JPH1125263A - Object feature point detector, focus adjusting device, exposure controller and camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a feature point of an object which is needed to perform optimum processing of various objects by having a feature part detecting means which detects a feature part of an object area detected by an object area detecting means, based on the contour shape of the object area. SOLUTION: In an object feature point checking device, a distance distribution measuring means 51 measures a distance distribution in an image. An object area detecting means 52 detects an area where an object exists from a distance distribution acquired by the means 51. A characteristic discriminating means 53 detects a feature part of an object area detected by the means 52 based on the contour shape of the object area. In this configuration, a feature point of the object area is detected, e.g. from the contour shape of an object area, the distance distribution of an object or the distance distribution and contour of the object area based on a actual side of the object.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object feature point detecting device for detecting a feature point of an object on a screen, a focus adjusting device for focusing on an object or a main object, and an exposure device for exposing an object or a main object. And to an improvement in a camera.

[0002]

2. Description of the Related Art A technique for optically measuring the distance to an object existing in a plurality of directions has been disclosed by the present applicant in Japanese Patent Publication No. 4-67.
No. 607. This is a technique in which, after obtaining distance distribution information of an object present in an object scene, an area where the main subject exists in the object scene is estimated based on the distance distribution information of the object.

A typical method of estimating a main subject area, which has been conventionally performed, will be described.

The scene of FIG. 18A is photographed by a stereo camera using a CCD or the like. Two images with parallax obtained by a stereo camera are referred to as “m
Xn blocks. When a well-known correlation operation is performed between a signal in one block of one image and a signal in a corresponding block captured by the other camera, the distance and data to an object in the previous block are calculated according to the principle of triangulation. Focus can be measured. By performing this measurement for all blocks, distance distribution information including “m × n” blocks as shown in FIG. 18B is obtained.

[0005] Next, region division (grouping) is performed to separate each object constituting the scene on the screen. When the grouping is performed, the object space composed of the aforementioned “m × n” blocks is divided into regions for each object as shown in FIG. (The shaded area in the figure is an area where the reliability of the correlation operation result is determined to be low due to insufficient contrast of the image signal, etc.) As a method of area division (grouping), the blocks constituting the object space and There is a method of comparing the similarity between two parameters related to a block adjacent thereto, and discriminating the same object if the similarity is high and the different object if the similarity is low. Information used as the parameter,
In the case where dense distance distribution data is obtained, it is often a normal vector of a surface, and in the case of relatively rough distance distribution data as in this conventional example, a distance value or a defocus value is simply used. .

For example, with respect to the distance information of each block in FIG. 18B, the distance information of two adjacent blocks is compared. If the difference between the distances is within a predetermined threshold value, the "two blocks" Are determined to form the same object ", and if the distance difference is greater than a predetermined threshold, it is determined that" the objects forming the two blocks are different objects ". By performing the above-described determination between all blocks and blocks adjacent to each other, the entire screen can be divided into regions for each object, and each divided region is treated as a group representing one object be able to.

Next, the characteristics of each region (each group) constituting the photographing space are evaluated, and a group representing the main subject is determined from all the groups.

For example, in the case of FIG.
For each of the groups 7, characteristics such as an average distance, an area width, a height, and a position on a screen are respectively calculated, and comprehensive evaluation is performed to determine an area considered as a main subject.

For example, a main subject degree evaluation function as shown in the following equation (1) can be considered.

(Main subject degree) = W ₁ × (width) × (height) + W ₂ / (distance from center on screen) + W ₃ (average distance) (1) In the above equation (1), W ₁ , W ₂ and W ₃ are weighting constants, the distance from the center of the screen is the distance between the center of the screen and the position of the center of gravity of the area, and the average distance represents the average distance of all blocks in the area. The main subject degree is calculated for all areas, and the subject having the highest main subject degree is determined as the main subject.

After one focus adjustment distance is determined based on the distance information in the main subject area so as to focus on the next area determined as the main subject, the lens is driven to focus.

[0012]

In the conventional focus adjusting device, one discriminant algorithm is used when one focal length is determined based on distance information in the main subject area.
For example, it is an algorithm for selecting a closest ranging point in the main subject area.

