JP2008003335A - Imaging apparatus, focus control method, focus control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus which controls the display of an automatic focus frame, based on the result of the recognition of a subject by a simple key operation or a recognition process, and also to provide a focus control method and a focus control program. <P>SOLUTION: In response to the depression of a SET button in an AF frame display alteration mode during a photographing standby period, an AF frame 44-1 displayed on a screen switches to an AF frame 44-2 taken out from a frame pattern memory. Each time the SET button is depressed, AF frame switches such that AF frames 44-3 to 44-5 are displayed on a subject 40 one after another. Thus, by operating the SET button, a user can display a desired AF frame matching each subject 40 onto the subject. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an imaging apparatus such as a digital camera that performs focus control based on a focus frame displayed on a monitor screen, a focus control method, and a focus control program.

  Some imaging devices such as digital cameras have an AF function (automatic focusing function) for automatically focusing on a subject. This AF function operates, for example, by pressing the shutter key halfway, and moves the focus lens so that it is focused on the target position of autofocus (for example, the center of the screen), and focuses on that position. At that time, it is common practice to display an autofocus frame (hereinafter referred to as an AF frame) in order to inform the user of the target position of autofocus.

In the above conventional technology, the focus position is fixed at the center of the screen, but the subject you want to focus on is not always in the center of the screen, so you must move the camera so that the subject you want to focus on is in the center of the screen. There was a problem of not becoming. In order to solve such a problem, for example, in Patent Document 1, an operation on a monitor screen of a television camera or the like is detected by a touch panel, and a position and a size of a focus frame are changed by the operation. An autofocus system is disclosed in which the position and size of a focus frame can be set and changed according to the position and size of a subject on the screen.
JP 2004-117490 A

  However, even in the technique disclosed in Patent Document 1, the degree of freedom for changing the state such as the position and size of the focus frame is still limited, and inconveniences often arise. For example, it may be easier to see if the focus frame is rotated forward or backward in accordance with the tilt of the camera or subject, but the technique disclosed in Patent Document 1 cannot rotate the focus frame.

  The present invention has been made to solve the above problems, and an imaging apparatus and a focus control method capable of controlling the display state of an autofocus frame based on a recognition result of a subject by simple key operation or recognition processing And a focus control program.

  In order to solve the above problems, in the imaging apparatus according to the first aspect of the present invention, an image acquisition unit that obtains an image from a subject light image via an imaging element, and an image that displays the image obtained by the image acquisition unit A display unit, a focus frame display control unit that superimposes and displays a focus frame for focusing on an image displayed on the image display unit, and drive control of the focus lens so that an image in the focus frame is in focus An in-focus control unit that includes an input unit that inputs a predetermined instruction, a timing instruction unit that instructs a predetermined timing, and a focus frame that variably generates a state of the focus frame Generating means, wherein the focus frame generating means changes the state of the focus frame based on an instruction via the input means, and the focus frame display control means The focus frame generated by the focus frame generation unit is displayed on the image display unit, and the focus control unit displays the focus displayed on the image display unit at a predetermined timing instructed by the timing instruction unit. The focus lens is driven and controlled so that the image in the frame is in focus.

  According to a second aspect of the present invention, in the imaging apparatus according to the first aspect of the invention, the focus frame generation unit rotates the focus frame based on an instruction via the input unit. .

  According to a third aspect of the present invention, in the imaging apparatus according to the first aspect of the invention, the focus frame generation means includes a frame pattern registration memory in which a focus frame pattern is registered in advance, and is currently selected. The focus frame is replaced with a new focus frame pattern read from the frame pattern registration memory based on an instruction via the input unit.

  According to a fourth aspect of the present invention, in the imaging apparatus according to the first aspect of the invention, the focus frame generating means expands and contracts the size of the focus frame based on an instruction via the input means. To do.

  According to a fifth aspect of the present invention, in the imaging apparatus according to the first aspect of the invention, the focus frame display control unit is positioned at a predetermined position of the image display unit based on an instruction via the input unit. The focus frame is moved and displayed.

In the imaging device according to the sixth aspect of the present invention, an image acquisition unit that obtains an image from a subject light image via an imaging device, an image display unit that displays an image obtained by the image acquisition unit, and an in-focus state A focus frame display control unit that superimposes and displays a focus frame on the image displayed on the image display unit; and a focus control unit that drives and controls a focus lens so that an image in the focus frame is focused. , An image recognition processing unit for recognizing and recognizing a predetermined subject shape in the image, a timing instruction unit for instructing a predetermined timing, and generating a state of the focus frame so as to be changeable A focus frame generation means, wherein the focus frame generation means determines the state of the focus frame based on the subject shape identified and recognized by the image recognition processing means, The focus frame display control unit displays the focus frame generated by the focus frame generation unit on the image display unit, and the focus control unit displays the image at a predetermined timing instructed by the timing instruction unit. The focus lens is driven and controlled so that an image in the focus frame displayed on the display unit is in focus.

  The invention according to claim 7 is the imaging apparatus according to claim 6, further comprising instruction means for instructing selection of a predetermined subject in the image, wherein the image recognition processing means is controlled by the instruction means. It is characterized by recognizing and recognizing the shape of the subject instructed to be selected.

  According to an eighth aspect of the present invention, in the imaging apparatus according to the sixth or seventh aspect of the invention, the focus frame display control means has the focus frame on the subject identified and recognized by the image recognition processing means. The focus frame generated by the generation unit is displayed in a superimposed manner.

  The invention described in claim 9 is characterized in that, in the image pickup apparatus according to claim 8, the focus frame display control means superimposes and displays the subject shape and the focus frame so as to coincide with each other.

  Further, in the imaging device according to any one of claims 6 to 9, the image display unit is obtained by the image acquisition unit every time an image is obtained by the image acquisition unit. The image recognition processing means identifies and recognizes a predetermined subject shape in the updated and displayed image, and the focus frame generation means identifies and recognizes the subject shape by the image recognition processing means. Each time, a new focus frame is generated based on the subject shape so as to correspond to the newly identified and recognized subject shape, and the focus frame display control means generates a new focus frame by the focus frame generation means. The focus frame is updated and displayed every time a frame is generated.

  The focus control method according to an eleventh aspect of the present invention includes an image display step of displaying an image obtained from a subject light image via an image pickup device, and a focus focus frame superimposed on the image. A focus control method comprising a focus frame display step, and a focus control step for driving and controlling the focus lens so that an image in the focus frame is in focus, an input step for inputting a predetermined instruction, A timing instructing step for instructing timing; and a focus frame generating step for generating the state of the focus frame in a changeable manner, wherein the focus frame generating step is based on a predetermined instruction by the input step. The focus frame display control step is configured to superimpose the focus frame generated by the focus frame generation step on the image. And the focus control process is characterized in that the image of the focus frame being displayed when the predetermined timing instructed by the timing instruction step controls driving of the focus lens to focus.

  In the focus control method according to the twelfth aspect of the present invention, an image display step for displaying an image obtained from a subject light image via an imaging device and a focus frame for focusing are superimposed and displayed on the image. A focus control method comprising a focus frame display step and a focus control step for driving and controlling a focus lens so that an image in the focus frame is in focus, and identifies and recognizes a predetermined subject shape in the image An image recognition processing step; a timing instruction step for instructing a predetermined timing; and a focus frame generation step for generating the focus frame state in a changeable manner. The focus frame generation step is performed by image recognition processing means. The focus frame state is determined based on the identified and recognized subject shape, and the focus frame display control step includes the focus frame generation step. The generated focus frame is superimposed on the image, and the focus control step is performed so that the image within the focus frame displayed at the predetermined timing instructed by the timing instruction step is in focus. The focus lens is driven and controlled.

  According to a thirteenth aspect of the present invention, there is provided a focus control program including: an image display control unit that causes a computer to display an image obtained from a subject light image via an image sensor; and a focus frame for focusing on the image. A focus frame display control unit that superimposes and displays a focus frame, and a focus control program that functions as a focus control unit that drives and controls the focus lens so that an image in the focus frame is focused. Means, a timing instruction means for instructing a predetermined timing, and a focus frame generation means for generating the state of the focus frame in a changeable manner. The focus frame generation means is based on an instruction input by the input means. The focus frame display control means is configured to change the focus frame state. The focus frame generated by the frame generation unit is superimposed on the image, and the focus control unit displays the focus frame displayed on the image display unit at a predetermined timing instructed by the timing instruction unit. The focus lens is driven and controlled so that the inside image is in focus.

