, a motion vector detection unit that detects a motion vector from the video signal obtained by the imaging unit, and the motion vector Evaluation region setting means for setting an evaluation region on the video for obtaining a predetermined evaluation value in accordance with the detection result, and the motion vector detection means outputs the video obtained by the imaging means in the x direction and Dividing into a plurality of blocks in the y direction, detecting a motion vector in each block, the evaluation area setting means calculates the intersection area of the motion vector detected in each block as the evaluation area, and is calculated in each block can not identify the intersection area of the motion vector, and, if the motion vector calculated for each block are oriented in one direction, the initial position of the predetermined fixed With that evaluation area, depending on the size of the motion vector, to change the size of the evaluation area.

  According to the present invention, an evaluation area for autofocus and exposure control is automatically set in in-vehicle shooting, and shooting with always stable focus and stable exposure becomes possible. For example, even when a consumer video camera is fixed to the vehicle body for in-vehicle shooting, by using a motion vector detected from the video signal, the evaluation area can be set in an area where the image flow is small, It becomes possible to acquire a stable evaluation value.

It is a figure which shows the structure of the video camera which is an imaging device which concerns on 1st Embodiment. It is a flowchart which shows focus adjustment control. It is a flowchart which shows the detailed process of TV-AF control of the flowchart of FIG. It is a flowchart which shows the detailed process of the micro drive mode of the flowchart of FIG. FIG. 10 is a characteristic diagram illustrating the operation of the focus lens in a minute driving mode. It is a flowchart which shows the detailed process of the mountain climbing mode of the flowchart of FIG. FIG. 10 is a characteristic diagram illustrating the operation of the focus lens in the hill-climbing drive mode. It is a figure for demonstrating the setting of the evaluation frame according to a motion vector. It is a figure which shows the relationship between the movement of a vehicle body, and a motion vector. It is a flowchart which shows the setting determination of the evaluation frame using a motion vector. It is a figure which shows the example of a setting of the evaluation frame using a motion vector. It is a figure which shows the example of a setting of the evaluation frame using a motion vector. It is a figure which shows the example of a setting of the evaluation frame using a motion vector. It is a figure which shows the example of a setting of the evaluation frame using a motion vector. It is a figure which shows the magnitude | size change of the evaluation frame according to a motion vector. It is a flowchart which shows the setting of the evaluation frame according to a motion vector. It is a figure which shows the structure of the video camera which is an imaging device which concerns on 2nd Embodiment. It is a figure which shows the program diagram at the time of performing exposure control. It is a figure which shows the data table for exposure control hold | maintained at a camera microcomputer. It is a flowchart which shows exposure adjustment control. It is a figure which shows the weighting of AE using the intersection area | region of a motion vector.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
<First Embodiment>
FIG. 1 is a diagram illustrating a configuration of a video camera according to the first embodiment. Although the present embodiment describes a video camera, the present invention can be applied to other imaging devices such as a digital still camera.

  In FIG. 1, reference numeral 101 denotes a first fixed lens. Reference numeral 102 denotes a variable power lens that moves in the optical axis direction to perform variable power. Reference numeral 103 denotes an aperture. Reference numeral 104 denotes a second fixed lens. Reference numeral 105 denotes a focus compensator lens (hereinafter referred to as a focus lens) having both a function of correcting the movement of the focal plane due to zooming and a focusing function. The first fixed lens 101, the variable power lens 102, the diaphragm 103, the second fixed lens 104, and the focus lens 105 constitute an imaging optical system.

  Reference numeral 106 denotes an imaging element as a photoelectric conversion element that converts an optical image formed by the imaging optical system into a video signal, and is constituted by a CCD sensor or a CMOS sensor. Reference numeral 107 denotes a CDS / AGC / AD converter that samples, gain adjusts, and digitizes the output of the image sensor 106. A camera signal processing circuit 108 performs various image processing on the output signal from the CDS / AGC / AD converter 107. Reference numeral 109 denotes a display device that displays a video signal from the camera signal processing circuit 108. A recording device 110 records the video signal from the camera signal processing circuit 108 on a recording medium such as a magnetic tape, an optical disk, or a semiconductor memory.

  Reference numeral 111 denotes an AF gate which passes only signals in an area used for focus detection among output signals of all pixels from the CDS / AGC / AD converter 107. A focus signal processing circuit 112 is a high-frequency component from a signal that has passed through the AF gate 111, a luminance difference component generated from the high-frequency signal (difference between the maximum value and the minimum value of the luminance level of the signal that has passed through the AF gate 111), etc. To extract a focus signal. Here, the focus signal represents the sharpness (contrast state) of the image generated based on the output signal from the image sensor 106, but the sharpness changes depending on the focus state of the image pickup optical system. In other words, the signal represents the focus state of the imaging optical system.

  A motion vector detection circuit 113 performs a known motion vector detection process on the video signal, and detects a motion vector for a plurality of regions on the video. As a motion vector detection method necessary for an image encoding device and an image touch correction device, a spatio-temporal gradient method described in Patent Document 2, Patent Document 3, etc., or a correlation method based on correlation calculation or a block matching method (template matching) Law). The spatiotemporal gradient method is discussed in detail in Non-Patent Document 1. The block matching method is discussed in detail in Non-Patent Document 2. The spatiotemporal gradient method is a method of expressing the amount of motion of an image as d / Δ from a luminance difference d between frames (or fields) and a luminance difference Δ between pixels in the screen. This is because the signal obtained from the camera is the time average of the field period, and as the amount of motion of the image increases, the edge becomes dull, and the luminance difference Δ between pixels becomes small. The difference d is normalized by the signal Δ. On the other hand, in the block matching method, an input image signal is divided into blocks of an appropriate size (for example, 8 pixels × 8 lines), and the difference from a certain range of pixels in the previous frame (or field) is calculated for each block. . Then, the block of the previous frame (or field) in which the sum of the absolute values of the differences is minimized is searched. The relative shift of the block represents the motion vector of the block.

