JP4839908B2 - Imaging apparatus, automatic focus adjustment method, and program - Google Patents

Description

  The present invention relates to an automatic focusing technique for recognizing a subject in a field of view of an imaging apparatus and focusing in accordance with the movement of the subject.

  Some electronic cameras such as digital cameras have a contrast AF function (contrast autofocus (autofocus) function) that automatically adjusts focus by detecting a contrast peak of a subject. As such an AF function, a method of focusing on the center of the composition at the time of imaging, displaying an AF frame (spot AF area) at the center of the screen, and notifying the user of the focused portion (for example, Patent Documents) 1) and the focus information at the shortest distance from the plurality of focus detection zones (multi-AF areas) where the contrast is higher than a predetermined value is selected, and the object is automatically focused. There is a so-called multi-focus method (for example, Patent Document 2).

  When capturing a moving image, the subject is not necessarily in the center, so that if the camera is focused at the center as in the technique described in Patent Document 1, the camera is moved so that the subject is in the center. There is a need, but it is not easy to follow a moving subject. Further, even if the closest focus information is selected from the multi-AF area as in the technique described in Patent Document 2 above and the object is automatically focused, the moving subject is not necessarily in the multi-AF area. Not necessarily. On the other hand, when capturing a moving image, the subject does not necessarily have to be in the center, and in order to always obtain a subject image having a constant size even when the subject moves, the subject image depends on the size of the recognized face image. Some zooming operations are performed (see, for example, Patent Document 3).

JP 2000-92354 A JP-A-10-153735 JP-A-6-2217187

If the technique described in Patent Document 3 and the contrast AF technique are combined, a face area 151 is detected as shown in FIG. 15 in a moving image frame, and contrast AF is continued using the area as a sample area during moving image capturing. (Contrast type continuous AF).
In contrast AF, it is not possible to detect a contrast peak unless the focus lens is moved and scanned to some extent during recording (that is, the focus lens moves back and forth between “far” and “close”). Therefore, if the moving image is captured and recorded by this focusing method, the reproduced image is in focus as shown in FIG. Person 161-1) → out of focus (person 161-2) → focus (person 161-3) → out of focus (person 1681-4) →...
Since many video cameras and digital cameras employ contrast AF, there is a problem that the above-described image is obtained.

  The present invention has been made to solve the above problems, and recognizes a subject in the field of view of an imaging apparatus and moves the focus lens by an AF method different from the contrast method AF so that the camera follows the movement of the subject. It is an object of the present invention to provide an imaging device that can be focused on, an automatic focus adjustment method based on subject recognition, and a program recording medium.

In order to solve the above-described problem, in the invention described in claim 1, a moving image capturing unit that captures a moving image, a moving image recording unit that records and stores the moving image captured by the moving image capturing unit, and an image captured by the moving image capturing unit The moving image display control means for displaying the moving image, the index display means for displaying the index of the subject, and the size of the desired subject image in the moving image displayed by the moving image display control means is approximately the same size. A size adjusting unit that adjusts the size of the index, and an index image whose size is adjusted by the size adjusting unit is detected from images displayed by the moving image display control unit when the moving image is captured by the moving image capturing unit. and the index image detector for the distance measuring means for measuring a distance to a subject when capturing a moving by the moving image pickup unit, said video image pickup means A feature data acquisition means for acquiring characteristic data of the object when capturing a moving I, imaging size to get the size of the index image in the imaging range of said video image pickup means when capturing a moving by the moving image pickup unit Acquisition means; subject size estimation means for estimating the actual size of the subject based on the distance to the subject measured by the distance measurement means and the size of the index image acquired by the imaging size acquisition means; and Storage means for associating and storing the feature data acquired by the feature data acquisition means and the actual size data of the subject estimated by the subject size estimation means, and acquiring the feature data when capturing a moving image by the moving image imaging means The feature data of the subject is acquired by the means, and the matching feature data is recorded by the storage means. If it is, instead of the distance measurement by the distance measuring means, the object distance based on the size of the index image acquired by the actual size and the imaging size acquisition means is stored in association with the feature data Subject distance estimation means for estimating the subject distance, and subject position estimated by the subject distance estimation means and focus position adjustment control means for moving the focus lens to a position corresponding to the subject distance measured by the distance measurement means , Provided is an imaging apparatus characterized by comprising the above.
This allows the user to follow the movement of the subject simply by adjusting the size of the index so that it is the same size as the image of the desired subject in the image that is displayed once through when shooting a moving image. its estimated the distance between the subject and the camera, Runode to move the focus lens to a position corresponding to the estimated distance, lens for converging the focus position of the lens position as in the case of autofocus of the contrast system Te There is no need for scanning, and there will be no occurrence of wobbling during movie shooting.

According to the second aspect of the present invention, when there are a plurality of lens addresses indicating the range of the depth of field including the subject distance estimated by the subject distance estimating means, the subject distance is increased or decreased. The focus position adjustment control means subtracts the subject distance from the rear depth of field corresponding to the plurality of lens addresses when the subject distance increases. When the focus lens is moved to the lens address corresponding to the maximum depth of field and the subject distance decreases, the depth of field in front of the depth of field corresponding to multiple lens addresses is reduced from the subject distance. The imaging apparatus according to claim 1, wherein the focus lens is moved to a lens address corresponding to a maximum depth of field obtained by subtraction.
By using a depth-of-field table in which the front-side depth of field and the rear-side depth of field are slightly overlapped, there is no unnatural feeling because there is no sudden change in focus. It is possible to further reduce the “smooth out” feeling that occurs when capturing a moving image.

According to the third aspect of the present invention, the step of displaying a moving image captured at the time of moving image capturing, the step of displaying an index of a subject, and the size of a desired subject image in the displayed moving image are abbreviated. Adjusting the size of the index so as to be the same size, detecting the size-adjusted index from moving images displayed when capturing a moving image, and subject when capturing a moving image measuring a distance to, a step of acquiring a step of acquiring the characteristic data of the object when capturing a moving, the size of the index image in the imaging range of the imaging device when imaging the moving picture, is measured The step of estimating the actual size of the subject based on the distance to the subject and the size of the acquired index image is associated with the acquired feature data and the estimated actual size data of the subject. And when the moving image is captured, the feature data of the subject is acquired, and when the matching feature data is stored in the storage means, the distance measurement is performed instead of the distance measurement in the step of measuring the distance. the step of measuring a step of estimating the actual size and the subject distance based on the size of the index image stored in association with the feature data, the estimated subject distance and the distance by the step of estimating the object distance And a step of moving the focus lens to a position corresponding to the measured subject distance .
Thus, when the size of the index is adjusted so as to be the same size as the image of the desired subject in the image that is displayed once through when shooting a moving image, the movement of the subject is followed. Since the distance between the subject and the camera is estimated and the focus lens is moved to a position corresponding to the estimated distance, lens scanning is required to converge the lens position to the in-focus position, as in contrast autofocus. Otherwise, the camera will not be out of focus during movie recording.