  According to a fourteenth aspect of the present invention, there is provided a focus control program comprising: an image display control unit that causes a computer to display an image obtained from a subject light image via an image sensor; and a focus frame for focusing on the image. A focus frame display control unit that superimposes and displays a focus frame, and a focus control program that functions as a focus control unit that drives and controls a focus lens so that an image in the focus frame is in focus, and includes a predetermined subject in the image The image recognition processing means for recognizing and recognizing the shape, the timing instruction means for instructing a predetermined timing, and the focus frame generation means for generating the state of the focus frame in a changeable manner, the focus frame generation means Based on the subject shape identified and recognized by the processing means, the state of the focus frame is determined, and the frame is The focus frame display control unit displays the focus frame generated by the focus frame generation unit on the image display unit, and the focusing control unit displays the image at a predetermined timing instructed by the timing instruction unit. The focus lens is driven and controlled so that the image within the focus frame displayed on the display unit is focused.

  According to the present invention, the focus frame display state, for example, focus frame rotation, focus frame replacement, expansion / contraction, movement, and the like is controlled based on the recognition result of the subject by simple key operation or recognition processing. Since the image within the frame can be focused, the phenomenon that the focus is not on the subject but on the background (so-called “missing”) does not occur. According to the invention described in claims 1 to 5, claim 11 and claim 13, the state of the focus frame can be controlled by an instruction based on a simple key operation by the user. According to the sixth to ninth, twelfth and twelfth aspects of the present invention, the state of the focus frame can be controlled based on the recognition result of the subject shape by the image recognition processing. According to the tenth aspect of the present invention, since the focus frame can be automatically changed following the change in the subject shape and position, the focus does not shift even if the subject shape or position changes.

(Embodiment 1)
In the present embodiment, an example in which an autofocus frame (hereinafter referred to as an AF frame) is rotated by a simple key operation or automatically will be described.

  FIG. 1 is a diagram showing the appearance of a digital camera as an embodiment of an imaging apparatus according to the present invention. Here, mainly a front surface (FIG. 1A), a rear surface (FIG. 1B), and an upper surface ( The external appearance of FIG.1 (c) is shown. The digital camera 100 has an imaging lens 1 on the front side as shown in FIG. Further, as shown in FIG. 1B, a mode dial 3, a liquid crystal screen 4, a cursor key 5, a SET button 6, a menu key 10, and the like are provided on the back of the digital camera 100. Further, as shown in FIG. 1C, a zoom lever 7, 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 illustrating an example of the electrical configuration of the digital camera according to the present embodiment. The digital camera 100 includes an imaging unit 31, an image data processing unit 32, a system control unit 35, a temporary storage memory 36, An image display unit 37, a recording unit 38, an external input / output unit 40, an operation unit 41, and a frame rotation processing unit 42 are provided. The imaging unit 31 and the image data processing unit 32 constitute an image acquisition unit of the present invention. Further, it has an autofocus function, a shooting function such as a still image shooting mode and a moving image shooting mode, and an AF frame display change mode based on the present invention that can be selected under these shooting functions.

  In addition to the photographic lens 1, the imaging unit 31 moves the zoom lens in the imaging mode, which is the basic mode, and a focus control that moves the zoom lens to perform an optical zoom operation and a focus control by moving a focus lens. It has a lens drive system including an AF drive controller as a means, and an image pickup system including an image sensor, a signal converter, an imaging timing controller, an image sensor drive controller, etc. The subject light image incident on the image sensor disposed behind the imaging optical axis of the imaging lens is photoelectrically converted by the image sensor and output as an image signal (analog). The output signal of the image sensor is correlated double sampling and gain adjustment by a signal conversion unit, and converted to a digital signal by A / D conversion. The A / D converted image signal is sent to the image data processing unit 32 at a predetermined cycle. The imaging element is a solid-state imaging device such as a complementary metal oxide semiconductor (CMOS) that captures a two-dimensional image of a subject, and typically captures an image of several tens of frames per second. Note that the image sensor is not limited to a CMOS.

  The image data processing unit 32 performs a color process process including an image interpolation process and a γ correction process on the digital signal (image data) output from the signal conversion unit to obtain a digital luminance signal Y and color difference signals Cb, Cr. And DMA-transferred to the temporary storage memory 36 such as DRAM via the bus 30.

  The system control unit 35 controls the overall control operation of the digital camera 100, and includes a CPU or MPU (hereinafter referred to as CPU), a program storage memory such as a flash memory that stores an operation program executed by the CPU, and the like. It is comprised by RAM etc. which are used as a work memory. The system control unit 35 reads the luminance and color difference signals from the temporary storage memory 36 after the DMA transfer of the image data (luminance and color difference signals) from the image data processing unit 32 to the temporary storage memory 36 such as a DRAM. Control is performed to write to the display buffer memory of the image display unit 39.

  The system control unit 35 functions as an in-focus position determining unit that determines an in-focus position, and also instructs timing of AF frame display control based on an instruction based on a user's key operation in the AF frame display change mode. It functions as instruction means and AF frame display control means for controlling the display state of the AF frame displayed on the subject to be focused (hereinafter referred to as “main subject”). Specifically, the AF frame displayed on the liquid crystal screen 4 by controlling the frame rotation processing unit 42 when there is a predetermined frame rotation instruction operation or camera tilt detection by the tilt detection unit 43 in the AF frame display change mode. For example, functions as a frame rotation control means for rotating the liquid crystal screen 4 so as to cancel the tilt by the camera.

  The temporary storage memory 36 is configured by a DRAM or the like, and can be used as a buffer memory that temporarily stores a captured image obtained from the image data processing unit 32 in a part of the area in the shooting mode.

  The image display unit 37 includes a display buffer memory such as a VRAM, a display control unit, and a liquid crystal screen 4, and displays the luminance and color difference signals written in the display buffer memory under the control of the system control unit 35. Are periodically read out, a video signal is generated based on these data, and is output to the liquid crystal screen 4.

  The recording unit 38 includes a data compression / decompression unit that compresses or decompresses image data, and a controller that writes data to and from the recording medium 39 transferred from a buffer memory such as a DRAM. ing. The recording medium 39 is a rewritable recording medium such as a built-in memory (flash memory), an optical disk, or a removable memory card, and stores and records image data and imaging information written by the recording unit 38.

  The external input / output unit 40 is an input / output interface for inputting / outputting image data, a program, and the like between the digital camera 100 and an external device connected to the digital camera 100 via a connection means such as a USB cable or a communication network such as the Internet. Etc.

  The operation unit 41 is operated with keys such as the mode dial 3, the cursor key 5, the SET button 6, the zoom lever 7, the shutter key 8, the power button 9, and the menu key 10 shown in FIG. And a key processing unit that generates an operation signal for the operated key and sends it to the system control unit 35, and functions as a key input means for inputting a predetermined instruction in the AF frame display change mode.

  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 a still image imaging mode, a macro imaging mode, a continuous shooting mode, a rapid shooting mode,. The AF frame display change mode can be selected from a process selection menu displayed under the shooting mode. The mode dial 3 may be configured so that the AF frame display change mode can be selected.

  The cursor key 5 is a key operated when pointing (specifying) a menu or icon displayed on the liquid crystal screen 4 with a cursor when setting a mode or selecting a menu. The cursor is moved up and down or left and right by the operation of the cursor key 5. Can be moved.

  The SET button 6 is a key that is pressed when the item displayed by the cursor key 5 is selected and set. In this embodiment, the SET button 6 is used as an AF frame frame rotation instruction unit in the AF frame display change mode. For example, each time the SET button 6 is pressed once, the displayed AF frame is rotated by a predetermined angle with respect to the liquid crystal screen 4. Other keys may be configured as frame rotation instruction means for the AF frame. The digital camera 100 may be provided with a dedicated key for instructing the rotation of the AF frame.

  The zoom lever 7 is used for a zoom operation. In the case of optical zoom, the zoom lens (variable focal length lens) is moved to the wide side or the tele side in response to the operation of the zoom lever 7 and corresponds to the operation of the zoom bar 7. Thus, the zoom value is determined, the angle of view actually changes following the change of the zoom value, and a wide (wide angle) image or a tele (telephoto) image is displayed on the liquid crystal monitor screen 4. In the case of electronic zoom, the zoom value is determined in response to the operation of the zoom lever 7, but the actual angle of view does not change, and an image of a size corresponding to the zoom value is trimmed on the LCD monitor screen 4. To zoom in / out. Further, when the AF frame display change mode is selected, instead of the SET button 6, the zoom lever 7 is used as a frame rotation instruction means for the AF frame and the zoom lever 7 is rotated to the right to display the AF. When the frame rotates to the right and the zoom lever 7 rotates to the left, the displayed AF frame may rotate to the left.