  An intersection area detection circuit 114 calculates a motion vector intersection area based on the detection result of the motion vector detection circuit 113 and transmits the calculation result to the camera / AF microcomputer 115. The processing of the intersection area detection circuit 114 will be described later. Reference numeral 115 denotes a camera / AF microcomputer (hereinafter referred to as a camera microcomputer). Based on the detection result of the motion vector detection circuit 113, the camera microcomputer 115 sets an autofocus frame (hereinafter referred to as an AF frame) that is an evaluation frame (evaluation region) used for focus detection in the intersection region. Information is transmitted to the gate 111. The camera microcomputer 115 controls a focus lens driving source 116 (to be described later) based on the output signal from the focus signal processing circuit 112 to drive the focus lens 105 and outputs an image recording command to the recording device 110.

  Reference numeral 117 denotes a variable power lens driving source, which includes an actuator for moving the variable power lens 102 and its driver. Reference numeral 116 denotes a focus lens driving source, which includes an actuator for moving the focus lens 105 and its driver. The zoom lens drive source 117 and the focus lens drive source 116 are configured by actuators such as a stepping motor, a DC motor, a vibration motor, and a voice coil motor.

  Next, an outline of the focus adjustment control executed by the camera microcomputer 115 will be described. FIG. 2 is a flowchart showing focus adjustment control in the present embodiment. First, in step S201, the camera microcomputer 115 sets the position and size of an AF frame for acquiring a focus signal that is the basis of TV-AF control. When an intersection area is detected by the intersection area detection circuit 114, an AF frame is set in the intersection area, and when no intersection area is extracted, a fixed AF frame (initial position) is set. Details of this processing will be described later with reference to FIGS.

  In step S202, the focus signal of the designated AF frame is acquired from the focus signal processing circuit 112 under the control of the camera microcomputer 115. At this time, filter coefficients in the focus signal processing circuit 112 are set, and a plurality of band pass filters having different extraction characteristics are constructed. The extraction characteristic is the frequency characteristic of the bandpass filter, and the setting here means changing the setting value of the bandpass filter in the focus signal processing circuit 112.

  In step S203, the camera microcomputer 115 performs focus adjustment by TV-AF control. Details of this processing will be described later with reference to FIG. Then, it returns to step S201.

  FIG. 3 is a flowchart showing details of the TV-AF control executed in step S203 of FIG. First, in step S301, the camera microcomputer 115 determines whether or not it is in the minute drive mode. If it is in the minute drive mode, the process proceeds to step S302, and if not in the minute drive mode, the process proceeds to step S308. In step S302, the camera microcomputer 115 performs a minute driving operation, drives the focus lens 105 with a predetermined amplitude, and determines whether it is in focus or in which direction the focus is present. Details of this processing will be described later with reference to FIGS. In step S303, the camera microcomputer 115 determines whether or not the focus determination is successful by the micro-driving operation in step S302. If it is successful, the process proceeds to step S306. If not, the process proceeds to step S304. In step S304, the camera microcomputer 115 determines whether or not the direction determination is successful by the minute driving operation in step S302. If the direction determination is successful, the process proceeds to step S305 to shift to the hill-climbing drive mode. If the direction determination is not successful, the process returns to step S301 and the minute drive mode is continued. In step S306, the camera microcomputer 115 stores the focus signal level at the time of focusing in the memory in the camera microcomputer 115, and then transitions to step S307 to shift to the restart determination mode.

  On the other hand, in step S308, the camera microcomputer 115 determines whether or not the hill-climbing drive mode is selected. If the hill-climbing drive mode is selected, the process proceeds to step S309. If not, the process proceeds to step S313. In step S309, the camera microcomputer 115 performs a hill-climbing drive operation, and drives the focus lens 105 to a hill-climb at a predetermined speed in a direction in which the focus signal increases. Details of this processing will be described later with reference to FIGS. In step S310, the camera microcomputer 115 determines whether or not the peak position of the focus signal has been found by the hill-climbing driving operation in step S309. If found, the process proceeds to step S311, and if not found, the process returns to step S301 to continue the hill-climbing drive mode. In step S311, the camera microcomputer 115 sets the position of the focus lens 105 at which the focus signal has reached its peak as the target position, and then proceeds to step S312 and transitions to the stop mode.

  On the other hand, in step S313, the camera microcomputer 115 determines whether or not the stop mode is set. If the stop mode is set, the process proceeds to step S314. If the stop mode is not set, the process proceeds to step S316. In step S314, the camera microcomputer 115 determines whether or not the focus lens 105 has returned to the position where the focus signal is peaked. When the position returns to the peak, the process proceeds to step S315, and the mode shifts to the minute driving (focus determination) mode. When the position does not return to the peak position, the process returns to step S301, and the stop mode is continued.

  On the other hand, in step S316, the camera microcomputer 115 compares the current focus signal level with the focus signal level held in step S306, and determines whether or not the fluctuation amount is greater than a predetermined value. If the variation amount is large, the process proceeds to step S317, and the mode is shifted to the minute driving (direction determination) mode. If the variation amount is not large, the process returns to step S301, and the restart determination mode is continued.

  Detailed processing in the minute drive mode executed in step S302 of FIG. 3 will be described with reference to FIGS. FIG. 4 is a flowchart showing detailed processing of the minute driving mode executed in step S302 of FIG. In step S401, the camera microcomputer 115 determines whether or not the counter indicating the operation state of minute driving is currently 0. If it is 0, the process proceeds to step S402, and if not, the process proceeds to step S403. In step S402, the camera microcomputer 115 holds the current AF evaluation value level as processing when the focus lens 105 is on the close side. The AF evaluation value here is based on an image signal generated from the charge accumulated in the image sensor 106 when the focus lens 105 is on the infinity side in step S410 described later.

  In step S403, the camera microcomputer 115 determines whether or not the current counter is 1. If 1, the process proceeds to step S404. If not, the process proceeds to step S409. In step S404, the camera microcomputer 115 calculates a vibration amplitude and a center movement amplitude for driving the focus lens 105 in step S408 described later. Usually, these amplitudes are generally set within the depth of focus. In step S405, the camera microcomputer 115 compares the infinite AF evaluation value level held in step S402 with the closest AF evaluation value level held in step S410 described later. As a result, when the former is large, the process proceeds to step S406, and when the latter is large, the process proceeds to step S407. In step S406, the camera microcomputer 115 adds the vibration amplitude and the center movement amplitude to obtain a drive amplitude. On the other hand, in step S407, the camera microcomputer 115 sets the vibration amplitude as the drive amplitude. In step S408, the camera microcomputer 115 drives in an infinite direction based on the drive amplitude obtained in step S406 or step S407.