In the invention according to claim 4 , a function of capturing a moving image, a function of recording and storing the captured moving image, a function of displaying the captured moving image, and a function of displaying a subject index , a function of adjusting the size of the index as approximately the same size as the size of the desired object image in the moving image displayed, from among the moving image displayed at the time of capturing a moving, wherein the size A function for detecting an adjusted index image, a function for measuring a distance to a subject when capturing a moving image , a function for acquiring feature data of a subject when capturing a moving image , and an image capturing when capturing a moving image A function of acquiring the size of the index image in the imaging range of the element, a function of estimating the actual size of the subject based on the measured distance to the subject and the size of the acquired index image, and Special A function for associating data and estimated actual size data of a subject to be stored in a storage unit, and acquiring feature data of a subject when capturing a moving image, and matching feature data being stored in the storage unit is, instead of the distance measurement by the ability to measure the distance estimate, the function of estimating the size the object distance based on the actual size and the target image is stored in association with the feature data, the object distance , features and you move the focus lens to a position corresponding to the measured subject distance by the ability to measure the estimated subject distance and the distance by the ability to provide a program to be executed.
As a result, the size of the index is adjusted so as to be the same as the size of the image of the desired subject in the image that is displayed once through when shooting a moving image, and the subject follows the movement of the subject. The distance between the camera and the camera is estimated, and the focus lens is moved to a position corresponding to the estimated distance, so that it is necessary to scan the lens to converge the lens position to the in-focus position as in the case of contrast autofocus. In addition, the camera does not fluctuate during movie shooting.

  According to the present invention, it is possible to capture a sharp image that follows the movement of a subject when capturing a moving image.

  The automatic focus adjustment method of the present invention detects the size of the subject's face, height, etc., calculates the “subject distance” estimated from the subject size and the lens focal length in the imaging range of the imaging device, and determines the subject distance. By moving the focus lens to the corresponding position, it is possible to capture a sharp image that follows the movement of the subject during moving image capturing.

(Embodiment 1)
FIG. 1 is a diagram showing an appearance of a digital camera as an embodiment of an imaging apparatus according to the present invention. Here, the appearance of mainly a front surface (FIG. 1A) and a rear surface (FIG. 1B) is shown. . The digital camera 100 has an imaging lens (lens group) 2 on the front side as shown in FIG. Further, as shown in FIG. 1B, the back of the digital camera 100 has a mode dial 3, a liquid crystal monitor screen 4, a cursor key 5, a SET key 6, a zoom button 7 (W button 7-1, T button 7- 2) A menu key 10 or the like is provided. A shutter key 8 and a power button 9 are provided on the upper surface. Although not shown in the figure, a USB terminal connection portion used when connecting to an external device such as a personal computer (hereinafter referred to as a personal computer) or a modem and a USB cable is provided on the side portion.

  FIG. 2 is a block diagram showing an embodiment of the electronic circuit configuration of the digital camera shown in FIG. In FIG. 2A, the digital camera 100 moves the zoom lens 11-1 and the focus lens 12-2 that move the zoom lens 12-1 and perform the optical zoom operation in the imaging mode that is the basic mode. An AF driving unit 11-2 that performs focusing operation, a lens optical system 12 that constitutes the imaging lens 2 including the zoom lens 12-1 and the focus lens 12-2, a CCD 13 that is an imaging element, and a timing generator (TG) 14 , Vertical driver 15, sample hold circuit (S / H) 16, A / D converter 17, color process circuit 18, DMA (Direct Memory Access) controller 19, DRAM interface (I / F) 20, DRAM 21, control unit 22 , VRAM controller 23, VRAM 24, digital video encoder 25, LCD 26 Data compression and expansion circuit 27, the media controller 28, a key input unit 30, a voice processing unit 31, recognition unit 32, the person identification database 33, and the contour extraction unit 34.

In the monitoring state in the imaging mode, when there is an optical zoom instruction, the zoom drive unit 11-1 drives a zoom lens drive motor (not shown) based on a control signal from the control unit 22 to light the zoom lens 12-1. By moving back and forth along the axis, the magnification itself of the image formed on the CCD 13 is changed.
The AF drive unit 11-2 drives a focus lens drive motor (not shown) to move the focus lens 12-2.
Then, a CCD 13 which is an image pickup element disposed behind the image pickup optical axis of the optical system 12 constituting the image pickup lens 2 is scanned and driven by a timing generator (TG) 14 and a vertical driver 15 to form an image at regular intervals. A photoelectric conversion output corresponding to the optical image is output for one frame.

  The CCD 13 is a solid-state imaging device that captures a two-dimensional image of a subject, and typically captures an image of several tens of frames per second. The imaging element is not limited to a CCD, and may be a solid-state imaging device such as a CMOS (Complementary Metal Oxide Semiconductor).

  The photoelectric conversion output is appropriately gain-adjusted for each primary color component of RGB in the state of an analog value signal, sampled and held by a sample hold circuit (S / H) 16, and digital data by an A / D converter 17. The color process circuit 18 is subjected to color process processing including image interpolation processing and γ correction processing to generate a digital value signal Y and color difference signals Cb, Cr, and DMA (Direct Memory Access). ) Is output to the controller 19.

  The DMA controller 19 uses the luminance signal Y and the color difference signals Cb and Cr (hereinafter referred to as YUV data) output from the color process circuit 18 as a composite synchronization signal, a memory write enable signal, and a clock from the color process circuit 18. After being converted to a preset image size via a DRAM interface (I / F) 20 using a signal, data for one frame is DMA-transferred sequentially to a DRAM 21 used as a buffer memory. The DMA controller 19 also performs processing for improving image quality, such as auto iris (AE), white balance (WB), and edge enhancement.

  One frame of YUV data stored in the DRAM 21 during imaging in the still image mode is sent to the VRAM controller 23, where it is converted into a video signal, and then displayed as a through image on the LCD (liquid crystal display unit) 26.