  The shutter key 8 performs a release operation at the time of imaging, and has a two-stage stroke. The system control unit 35 performs autofocus (AF) by operating the shutter key 8 in the first stage (half-pressed state). A focus instruction signal for performing automatic exposure (AE) is generated, and an imaging instruction signal for performing an imaging process is generated by the second-stage operation (fully pressed state).

  In the AF frame display change mode, the frame rotation processing unit 42 outputs AF frame data obtained by rotating the AF frame displayed on the liquid crystal screen 4 left and right by a predetermined angle under the control of the system control unit 35 based on the frame rotation instruction. It is generated and sent to the image display unit 37. As a method for rotating the AF frame displayed on the liquid crystal screen 4, a known rotation technique related to the display figure can be used as appropriate. A plurality of AF frames may be displayed. It should be noted that when the AF frame display change mode is not selected, the operation of the frame rotation processing unit 42 is prohibited, and a rectangular AF frame is displayed at the center of the screen, for example, when displaying a through image.

  FIG. 3 shows an example of a rotating AF frame, and FIG. 3A shows the state of the AF frame 30 during shooting standby, that is, when a through image is displayed. In the illustrated example, three rectangular AF frames 30-1, 30-2, and 30-3 are displayed in the horizontal position row at the center of the horizontally long screen. 3B shows the state of the AF frame 30 slightly rotated clockwise toward the screen, and FIG. 3C shows the AF frame rotated 90 ° clockwise from the horizontal state and perpendicular to the screen. FIG. 3D shows the state of the AF frame 30 rotated further clockwise.

  FIG. 4 is a diagram showing an embodiment of the AF frame rotation operation. In the illustrated example, a frame rotation instruction is performed by the user operating the SET button 6 in the AF frame display change mode. FIG. 4A shows the AF frame 30 displayed on the subject 40 at the center of the screen during shooting standby, that is, when a through image is displayed. When the SET button 6 is pressed in this state, the AF frame 30 rotates clockwise by a predetermined angle and is displayed obliquely on the subject 40 as shown in FIG. When the SET button 6 is pressed several times, the AF frame 30 becomes vertical at the center of the vertically long subject 40 as shown in FIG. 4C, and when the SET button 6 is further pressed, the AF frame 30 becomes AF as shown in FIG. 4D. The frame 30 further rotates clockwise by a predetermined angle.

  FIG. 5 is a flowchart showing an example of an AF frame display control operation performed by the system control unit 35 according to the present embodiment, for explaining a program for causing the digital camera 100 to realize the AF frame rotation function of the present invention. is there. Hereinafter, description will be given with reference to FIGS.

  When the power key 9 of the digital camera 100 is on and the user operates the mode dial 3 to select the shooting mode, the system control unit 35 controls the image display unit 37 to set the AF frame display change mode on the liquid crystal screen 4. When the user selects the AF frame display change mode, the AF frame display change flag is turned on and the process proceeds to step S2. Otherwise, the AF frame display change flag remains off and the process proceeds to step S2. (Step S1).

  Next, after performing various initial settings for photographing (step S2), the system control unit 35 displays an AF frame of a predetermined size at a predetermined position, for example, the center of the liquid crystal screen 4 (step S3). As a result, the user can perform framing so that the center of the main subject to be focused on in the through-displayed image falls within the AF frame so that an image with a suitable composition can be accommodated in the screen. Note that the number of AF frames to be displayed is not limited to one. For example, a plurality of AF frames may be displayed as shown in FIG. In this case, the number of AF frames to be displayed on the selection menu may be specified, or after the auto force frame is displayed, for example, when the menu key 10 is pressed, a menu for specifying the number of frames is displayed. The number may be specified.

  Next, the system control unit 35 controls the imaging unit 31 and the image data processing unit 32 to execute AE processing at a focal length corresponding to the zoom value at that time, and captures the subject light image captured via the photographing lens 1. The image data is obtained from the image data and is adjusted so that the white balance corresponding to the color of the light source is obtained by automatic white balance (AWB) processing, and image data for one frame is obtained at a predetermined cycle to temporarily store the memory 36. The display buffer of the image storage unit 37 is rewritten with the video through image data obtained by thinning the number of pixels from the image data fetched into the temporary storage memory 36 and the through image is displayed on the liquid crystal screen 4 (step S4).

  Further, the system control unit 35 checks the value of the AF frame display change flag. If the AF frame display change flag is on, the system control unit 35 proceeds to step S6, and otherwise proceeds to step S8 (step S5).

  If the AF frame display change flag is on in step S5, the system control unit 35 checks the signal from the operation unit 41. If an AF frame rotation instruction signal is received, the system control unit 35 proceeds to step S7. The process proceeds to step S8 (step S6).

  Upon receiving the AF frame rotation instruction signal in step S6, the system control unit 35 sends a control signal to the frame rotation processing unit 42, and displays the AF frame displayed in a predetermined direction, for example, as shown in FIG. It is rotated clockwise by a predetermined angle (step S7). The AF frame rotation instruction signal is sent from the operation unit 41 to the system control unit 35 when a predetermined key, for example, the SET key 6 is pressed. As will be described in detail in Modification 1-1, which will be described later, the main subject, that is, the subject to be focused is changed, or the camera tilt is detected as described in detail in Modification 1-2. For example, the AF frame can be automatically rotated so as to be horizontal with respect to the ground surface.

  The system control unit 35 examines a signal from the operation unit 41, and proceeds to step S9 if the first operation (half-pressed state) of the shutter key 8 is performed, and proceeds to step S4 if the shutter key 8 is not depressed. Return (step S8).

  When the first stage operation (half-pressed state) of the shutter key 8 is performed, the system control unit 35 performs an automatic focusing process (autofocus process). That is, the imaging unit 31 is controlled to move the focus lens so as to focus on the focus area as a range defined by the AF frame displayed at this time in the subject image area and perform aperture control. Do. Specifically, the focus lens is sequentially moved at predetermined intervals within a predetermined movement range. A focus evaluation value is calculated based on the image in the focus area of the subject image at each movement position of the focus lens, and the subject image in the focus area is in focus from each obtained focus evaluation value The lens position is derived as the focus position, and the focus lens is moved to the derived focus position. When the automatic focusing process is completed, the focus lens is locked at the in-focus position and the process proceeds to step S10 (step S9). Although not shown, the through image is displayed even during the focusing operation.

  The system control unit 35 checks the signal from the operation unit 41 to determine whether or not the second operation (full-pressed state) of the shutter key 8 has been performed. If the shutter key 8 has been fully pressed, the process proceeds to step S11. Proceed (step S10).

  When the shutter key 8 is fully pressed, the imaging system including the imaging unit 31 and the image data processing unit 32 is immediately controlled at that time to perform imaging. In other words, the path from the image data processing unit 32 to the temporary storage memory 36 is immediately stopped at that time, and the switching to the imaging element driving method at the time of main photographing different from the through image acquisition is executed, and the recording unit 38 is controlled. Then, the image data is taken in and subjected to image compression processing, and an image file composed of the compressed data is recorded on the recording medium 39 (step S11).

  When the AF frame display change mode is selected by the operation shown in the flowchart of FIG. 5, the digital camera 100 captures an image focused on the focus area in the range defined by the fixed or rotated AF frame. can do. As a result, when the subject or the camera is tilted, the AF frame can be rotated to match the tilt of the subject or the camera. When the AF frame display change mode is not selected, an image focused on the focus area in the range defined by the AF frame displayed at the center of the liquid crystal screen 4 can be taken.

<Modification 1-1>
In the flowchart shown in FIG. 5, in the AF frame display change mode, during the through image display, the subject at the center of the camera is displayed as the main subject, and the AF frame is displayed when the user issues an AF frame rotation instruction. However, in addition to the rotation, when the user designates the face portion 64 of the subject 62 by a key operation as shown in FIG. 6A, the face is designated as shown in FIG. When the subject 62 is the main subject and the AF frame 63 on the subject 61 is moved to the designated portion 64 and displayed, and then the user issues a frame rotation instruction of the AF frame, as shown in FIG. The AF frame 63 can also be configured to rotate and display.

  FIG. 7 is a flowchart showing a modification of the AF frame display change control operation example (AF frame rotation control operation), in which step S6 in the flowchart of FIG. 5 is replaced by steps S6-1 to S6-3 below. .

  In FIG. 7, when the AF frame display change flag is on, the system control unit 35 checks the signal from the operation unit 41. If the AF frame display change flag is received, the system control unit 35 proceeds to step S6-2, but does not. In this case, the process proceeds to step S7 (step S6-1).