  In step S409, the camera microcomputer 115 determines whether or not the current counter is 2. If it is 2, the process proceeds to step S410. If it is not 2, the process proceeds to step S411. In step S410, the camera microcomputer 115 holds the current AF evaluation value level as processing when the focus lens 105 is on the infinity side. The AF evaluation value here is based on the image signal generated from the charge accumulated in the image sensor 106 when the focus lens 105 is on the close side in step S402. In step S411, the camera microcomputer 115 calculates a vibration amplitude and a center movement amplitude for driving the focus lens 105 in step S415 described later. Usually, these amplitudes are generally set within the depth of focus. In step S412, the camera microcomputer 115 compares the closest AF evaluation value level held in step S410 with the infinite AF evaluation value level held in step S402. As a result, when the former is large, the process proceeds to step S413, and when the latter is large, the process proceeds to step S414. In step S413, the camera microcomputer 115 adds the vibration amplitude and the center movement amplitude to obtain a drive amplitude. On the other hand, in step S414, the camera microcomputer 115 sets the vibration amplitude as the drive amplitude. In step S415, the camera microcomputer 115 drives in the closest direction based on the drive amplitude obtained in step S413 or step S414.

  In step S416, the camera microcomputer 115 determines whether or not the current direction determination mode is set. If the mode determination mode is set, the process proceeds to step S417. If the direction determination mode is not set, the process proceeds to step S419. In step S417, the camera microcomputer 115 determines whether or not the focal point exists in the same direction for a predetermined number of times. If yes, the process proceeds to step S418. If not, the process proceeds to step S421. In step S418, the camera microcomputer 115 determines that the orientation has been determined. On the other hand, in step S419, the camera microcomputer 115 determines whether or not the focus lens has reciprocated in the same area a predetermined number of times. If so, the process proceeds to step S420, and if not, the process proceeds to step S421. In step S420, the camera microcomputer 115 determines that the in-focus determination has been made. In step S421, the camera microcomputer 115 returns the value to 0 if the counter indicating the operation state of minute driving is 3, and adds the counter if it is any other value.

FIG. 5 is a characteristic diagram showing the operation of the focus lens 105 in the minute driving mode. The upper diagram shows the vertical synchronization signal of the image signal, and the lower diagram shows the time on the horizontal axis and the position of the focus lens 105 on the vertical axis. The AF evaluation value EV _A for the charge accumulated in the image sensor 106 at the time of label A is taken into the camera microcomputer 115 at time T _A. Also, the AF evaluation value EV _B for the charge accumulated in the image sensor 106 at the time of label B is taken into the camera microcomputer 115 at time T _B. At time T _C , the AF evaluation values EV _A and EV _B are compared, and the vibration center is moved only when EV _B is large. Here, the movement of the focus lens 105 is set to a movement amount that cannot be recognized on the screen on the basis of the depth of focus.

  Detailed processing in the hill-climbing drive mode executed in step S308 in FIG. 3 will be described with reference to FIGS. FIG. 6 is a flowchart showing detailed processing of the hill-climbing drive mode executed in step S308 of FIG. In step S601, the camera microcomputer 115 sets the drive speed of the focus lens 105. In step S602, the camera microcomputer 115 determines whether the current AF evaluation value level has increased from the previous time. If it has increased, the process proceeds to step S603, and if not, the process proceeds to step S604. . In step S603, the camera microcomputer 115 drives the focus lens 105 to climb in the same direction as the previous time based on the speed set in step S601.

  In step S604, the camera microcomputer 115 determines whether or not the AF evaluation value level exceeds the peak position. If the peak value is exceeded, the process proceeds to step S605. If the peak value is not exceeded, the process proceeds to step S606. . In step S605, the camera microcomputer 115 determines that the peak position has been found. In step S606, the camera microcomputer 115 drives the focus lens 105 to climb in the direction opposite to the previous time based on the speed set in step S601. Note that when step S606 is repeated in the hill-climbing drive mode, it means that the focus lens 105 is in the hunting state because a sufficient amount of change in the AF evaluation value of the subject cannot be obtained.

  FIG. 7 is a characteristic diagram showing the operation of the focus lens 105 in the hill-climbing drive mode. The horizontal axis represents the position of the focus lens 105, and the vertical axis represents the focus signal. When the focus lens 105 is driven in the range A, since the AF evaluation value is increased, the mountain climbing drive in the same direction is continued. Here, when the focus lens 105 is driven in the range B, the AF evaluation value decreases beyond the peak position. At this time, the hill-climbing driving operation is terminated assuming that the in-focus point exists, and after the focus lens 105 is returned to the peak position, the operation shifts to the minute driving operation. On the other hand, when the AF evaluation value decreases without exceeding the peak position as in the range C, the driving direction is reversed and the hill-climbing driving operation is continued.

  As described above, in the focus adjustment control by the TV-AF method, the AF evaluation value is always maximized by moving the focus lens 105 while repeating the restart determination → micro drive → mountain climbing drive → stop → micro drive → restart determination. The in-focus state is maintained so that

  The AF frame setting method according to the motion vector detection result will be described below with reference to FIGS. This is a detailed description of the AF frame region information determination process in step S201 of FIG. FIG. 8A shows an input image, which is divided into [7 * 5] blocks in the x and y directions. The traveling direction is the back direction of the image. FIG. 8B shows the result of detecting a motion vector in each block. Such a motion vector distribution diagram is generally called an optical flow diagram. Since the motion vector is traveling in the depth direction of the screen, the motion vectors are radiating around the traveling direction. FIG. 8C shows the motion vector value converted into (x component, y component) and displayed. An evaluation frame is determined using the values converted into the respective components. FIG. 8D shows a simplified method for setting the evaluation frame. Since each motion vector appears radially, it can be seen that the intersection region of the motion vectors is a region S. By using the intersection area of the motion vectors as an evaluation frame, a stable AF evaluation value can be acquired and appropriate autofocus can be performed. The evaluation frame setting method will be described below.