  One frame of YUV data stored in the DRAM 21 during imaging in the still image mode is encoded by the data compression / expansion circuit 27 after data compression by the JPEG method, etc., and filed in the DRAM. Through the recording medium 29 as still image data (still image file).

  At the time of imaging in the moving image mode, the YUV data stored in the DRAM 21 is sequentially sent to the data compression / decompression circuit 27 and is encoded after data compression by a codec of a predetermined moving image recording method (for example, Motion-JPEG or MPEG). After being filed in the DRAM 21, it is recorded on the recording medium 29 as a moving image file via the media controller 28. The frame rate of moving image capturing is determined by the timing signal generated by the timing generator 14, and the compression rate of the encoded data is determined by the digitization table value in the data compression / decompression circuit 27.

  The control unit 22 controls the overall operation of the digital camera 100, and is an operation program executed by the CPU or MPU (hereinafter referred to as CPU) and the CPU including an automatic focus adjustment program based on subject recognition as described later. And a program storage memory such as a flash memory storing the depth of field correspondence table 50 (FIG. 4), a RAM used as a work memory, and the like. After the DMA transfer of the YUV data to the DRAM 21 is completed, the YUV Data is read from the DRAM 21 via the DRAM interface 20 and written to the VRAM 24 via the VRAM controller 23.

  The control unit 22 also extracts a processing program and menu data corresponding to each mode stored in a program storage memory such as a flash memory in response to the status signal from the key input unit 30, and Execution control of each function, for example, auto focus control by subject recognition performed when the auto focus adjustment function is turned on in movie shooting mode, zoom lens operation control during optical zoom, electronic zoom, through display, Execution control such as automatic focusing, imaging, recording, and reproduction / display of recorded images, display control of a function selection menu when selecting a function, display control of a setting screen, and the like are performed.

  In response to the focus instruction, the control unit 22 immediately stops the path from the CCD 13 to the DRAM 21 after the DMA transfer of the YUV data for one frame captured from the CCD 13 to the DRAM 21 at that time, and performs recording and storage. Transition to the state.

  In this stored recording state, the control unit 22 transmits the YUV data for one frame written in the DRAM 21 through the DRAM interface 20 to a basic of 8 pixels × 8 pixels for each of Y, Cb, and Cr components. A unit called a block is read out and written into a JPEG (Joint Photograph Cording Experts Group) circuit 27. The data compression / decompression circuit 27 uses ADCT (Adaptive Discrete Cosine Transform) and Huffman, which is an entropy coding method. Data compression is performed by processing such as encoding. The obtained code data is read out from the data compression / decompression circuit 27 as a data file of one image and recorded and stored in the media controller 28. Further, the controller 22 activates the path from the CCD 13 to the DRAM 21 again with the compression processing of one frame of YUV data and the completion of writing all the compressed data to the recording medium 29 via the media controller 28.

  In the playback mode which is the basic mode, the control unit 22 selectively reads out the image data recorded on the recording medium 30 via the media controller 28, and the data compression / decompression circuit 27 performs data compression in the image capturing mode. The compressed image data is decompressed by a procedure opposite to the procedure described above, and the decompressed image data is expanded and stored in the VRAM 24 via the VRAM controller 23, and then periodically read from the VRAM 24. A video signal is generated based on the image data and reproduced and output on the LCD 26.

  The digital video encoder 25 periodically reads the YUV data from the VRAM 24 via the VRAM controller 23, generates a video signal based on these data, and outputs the video signal to the LCD 26.

  As described above, the LCD 26 functions as a monitor display unit (electronic finder) in the image pickup mode. By performing display based on the video signal from the digital video encoder 25, the LCD 26 captures from the VRAM controller 23 at that time. An image based on the existing image information is displayed on the LCD 26 in real time. The LCD 26 displays not only images but also menu screens and setting screens for selecting and setting various functions in the digital camera 100 as necessary.

  The data compression / decompression circuit 27 decompresses the still image or moving image data read from the recording medium 29 when reproducing a still image or moving image, and expands it in the DRAM 21 as still image data or moving image frame data. The developed image is sent to the display controller 21, where it is converted into a video signal and then displayed on the LCD 26 as a reproduced image.

The data compression / decompression circuit 27 supports a plurality of compression ratios, and a mode for storing data corresponding to the compression ratios corresponds to a high resolution (generally called high definition, fine, normal, etc.) with a low compression ratio. Mode with high compression ratio and low resolution (commonly called economy) mode.
It also supports high to low pixel counts. For example, there are pixel sizes called SXGA (1600 × 1200), XGA (1024 × 786), SVGA (800 × 600), VGA (640 × 480), QVGA (320 × 240) and the like.

  The media controller 28 corresponds to an image recording control unit, and performs writing control of image data and imaging information on the recording medium 29 and reading control of image data and imaging information from the recording medium 29.

  The recording medium 29 corresponds to the moving image recording means of the present invention, and includes a recording medium such as a DRAM (flash memory), a hard disk, or a removable memory card, and stores and records image data, imaging information, and the like.

  The key input unit 30 includes the mode dial 3, the cursor key 5, the SET key 6, the zoom button 7 (W button 7-1, T button 7-2), the shutter key 8, the power button 9, and the menu key 10 described above. , A key processing unit (not shown) that generates an operation signal of the operated key and sends it to the CPU 23 when the key is operated.

  The mode dial 3 is used to select an imaging mode and a playback mode. The user can operate the mode dial 3 to select an imaging mode such as (still image) normal imaging mode, macro imaging mode, continuous shooting mode, rapid shooting mode,..., Moving image imaging mode,.

  The cursor key 5 is a key operated when pointing (designating) a menu or icon displayed on the liquid crystal monitor screen 4 with the cursor when setting a mode or selecting a menu. Can be moved to. The SET key 6 is also a key that is pressed when the item displayed by the cursor key 5 is selected and set. The SET key 6 can also be used as a confirmation key.

  The zoom button 7 is used for a zoom operation. In the case of optical zoom, the zoom lens (variable focal length lens) 12-1 corresponds to the operation of the zoom button 7 (W button 7-1 or T button 7-2). The zoom value is determined in response to the operation of the zoom button 7 by moving to the wide side or the tele side, the angle of view actually changes following the change of the zoom value, and a wide (wide angle) image is displayed on the LCD monitor screen 4. Alternatively, a tele (telephoto) image is displayed.

  The shutter key 8 performs a release operation at the time of imaging, has a stroke of two steps, and performs auto focus (AF) and automatic exposure (AE) by the first step operation (half-pressed state). And an imaging instruction signal for performing imaging processing by the second stage operation (fully pressed state).