However, there are various main objects, and the position to be focused is different depending on the object. For example, when the main subject is a human, it is desirable to focus on the face, that is, on the upper part of the main subject area, and when the main subject is a car, it is desirable to focus on the center of the main subject area.

However, in the conventional method, since the focus adjustment distance is determined by one algorithm, it is not always possible to appropriately perform focus adjustment on any subject.

(Object of the Invention) A first object of the present invention is to detect a feature point of an object which can detect feature points of the object, which is necessary for performing optimal processing on various objects. It is intended to provide a device.

A second object of the present invention is to provide a focus adjustment device and a camera capable of performing appropriate focus adjustment on various objects and main subjects.

A third object of the present invention is to provide an exposure control apparatus and a camera capable of performing appropriate exposure control on various objects and main subjects.

[0018]

In order to achieve the first object, according to the present invention, there is provided a distance distribution measuring means for measuring a distance distribution in a screen, and the distance distribution measuring means. In an object feature point detection device having an object area detection means for detecting an area where the object is present from the distance distribution obtained by the feature portion of the object area detected by the object area detection means, An object feature point detecting device having a characteristic portion detecting means for detecting based on a contour shape of the object region.

In the above configuration, for example, the characteristic points of the object area are determined based on the actual shape of the object based on the contour shape of the object area, the distance distribution of the object, or the distance distribution and the outline of the object area. I try to detect.

In order to achieve the second object,
According to a fourth aspect of the present invention, there is provided a distance distribution measuring unit for measuring a distance distribution or a defocus distribution in a screen, and an object for detecting an area where the object is present from the distance distribution obtained by the distance distribution measuring unit. Area detection means, and has a characteristic determination means for determining the characteristics of the target object area detected by the target object area detection means, based on the output result of the characteristic determination means, from the distance distribution information of the target object area The focus adjustment device has an algorithm for determining a final focus adjustment distance.

According to another aspect of the present invention, there is provided a distance distribution measuring means for measuring a distance distribution or a defocus distribution in a screen.
Main subject area detection means for detecting an area where the main subject is present from the distance distribution obtained by the distance distribution measurement means,
Characteristic determining means for determining characteristics of the main subject area detected by the main subject area detecting means, and based on an output result of the characteristic determining means, a final focus adjustment distance is obtained from distance distribution information of the main subject area. Is a focus adjusting device having an algorithm for determining

In the above configuration, according to each characteristic of the object region such as the main subject, that is, the contour shape of the object region,
According to the distance distribution of the object area or the actual size of the object from the distance distribution and the contour of the object area, an algorithm for determining the focus adjustment distance is selected from a plurality of algorithms.

In order to achieve the third object,
According to another aspect of the present invention, there is provided a distance distribution measuring means for measuring a distance distribution in a screen, and a main subject area detection for detecting an area where a main subject is present from the distance distribution obtained by the distance distribution measuring means. Means, photometric value determining means for determining one photometric value from the distance distribution information in the main subject area measured by the distance distribution measuring means, and exposure control means for performing exposure control based on the determined photometric value. An algorithm storage means storing a plurality of algorithms for determining one photometric value from the distance distribution information of the main subject area in advance, and a main subject area detected by the main subject area detection means. Characteristic determining means for determining the characteristic of the image data. The photometric value determining means stores the measured value in the algorithm storage means based on the determination result of the characteristic determining means. It is an exposure control device for determining a photometric value used by the exposure control to select one algorithm from among a plurality of algorithms.

In the above configuration, the actual size of the subject is determined according to the characteristics of the main subject area, that is, the contour shape of the main subject area, the distance distribution of the main subject area, or the distance distribution and the contour of the main subject area. , A photometric value determination algorithm used for exposure control is selected from among a plurality of algorithms.