  If an AF frame movement instruction signal is received in step S6-1, the system control unit 35 controls the image display unit 37 to erase the AF frame displayed at the current position, and also receives the received movement instruction signal. The AF frame of a predetermined size is displayed at the position of the movement destination included in step S6-3, and the process proceeds to step S6-3 (step S6-2). The movement instruction signal is generated by, for example, pressing the cursor key 5 to operate upward (↑), downward (↓), left (←), or right (→) and release the press (that is, a finger from the cursor key 5). It is sent from the operation unit 41 to the system control unit 35 at the time of release, and includes coordinates on the screen at the position where the pressure is released. Further, the AF frame display at the destination may be such that the coordinates (X, Y) of the destination coincide with the center point of the AF frame, or the coordinates (X, Y) of the destination are at the four corners of the AF frame. You may make it correspond with either. In addition, as the movement technique of the AF frame, a known movement technique relating to the display figure can be used as appropriate.

  The system control unit 35 examines a signal from the operation unit 41, and when receiving a destination confirmation signal, proceeds to step S7 and rotates the displayed AF frame by a predetermined angle. If the destination confirmation signal has not been received, the process returns to step S6-2 (step S6-3). The movement destination determination signal is output when the SET key 6 is pressed when the movement instruction is performed by operating the cursor key 5, but other keys may be used for movement destination determination.

  When the AF frame display change mode is selected by the operation shown in the flowchart of FIG. 7, the digital camera 100 moves the AF frame to the subject designated by the user. An image focused on the focus area in the range defined by the AF frame when the half-press state is made can be taken. Further, after the AF frame is moved, if the user gives a frame rotation instruction, the AF frame is rotated in a predetermined direction, and then an image focused on the focus area in the range defined by the AF frame can be taken. it can. Thus, the user can designate a desired subject on the screen as the main subject and display the AF frame thereon without moving the camera so that the main subject is located at the center of the screen. Even when the main subject moves, the AF frame can be moved and displayed on the main subject without moving the camera.

<Modification 1-2>
In the flowcharts shown in FIG. 5 and FIG. 7, when the AF frame is displayed on the main subject during the through image display in the AF frame display change mode, and the user instructs the frame rotation of the AF frame by key operation, Although the frame is configured to rotate, as shown in FIGS. 9 and 10, the AF frame can also be configured to automatically rotate without any key operation.

  FIG. 8 is a block diagram showing an embodiment of the electrical configuration of a digital camera according to this modification. The external configuration of the digital camera 200 is the same as the external configuration of the digital camera 100 shown in FIG. Further, the electrical configuration of the digital camera 200 is a configuration in which an inclination detection unit 43 is added to the electrical configuration of the digital camera 100 shown in FIG. 2, and the electrical configuration and function of the frame rotation processing unit 42 are the same. The electrical configuration and function are the same.

  The tilt detection unit 43 includes, for example, a tilt sensor that detects the tilt angle of the camera, detects the tilt of the digital camera 100, and sends a detection result (angle information) to the control unit 25.

  FIG. 9 is an explanatory diagram showing an example of AF frame position adjustment by an AF frame automatic rotation control operation when the camera is tilted with respect to the ground surface, for example. FIG. 9A shows a subject 81 and an AF frame 82 displayed in the vicinity thereof when the camera is horizontal with respect to the ground surface. FIG. 9B shows the subject 81 and the AF frame 82 displayed on the vicinity thereof when the camera is tilted with respect to the ground surface, and FIG. 9C shows the position by the automatic rotation control operation of the AF frame. The adjusted AF frame 82 is shown. When the camera is horizontal with respect to the ground surface, the AF frame 82 is also displayed horizontally with respect to the liquid crystal screen 4 as shown in FIG. 9A, but when the camera is tilted with respect to the ground surface, FIG. As shown in b), the subject 81 remains on the ground surface, whereas the AF frame 82 follows the tilt of the camera, that is, follows the direction of the liquid crystal screen 4 to the ground surface. And tilted. As described above, when the relative positional relationship between the subject 81 and the camera changes, the relative positional relationship between the subject 81 and the AF frame 82 also changes. Therefore, by the automatic rotation control operation of the AF frame, as shown in FIG. 9C, when the camera is tilted with respect to the ground surface, the camera is tilted in the direction opposite to the ground surface, that is, the camera ground. The AF frame is automatically rotated by a tilt angle with respect to the ground surface of the camera in a direction that cancels the tilt with respect to the top surface. Thus, the relative positional relationship between the subject 81 and the AF frame 82 is returned to the relative positional relationship between the main subject 81 and the AF frame 82 when the camera is horizontal with respect to the ground surface.

  FIG. 10 is a flowchart showing a modification of the automatic rotation control operation of the AF frame. Steps S6 and S7 in the flowchart in FIG. 5 may be replaced by the following steps T1 and T2, and the steps in the flowchart in FIG. The following steps T1 and T2 are added as transition destinations when there is no AF frame movement instruction in step S6-1 between S6-3 and S7, or when the movement destination is not fixed in step S6-3. May be.

  Specifically, for example, when the AF frame display change flag is on in step S5, the system control unit 35 proceeds to step T2 upon receiving a tilt detection signal including camera tilt angle information from the tilt detection unit 43. If not, the automatic rotation control of the AF frame is terminated (step T1). That is, when the tilt detection unit 43 does not detect a tilt of the camera that is equal to or greater than a predetermined threshold, the process proceeds to, for example, step S8 in the flowchart of FIG.

  In step T1, when the tilt detection unit 43 detects a tilt of the camera that is equal to or greater than a predetermined threshold, the system control unit 35 sends a control signal to the frame rotation processing unit 42, and displays the displayed AF frame as a camera. Is rotated by the angle detected by the tilt detector 43 in the direction opposite to the tilted direction (step T2).

  As described above, when the AF frame display change mode is selected by replacing steps S6 and S7 in the flowchart of FIG. 5 with steps T1 and T2 of FIG. Thus, the AF frame is automatically rotated so as to maintain the relative positional relationship between the main subject and the AF frame, and an image focused on the focus area in the range defined by the AF frame can be taken. As a result, the user can capture an image without a hollow even when the camera is tilted. Therefore, for example, when performing a portrait shooting with a horizontally long camera rotated 90 °, there is no need to rotate the AF frame 90 ° by key operation. In particular, at this time, the relative positional relationship between the main subject and the AF frame. It is not necessary to detect the aspect ratio of the camera and display the AF frame widened vertically so that the main subject surely enters the AF frame even when the image is shifted. Similarly, when shooting a horizontally long camera with a vertically long LCD screen, it is not necessary to rotate the AF frame by 90 ° by key operation, and an AF frame that is widened by detecting the aspect ratio of the camera is not required. It does not have to be configured to display.

  Further, the AF frame automatic rotation control operation shown in the flowchart of FIG. 10 is added as a transition destination of step S5 between step S5 and step S6 of the flowchart of FIG. 5, or step S6- of the flowchart of FIG. By adding as a transition destination of step S6-1 or step S6-3 between step 3 and step S7, the AF frame that has been automatically rotated according to the tilt of the camera and adjusted in position is adjusted to the composition. It can be rotated manually or the main frame can be designated and the AF frame can be moved while maintaining the adjusted angle. In this case, whether to apply the AF frame position manually moved with priority or to apply the AF frame position moved by the AF frame automatic rotation control with priority can be set as appropriate. What is necessary is just to comprise.

(Embodiment 2)
In the first embodiment and the modified example thereof, an example in which the AF frame having a fixed shape is rotated or moved has been described. However, in the present embodiment, the AF frame is switched to another AF frame according to the shape of the subject. An example in which the image is displayed or the display size of the AF frame is enlarged or reduced will be described. Note that the external configuration of the digital camera 300 as an embodiment of the imaging apparatus according to the present invention may be the same as that of the digital camera 100 shown in FIG.

  FIG. 11 is a block diagram illustrating an example of the electrical configuration of the digital camera according to the present embodiment. The digital camera 300 includes an imaging unit 31, an image data processing unit 32, a frame expansion / contraction processing unit 33, and a system control unit. 35, a temporary storage memory 36, an image display unit 37, a recording unit 38, an external input / output unit 40, an operation unit 41, and a frame pattern registration memory 44. The imaging unit 31 and the image data processing unit 32 constitute an image acquisition unit of the present invention. The configurations and functions of the imaging unit 31 and the image data processing unit 32, the system control unit 35, the temporary storage memory 36, the image display unit 37, the recording unit 38, the external input / output unit 40, and the operation unit 41 are shown in FIG. The configuration and function are the same as those of the digital camera 100 shown, and a configuration in which a frame expansion / contraction processing unit 33 is added to the configuration of the digital camera 100 shown in FIG. Further, it has an autofocus function, a shooting function such as a still image shooting mode and a moving image shooting mode, and an AF frame display change mode based on the present invention that can be selected under these shooting functions.