  The audio processing unit 31 converts audio input to a microphone (not shown) built in the camera body at the time of moving image capturing into a digital signal, and sends it to the DRAM 21 as audio data after data compression. The audio data sent to the DRAM 21 is sequentially written to the recording medium 29 as stream data together with the frame data. In addition, the audio processing unit 31 decodes the audio data sent from the DRAM 21 and converts it into an analog audio signal at the time of moving image capturing, and then outputs the audio from an internal speaker (not shown) built in the camera body.

  The recognition unit 32 recognizes a person's face from the image signal of each frame of the moving image and registers it in the recognition database or compares it with a registered face to detect the face of the same person. The face may be acquired as a rectangular area that divides the face image. Further, as shown in FIG. 2 (b), the recognition unit 32 extracts a facial feature data of a person image of each frame, and a facial feature data of a person registered in the person database 33. And a feature comparison unit 32-2 that compares feature parts extracted from the face recognized by the recognition unit 32, and the face feature data and face information when the face recognized by the recognition unit 32 is not registered in the person database 33. It may be configured to include a registration unit 32-3 for registering the size, and the feature comparison unit 32-2 may compare the face recognized with the registered person's face. The face detection method described above is an example of a concept, and other known methods can be used. For example, the face recognition method described in Patent Document 3 (Japanese Patent Laid-Open No. 6-217187) described above can be appropriately employed. A method for identifying a person by detecting a face image from a designated frame in a video and comparing it with individual face data extracted from the designated frame in the video is a known method, for example, as described above. Patent Document 1 (Japanese Patent Laid-Open No. 2004-145563) can be adopted as appropriate. A dedicated circuit may be provided for the recognition process, or the CPU 23 may execute a program for the recognition process.

  The recognition database 33 includes recognition data 40 (see FIG. 3) including facial feature data and height extracted from the image signal of each frame of the moving image. For example, as shown in FIG. 3A, the recognition data 40 includes a feature data column 41 for storing facial feature data and a height column 43 (pixels) for storing individual heights (pixels). By doing so, the distance between the subject and the camera can be obtained from the height that the recognized height occupies in the imaging range of the CCD 13 and the registered height and the size coefficient of the CCD 13 as described later. The recognition data 40 may be provided with a face size column for storing the vertical size of the face instead of the height column 43. In this case, the distance between the subject and the camera can be obtained from the height that the vertical size of the recognized face occupies in the imaging range of the CCD 13 and the vertical size of the registered face. Further, as shown in FIG. 3B, a face size column 42 for storing the vertical size (pixels) of the face may be included. The recognition database 33 may use a predetermined area of the recording medium 29 as a recording area, or may use a dedicated memory. As the feature data stored in the feature data column 41, for example, the position of each part of the face (eyes, nose, mouth, ear, forehead,...), The size of each part, the angle of each part, The relative relationship between each part of the face can be used.

  The contour extraction unit 34 extracts the contour of the entire person based on the face recognized by the recognition unit 32 and outputs contour size information (height and width). A well-known method (for example, the contour extracting method described in Japanese Patent Application Laid-Open No. 07-274067 and Japanese Patent Application Laid-Open No. 2004-297274) can be appropriately employed as the method for extracting a person's contour.

  FIG. 4 is a diagram showing an embodiment of a depth-of-field correspondence table in which lens addresses are associated with depth of field. The depth of field is a range in which a subject is sharply captured before and after focusing on the subject, and varies depending on the focal length of the lens, the aperture, and the imaging distance. The depth-of-field correspondence table 50 is formed by associating the front-side depth-of-field 52 and the rear-side depth-of-field 53 with the lens address 51, and the lens address 51 is an index representing the position of the focus lens 12-2. In the illustrated example, the depth of field 52 and the rear depth of field 53 are expressed in units of meters. In the illustrated example, when the address of the focus lens 12-2 is “5”, it means that the focus is between “1.5 m” and “2.00 m”, and when the address is “6”, “1. "00m" to "1.5m" means that the subject is in focus .... When the address of the focus lens 12-2 is "10", between "0.05m" and "0.15m" Means that it is in focus. In this embodiment, the depth-of-field correspondence table 50 is stored in advance in a program storage memory such as a ROM, but is included in the automatic focus adjustment program as a constant of the automatic focus adjustment program based on subject recognition. May be.

  FIG. 5 is a flowchart showing a control operation at the time of automatic focus adjustment by subject recognition according to the present embodiment, and a program for causing the digital camera 100 to realize an automatic focus adjustment function by subject recognition (corresponding to steps S4 to S20). It is for explaining. The following processing is basically explained by an example in which the CPU executes in accordance with a program stored in a program memory such as a flash memory in advance, but it is not necessary to store all functions in the program memory. You may make it implement | achieve by receiving a part or all through a network. Hereinafter, a description will be given with reference to FIGS. In the following flowcharts, the moving image capturing mode will be described as an example. However, the scope of application of the present invention is not limited to the moving image capturing mode. For example, the continuously captured images (high-speed continuous shooting images) in the high-speed continuous shooting mode described above. It can also be applied during imaging.

In FIG. 5, when the moving image capturing mode is selected, the control unit 22 executes AE processing at a focal length corresponding to the zoom value at that time, and obtains image data from the CCD 13 based on the subject image from the optical system 12. At the same time, the color process circuit 18 adjusts the white balance corresponding to the color of the light source by automatic white balance (AWB) processing, and then the DRAM 21 is connected to the DRAM 21 via the DMA controller 19 and the DRAM interface (I / F) 20. and DMA transfer to the through display on the LCD26 rewrites VRAM27 the video data obtained by thinning the number of pixels from the image data taken in DRAM 21 (video through image data). At this time, the control unit 22 displays a menu for selecting an automatic focus adjustment function by distance estimation in a predetermined area of the screen 26 of the LCD 26 to prompt the user to select, and when the user selects an automatic focus adjustment function by distance estimation. The automatic focus adjustment function is turned on (step S1).

  When the user fully presses the shutter key 8, the moving image capturing is started (step S 2), and it is checked whether or not the automatic focus adjustment function is on. If it is on, the process proceeds to step S 4. Then, the process proceeds to a normal moving image capturing process (step S3).

  When the automatic focus adjustment function is on, the controller 22 is a parameter for calculating the distance L to the subject, the focal length f, the size coefficient n of the CCD 13 (that is, n when expressed as 1 / n inch CCD), And the height Y1 (pixels) of the imaging range of the CCD 13 is set.