In order to achieve the second object,
According to the present invention, a distance distribution measuring means for measuring a distance distribution or a defocus distribution in a screen, and an area where a main subject is present is detected from the distance distribution obtained by the distance distribution measuring means. A main subject region detection unit, a focus adjustment distance determination unit that determines one focus adjustment distance from the distance distribution information in the main subject region measured by the distance distribution measurement unit, and a determined focus adjustment distance. In a camera having a lens driving unit that performs focus adjustment by driving a lens, the focus adjustment distance determination unit is one of a plurality of focus adjustment distance determination algorithms according to a setting state of the camera at the time of shooting. A camera is characterized in that an algorithm is selected to determine a focus adjustment distance used for focus adjustment.

In the above arrangement, a plurality of focus adjustments are made according to the detection result of the attitude detecting means for detecting the attitude (vertical position, horizontal position) of the camera, or according to the photographing mode detected by the photographing mode detecting means. One of the algorithms for determining the distance is selected to determine the focus adjustment distance.

In order to achieve the third object,
According to the present invention, there is provided a distance distribution measuring means for measuring a distance distribution in a screen, and a main subject area detection for detecting a region where a main subject is present from the distance distribution obtained by the distance distribution measuring means. Means, photometric value determining means for determining one photometric value from the distance distribution information in the main subject area measured by the distance distribution measuring means, and exposure control means for performing exposure control based on the determined photometric value. Wherein the photometric value determining means selects one of a plurality of photometric value determining algorithms from among a plurality of photometric value determining algorithms and determines a photometric value to be used for exposure control, according to a setting state of the camera at the time of photographing. A camera.

In the above configuration, a plurality of photometric values can be set according to the detection result of the attitude detecting means for detecting the attitude (vertical position, horizontal position) of the camera, or according to the photographing mode detected by the photographing mode detecting means. One of the determination algorithms is selected to determine a photometric value.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments.

A first embodiment of the present invention for selecting a focus adjustment distance determination algorithm from the contour shape of the main subject area, taking an example of an automatic ranging point selection function of the camera, will be described in detail below.

FIG. 1 is a block diagram of the basic components of the camera according to the first embodiment of the present invention.

In the drawing, 51 is a distance distribution measuring means for measuring the distance of an arbitrary place in the scene, 52 is a main subject area detecting means for detecting a region where the main subject is present in the photographing screen, and 53 is a main subject area detecting means. A characteristic determining unit for determining the characteristics of the subject area; 54, a photographing optical system; 55, a lens driving unit for driving a lens to adjust the focus; 56, a focal length adjusting unit; and 57, a focal length adjusting unit. An algorithm storage unit that stores a plurality of algorithms. The dotted line 58 indicates the microcomputer CPU and RA in practice.
M and an area embodied by ROM. Among them, the distance distribution measuring means 51 is embodied by the microcomputer and the measuring optical system, so that it is expressed over a dotted line.

The detailed operation of each unit and the flow of the entire process will be described below with reference to FIG.

When the photographer presses a shutter button (not shown) or the like, the photographing process is started via step (100).

In step (101), the subroutine for measuring the distance distribution of the object scene by the distance distribution measuring means 51 is called. The measurement of the distance distribution is performed by an optical system and a microcomputer. Hereinafter, the configuration of the optical system and the contents of the subroutine executed by the microcomputer will be described.

FIG. 3 is a view showing the arrangement of optical components of a camera for detecting the distance of the object field. In FIG. 3, reference numeral 1 denotes a photographing lens, 8 denotes a field lens, 9 denotes a secondary imaging lens,
Is an area sensor.

Two photographing screens 1 of the area sensor 10
Light beams from different pupil positions of the photographing lens 1 are respectively guided onto 0a and 10b, and are re-imaged at an imaging magnification determined by the field lens 8 and the secondary imaging lens 9. The area sensor 10 is located at a position optically equivalent to the photographic film surface with respect to the photographic lens 1, and has a photographic screen 10a,
0b has a field of view equal to a part of the photographing screen or the photographing screen.

FIG. 4 shows a layout when the detection optical system shown in FIG. 3 is suitable for a camera.
6 is a quick return mirror, 18 is a pentaprism,
19 is a split prism, 20 is a reflection mirror and the others are shown in FIG.
Is the same as

FIG. 5 is a view of the layout of FIG. 4 as viewed from above the camera.

With the above-described configuration, captured images 10a and 10b having a predetermined parallax can be obtained.