  The frame expansion / contraction processing unit 33 performs AF frame reduction processing or enlargement processing based on a user key operation, for example, a frame expansion / contraction instruction by operating the cursor key 5, and sends the reduced or enlarged frame data to the image display unit 37. . The frame expansion / contraction processing unit 33 can also be configured to perform AF frame reduction processing or enlargement processing in proportion to the size of the subject, as will be described later (see Embodiment 3). A known image expansion / contraction technique can be used as appropriate for the frame expansion / contraction processing.

  The system control unit 35 functions as an in-focus position determining unit that determines an in-focus position, and also indicates a timing instruction unit that instructs the timing of AF frame display control based on a user key operation in the AF frame display change mode. Also, it functions as an AF frame display control means for controlling the display state of the AF frame displayed on the main subject. Specifically, a frame rotation control unit that controls the rotation processing unit 42 to rotate the AF frame, a frame switching control unit that performs a switching process of the AF frame displayed based on a predetermined frame switching instruction, and a predetermined It functions as a frame expansion / contraction control means for controlling the frame expansion / contraction processing unit 33 based on the frame expansion / contraction instruction to perform AF frame reduction processing or enlargement processing.

  The frame pattern registration memory 44 is a memory in which frame pattern data for frame patterns 44-1, 44-2, 44-3, 44-4 as shown in FIG. The frame pattern registration memory 44 may be a dedicated memory. For example, a predetermined area secured in a work memory such as a RAM of the system control unit 35 may be used as the frame pattern registration memory 44, or the temporary storage memory 36 may be used. A predetermined area secured in the above may be used as the frame pattern registration memory 44.

  FIG. 13 is a diagram showing an embodiment of the AF frame switching operation. In the illustrated example, an AF frame switching instruction is performed by the user operating the SET button 6 in the AF frame display change mode. FIG. 13A shows an AF frame 44-1 displayed on the subject 40 at the center of the screen during shooting standby, that is, when a through image is displayed. When the SET button 6 is pressed in this state, the displayed AF frame is switched, and the AF frame 44-2 is displayed on the subject 40 as shown in FIG. As described above, the AF frame is switched every time the SET button 6 is pressed, and the AF frames 44-3 to 44-5 are sequentially displayed on the subject 40 as shown in FIGS. 13 (c) to 13 (e). Thus, the user can display a desired AF frame on the subject 40 by operating the SET button 6.

  FIG. 14 is a diagram showing an embodiment of the frame expansion / contraction operation. In the illustrated example, a frame expansion / contraction instruction is performed by the user operating the cursor key 5 in the AF frame display change mode. FIG. 14A shows an AF frame 44-5 selected by the user during shooting standby, that is, when a through image is displayed. In this state, when the key operation, for example, the cursor key 5 is operated upward (↑), the AF frame 44-5 is enlarged and displayed. When the cursor key 5 is operated downward (↓), the AF frame 44-5 is reduced and displayed. As described above, the AF frame 44-5 having a size corresponding to the size of the subject 40 can be displayed on the subject 40 as shown in FIG.

  FIG. 15 is a flowchart showing an example of an AF frame display control operation performed by the system control unit 35 according to the present embodiment, for explaining a program for causing the digital camera 300 to realize the AF frame selection / extension function of the present invention. Is. Hereinafter, a description will be given based on FIGS. 1 and 11 to 15.

  When the power key 9 of the digital camera 300 is on, when the user operates the mode dial 3 to select the shooting mode, the system control unit 35 controls the image display unit 37 to set the AF frame display change mode on the liquid crystal screen 4. When the user selects the AF frame display change mode, the AF frame display change flag is turned on and the process proceeds to step U2. Otherwise, the AF frame display change flag remains off and the process proceeds to step U2. (Step U1).

  Next, after performing various initial settings for shooting (step U2), the system control unit 35 extracts the frame pattern data stored at the head position of the frame pattern registration memory 44 and sends it to the image display unit 37. It is displayed at a predetermined position on the liquid crystal screen 4, for example, at the center (step U3).

  Next, the system control unit 35 controls the imaging unit 31 and the image data processing unit 32 to execute AE processing at a focal length corresponding to the zoom value at that time, and captures the subject light image captured via the photographing lens 1. The image data is obtained from the image data and is adjusted so that the white balance corresponding to the color of the light source is obtained by automatic white balance (AWB) processing, and image data for one frame is obtained at a predetermined cycle to temporarily store the memory 36. The display buffer of the image storage unit 37 is rewritten with the video through image data obtained by thinning the number of pixels from the image data fetched into the temporary storage memory 36 and the through image is displayed on the liquid crystal screen 4 (step U4).

  Further, the system control unit 35 checks the value of the AF frame display change flag. If the AF frame display change flag is on, the system control unit 35 proceeds to step U6. If the AF frame display change flag is off, the process proceeds to step U10 (step U5).

  If the frame display change flag is on in step U5, the system control unit 35 checks the signal from the operation unit 41. If an AF frame switching instruction signal is received, the system control unit 35 proceeds to step U7. If an AF frame expansion / contraction instruction signal is received, the process proceeds to step U8. If it is neither, the process proceeds to Step U10 (Step U6).

  The AF frame switching instruction signal is sent from the operation unit 41 to the system control unit 35 every time the user presses an AF frame switching instruction key, for example, the SET key 6 when the AF frame display change flag is on. The AF frame expansion / contraction instruction signal is sent from the operation unit 41 to the system control unit 35 every time the user presses an AF frame expansion / contraction instruction key, for example, the cursor key 6 when the AF frame display change flag is on.

  When the AF frame switching instruction signal is received at step U6, the system control unit 35 searches the frame pattern registration memory 44, extracts the frame pattern data stored at the next position in the frame pattern registration memory 44, and displays the image. The image is sent to the unit 37, displayed at a predetermined position (for example, the same position as the previous time) on the liquid crystal screen 4, and the process returns to Step U4 (Step U7).

  If an AF frame expansion / contraction instruction signal is received in step U6, the system control unit 35 sends an enlargement control signal or a reduction control signal to the frame expansion / contraction processing unit 33 based on the received AF frame expansion / contraction instruction signal. To generate pattern data obtained by enlarging or reducing the pattern data of the displayed AF frame at a predetermined ratio (for example, 10%) (step U8). Then, the generated frame pattern data is sent to the image display unit 37 for display, and the process returns to step U4 (step U9).

  The system control unit 35 checks the signal from the operation unit 41, and proceeds to step U11 if the shutter key 8 is half-pressed, and returns to step U4 if not pressed (step U10).

  When the first stage operation (half-pressed state) of the shutter key 8 is performed, the system control unit 35 performs an automatic focusing process (autofocus process). That is, the imaging unit 31 is controlled to move the focus lens so as to focus on the focus area as a range defined by the AF frame displayed at this time in the subject image area and perform aperture control. Do. Specifically, the focus lens is sequentially moved at predetermined intervals within a predetermined movement range. A focus evaluation value is calculated based on the image in the focus area of the subject image at each movement position of the focus lens, and the subject image in the focus area is in focus from each obtained focus evaluation value The lens position is derived as the focus position, and the focus lens is moved to the derived focus position. When the automatic focusing process ends, the focus lens is locked at the in-focus position, and the process proceeds to Step U12 (Step U11). Although not shown, the through image is displayed even during the focusing operation.

  The system control unit 35 checks the signal from the operation unit 41 to determine whether or not the shutter key 8 has been fully pressed. If the shutter key 8 has been fully pressed, the system control unit 35 proceeds to step U13 (step U12).

  When the shutter key 8 is fully pressed, the imaging system including the imaging unit 31 and the image data processing unit 32 is immediately controlled at that time to perform imaging. In other words, the path from the image data processing unit 32 to the temporary storage memory 36 is immediately stopped at that time, and the switching to the imaging element driving method at the time of main photographing different from the through image acquisition is executed, and the recording unit 38 is controlled. Then, the image data is taken in and subjected to image compression processing, and an image file composed of the compressed data is recorded on the recording medium 39 (step U13).

  When the AF frame display change mode is selected by the operation shown in the flowchart of FIG. 15, the user selects and displays an AF frame that matches the shape of the subject from the frame patterns registered in the memory by key operation. be able to. Also, the AF frame can be expanded and contracted according to the size of the subject. In the example of the flowchart, the frame pattern is switched and the desired AF frame is selected every time the user presses the AF frame switching instruction key in Step U6 and Step U7. However, the menu display key, for example, the menu key 10 is pressed. When pressed, the window may be opened to display a list of frame patterns, and the user may select a desired frame pattern from the frame patterns displayed as a list by key operation.