  The control unit 22 controls the recognition unit 32 to detect the face of a person in the currently displayed image (that is, the image data currently captured in the DRAM 21) (step S5), and the detected facial features. Data is extracted (step S6). Although not shown, if a face cannot be detected from the image data for one frame in step S5 (that is, if a person is not shown in the frame of the through image), the next frame is detected until the face is detected. It is assumed that the operation of capturing an image and displaying it through is continued. Step S5 corresponds to subject detection means of the present invention.

  Next, the control unit 22 refers to the recognition database 33 (step S7), compares the facial feature data detected in step S6 with the facial feature data 41 of the recognition data registered in the recognition database 33, and When the difference between the feature amounts is within a predetermined threshold, the recognition data is registered, and the process proceeds to step S13. Otherwise, the process proceeds to step S9 (step S8).

  When the recognition data is not registered, the control unit 22 controls the contour extraction unit 34 to extract the contour of the subject person including the face detected in step S5, and the height occupied by the person's height in the CCD. Y2 (pixels) is obtained (step S9), the contrast autofocus is performed only once to obtain the distance X0 to the subject person (step S10), the size coefficient n of the CCD 13 set in step S4, the CCD 13 The height L of the person is calculated as L = X0 × (Y2 / Y1) × n based on the height Y1 of the imaging range, the height Y2 acquired in step S9, and the distance X0 acquired in step S10 (step S11). ), Recognition data is generated together with the facial feature data acquired in step S6 and registered in the recognition database 33, and the process proceeds to step S16 (step S16) S12). Here, step S9 corresponds to the imaging size detection means of the present invention. FIG. 6 shows an image image in the imaging range of the CCD 13 when Y1 = 480 pixels (pixels), Y2 = 400 pixels, and height = 180 cm.

  When the recognition data is already registered, the control unit 22 reads the height H (height data 42) registered in the recognition database 33 (step S13), controls the contour extraction unit 34, and detects the face detected in step S5. The height of Y2 that the person's height occupies in the CCD is obtained (step S14), and the estimated distance L from the subject person is calculated (step S15). The estimated distance L can be calculated as L = {(H × n × f) /11.8} × (Y2 / Y1), for example, when the height size of the imaging range of the CCD 13 is 480 pixels. Here, H is the actual height (= height registered in the recognition database), and f is the focal length. Here, steps S14 and S15 correspond to the first subject distance estimating means of the present invention.

  Next, the control unit 22 controls the AF driving unit 11-2 to move the focus lens 12-2 to the lens step position (= lens address (see FIG. 4)) corresponding to the estimated distance calculated by step S21. (Step S16). Step S16 corresponds to the first focus position adjustment control means of the present invention.

  The control unit 22 controls the recognition unit 32 to detect the face of a person in one frame of image data taken into the DRAM 21 via the CCD 13, and proceeds to step S18 (step S17). Although not shown, if a face cannot be detected from the image data for one frame in step S18 (that is, if a person is not shown in the frame of the through image), the next frame is detected until the face is detected. It is assumed that the operation of capturing an image and displaying it through is continued.

  The control unit 22 controls the contour extracting unit 34 to extract the contour of the subject person including the face detected in step S17, and obtains the height Y2 occupied by the person's height in the CCD (step S18). The estimated distance L with the person is calculated (step S19). The estimated distance L can be calculated in the same manner as described in the description of step S15. Here, steps S18 and S19 correspond to the second object distance estimating means of the present invention.

  Next, the control unit 22 moves the focus lens 12-2 to the lens step position (= lens address (see FIG. 4)) corresponding to the estimated distance L calculated by controlling the AF driving unit 11-2 ( In step S20), one frame of moving image data is generated from the image data taken into the DRAM 21 via the CCD 13 (step 21) and stored in the image buffer (step S22). A predetermined area of the DRAM 21 may be used as the image buffer, or a dedicated image buffer may be provided. Here, step S20 corresponds to the second focus position adjustment control means of the present invention.

  The control unit 22 checks whether or not the image buffer is full. If the image buffer is full, the process proceeds to step S24; otherwise, the process returns to step S17 (step S23).

  When the image buffer becomes full, the control unit 22 controls the data compression / decompression circuit 27 to perform the compression processing of the moving image data, and also controls the media controller 20 to transfer the compressed moving image data to the recording medium 29. Recording is performed (step S24).

  The control unit 22 examines the signal from the key input 30, and if the user performs a moving image capturing end operation (for example, full-pressing the shutter key 8), the moving image capturing ends, otherwise returns to step S17 to return the moving image. Imaging is continued (step S25).

  Through the operation shown in the flowchart of FIG. 5, the digital camera 100 recognizes the face of a person, detects the height of the person image in the imaging range of the CCD 13, obtains the estimated distance between the camera and the subject person, and obtains the focus lens. Therefore, it is not necessary to scan the lens for converging the lens position to the in-focus position as in the case of the contrast type autofocus, and the focus may fluctuate as shown in FIG. Does not occur.

(Modification 1)
In the example shown in the flowchart of FIG. 5, if the contour 61 of the person extracted in step S14 or S18 does not fit within the frame as shown in FIG. 7, the distance L to the subject person based on the height is estimated. It will not be possible. In such a case, the distance L can be estimated based on the vertical size of the face 62. In this case, as shown in FIG. 3B, the recognition database 33 is composed of recognition data including face feature data 41, a face vertical size 42, and a height 43.

  FIG. 8 is a flowchart showing a control operation at the time of automatic focus adjustment by subject recognition according to the modification 1. The operations of steps S1 to S14, S16 to S18, and S20 to S25 of the flowchart of FIG.・ Calculate the height of the person and the vertical size of the face. ”In step S12,“ Recognition data including the height of the object and the vertical size of the face acquired in step S11 is generated in the recognition database and registered in the recognition database 33. The process is the same as that in steps S1 to S13, S16 to S18, and S20 to S25 in the flowchart shown in FIG.

  In FIG. 8, after extracting the contour of the subject person including the face in step S14 (or step S18) and obtaining the height Y2 that the person's height occupies in the CCD (see FIG. 5), the control unit 22 increases the height. The height Y2 is compared with the vertical size of the frame, and if the height Y2 exceeds the vertical size of the frame, that is, if the whole body image of the subject person does not fit within the frame, the process proceeds to step S15-2. If it is within the vertical size, the process proceeds to step S15-5 (step S15-1).