The camera having the above configuration is disclosed in detail in Japanese Patent Application No. 5-278433.

FIG. 6 is a circuit diagram showing an example of a specific configuration of a camera provided with each of the above devices. First, the configuration of each unit will be described.

In FIG. 6, PRS is a camera control device, for example, a CPU (central processing unit), ROM,
It is a one-chip microcomputer having a RAM and an A / D conversion function. The camera control device (hereinafter referred to as a microcomputer) PRS performs a series of camera operations such as an automatic exposure control function, an automatic focus adjustment function, and film winding / rewinding in accordance with a camera sequence program stored in a ROM. Is going. For that, the microcomputer PRS
Communication signals SO, SI, SCLK, communication selection signal CKC
By using M, CDDR, and CICC, communication is performed with a peripheral circuit in the camera body and a control device in the lens to control each circuit and lens.

SO is a data signal output from the microcomputer PRS, SI is a data signal input to the microcomputer PRS, and SCLK is a synchronous clock of the signals SO and SI.

LCM is a lens communication buffer circuit,
When the camera is in operation, power is supplied to the lens power supply terminal VL and a selection signal C from the microcomputer PRS is supplied.
When the LCM is at a high potential level (hereinafter, abbreviated as “H” and the low potential level is abbreviated as “L”), communication between the camera and the lens is buffered.

When the microcomputer PRS sets CLCM to "H" and sends out predetermined data from the SO in synchronization with SCLK, the lens communication buffer circuit LCM causes each of SCLK and SO to pass through the camera-lens communication contact. The buffer signals LCK and DCL are output to the lens. At the same time, a buffer signal of the signal DLC from the lens is output to the SI, and the microcomputer PRS synchronously inputs lens data from the SI.

DDR is a detection and display circuit for various switches SWS, which is selected when the signal CDDR is "H", and is controlled by the microcomputer PRS using SO, SI and SCLK. That is, based on data sent from the microcomputer PRS, the display of the display member DSP of the camera is switched, and the on / off state of various operation members of the camera is notified to the microcomputer PRS by communication. OLC is an external liquid crystal display device located above the camera, and ILC is a viewfinder internal liquid crystal display device.

SW1 and SW2 are switches linked to a release button (not shown). The switch SW1 is turned on when the first step of the release button is pressed, and subsequently the switch SW2 is turned on when pressed in the second step. The microcomputer PRS performs photometry and automatic focus adjustment when the switch SW1 is turned on, and performs exposure control and subsequent film winding with the switch SW2 turned on as a trigger.

The switch SW2 is connected to the "interrupt input terminal" of the microcomputer PRS. Even when the program is executed when the switch SW1 is turned on, an interrupt is generated by turning on the switch SW2, and the control is immediately transferred to a predetermined interrupting program. Can be.

MTR1 is for film feeding, MTR2 is for mirror up / down and shutter spring charging,
Each is a motor, and each drive circuit MDR1, MD
R2 controls normal rotation and reverse rotation. Microcomputer PR
Signals M1F, M1R, M2F, and M2R input from S to the drive circuits MDR1 and MDR2 are motor control signals.

MG1 and MG2 are magnets for starting the movement of the first and second curtains of the shutter, respectively, and are energized by signals SMG1 and SMG2 and amplification transistors TR1 and TR2.
Shutter control is performed by RS.

The motor drive circuits MDR1, MDR2,
Since the shutter control does not directly relate to the present invention, a detailed description is omitted.

A signal DCL input to the in-lens control circuit LPRS in synchronization with LCK is transmitted from the camera to the lens LNS.
, And the operation of the lens in response to the command is determined in advance. This in-lens control circuit LPR
S analyzes the command in accordance with a predetermined procedure, and performs operations of focus adjustment and aperture control, the operation status of each part of the lens (driving status of focus adjustment optical system, driving status of aperture, etc.) from output DLC, and various parameters. (Open F-number, focal length,
It outputs distance information such as the defocus amount versus the coefficient of the movement amount of the focus adjustment optical system, various focus correction amounts, and the like.