  First, it is not necessary to always move the evaluation frame according to the motion vector, and is a process performed only when the vehicle body is moving while being fixed to a part of the vehicle body as an in-vehicle camera. With reference to FIGS. 9 and 10, processing for switching between using an evaluation frame at an initial position or using an evaluation frame according to a motion vector in setting an evaluation frame will be described.

  FIG. 9 is a diagram simply showing the determination of switching between using the initial position evaluation frame or using the evaluation frame corresponding to the motion vector. When FIG. 8A is an input image, FIG. 9A is a diagram simulating an initial state in which the vehicle body is driven in the depth direction of the image. Since there is little image flow in the center of the screen, there are few motion vectors. Since the edge of the screen has a large image change, motion vectors are generated. FIG. 9B is a diagram simulating the state in which the vehicle body is accelerated. Since the amount of movement of the vehicle body has increased, a motion vector for the inner part of the screen is generated. The edge of the screen tends to increase the intensity of the motion vector due to the increased amount of movement. FIG. 9C is a diagram simulating a state where the vehicle body is further accelerated. A motion vector is generated except for the center of the screen. Thus, when the vehicle body shifts from the stop state to the driving state, the motion vector increases with the amount of movement of the vehicle body. Using this, the increase in the motion vector in the same area is monitored, and if the increase in the motion vector for a predetermined time is confirmed, it is determined that the vehicle body is driven, and the evaluation frame corresponding to the motion vector is determined. Move on to the process of setting. FIG. 9D is a diagram showing changes in motion vectors in a certain area in the screen. In the present embodiment, it is determined that the movement of the vehicle body has started when the motion vector sampling interval has increased continuously K times.

  FIG. 10 is a flowchart of setting determination of an evaluation frame using a motion vector. In step S1002, the camera microcomputer 115 determines whether a motion vector has been detected from the video. If a motion vector is detected, the process proceeds to step S1003, and if no motion vector is detected, the process proceeds to step S1012.

  In step S1003, the camera microcomputer 115 stores the detected motion vectors in the three-dimensional arrays Vector_x [n] [h] [i] and Vector_y [n] [h] [i]. h represents the number of motion vector detection areas in the x-axis direction, i represents the number of motion vector detection areas in the y-axis direction, and n represents the number of the stored array. As a storing method, a motion vector is divided into an x component and a y component, and each is stored. After storing, the process proceeds to step S1004. In step S1004, the camera microcomputer 115 increments n indicating the array number to n + 1. In step S1005, the camera microcomputer 115 determines whether n exceeds 1. If n is greater than 1, that is, if more than 1 motion vectors are already stored, the process proceeds to step S1006, and if not, the process proceeds to step S1012.

  In step S1006, the camera microcomputer 115 compares the vector components of the respective motion vector detection areas stored in n-1 (one previous), and determines whether the vector component has increased. In the comparison of vectors, each difference is extracted and a decrease / increase is determined. After the comparison, the process proceeds to step S1007.

  In step S1007, the camera microcomputer 115 checks what percentage of the motion vector detection area has increased. In the present embodiment, the case where about 60% or more of the entire detection area is increased is set as the threshold value Th1, but the value of the threshold value Th1 can be set to an arbitrary value after sufficient measurement. is there. The total number of areas Vsum = h * i is counted, and the number of areas is set to Vnum. When the increase rate [%] = Vnum ÷ Vsum × 100 is calculated and the increase rate is greater than or equal to Th1, it is determined that the increase of the entire motion vector is confirmed, and the process proceeds to step S1008. Otherwise, the process proceeds to step S1009. In step S1009, the camera microcomputer 115 performs a process of initializing VCount for counting the number of vector increases to 0, and proceeds to step S1012.

  In step S1008, the camera microcomputer 115 increments VCount for counting the number of vector increases, and the process proceeds to step S1010. In step S1010, the camera microcomputer 115 determines whether or not the vector increase count VCount has increased continuously K times. In this embodiment, the threshold value K is set to 30 times (corresponding to a real time of 0.5 seconds). However, the threshold value K can be set to an arbitrary value after sufficient measurement. is there. That is, when the motion vector is increasing, specifically, when the increase in the motion vector is continuously generated for 0.5 seconds or more, it is determined that the vehicle body is being driven in either direction, and step S1011 is performed. Transition to. Otherwise, the process proceeds to step S1012. In step S1011, the camera microcomputer 115 performs processing for changing the evaluation frame according to the motion vector. Details of this processing will be described later with reference to FIG.

  In step S1012, the evaluation frame cannot be moved according to the motion vector, such as no increase in the motion vector continuously occurring for 0.5 seconds or more, or no motion vector is generated. The evaluation frame at the position is set.

  FIG. 11 is a diagram illustrating a method for calculating a motion vector intersection region, which is a region in which an evaluation frame is set according to a motion vector. FIG. 11A shows an input image. FIG. 11B is an optical flow diagram illustrating motion vectors. FIG. 11C shows a motion vector divided into components. L1 extracts only the x component in the image and graphs the value of the component. The x component increases from the coordinate x = 1 to 7 and it can be confirmed that there is a zero cross point at the coordinate x = 4. This is because motion vectors are generated radially around the coordinate x = 4. Therefore, by obtaining the zero cross point of the x component graph, the intersection region in the x direction of the motion vector can be specified. Similarly, L2 is obtained by extracting only the y component in the image and graphing the value of the component. The y component increases from the coordinate y = 1 to 5, and it can be confirmed that there is a zero cross point at the coordinate y = 3. This is because motion vectors are generated radially around the coordinate y = 3. Therefore, by obtaining the zero cross point of the y component graph, the intersection region in the y direction of the motion vector can be specified. As described above, in the input image of FIG. 11A, it can be estimated that there is a motion vector intersection region at the position of coordinates (4, 3), and that region has the smallest motion vector. By setting an evaluation frame at the coordinates (4, 3), a stable evaluation value can be obtained and appropriate autofocus can be performed. By performing such processing, it is possible to specify the intersection area of motion vectors from the input image.