  If the height exceeds the vertical size of the frame, the control unit 22 reads the vertical size h of the face from the recognition data 40 (step S15-2), and further detects the height Y3 occupied by the vertical size of the face in the CCD. (Step S15-3) The estimated distance L to the subject person is calculated based on the height Y3, that is, the face size, and the process proceeds to Step S16 (or Step S20) (Step S15-4). The estimated distance L can be calculated as L = {(h × n × f) /11.8} × (Y2 / Y1), for example, when the height size of the imaging range of the CCD 13 is 480 pixels. Here, h is the actual vertical size of the face (= the vertical size of the face registered in the recognition database 33), and f is the focal length.

  If the height is within the vertical size of the frame, the estimated distance L from the subject person is calculated based on the height Y2, that is, the height, and the process proceeds to step S16 (or step S20) (step S15-5). The estimated distance L in this case can be calculated as L = {(H × n × f) /11.8} × (Y2 / Y1), for example, when the height size of the imaging range of the CCD 13 is 480 pixels. Here, H is the actual height (= the height registered in the recognition database 33), and f is the focal length. Here, steps S14, S15-1 to S15-5 correspond to the first subject distance estimating means of the present invention, and the operations of steps S18, S19-1 to S19-5 are steps S14, S15-1 to S15-. 5 and corresponds to the second subject distance estimating means of the present invention.

  The operation of the flowchart shown in FIG. 8 allows the distance L to the subject person to be estimated even when the subject person approaches too much during video shooting and the whole body image does not fit in the frame. Even in this case, the subject can be focused and focused.

  In the first modification, the face size stored in the recognition data 40 is detected when the subject person is too close to fit the whole body image in the frame. Even if the size is not registered, if the height is registered, the face size can be obtained based on the registered height, so that the height of the recognized face size within the photographing range of the CCD 13 can be obtained. The distance between the subject person and the camera can be calculated from the face size acquired from the height. The face size P can be obtained as, for example, P = Q / R, where Q is the registered height. Here, R is a coefficient, and may be a value that varies depending on gender, age group, or race.

(Modification 2)
In the example shown in the flowchart of FIG. 5 above, the case where there is one subject person is taken as an example, but the automatic focus adjustment method by subject recognition of the present invention can also be applied to a case where there are a plurality of subject persons.
FIG. 9 is an explanatory diagram of an automatic focus adjustment method when there are a plurality of subject persons, and shows an example of selectively focusing on a person closest to the camera among a plurality of persons. In the example of FIG. 9, the closest person 92 with a distance of 2 m from the camera among the persons 91, 92, and 93 is automatically focused. Specifically, when a plurality of faces are extracted in step S4 in the flowchart of FIG. 5, the processes of steps S5 to S15 are repeated for the number of people extracted to obtain the distance between each person and the camera, and calculated in step S16. The focus lens 12-2 is moved to the lens step position (= lens address (see FIG. 4)) corresponding to the shortest estimated distance l, and the process proceeds to step S21. In step S17, the camera focused in step S16 is selected. The closest person (that is, the person who is a close-up copy of the Mott) is extracted.

(Modification 3)
In the example shown in FIG. 9, the focus is selectively on the person closest to the camera among the plurality of persons. However, the focus is selectively focused on the average distance between the plurality of persons and the camera. Also good. For example, when the distance between the three persons 91, 92, and 93 shown in FIG. 10 and the camera is 2 m, 3.3 m, and 4.1 m, respectively, the distance range from the camera to 2 m to 4.1 m is as much as possible. The focus is automatically adjusted to a position (= 2.7 m) within the depth. Specifically, when a plurality of faces are extracted in step S4 in the flowchart of FIG. 5, the processes of steps S5 to S15 are repeated for the number of persons extracted to determine the distance between each person and the camera, and in step S15, those distances are determined. A distance range (farthest distance and closest distance) from the camera is further acquired from the distance, and a depth-of-field correspondence table (depth-of-field correspondence table 50 in the example of FIG. 4) as shown in FIG. Referring to the lens address so that the distance range from the camera is within the depth of field, the focus lens 12-2 is moved to the lens step position (= lens address) in step S16, and the process proceeds to step S21. The same operation is repeated in steps S17 to S25. In this way, it is possible to capture sharp images of a plurality of persons.

(Modification 4)
In the flowchart of FIG. 5, when the size of the subject person changes in the CCD 13, the estimated distance L is calculated based on the change, and immediately at step S 20, the lens step position (= lens address) corresponding to the calculated estimated distance L. The focus lens 12-2 is moved until the focus lens 12-2 is moved, but the focus lens 12-2 is not moved immediately, and the focus lens is moved at a low speed when the focus lens 12-2 is likely to deviate from the depth of field. Also good. Further, the control may have a certain hysteresis characteristic.

FIG. 11 is an explanatory diagram of changes in the depth of field accompanying changes in the size of the subject person, and FIGS. 11A to 11C are examples of changes in the size of the subject person 131. FIG. 11D shows an example of the depth of field that changes according to the change of the subject person 131.
If the distance L between the subject person 111 and the camera is 1.8 m as shown in FIG. 11A, the distance L is within the depth of field of 2 m to 3 m as shown in FIG. Next, when the size of the subject person 111 in the camera field of view changes as shown in FIG. 11B and the distance L becomes 2.8 m, the distance L becomes the object field as shown in FIG. Although the depth is within a range of 2 m to 3 m, if the size of the subject person 131 changes as it is, the depth of field is likely to protrude. Therefore, as shown in FIG. 11C, the next depth of field including the distance L at the time when the distance L = 2.8 m (lens with depth of field of 2.5 m to 4.4 m in FIG. 11F). The focus lens 12-2 is moved to the step position (= lens address).

  FIG. 12 is a flowchart showing a control operation at the time of automatic focus adjustment by subject recognition according to the modification 4, and is an example in which the following steps S20-1 to S20-5 are provided in place of step S20 in FIG.

  In FIG. 12, when the estimated distance L between the subject person and the camera is calculated in step S19, the control unit 22 refers to the depth of field correspondence table (for example, the depth of field correspondence table 50 of FIG. A search is performed to extract a lens address whose distance L is within the depth of field range (the front depth of field 52 and the rear depth of field 53 in the example of FIG. 4) (step S20-1).

  The control unit 22 checks whether or not there are a plurality of lens addresses extracted from the depth-of-field correspondence table. If there are a plurality of lens addresses, the process proceeds to step S20-6), and in the case of one, the process proceeds to step S20-4 (step S20-). 2).