In this embodiment, a zoom lens is shown as an example. When a focus adjustment command is sent from a camera, the focus adjustment motor LTMR is sent to a signal KMF in accordance with the simultaneously transmitted drive amount and direction. , LMR to adjust the focus by moving the optical system in the direction of the optical axis.
The amount of movement of the optical system is monitored by a pulse signal SENCF of an air coder circuit ENCF that detects a pattern of a pulse plate that rotates in conjunction with the optical system with a photocoupler and outputs a number of pulses corresponding to the amount of movement. The coefficient is calculated by a counter in the internal control circuit LPRS, and when the predetermined movement is completed, the LPRS itself sets the signals LMF and LMR to 'L' to brake the motor LMTR.

Therefore, once the camera focus adjustment command is sent, the microcomputer PRS does not need to be involved in driving the lens at all until the driving of the lens is completed. Further, when a request from the camera is met, the contents of the counter can be sent to the camera.

When an aperture control command is sent from the camera, a well-known stepping motor DMTR for driving an aperture is driven in accordance with the number of aperture stages sent at the same time. Since the stepping motor can perform open control, it does not require an encoder for monitoring the operation.

ENCZ is an encoder circuit attached to the zoom optical system, and the in-lens control circuit LPRS receives the signal SENCZ from the encoder circuit ENCZ to detect the zoom position. Lens parameters at each zoom position are stored in the in-lens control circuit LPRS, and when a request is received from the microcomputer PRS on the camera side, a parameter corresponding to the current zoom position is sent to the camera.

ICC is a photometric area sensor for focus detection and exposure control composed of a CCD or the like, and its driving circuit. ICC is selected when the signal CICC is "H", and SO, S
It is controlled by the microcomputer PRS using I and SCLK.

ΦV, φH, and φR are read signals of the area sensor output and reset signals, and a sensor control signal is generated by a drive circuit in the ICC based on the signal from the microcomputer PRS. The sensor output is amplified after reading from the sensor unit, and is input as an output signal IMAGE to an analog input terminal of the microcomputer PRS. The microcomputer PRS converts the signal into an analog signal, and sequentially stores the digital value in a predetermined address on the RAM. Go. Using these digitally converted signals, distance distribution measurement and focus adjustment or photometry of the object scene are performed.

In FIG. 6, the camera and the lens are shown as being separate (lens can be replaced).
The present invention has no problem even if the camera and lens are integrated, and the present invention is not limited to these.

Based on the above configuration, the distance distribution is measured based on the flowchart of FIG.

In step (201), a sensor image is captured. The capture of the sensor image is performed as follows.

First, the sensor is reset. More specifically, the reset operation is performed inside the ICC by setting the control signals φV, φH, and φR to “H” at the same time by the microcomputer PRS for a certain period of time. Next, an accumulation start command is sent from the microcomputer PRS to start accumulation, and later the end of accumulation is detected. Then, the control signals φV and φH are driven to output the sensor output IMAG.
E are sequentially read out, A / D converted by the microcomputer PRS and stored in the RAM, and the capture of the output signal of the sensor in step (201) is completed.

The output signal data of the two sensors is stored in RAM
They are stored in the upper predetermined areas IMG1 and IMG2.

Next, in step (202) and thereafter, "m
Defocus distribution information (defocus map) composed of (× n) blocks (m and n are integers of 1 or more) is created.

In step (202), variables х and 指示 indicating the coordinates of the block are initialized. In the next step (203), a signal necessary for the distance calculation of the block (х, у) is extracted from the image data IMG1 on the RAM and copied to a predetermined address A on the RAM. In the following step (204), another signal necessary for the distance calculation of the block (х, у) is extracted from IMG2,
It is copied to a predetermined address B on the RAM.

In the next step (205), the address A
A known correlation operation COR (A, B) is performed on the luminance distribution signal stored at the address B and the luminance distribution signal stored at the address B, and a shift amount δ between the two image signals is calculated. In the following step (206),
The calculation of the distance value from the image shift amount δ is performed by a well-known function f (δ), and the distance value or the defocus is stored in a predetermined address D (х, у) secured for the distance distribution recording on the RAM. You. Then, in step (207), the value of х is increased by one, and the processing target is moved to an adjacent block.