  FIG. 11 shows an example in which the intersection area of the motion vector is at the center of the image. Subsequently, an example in which the intersection area is outside the center of the image is shown. FIG. 12A shows an input image. This image is an image that may occur when there is a curve ahead of the traveling direction or when the camera is installed at a certain angle with respect to the traveling direction. FIG. 12B is an optical flow diagram illustrating motion vectors. FIG. 12C shows a motion vector divided into components. L3 is a graph in which only the x component in the image is extracted and the value of the component is graphed. The x component increases from the coordinate x = 1 to 7 and it can be confirmed that there is a zero cross point at the coordinate x = 6. This is because motion vectors are generated radially around the coordinate x = 6. Therefore, by obtaining the zero cross point of the x component graph, the intersection region in the x direction of the motion vector can be specified. Similarly, L4 to L6 are obtained by extracting only the y component in the image and graphing the value of the component. The y component increases from the coordinate y = 1 to 5, and it can be confirmed that there is a zero cross point at the coordinate y = 3. This is because motion vectors are generated radially around the coordinate y = 3. Therefore, by obtaining the zero cross point of the y component graph, the intersection region in the y direction of the motion vector can be specified. However, since the motion vector becomes parallel as the distance from the intersection increases, L6 that graphs the value of the first row of the X coordinate is y compared to L4 that graphs the value of the X coordinate of the third to seventh rows. The change of the component becomes small. If the change in the y component is small and there is no zero cross point, the value of that line is ignored, and the intersection point is obtained with reference to the zero cross points of other lines. As described above, it can be estimated that the input image of FIG. 12A has an intersection region of motion vectors at the coordinates (6, 3).

  Next, an example in which there is a reflection of a hood, a room, etc. in the screen will be shown. FIG. 13A shows an input image, and the object P is a subject that is always captured. FIG. 13B is an optical flow diagram illustrating motion vectors. Since the object P has no motion, it can be confirmed that no motion vector is generated. FIG. 13C shows a motion vector divided into components. L7 is a graph in which only y components in the 2nd to 5th columns of the y coordinate are extracted and the values of the components are graphed. The x component increases from the coordinate x = 1 to 7 and it can be confirmed that there is a zero cross point at the coordinate x = 4. This is because motion vectors are generated radially around the coordinate x = 4. L8 is a graph of the x component in the first column of the y coordinate. Since the first column does not have a motion vector due to the object P, there is no zero cross point in the graph. Therefore, the graph where the zero cross point does not exist is ignored, and the intersection of the vectors is obtained from the zero cross point in the 2nd to 5th columns of the y coordinate. Therefore, the zero cross point of the x component graph is x = 4. Similarly, L9 in FIG. 13 is obtained by extracting only the y component in the x-coordinates 6 to 7 and graphing the value of the component. The y component increases from the coordinate y = 1 to 5, and it can be confirmed that there is a zero cross point at the coordinate y = 3. This is because motion vectors are generated radially around the coordinate y = 3. L10 is a graph in which only the y component in the first to fifth columns of the x coordinate is extracted and the values of the components are graphed. This also has a zero cross point at the coordinate y = 3. As described above, it can be estimated that the input image of FIG. 13A has a motion vector intersection region at the position of coordinates (4, 3).

  FIG. 14A shows an input image. FIG. 14B is an optical flow diagram illustrating motion vectors. FIG. 14C shows a motion vector divided into components. L11 is obtained by extracting only the x component of the image and graphing the value of the component. It can be seen that there is no change in the x component and no zero cross point. L12 is a graph of the y component. Similarly, it can be seen that there is no change in the y component and no zero cross point. As described above, since the input image of FIG. 14A does not have a zero cross point, there is no intersection region of motion vectors. In this case, it is determined that a flow has occurred on the entire screen, and the size of the evaluation frame at the initial position is changed according to the motion vector.

  FIG. 15 is a diagram illustrating a change in the size of the evaluation frame according to the motion vector. As shown in FIGS. 15A and 15B, when the motion vector exceeds a predetermined amount Th2, the size is changed from the initial evaluation frame Q to the evaluation frame R according to the motion vector. To do. As a result, even when an image flow occurs, it is possible to reduce the fluctuation of the evaluation value by increasing the evaluation frame, and stable autofocus is possible. As shown in FIG. 15C, when the motion vector exceeds the predetermined amount Th3, the flow of the image is large, and the evaluation value is not stable even if the evaluation frame is set large. Therefore, the evaluation frame is not set, the previous focus state is maintained, and the fluff of the focus is prevented. The process flow described above will be described with reference to the flowchart of FIG.

  FIG. 16 is a process for setting an evaluation frame according to a motion vector. In step S1602, the camera microcomputer 115 extracts a motion vector component in the x-axis direction of the j-th row of the coordinate x. Although the number of components differs depending on the system, in the present embodiment, since the 7 * 5 detection area is used, the number of components is seven. After the extraction is completed, the process proceeds to step S1603. In step S1603, the camera microcomputer 115 calculates a region that is a zero cross point of a curve drawn by the extracted component. As an example of the calculation method, it is confirmed that the value increases or decreases in the direction of coordinates x = 1 to 7, and a point where the value exceeds 0 or the code is switched is specified as a zero cross point. If the zero cross point cannot be specified, x = 0. After calculating the zero cross point, the process proceeds to step S1604. In step S1604, the camera microcomputer 115 increments the value in the j-th row by one.

  In step S <b> 1605, the camera microcomputer 115 checks whether calculation has been completed for all rows in the image. If j is larger than the number of detection frames, it is determined that all the columns have been calculated, and the process proceeds to step S1606. When that is not right, it changes to step S1602 and repeats the same process.

  In step S1606, the camera microcomputer 115 determines the coordinates of the intersection region of the x component calculated by the above processing. In the example of FIG. 11, since all the j rows have the same component, one intersection area is obtained. However, in the case of the input image as shown in FIG. 13, two or more intersection area candidates may be specified. . In that case, a zero cross point that occupies a majority in j rows is adopted, and the other points are ignored. The identified point is set as Xcross, and the process proceeds to step S1607.