<Modification 2-1>
In the example shown in the flowchart of FIG. 15, the AF frame is displayed at a predetermined position (for example, the center of the screen). However, the display position of the AF frame is not fixed, and the subject to be focused, that is, the position of the main subject. It can also be comprised so that it can move to.

  FIG. 16 is a flowchart showing a modification of the AF frame movement control operation in the AF frame display change mode, in which step U4 in FIG. 15 is replaced by the following steps U4-1 to U4-4.

  In FIG. 16, the system control unit 35 controls the imaging unit 31 and the image data processing unit 32 to execute the AE process at a focal length corresponding to the zoom value at that time, and captures the subject light captured via the photographing lens 1. After obtaining image data from the image and adjusting the white balance corresponding to the color of the light source by automatic white balance (AWB) processing, image data for one frame is obtained at a predetermined cycle and temporarily stored in memory. The display buffer of the image storage unit 37 is rewritten with the video through image data obtained by DMA transfer to 36 and the number of pixels is thinned out from the image data taken into the temporary storage memory 36 to display the through image on the liquid crystal screen 4 (step U4- 1).

  The system control unit 35 examines the signal from the operation unit 41, and proceeds to step U4-2 if an AF frame movement instruction signal is received, otherwise proceeds to step U5 (step U4-2).

  In step U4-2, when the AF frame movement instruction signal is received, the system control unit 35 controls the image display unit 37 to delete the AF frame displayed at the current position, and the received movement instruction signal is received. An AF frame of a predetermined size is displayed at the coordinates (X, Y) of the included movement destination, and the process proceeds to step U4-4 (step U4-3). The movement instruction signal is generated by, for example, pressing the cursor key 5 to operate upward (↑), downward (↓), left (←), or right (→) and release the press (that is, a finger from the cursor key 5). It is sent from the operation unit 41 to the system control unit 35 at the time of release, and includes coordinates on the screen at the position where the pressure is released. Further, the AF frame display at the destination may be such that the coordinates (X, Y) of the destination coincide with the center point of the AF frame, or the coordinates (X, Y) of the destination are at the four corners of the AF frame. You may make it correspond with either.

  The system control unit 35 examines the signal from the operation unit 41. If the destination determination signal is received, the system control unit 35 proceeds to step U5, and otherwise returns to step U4-3 (step U4-4). The movement destination determination signal is output when the SET key 6 is pressed when the movement instruction is performed by operating the cursor key 5, but other keys may be used for movement destination determination.

  With the operation shown in the flowchart of FIG. 16, after displaying the through image, the user moves the AF frame displayed at a predetermined position (for example, the center of the screen) to the main subject by key operation, and then switches the AF frame. Since the AF frame corresponding to the main subject can be displayed by adjusting the size and size of the main subject by the AF expansion / contraction processing, even if the main subject is displayed at the corner of the liquid crystal screen 4, the main subject is displayed on the liquid crystal screen 4. There is no need to change the composition so that it is displayed in the center.

(Embodiment 3)
In the first embodiment, the second embodiment, and the modifications thereof, the AF frame is rotated and / or moved by a manual operation, that is, a user's key operation (first embodiment), AF frame display switching and / or Although the AF frame expansion / contraction and the AF frame movement are performed, it is also possible to configure such that these processes are automatically performed by a recognition process instead of manually. In the following description, the external configuration of the digital camera 400 is described as being the same as that of the digital camera 100 of FIG.

  FIG. 17 is a block diagram illustrating an example of the electrical configuration of the digital camera 400 according to the present embodiment. In the digital camera 400, the imaging unit 31, the image data processing unit 32, the frame expansion / contraction processing unit 33, and system control are illustrated. The configuration and functions of the unit 35, temporary storage memory 36, image display unit 37, recording unit 38, external input / output unit 40, operation unit 41, and frame pattern registration memory 44 are the electrical configuration of the digital camera 300 shown in FIG. The contour extraction unit 34 and the frame rotation processing unit 42 are added to the digital camera 300 shown in FIG. The imaging unit 31 and the image data processing unit 32 constitute an image acquisition unit of the present invention. Further, it has an autofocus function, a shooting function such as a still image shooting mode and a moving image shooting mode, and an automatic AF frame display change mode based on the present invention that can be selected under those shooting functions. In this embodiment, the contour extracting unit 34 is provided as the subject recognizing unit. However, the subject recognizing unit is not limited to the contour extracting unit 34, and extracts the features of the subject and the expansion / contraction rate, inclination, and position information (coordinates). ) Can be used.

  The contour extraction unit 34 extracts the contour of the designated subject from the frame image, generates contour data obtained by normalizing the size and contour, and then the feature (subject feature), the contour before normalization, and the normalized contour The size ratio with the contour (that is, the expansion / contraction ratio), the inclination (angle), the position information (coordinates), and the like are output. The contour extraction processing by the contour extraction unit 34 can use a known contour extraction technique as appropriate. For example, the contour can be normalized by processing such as enlargement or reduction, tilt angle adjustment, rotation, and the like of the contour of the face portion, the orientation and size of the face and body. As features, for example, normalized body shape, aspect ratio of the face, shoulder width, position and interval between both banks, position and size of nose and mouth, and the like can be extracted or registered. For example, determination of feature coincidence / disagreement is performed by obtaining a distance (root mean square) from the difference between the feature of each frame pattern data registered in the frame pattern registration memory 44 and the feature of the detected contour, and the distance is equal to or less than a predetermined threshold value. In this case, it can be determined that there is a match, and if it is less than the predetermined threshold value, it can be determined that there is a mismatch. A dedicated circuit may be provided for the contour feature extraction processing, or the system control unit 35 may execute a feature extraction program.

  The frame rotation processing unit 42 purifies AF frame data obtained by rotating the AF frame displayed on the liquid crystal screen 4 to the left and right by a predetermined angle based on a frame rotation instruction under the control of the system control unit 35, and the image display unit 37. To send. As a method for rotating the AF frame displayed on the liquid crystal screen 4, a known rotation technique related to the display figure can be used as appropriate.

  The system control unit 35 functions as an in-focus position determining unit that determines an in-focus position, and also indicates a timing instruction unit that instructs the timing of AF frame display control based on a user key operation in the AF frame display change mode. Also, it functions as an AF frame display control means for controlling the display state of the AF frame displayed on the main subject. Specifically, a frame rotation control unit that controls the frame rotation processing unit 42 to rotate the AF frame, and controls the frame expansion / contraction processing unit 33 based on a predetermined frame expansion / contraction instruction to perform AF frame reduction processing or enlargement processing. The frame expansion / contraction control means to be performed and the contour extraction unit 34 are controlled to extract the contour of the subject and to function as subject recognition control means for outputting subject characteristics and expansion / contraction ratio), inclination, and position information.

  FIG. 18 is a flowchart showing an example of AF frame display control operation by subject recognition according to the present embodiment, for explaining a program for causing the digital camera 100 to realize the AF frame selection / extension function of the present invention. It is. In the following, description will be given based on FIG. 1, FIG. 17, and FIG.

  When the power key 9 of the digital camera 400 is on, when the user operates the mode dial 3 to select the shooting mode, the system control unit 35 controls the image display unit 37 to display the automatic AF frame display change mode on the liquid crystal screen 4. Displays a selection menu containing. When the user selects the AF frame display change mode, the AF frame display change flag is turned on and the process proceeds to step V2. If the AF frame display change flag is off, the AF frame display change flag remains off and the process proceeds to step V2 (step V1).

  Next, after performing various initial settings for shooting (step V2), the system control unit 35 controls the imaging unit 31 and the image data processing unit 32 to perform AE processing at a focal length corresponding to the zoom value at that time. The image data is obtained from the subject light image captured through the photographing lens 1 and adjusted to a white balance corresponding to the color of the light source by automatic white balance (AWB) processing, and then a predetermined value is obtained. Image data for one frame is obtained in a cycle and DMA-transferred to the temporary storage memory 36, and the display buffer of the image storage unit 37 is rewritten with video-through image data obtained by thinning out the number of pixels from the image data captured in the temporary storage memory 36. The through image is displayed on the liquid crystal screen 4 (step V3).

  The system control unit 35 checks the value of the AF frame display change flag. If the AF frame display change flag is on, the system control unit 35 proceeds to step V5. If the AF frame display change flag is off, the system control unit 35 proceeds to step V12 (step V4).