In step (208), x is compared with the resolution m of the distance map in the x direction, where "x <
If "m" is determined to be true, the process returns to step (203), and the calculation and storage of the distance value are performed on the adjacent block in the x direction in the same manner as described above. If “x <m” is determined to be false, the process proceeds to step (209), where x is initialized and y is increased by one.

In step (210), the value of y is evaluated. When it is determined that "y <n" is true, the process returns to step (203), and the operation for the next block sequence is started. When it is determined that “y <n” is false, the distance calculation for all blocks is completed, the distance distribution creation subroutine ends, and step (10) in FIG.
End 1).

Next, in step (103), the main subject area detection subroutine is called.

The contents of the main subject area detection subroutine will be described with reference to FIG.

In step (301) of FIG. 8, numbering is performed for each object (group) constituting the object scene.

For example, as shown in FIG. 9, when performing the division processing while performing raster scanning from the upper left block of the screen as indicated by the arrow in the figure, the block G (x, y) above the block of interest G (x, y) y-1) and the left lock G (x-1, y)
If it is determined whether or not the block belongs to the same group, it can be determined whether all adjacent blocks are the same block. At this time, the upper side of the screen (y =
0) and the block on the left side (x = 0) do not have the upper block and the left block, respectively, so that no processing is performed on them.

The result of the determination is stored in the memory G on the RAM.
Record in (0,0) to G (m-1, n-1). First,
The block of (x, y) = (0, 0) has a group number g =
Registered as 1, and if a group having a different area is detected, the number of g is increased by one and set as the group number of the block.

By this processing, for example, a shooting scene as shown in FIG. 10A is given a number for each group as shown in FIG. Since the numbering process itself is a known technique called “labeling method”, a flowchart of the entire area division is omitted.

The method of determining whether each block is the same block is described in detail in Japanese Patent Application No. 08-325327 proposed by the present applicant. When the difference between the defocus amounts (distance values) in the matching blocks is within a predetermined range, the blocks are processed as the same block.

Next, in step (302), the number of subjects detected in step (301) is set in a variable Gnum.

After step (303), the characteristics of each group constituting the photographing space are evaluated, and the group representing the main subject is determined from all the groups based on the characteristics.

In step (303), 1 is set to a variable Gcur representing a group to be operated. In the next step (304), the main subject degree S (Gcur) of the subject area of the group number Gcur is calculated. The main subject degree calculates characteristics such as an average distance, an area width, a height, and a position on a screen, and evaluates them comprehensively to determine an area considered as a main subject. For example, as the main subject degree evaluation function S (Gcur), the aforementioned equation (1) can be considered.

In step (305), the value of the variable Gcur is increased by one, and the operation target is moved to the next group. In the next step (306), the values of the variables Gcur and Gnum are compared to check whether or not the operation has been completed for all the groups. As a result, if “Gcur ≦ Gnum”,
Since the operations for all the groups have not been completed, the process returns to step (304), and if "Gcur>Gnum",
Move to step (307).

In step (307), a function MAX for obtaining a group number having the largest value among all the calculated main subject degrees S (1) to S (Gnum) is used to determine a group having the highest main subject degree. The number is assigned to the variable Gmain. The area corresponding to the number represented by Gmain represents the main subject area. Then, in step (308), the main subject area detection subroutine ends, and step (102) in FIG.
Is completed.

Next, the main subject characteristic determination subroutine of step (103) is called.

The operation of this subroutine will be described with reference to the flowchart of FIG.

In step (401), the average width of the main subject area is calculated and stored in a variable Wa. Here, the average width is obtained by examining the width of the main subject area for each line of the distance distribution at the resolution of the distance distribution and calculating the average thereof. Thus, even when a person spreads his arms, it is possible to detect an appropriate object width without discriminating an object having an unnecessarily wide width.

Next, in step (402), the maximum height of the main subject area is calculated and stored in a variable Hx. Here, the maximum height is the top and bottom of the main subject area in the screen in the resolution of the distance distribution.

In the following step (403), Wa / Hx is stored in a variable ASP representing the aspect ratio of the main subject area. The meaning represented by the value of the aspect ratio ASP of the main subject area will be described with reference to FIG.