  In step S1607, the camera microcomputer 115 extracts a motion vector component in the y-axis direction of the k-th column of the coordinate y. Although the number of components differs depending on the system, in the present embodiment, since the detection area of 7 * 5 is used, the number of components is five. After the extraction is completed, the process proceeds to step S1608. In step S1608, the camera microcomputer 115 calculates a region that becomes a zero cross point of a curve drawn by the extracted component. As an example of the calculation method, it is confirmed that the value increases or decreases from the coordinate y = 1 to 5, and the point where the value exceeds 0 or the sign is switched is specified as the zero cross point. When the zero cross point cannot be specified, y = 0 is set. After the zero cross point is calculated, the process proceeds to step S1609. In step S1609, the camera microcomputer 115 increments the value in the k-th row by one.

  In step S <b> 1610, the camera microcomputer 115 checks whether the calculation has been completed for all columns in the image. When k is larger than the number of detection frames, it is determined that calculation of all the columns is completed, and the process proceeds to step S1611. Otherwise, the process proceeds to step S1607 and the same process is repeated.

  In step S1611, the camera microcomputer 115 determines the coordinates of the intersection region of the y component calculated by the above processing. In the example of FIG. 11, since all the k columns are the same component, one intersection area is obtained. However, in the case of the input image as shown in FIG. 13, two or more intersection area candidates may be identified. . In that case, a zero-cross point that occupies a majority in the k columns is adopted, and the other points are ignored. The identified point is set to Ycross, and the process proceeds to step S1612.

  In step S1612, the camera microcomputer 115 confirms the intersection area of the vector specified above. In the above processing, when the intersection area (Xcross, Ycross) is calculated, the process proceeds to step S1616. In the above processing, if the intersection cannot be specified, that is, if it is the intersection region (0, 0), the process proceeds to step S1613. In step S1616, since the intersection area is obtained, the camera microcomputer 115 sets the evaluation frame to the intersection area (Xcross, Ycross), and ends the process. On the other hand, if the intersection area cannot be specified, it is conceivable that the camera is not fixed in the direction of travel, or that all images are flowing due to a right turn or a left turn. In this case, processing for changing the evaluation frame is performed according to the amount of the motion vector. Since the changing method has already been described with reference to FIG.

  In step S <b> 1613, the camera microcomputer 115 confirms the direction of the motion vector in the screen when the intersection area cannot be specified. If the motion vectors in the screen are in the same direction, the process proceeds to step S1614. Otherwise, the process proceeds to step S1617. In step S1614, it is confirmed whether or not the magnitude of the motion vector is greater than Th2. If it is equal to or greater than Th2, it is determined that the flow of video in the screen is large and the evaluation value cannot be stabilized, and the process proceeds to step S1615. Otherwise, the process proceeds to step S1617. In step S <b> 1617, the camera microcomputer 115 is in a situation where the intersection region cannot be specified or the motion vector is small, and thus the evaluation value is acquired with the evaluation frame remaining at the initial position. Therefore, the evaluation frame is set to the initial position, and the process is terminated.

  In step S1615, the camera microcomputer 115 checks whether the magnitude of the motion vector is equal to or greater than Th3. If it is greater than or equal to Th3, it is determined that an appropriate evaluation value cannot be calculated from the video in the screen, and the process proceeds to step S1619. Otherwise, the process proceeds to step S1618. In step S <b> 1618, the camera microcomputer 115 performs processing for obtaining a stable evaluation value by increasing the evaluation frame because the motion vector is greater than or equal to the predetermined amount Th <b> 2 and Th <b> 3. The size of the evaluation frame is set based on the graph of FIG. After setting the evaluation frame, the process ends. In step S1619, the camera microcomputer 115 does not set an evaluation frame because an appropriate evaluation value cannot be obtained from the image because the motion vector is greater than or equal to the predetermined amount Th3. Furthermore, in order to suppress blurring and fluffing of the image, the autofocus control is not performed and the focus is locked in the previous state.

  As described above, in in-vehicle shooting, an AF frame is automatically set, and shooting with stable focus is always possible. For example, even when a consumer video camera is fixed to the vehicle body for in-vehicle shooting, an AF frame can be set in an area where the flow of the image is small by using a motion vector obtained from the image, and stable evaluation is performed. It becomes possible to get the value.

  If the camera is fixed at an angle with respect to the direction of travel, or if there is a curve in the direction of travel, the center image of the image will flow, but by specifying the intersection area from the motion vector, the main subject of shooting An evaluation frame can be set in an area where there is little flow of the image in the traveling direction that will become. This makes it possible to perform appropriate shooting even when the camera is fixed.

  Further, by specifying the intersection area from the motion vector obtained from the image, it is possible to avoid the area where the image flow is caused by the movement of the vehicle body and set the evaluation frame in the area where the image flow is small.

  Furthermore, even if the car body or part of the interior of the vehicle is reflected in a part of the image, by specifying the intersection area from the motion vector, an evaluation frame is added to the area where the flow of the image outside the vehicle is small. It can be set, and shooting with stable focus and stable exposure becomes possible.

<Second Embodiment>
FIG. 17 is a diagram illustrating a configuration of a video camera according to the second embodiment. Although the present embodiment describes a video camera, the present invention can be applied to other imaging devices such as a digital still camera. In the following, differences from the first embodiment will be mainly described, the same components as those of the video camera according to the first embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted.

  Reference numeral 118 denotes an aperture member drive source, which includes an actuator for driving the aperture 103 and its driver. Reference numeral 119 denotes an ND filter for attenuating light incident from the lens. An ND member driving source 120 includes an actuator for driving the ND filter 119 and a driver thereof.

  Reference numeral 121 denotes a photometric frame setting circuit which passes only signals in a region used for photometric value detection among output signals of all pixels from the CDS / AGC / AD converter 107. Reference numeral 122 denotes a luminance information detection / calculation circuit, which detects a luminance value based on digital image data and performs an arithmetic process on the detected luminance value. Reference numeral 123 denotes an image sensor driving circuit.