  Next, the system control unit 35 displays a message prompting the user to specify the main subject on a part of the screen displayed through (for example, the top row), for example, “When the subject to be focused is specified, a focusing frame is displayed. When the user designates the main subject by a key operation, the process proceeds to Step V6. When the main subject is not designated, the AF of a predetermined shape on the liquid crystal screen 4, for example, the center is designated. The frame is displayed and the process proceeds to Step V12 (Step V5). The main subject can be specified, for example, by pressing the SET button 6 after the user moves the cursor displayed on the liquid crystal screen 4 with the cursor key 5 and positions the cursor on the desired subject. In addition, when the subject is designated, the operation unit 41 sends main subject designation information including position information of the designated subject to the system control unit 35. When the SET button 6 is pressed, the message is deleted.

  When the main subject is designated, the system control unit 35 sends control data including the position information of the subject to the contour extraction unit 34 to extract the contour of the designated subject, and the normalized contour feature (contour feature) Then, the expansion / contraction ratio at the time of normalization, the inclination (angle) of the contour before normalization, and position information (for example, the center coordinates of the face portion) are acquired and stored in a memory (for example, RAM) (step V6).

  Next, the system control unit 35 sequentially searches the frame pattern registration memory 44 and compares the outline features acquired in step V5 with the frame pattern features registered in the frame pattern registration memory 44 (step V7). Are extracted from the frame pattern registration memory 44 (step V8).

  The system control unit 35 sends the control signal including the expansion / contraction rate acquired in step V5 to the frame expansion / contraction processing unit 33 to perform the expansion / contraction processing of the frame pattern extracted in step V6 (step V9).

  The system control unit 35 sends a control signal including the inclination information (angle) of the contour before normalization acquired in step V5 to the frame rotation processing unit 42 to rotate the AF frame to match the inclination of the subject. The frame pattern data is generated (step V10), and the frame pattern data is sent to the image display unit 37 to be superimposed and displayed on the designated subject (step V11).

  The system control unit 35 checks the signal from the operation unit 41, and proceeds to step V13 if the shutter key 8 is half-pressed, and returns to step V4 if it is not half-pressed (step V12).

  When the first stage operation (half-pressed state) of the shutter key 8 is performed, the system control unit 35 performs an automatic focusing process (autofocus process). That is, the imaging unit 31 is controlled to move the focus lens so as to focus on the focus area as a range defined by the AF frame displayed at this time in the subject image area and perform aperture control. Do. Specifically, the focus lens is sequentially moved at predetermined intervals within a predetermined movement range. A focus evaluation value is calculated based on the image in the focus area of the subject image at each movement position of the focus lens, and the subject image in the focus area is in focus from each obtained focus evaluation value The lens position is derived as the focus position, and the focus lens is moved to the derived focus position. When the automatic focusing process is completed, the focus lens is locked at the in-focus position, and the process proceeds to Step V14 (Step V13). Although not shown, the through image is displayed even during the focusing operation.

  The system control unit 35 checks the signal from the operation unit 41 to determine whether or not the shutter key 8 has been fully pressed. If the shutter key 8 has been fully pressed, the system control unit 35 proceeds to step V15 (step V14).

  When the shutter key 8 is fully pressed, the imaging system including the imaging unit 31 and the image data processing unit 32 is immediately controlled at that time to perform imaging. In other words, the path from the image data processing unit 32 to the temporary storage memory 36 is immediately stopped at that time, and the switching to the imaging element driving method at the time of main photographing different from the through image acquisition is executed, and the recording unit 38 is controlled. Then, the image data is taken in and subjected to image compression processing, and an image file composed of the compressed data is recorded on the recording medium 39 (step V15).

  When the AF frame display change mode is selected by the operation shown in the flowchart of FIG. 18, the user simply specifies the main subject and displays the AF frame that matches the shape and size of the subject on the designated subject. , Can be focused.

(Embodiment 4)
In the third embodiment, the AF frame can be displayed on the main subject. However, if the main subject moves or the composition of the camera is changed, the AF frame and the main subject will be shifted unless the main subject is designated again. The main subject may be blurred. Therefore, an example of the digital camera 500 that once displays the AF frame following the movement of the main subject (or the apparent movement of the subject when the camera moves) will be described. In the following description, the external configuration of the digital camera 500 is the same as that of the digital camera 100 of FIG. 1, and the electrical configuration is the same as that of the digital camera 400 of FIG.

  FIG. 19 is a flowchart showing an example of an AF frame display control operation performed by the system control unit 35 according to this embodiment. The program (or subprogram) for causing the digital camera 500 to realize the AF frame tracking function by subject recognition according to the present invention. ), Step V12 in the flowchart shown in FIG. 18 is replaced by steps V12-1 to V12-9 below. Hereinafter, a description will be given based on FIGS. 1, 17, 18, and 19.

  The system control unit 35 superimposes the frame pattern data on the designated subject in step V11 in FIG. 18, and then checks the signal from the operation unit 41. If the shutter key 8 is not half-pressed, the system control unit 35 performs step V12-. Go to step 2 (step V12-1). If the shutter key 8 is half-pressed, the process proceeds to step V13 in FIG. 18 to start the automatic focusing process.

  When the shutter key is not half-pressed, the system control unit 35 controls the contour extraction unit 34 at a predetermined time interval (for example, 0.3 second interval), and the contour of the subject from the frame image corresponding to the through-displayed image. Are extracted, and the normalized feature (contour feature) of each subject, the inclination (angle) of the contour before normalization, and position information (for example, the center coordinates of the face portion) are acquired (step V12-2). ). In step V12-2, contour extraction may be performed for each frame. However, by performing contour extraction at predetermined time intervals, the load on the CPU can be reduced.

  Next, the system control unit 35 sequentially compares the normalized contour characteristics of the main subject acquired last time with the contour characteristics of each subject acquired in this step 12-2 (step V12-3), and this time step 12-. Among the contour features of each subject acquired in step 2, the subject having the contour feature having the highest similarity to the contour feature of the previous main subject is set as the current main subject. Then, the expansion rate, inclination, and position information of the subject are acquired (step V12-4).

  Next, the system control unit 35 takes out the frame pattern data of the AF frame currently displayed from the frame pattern registration memory 44 (step V12-4). Then, the control signal including the expansion / contraction rate of the current main subject acquired in step V12-4 is sent to the frame expansion / contraction processing unit 33 to perform the expansion processing of the frame pattern extracted in step V12-5 (step V12-6). .

  Further, the system control unit 35 sends a control signal including the current main subject tilt information (angle) acquired in step V12-2 to the frame rotation processing unit 42 to match the AF frame tilt with the subject tilt. The frame pattern data rotated in this way is generated (step V12-7), and the frame pattern data and the current position information of the main subject are sent to the image display unit 37 and displayed superimposed on the designated subject (step V12-). 8).

  Next, the system control unit 35 controls the imaging unit 31 and the image data processing unit 32 to execute AE processing at a focal length corresponding to the zoom value at that time, and captures the subject light image captured via the photographing lens 1. The image data is obtained from the image data and is adjusted so that the white balance corresponding to the color of the light source is obtained by automatic white balance (AWB) processing, and image data for one frame is obtained at a predetermined cycle to temporarily store the memory 36. The display buffer of the image storage unit 37 is rewritten with the video through image data obtained by thinning the number of pixels from the image data fetched into the temporary storage memory 36, and the through image is displayed on the liquid crystal screen 4, step V12-1 (Step V12-9).

  When the AF frame display change mode is selected by the operation shown in the flowchart of FIG. 19, if the user designates the main subject once, the AF frame moves following the movement of the subject when the user moves. Therefore, even if the main subject moves, the user does not have to operate the key to move the AF frame onto the main subject, or move the camera to superimpose the AF frame on the main subject. .

  If the electrical configuration of the digital camera 100 or the digital camera 200 is the same as that of the digital camera 500 shown in FIG. 17, the AF frame tracking function described above is applied to the first and second embodiments. Can do. To apply this AF frame tracking function to the first embodiment, for example, step S8 in FIG. 5 may be replaced with steps V12-1 to V12-9 shown in FIG. For example, step U10 in FIG. 15 may be replaced with steps V12-1 to V12-9 shown in FIG.

  In the description of each of the above embodiments, the processing shown in the flowcharts of FIGS. 5, 7, 10, 15, 16, 18, and 19 is performed by the system control unit 35 in advance using a program memory such as a flash memory. However, it is not necessary to store all the functions in the program memory. If necessary, a part or all of the functions may be received via the network. It may be.

  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. The term “imaging device” is not limited to a digital camera, but includes a device provided with means for taking an image via an imaging device, such as a mobile phone with a camera.