  If the distance L is within the range of multiple sets of depth of field, the control unit 22 checks whether the distance L has increased or decreased from the previous distance, and if it has increased (that is, When the distance becomes longer, the process proceeds to step S20-4. When the distance decreases (when the distance to the subject person becomes shorter), the process proceeds to step S20-5 (step S20-3).

  When the distance L increases from the previous distance, the lens address of the depth of field that is farthest from the rear depth of field (see FIG. 4) is extracted. S20-4). For example, when the distance L = 2.8 as shown in FIG. 11B, searching the depth-of-field correspondence table 50 in FIG. 4 results in a depth of field of 2 m to 3 m (lens address = 3). The distance L = 2.8 falls within the range of the depth of field 2.5 m to 4.4 m (lens address 2). In such a case, the difference between the rear depth of field and the distance L is ΔD3 = 3 m−2.8 m = 0.2 m for the lens address 3, and ΔD2 = 4.4 m− for the lens address 2. 2.8 m = 1.4 m. Therefore, ΔD3 <ΔD2, and the lens address 2 corresponding to the depth of field of 2.5 m to 4.4 m shown in FIG. 11C is acquired.

  If the distance L has decreased from the previous distance, the lens address of the depth of field that is farthest from the front depth of field (see FIG. 4) of the depth of field is extracted (step S20). -5). For example, when the distance L = 2.8, searching the depth-of-field correspondence table 50 in FIG. 4 searches the depth of field 2 m to 3 m (lens address = 3) and the depth of field 2.5 m to 4.4 m ( The distance L = 2.8 falls within the range of the lens address 2). In such a case, the difference between the distance L and the front side depth of field is ΔD3 = 2.8 m−2 m = 0.8 m in the case of the lens address 3, and ΔD2 = (2.8− in the case of the lens address 2. Therefore, ΔD3> ΔD2, and the lens address 3 corresponding to the depth of field of 2.5 m to 3 m is acquired.

  The control unit 22 controls the AF driving unit 11-2 to move the focus lens 12-2 to the lens step position (= lens address) acquired in step S20-1, S20-4, or step 20-5. The process proceeds to step S21 (step S20-6).

  As shown in the flowchart of FIG. 12 above, by using a depth-of-field table in which the depth of field is slightly overlapped, there is no unnatural feeling because there is no sudden change in focus. It is possible to reduce the “smoothness” feeling (see FIG. 16) that occurs when an image is captured.

(Embodiment 2)
In the first embodiment and the modifications thereof, only a person is a subject, the face and body are automatically recognized, the vertical size of the subject person in the CCD 13 is obtained based on the vertical size, and the subject The estimated distance L is calculated, and the focus lens 12-2 is moved to the lens step position corresponding to the calculated estimated distance L. However, in the present invention, by changing a part of the focus lens 12-2, the subject is other than a person. It can also be applied to.

FIG. 13 is an explanatory diagram of a subject recognition method according to this embodiment. In this embodiment, a frame 131 (indicator for subject size detection) as shown in the figure is displayed in the through-displayed image at the time of moving image imaging preparation (corresponding to steps S1 to S16 in FIG. 5), and its size is changed. Then, after the subject 132 to be focused is placed within the frame, the distance to the subject 132 is measured only once, and the height of the image of the frame 131 is detected. Also, the vertical size H of the frame 131 acquired at this time is registered in the recognition database 33 as the vertical size of the subject 152, and is used when calculating the estimated distance at the time of imaging.

  FIG. 14 is a flowchart showing a control operation at the time of automatic focus adjustment by subject recognition according to the present embodiment. Steps S9-1 to S9-4 shown below are substituted for steps S9 and S10 to S12 in FIG. 5 (and FIG. 12). , And steps S10 to S12. In this embodiment, in the steps S1 to S8 and steps S13 to S25 in the flowchart of FIG. 5 (and FIG. 12) and the description of each step, “height” is “vertical frame size” and “subject person” is “subject”. ”And“ face ”are read as“ specific part of the subject ”. Also in the description of the recognition data 40, “height” is read as “vertical size of frame”, “subject person” is read as “subject”, and “face” is read as “specific part of subject”.

  In FIG. 14, when it is determined in step S8 that the recognition data is not registered, the control unit 22 displays the frame 131 on the LD 26 to change the size of the user and prompt the user to surround the desired subject ( Step S9-1).

  Since the user changes the size of the frame 131 using the cursor key 5 and moves the camera so that the desired subject 132 fits in the frame 131, the control unit 22 examines the signal from the key input unit 30, When the size of the frame 131 displayed on the LCD 26 is changed in accordance with the operation of the cursor key 5 (step S9-2) and there is a confirmation operation (in this example, the SET key 6 is depressed) (step S9-3), The control unit 22 determines the height Y2 (pixels) occupied by the vertical size of the frame in the CCD, and proceeds to step S10 (step S9-4). As for the enlargement / reduction operation of the frame 131 in step S9-2, for example, when the cursor key 5 is operated to the right (>), the predetermined frame 131 is enlarged, and when the cursor key 5 is operated to the right (>), the predetermined frame 131 is reduced. You can do that. Further, it is desirable to perform the enlargement / reduction operation to the extent that the frame 131 circumscribes the subject 132.

  Next, the control unit 22 performs the contrast autofocus only once on the subject existing in the frame 131 to obtain the distance X0 to the subject 132, and proceeds to step S11 (step S10). Based on the set size coefficient n of the CCD 13, the height Y1 of the imaging range of the CCD 13, the height Y2 of the subject image 132 in the CCD 13 acquired in step S9-4, and the distance X0 acquired in step S10, The size is calculated as L = X0 × (Y2 / Y1) × n (step S11), recognition data is generated together with the feature data of the subject acquired in step S6, is registered in the recognition database 33, and the process proceeds to step S16 (step S16). Step S12). Thereby, in the subsequent autofocus (that is, the autofocus operation in steps S17 to S20), only the height Y2 that the image of the subject 132 occupies in the CCD 13 becomes the variable of the estimated distance L.

  By the operation shown in the flowchart of FIG. 16, the user simply surrounds the image of the desired subject in the through-displayed image at the start of moving image capturing with a frame and follows the movement of the subject to determine the distance between the subject and the camera. Then, the focus lens can be focused by moving the focus lens to a position corresponding to the estimated distance.

  As mentioned above, although several Example of this invention was described, it cannot be overemphasized that this invention is not limited to said each Example, A various deformation | transformation implementation is possible. For example, the term imaging device can be applied to an electronic camera such as a digital camera, a mobile phone with a camera, an information device having an imaging function, a video device, and the like.