  Similar to the first embodiment, the intersection area detection circuit 114 calculates a motion vector intersection area based on the detection result of the motion vector detection circuit 113, and transmits the calculation result to the camera microcomputer 115. The camera microcomputer 115 transmits information to the photometric frame setting circuit 121 so as to set a photometric frame that is an evaluation frame (evaluation region) used for photometric value detection in the intersection area. Thereafter, in order to acquire the luminance value of the photometric frame in the screen, the photometric value is acquired by the luminance information detection / calculation circuit 122, and the photometric value is normalized by calculation. At this time, the luminance information detection / calculation circuit 122 calculates the photometric value of the entire screen at the same time. Then, the camera microcomputer 115 calculates the difference between the photometric value and the target value set so that proper exposure can be obtained. Thereafter, the camera microcomputer 115 calculates a correction driving amount of the diaphragm from the calculated difference, and controls the driving of the diaphragm member driving source 118 and the ND member driving source 120.

  Next, an outline of exposure adjustment control executed by the camera microcomputer 115 will be described. FIG. 20 is a flowchart showing exposure adjustment control in the present embodiment. First, in step S2001, under the control of the camera microcomputer 115, the position and size of a photometric frame for acquiring a luminance signal as a basis for exposure control are set from the luminance information detection / calculation circuit 122. When the intersection area detection circuit 114 detects the intersection area, the intersection area is set as the photometric frame position. If no intersection area is extracted, a fixed photometry frame (initial position: center-weighted photometry) is set as the evaluation frame. Note that the details of the method for specifying the intersection area have been described in the first embodiment, and thus will be omitted.

  In step S2002, the camera microcomputer 115 acquires a luminance signal of the designated photometric frame. Details of this processing will be described later with reference to FIG.

  In step S2003, the camera microcomputer 115 performs brightness adjustment by exposure control. Details of this processing will be described later with reference to FIG. Thereafter, the process returns to step S2001, and this process is repeated.

  Acquisition of luminance information of the photometric frame in step S2002 will be described with reference to FIG. FIG. 21A is an optical flow diagram illustrating motion vectors in the input image of FIG. A region S indicates an intersection region of vectors identified from a plurality of motion vectors in step S2001. FIG. 21B shows AE weighting and AE weighting recorded in the camera microcomputer. The AE weighting will be described later. Centering on the intersection area specified in step S2001, the weight of the AE of the area S ′ is set to 1, and the weight of the surrounding area is set to half of 0.5. By doing this, it is possible to acquire a photometric value of a portion of the image with little flow centered on the intersection area, and to enable stable exposure control. Note that this setting is an example, and it is possible to change the setting to a value that provides appropriate exposure based on the result of sufficient measurement. Similarly, FIG. 21C is an optical flow diagram illustrating motion vectors in the input image of FIG. In FIG. 21D as well, weighting is performed around the region S as described above. Since the weighting is as shown in the figure, the description thereof is omitted.

  Next, exposure control in step S2003 will be described. An optical image from the photographing lens is photoelectrically converted by the image sensor 106 through the diaphragm 103, converted into a video consonant signal through the CDS / AGC / AD converter 107, and sent to the camera signal processing circuit 108. As a signal for controlling exposure, the luminance signal output from the AGC circuit passes through the photometric frame setting circuit 121, passes through the luminance information detection / calculation circuit 122, and is taken into the camera microcomputer 115. The camera microcomputer 115 controls the diaphragm member drive source 118 so that the level falls within a predetermined range, and outputs the diaphragm member drive source 118 to the diaphragm 103. Exposure control is performed by aperture control that controls the drive current to vary the aperture amount of the aperture 103.

  The exposure control system by the CDS / AGC / AD converter 107 is similar to the exposure control system by the aperture 103 so that the output level of the luminance information detection / calculation circuit 122 captured by the camera microcomputer 115 falls within a predetermined range. An exposure control system is configured by a closed loop by controlling the gain level of the / AGC / AD converter 107 by the camera microcomputer 115.

  The exposure control system based on the shutter speed is a closed loop by controlling the image sensor driving circuit 123 with the camera microcomputer 115 so that the level taken into the camera microcomputer 115 falls within a predetermined range, like the exposure control system based on the aperture 103. Thus, an exposure control system is configured. First, using the program diagram of FIG. 18, how the three types of exposure control means by the shutter speed, the aperture, and the AGC circuit are controlled according to the illuminance will be described. This program diagram is stored in the camera microcomputer, and the data table thereof will be described later with reference to FIG.

  In FIG. 18, the horizontal axis represents subject illuminance, and the vertical axis represents the setting values of the exposure control means for iris, shutter speed, and gain. As is apparent from the figure, each exposure control means is divided into three areas A, B, and C according to subject illuminance. That is, exposure operation control is performed by combining three types of exposure control means in accordance with subject illumination. In the area A, the shutter speed is fixed at 1/60 (second) (PAL is 1/50 (second)), and the gain of the AGC circuit is fixed at 0 dB. Exposure is controlled. In the region B, the aperture member is fixed open and fixed at a gain 0 dB of the AGC circuit, and the shutter speed is fixed at 1/60 (second) (PAL is 1/50 (second)). By inserting the ND, the ND density can be continuously changed between 0 and 1/8 according to the illuminance, and the exposure is controlled by the ND. In the area C, the aperture member is fixed open and fixed at a gain of 0 dB of the AGC circuit, and ND is fixed at 1/8. By controlling the readout of the image sensor to control the amount of accumulated charge, the shutter speed is continuously changed according to the illuminance between the shutter speed 1/60 (second) and 1/8 (second). The exposure is controlled by the shutter. In the area D, the aperture is fixed at the open position and the shutter speed is fixed at 1/8 (second), and only the AGC circuit is controlled for exposure.

  The shooting mode data table for executing this exposure control mode is as shown in FIG. 19, and the characteristics of the program diagram for each of the iris (aperture), shutter, and AGC gain are attribute (function or fixed value) for each parameter. ), Data format (threshold, map format, numerical value definition, code definition, etc.) and actual data are stored, and the program line in FIG. The figure is set. In addition, other setting information is also stored in the information table, and the AE weighting in the figure stores weighting data of each photometric area in a map format when the imaging screen is divided into a plurality of photometric areas. Yes, as shown in the figure, the screen is divided into 16 parts, the weight of the central part is set to 1, and the weight of the periphery thereof is halved to 0.5, which is so-called center-weighted photometry.