1 is a diagram illustrating an external appearance of a digital camera as an embodiment of an imaging apparatus according to the present invention. 2 is a block diagram illustrating an example of an electrical configuration of the digital camera according to Embodiment 1. FIG. It is a figure which shows one Example of the AF frame which rotates. It is a figure which shows one Example of AF frame rotation operation. 6 is a flowchart illustrating an AF frame change display control operation example (AF frame rotation control operation) by the system control unit according to the first embodiment. It is a figure which shows one Example of AF frame movement operation. 10 is a flowchart illustrating a modification of an AF frame change display control operation example (AF frame movement control operation) according to the first embodiment. 6 is a block diagram illustrating an example of an electrical configuration of a digital camera according to a modification of the first embodiment. FIG. It is explanatory drawing which shows the example of position adjustment of the AF frame by the automatic rotation control operation of the AF frame when the camera is tilted. 7 is a flowchart illustrating a modification (AF frame movement control operation) of the automatic rotation control operation of the AF frame according to the first embodiment. 10 is a block diagram illustrating an example of an electrical configuration of a digital camera according to Embodiment 2. FIG. It is a figure which shows one Example of AF frame pattern. It is a figure which shows one Example of AF frame switching operation. It is a figure which shows one Example of AF frame expansion-contraction operation. 10 is a flowchart illustrating an example of an AF frame display control operation according to the second embodiment. 10 is a flowchart showing a modification (AF frame movement control) of the AF frame display control operation according to the second embodiment. 10 is a block diagram illustrating an example of an electrical configuration of a digital camera according to Embodiment 3. FIG. 14 is a flowchart illustrating an AF frame display control operation example based on subject recognition according to the third embodiment. 10 is a flowchart showing an AF frame display control operation (AF frame tracking control operation by subject recognition) according to the fourth embodiment.

Explanation of symbols

1 Imaging lens 31 Imaging unit
32 Image data processor
33 Frame expansion / contraction processing unit 34 Contour extraction unit
35 System controller
37 Image display
38 Recording section
41 Operation unit
42 Frame rotation processing unit 43 Tilt detection unit
44 Frame pattern registration memory 100, 200, 300 Digital camera

Claims (14)

An image acquisition unit that obtains an image from a subject light image via an imaging device;
An image display unit for displaying an image obtained by the image acquisition unit;
Focus frame display control means for superimposing and displaying a focus frame for focusing on the image displayed on the image display unit;
A focus control unit that drives and controls a focus lens so that an image in the focus frame is focused;
An input means for inputting a predetermined instruction;
Timing instruction means for instructing a predetermined timing;
Focus frame generation means for generating the state of the focus frame in a changeable manner,
The focus frame generation unit changes the state of the focus frame based on an instruction via the input unit,
The focus frame display control unit displays the focus frame generated by the focus frame generation unit on the image display unit,
The focus control unit drives and controls the focus lens so that an image within the focus frame displayed on the image display unit is in focus at a predetermined timing instructed by the timing instruction unit. An imaging device.   The imaging apparatus according to claim 1, wherein the focus frame generation unit rotates the focus frame based on an instruction via the input unit. The focus frame generation means includes a frame pattern registration memory in which a focus frame pattern is registered in advance.
2. The imaging apparatus according to claim 1, wherein the focus frame currently selected is replaced with a new focus frame pattern read from the frame pattern registration memory based on an instruction via the input unit.   The imaging apparatus according to claim 1, wherein the focus frame generation unit expands / contracts the size of the focus frame based on an instruction via the input unit.   The imaging apparatus according to claim 1, wherein the focus frame display control unit moves and displays the focus frame at a predetermined position of the image display unit based on an instruction via the input unit. An image acquisition unit that obtains an image from a subject light image via an imaging device;
An image display unit for displaying an image obtained by the image acquisition unit;
Focus frame display control means for superimposing and displaying a focus frame for focusing on the image displayed on the image display unit;
A focus control unit that drives and controls a focus lens so that an image in the focus frame is focused;
Image recognition processing means for recognizing and recognizing a predetermined subject shape in the image;
Timing instruction means for instructing a predetermined timing;
Focus frame generation means for generating the state of the focus frame in a changeable manner,
The focus frame generation means determines the state of the focus frame based on the subject shape identified and recognized by the image recognition processing means,
The focus frame display control unit displays the focus frame generated by the focus frame generation unit on the image display unit,
The focus control unit drives and controls the focus lens so that an image within the focus frame displayed on the image display unit is in focus at a predetermined timing instructed by the timing instruction unit. An imaging device. Instructing means for selecting and instructing a predetermined subject in the image,
The imaging apparatus according to claim 6, wherein the image recognition processing unit identifies and recognizes the shape of the subject selected and instructed by the instruction unit.   8. The focus frame display control unit superimposes and displays the focus frame generated by the focus frame generation unit on the subject identified and recognized by the image recognition processing unit. Imaging device.   9. The imaging apparatus according to claim 8, wherein the focus frame display control unit displays the subject shape and the focus frame so as to coincide with each other. The image display unit sequentially updates and displays the images obtained by the image acquisition unit every time an image is obtained by the image acquisition unit,
The image recognition processing means identifies and recognizes a predetermined subject shape in the image to be updated and displayed,
The focus frame generation unit generates a new focus frame based on the subject shape so as to correspond to the newly identified and recognized subject shape every time the subject shape is identified and recognized by the image recognition processing unit. ,
The imaging apparatus according to claim 6, wherein the focus frame display control unit updates and displays the focus frame every time a new focus frame is generated by the focus frame generation unit. . An image display step for displaying an image obtained from the subject light image via the imaging device;
A focus frame display step of superimposing and displaying a focus frame for focusing on the image;
A focus control method comprising a focus control step of driving and controlling a focus lens so that an image in the focus frame is in focus,
An input process for inputting predetermined instructions;
A timing instruction step for instructing a predetermined timing;
A focus frame generation step for generating the focus frame in a changeable manner, and
The focus frame generation step changes the state of the focus frame based on a predetermined instruction by the input step,
The focus frame display control step superimposes and displays the focus frame generated by the focus frame generation step on the image,
In the focus control step, the focus lens is driven and controlled so that an image in a focus frame displayed at a predetermined timing instructed by the timing instruction step is in focus. . An image display step for displaying an image obtained from the subject light image via the imaging device;
A focus frame display step of superimposing and displaying a focus frame for focusing on the image;
A focus control method comprising a focus control step of driving and controlling a focus lens so that an image in the focus frame is in focus,
An image recognition processing step for recognizing and recognizing a predetermined subject shape in the image;
A timing instruction step for instructing a predetermined timing;
A focus frame generation step for generating the state of the focus frame in a changeable manner, and the focus frame generation step determines the state of the focus frame based on the subject shape identified and recognized by the image recognition processing means,
The focus frame display control step superimposes and displays the focus frame generated by the focus frame generation step on the image,
In the focus control step, the focus lens is driven and controlled so that an image in a focus frame displayed at a predetermined timing instructed by the timing instruction step is in focus. . On the computer,
Image display control means for displaying an image obtained from the subject light image via the image sensor,
Focus frame display control means for superimposing and displaying a focus frame for focusing on the image;
A focus control program for functioning as focus control means for driving and controlling a focus lens so that an image in the focus frame is focused;
An input means for inputting a predetermined instruction;
Timing instruction means for instructing a predetermined timing;
Function as focus frame generation means for generating the state of the focus frame in a changeable manner;
The focus frame generation unit changes the state of the focus frame based on an instruction input by the input unit,
The focus frame display control means superimposes and displays the focus frame generated by the focus frame generation means on the image,
The focus control unit drives and controls the focus lens so that an image within the focus frame displayed on the image display unit is in focus at a predetermined timing instructed by the timing instruction unit. Focus control program. On the computer,
Image display control means for displaying an image obtained from the subject light image via the image sensor,
Focus frame display control means for superimposing and displaying a focus frame for focusing on the image;
A focus control program for functioning as focus control means for driving and controlling a focus lens so that an image in the focus frame is focused;
Image recognition processing means for recognizing and recognizing a predetermined subject shape in the image;
Timing instruction means for instructing a predetermined timing;
Function as focus frame generation means for generating the state of the focus frame in a changeable manner;
The focus frame generation means determines the state of the focus frame based on the subject shape identified and recognized by the image recognition processing means,
The focus frame display control means displays the focus frame generated by the focus frame generation means on the image display unit,
The focus control unit drives and controls the focus lens so that an image within the focus frame displayed on the image display unit is in focus at a predetermined timing instructed by the timing instruction unit. Focus control program.

Images