1 is a diagram illustrating an external appearance of a digital camera as an embodiment of an imaging apparatus according to the present invention. FIG. 2 is a block diagram illustrating an example of an electronic circuit configuration of the digital camera illustrated in FIG. 1. It is a figure which shows one Example of the recognition data which comprises a recognition database. It is a figure which shows one Example of the depth-of-field correspondence table which matched the lens address and the depth of field. 6 is a flowchart showing a control operation during automatic focus adjustment by subject recognition according to the first embodiment. It is a figure which shows the image image in the imaging range of CCD. It is a figure which shows the example which the magnitude | size of a person does not fit in a flame | frame. 10 is a flowchart showing a control operation during automatic focus adjustment by subject recognition according to Modification 1. It is explanatory drawing of the automatic focus adjustment method concerning the modification 2. It is explanatory drawing of the automatic focus adjustment method concerning the modification 3. It is explanatory drawing of the change of the depth of field accompanying the change of the magnitude | size of a to-be-photographed person. 10 is a flowchart showing a control operation during automatic focus adjustment by subject recognition according to Modification 4. FIG. 10 is an explanatory diagram of a subject recognition method according to a second embodiment. 10 is a flowchart showing a control operation during automatic focus adjustment by subject recognition according to the second embodiment. It is explanatory drawing in the case of performing contrast AF by using a face area as a sample area. It is explanatory drawing of the focus state of the image imaged by contrast method AF.

Explanation of symbols

11-2 AF Drive Unit 12-1 Zoom Lens 12-2 Focus Lens 13 CCD
21 DRAM
22 Control unit 26 LCD
27 Data compression / decompression unit 29 Media controller 30 Recording medium 32 Recognition unit 33 Recognition database 34 Outline extraction unit 61 Subject person 62 Face 100 Digital camera 131 Subject 151 Frame

Claims (4)

A moving image capturing means for capturing a moving image;
Moving image recording means for recording and storing the moving image captured by the moving image capturing means;
Moving image display control means for displaying a moving image captured by the moving image capturing means;
Index display means for displaying the index of the subject;
Size adjusting means for adjusting the size of the index so as to be substantially the same size as the size of a desired subject image in the moving image displayed by the moving image display control means;
Index image detecting means for detecting an index image whose size is adjusted by the size adjusting means from images displayed by the moving picture display control means when capturing a moving image by the moving image capturing means;
Distance measuring means for measuring a distance to a subject when the moving image is picked up by the moving image pickup means;
Feature data acquisition means for acquiring feature data of a subject when the moving image is picked up by the moving image pickup means;
An imaging size acquisition unit that acquires a size of the index image in an imaging range of the video imaging unit when capturing a video by the video imaging unit;
Subject size estimation means for estimating the actual size of the subject based on the distance to the subject measured by the distance measurement means and the size of the index image acquired by the imaging size acquisition means;
Storage means for storing the characteristic data acquired by the characteristic data acquisition means and the actual size data of the subject estimated by the subject size estimation means in association with each other;
When the moving image is picked up by the moving image pickup means, the characteristic data of the subject is acquired by the characteristic data acquisition means, and when the matching characteristic data is stored in the storage means, the distance measurement by the distance measurement means is replaced. Subject distance estimation means for estimating the subject distance based on the actual size stored in association with the feature data and the size of the index image acquired by the imaging size acquisition means ;
Focusing position adjustment control means for moving the focus lens to a position corresponding to the subject distance estimated by the subject distance estimation means and the subject distance measured by the distance measurement means ;
An imaging apparatus comprising: A distance increase / decrease determination unit that determines whether the subject distance has increased or decreased when there are a plurality of lens addresses indicating a range of depth of field including the subject distance estimated by the subject distance estimation unit;
When the subject distance increases, the focus position adjustment control unit has a maximum depth of field that is obtained by subtracting the subject distance from the rear depth of field corresponding to the plurality of lens addresses. When the focus lens is moved to the lens address corresponding to, and the subject distance decreases, the value obtained by subtracting the front depth of field of the depth of field corresponding to the plurality of lens addresses from the subject distance is the maximum. The imaging apparatus according to claim 1, wherein the focus lens is moved to a lens address corresponding to a depth of field. Displaying a moving image captured during moving image capturing;
A process of displaying an index of a subject;
Adjusting the size of the indicator so as to be approximately the same size as the size of a desired subject image in the displayed moving image;
A step of detecting the size-adjusted index from a moving image displayed when capturing a moving image;
Measuring the distance to the subject when capturing a video;
Acquiring feature data of a subject when capturing a video;
Obtaining a size of the index image in an imaging range of the imaging device when capturing a moving image;
Estimating the actual size of the subject based on the measured distance to the subject and the size of the acquired index image;
Storing the acquired feature data and the estimated actual size data of the subject in a storage unit in association with each other;
When the feature data of the subject is acquired when the moving image is captured and the matching feature data is stored in the storage unit, the feature data is associated with the feature data instead of the distance measurement in the step of measuring the distance. Estimating the subject distance based on the stored actual size and the size of the index image;
A step of moving the focus lens to a position corresponding to the subject distance measured by measuring the estimated subject distance and the distance by the step of estimating the object distance,
An automatic focus adjustment method characterized by comprising: On the computer,
A function of capturing a moving image, a function of recording and saving the captured moving image, a function of displaying a captured moving image,
A function to display the index of the subject,
A function of adjusting the size of the indicator so as to be approximately the same size as the size of a desired subject image in the displayed moving image;
From the moving image displayed at the time of capturing a moving, a function of detecting the size adjusted target images,
The ability to measure the distance to the subject when capturing a video;
A function to acquire subject characteristic data when capturing a video;
A function of acquiring the size of the index image in the imaging range of the image sensor when capturing a moving image;
A function of estimating the actual size of the subject based on the measured distance to the subject and the size of the acquired index image;
A function of storing the acquired feature data and the estimated actual size data of the subject in a storage unit in association with each other;
When feature data of a subject is acquired when capturing a moving image and matching feature data is stored in the storage unit, the feature data is associated with the feature data instead of the distance measurement by the function of measuring the distance. A function for estimating the subject distance based on the stored actual size and the size of the index image;
And ability to move the focus lens to a position corresponding to the subject distance measured by the ability to measure the estimated subject distance and the distance by the ability to estimate the object distance,
A program that executes

Images