  The AE reference value represents a target reference value when exposure control is performed so that the level of the imaging signal is constant. In addition, it is also set whether or not image quality adjustment and image effect processing are performed, such as changing the gamma characteristic according to the shooting state and applying a fade effect. In the present embodiment, “NORMAL” indicates that special image quality and image effect processing is not performed.

  In controlling the above four types of exposure control systems, in this embodiment, the exposure is controlled in the order of the aperture, ND, slow shutter, AGC circuit in order of increasing object illuminance, but the order is iris → AGC → ND. → It can be changed like a slow shutter.

  As described above, in in-vehicle shooting, the photometry frame is automatically moved, and shooting with stable exposure is always possible. For example, even when a consumer video camera is fixed to the body for in-vehicle shooting, a photometric frame can be set in an area where there is little flow of video by using a motion vector obtained from the video, and stable evaluation It becomes possible to get the value.

(Other embodiments)
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, etc.) of the system or apparatus reads the program. It is a process to be executed.

  101: first fixed lens, 102: variable power lens, 103: aperture, 104: second fixed lens, 105: focus compensator lens, 106: image sensor, 107: CDS / AGC / AD converter, 108: camera signal processing circuit 109: display device, 110: recording device, 111: AF gate, 112: focus signal processing circuit, 113: motion vector detection circuit, 114: intersection area detection circuit, 115: camera / AF microcomputer, 116: focus lens drive source 117: Magnification lens drive source, 118: Diaphragm member drive source, 119: ND filter, 120: ND member drive source, 121: Photometric frame setting circuit, 122: Luminance information detection / calculation circuit, 123: Image sensor drive circuit

Claims (11)

Imaging means for converting an optical image formed by the imaging optical system into a video signal;
Motion vector detection means for detecting a motion vector from the video signal obtained by the imaging means;
An evaluation area setting means for setting an evaluation area on the video for obtaining a predetermined evaluation value according to the detection result of the motion vector;
The motion vector detection means divides the video obtained by the imaging means into a plurality of blocks in the x direction and the y direction, detects a motion vector in each block,
The evaluation area setting means sets an intersection area of motion vectors detected in each block as the evaluation area,
If the intersection area of the motion vector calculated in each block cannot be specified and the motion vector calculated in each block is in one direction, the evaluation area is at a predetermined fixed initial position. , And changing the size of the evaluation area according to the size of the motion vector. Before Symbol evaluation area setting means, when the motion vector in the predetermined ratio or more regions of the image obtained by the imaging means is not in the increasing trend, characterized by the use of an evaluation area in an initial position of the predetermined fixed The imaging apparatus according to claim 1 .   The said evaluation area | region setting means calculates | requires the x cross-point of the x component of the motion vector detected in each said block, and the zero cross point of the y-component, and specifies the said intersection area | region, The Claim 1 or 2 characterized by the above-mentioned. Imaging device.   The evaluation area setting means uses an evaluation area at a predetermined fixed initial position when the motion vector does not tend to increase in an area of a certain ratio or more of the video obtained by the imaging means. The imaging device according to claim 1. The evaluation area imaging device according to any one of claims 1 to 4, characterized in that an auto-focus frame to obtain a focus signal. The evaluation area imaging device according to any one of claims 1 to 5, characterized in that a photometric frame for obtaining a photometric value.   The evaluation area setting means has an evaluation area at the initial position when the motion vector is in one direction on the video obtained by the imaging means and the magnitude of the motion vector is smaller than a first threshold value. When the magnitude of the motion vector is equal to or greater than the first threshold, the size of the evaluation region at the initial position is increased according to the magnitude of the motion vector, and the magnitude of the motion vector The imaging apparatus according to claim 1, wherein when the value becomes equal to or greater than a second threshold value greater than the first threshold value, the state of the previous evaluation region is maintained. An image pickup apparatus control method comprising an image pickup means for converting an optical image formed by an image pickup optical system into a video signal,
Detecting a motion vector from a video signal obtained by the imaging means;
Setting an evaluation region on the video for obtaining a predetermined evaluation value in accordance with the detection result of the motion vector,
In the step of detecting the motion vector, the video obtained by the imaging unit is divided into a plurality of blocks in the x direction and the y direction, and the motion vector is detected in each block,
In the step of setting the evaluation area, an intersection area of motion vectors detected in each block is set as the evaluation area,
If the intersection area of the motion vector calculated in each block cannot be specified and the motion vector calculated in each block is in one direction, the evaluation area is at a predetermined fixed initial position. And controlling the size of the evaluation area according to the size of the motion vector. In the step of setting the pre-Symbol evaluation area if the motion vector in the predetermined ratio or more regions of the image obtained by the imaging means is not in the increasing tendency, the use of the evaluation area in the initial position of the predetermined fixed The method for controlling an imaging apparatus according to claim 8 . A program for setting an evaluation region in an imaging apparatus including an imaging unit that converts an optical image formed by an imaging optical system into a video signal,
Processing for detecting a motion vector from a video signal obtained by the imaging means;
In accordance with the detection result of the motion vector, causing the computer to execute processing for setting an evaluation area on the video for obtaining a predetermined evaluation value,
In the process of detecting the motion vector, the image obtained by the imaging unit is divided into a plurality of blocks in the x direction and the y direction, and the motion vector is detected in each block.
In the process of setting the evaluation area, the intersection area of motion vectors detected in each block is set as the evaluation area,
If the intersection area of the motion vector calculated in each block cannot be specified and the motion vector calculated in each block is in one direction, the evaluation area is at a predetermined fixed initial position. And changing the size of the evaluation area according to the size of the motion vector . In the process of setting the pre-Symbol evaluation area if the motion vector in the predetermined ratio or more regions of the image obtained by the imaging means is not in the increasing tendency, the use of the evaluation area in the initial position of the predetermined fixed The program according to claim 10 .

Images