As shown in FIG. 12A, the aspect ratio of the main subject area is “Hx> W
a ", that is, it is often vertically long,
The position to be focused is often above the region where the face exists in the main subject region.

As shown in FIG. 12B, for objects other than a person such as a car, “Hx ≦ Wa” is often satisfied. In such a case, the position to be focused on is the entire area or the entire area. Often focuses on the closest part of the.

Therefore, according to the aspect ratio of the subject,
By changing the method of determining the focus position for the main subject area, more appropriate focus adjustment can be performed.

Therefore, the aspect ratio AS of the main subject area
With P, the feature amount is output, and the main subject feature determination subroutine ends.

Next, in step (104) of FIG. 2, an algorithm selection subroutine is called.

Here, an optimum algorithm is selected for the output result of the main subject characteristic discrimination. This processing will be described with reference to the flowchart of FIG.

In step (501), it is checked whether or not this value is smaller than a certain threshold value, for example, 0.7 with reference to the value of the output ASP representing the result of the characteristic discrimination. The ASP indicates the approximate aspect ratio (width Wa / height Hx) of the subject, and the smaller this value is, the more the main subject can be determined to be vertically long.

Therefore, in step (501), "AS
If P <0.7 ”is determined to be true, the step (50)
Move on to 2) and apply the algorithm to determine the focusing distance.
In order to form a subroutine A1 that embodies an optimal algorithm when the shape of the subject is vertically long, the address to A1 is stored in a variable PFN.

In step (501), "A
If SP <0.7 ”is determined to be false, step (50)
Move to 3), and determine the algorithm for determining the focus adjustment distance.
Subroutine A that embodies the optimal algorithm when the shape of the subject is close to a square or vertical.
In order to set it to 2, the address to A2 is stored in the variable PFN.

The function Address (Ai) in the figure represents a function that returns an address to the subroutine A in parentheses.

When the above processing ends, the algorithm selection processing subroutine ends.

Next, the focus adjustment distance determination subroutine of step (105) in FIG. 2 is executed.

Here, a subroutine for determining the focus adjustment distance is executed according to the result of the above algorithm selection processing. A case where the characteristic of the main subject area is a contour shape will be described with reference to the flowchart of FIG.

In step (601), the next execution step is switched between (602) and (606) in accordance with the variable PFN set in the previous algorithm selection subroutine.

In the step (602) and subsequent steps, when the shape of the main subject is vertically long, the upper portion of the effective subject area is prioritized. This is for the purpose of an operation of, for example, focusing on a face portion when a subject is a person. On the other hand, after step (606), the central part of the subject is prioritized assuming that the shape of the main subject is square or horizontally long.

In each of the next steps (603) and (607), according to the respective set priorities,
Set a target area within the subject area. In other words, the area that is actually focused is narrowed down according to the characteristics of the main subject area.

In the following step (604), the closest distance is determined from information in the previously set area in order to determine distance information for focus adjustment. Thus, when the upper part of the main subject area is prioritized, an aggressive algorithm is given such that priority is given further to the nearer part in the upper area.

On the other hand, in step (608), a general-purpose algorithm such as an average distance in the set area is used.

The respective distances obtained as described above are used in step (6).
In steps (05) and (609), the final focus adjustment distance is set, and the focus adjustment distance determination subroutine ends.

Step (1) in FIG.
After the calculations in the microcomputer PRS of steps (01) to (105), in step (106), a command for focus adjustment is sent from the microcomputer PRS to the lens so as to focus on the distance determined in step (105). Then, the in-lens control circuit LPRS controls the motor LMTR to focus on the main subject and complete the focus adjustment on the main subject.

Then, in step (107), the microcomputer PRS outputs the MG1, M2 for starting the shutter front curtain / rear curtain travel.
With respect to G2, signals SMG1 and SMG2 are generated at appropriate time intervals, an exposure operation is performed, and photographing is completed.

As described above, the algorithm for deciding how to set the focal length from the information on the main subject area with respect to the shape of the main subject area, particularly in this embodiment, especially the aspect ratio, is optimized. By making a selection, it is possible to perform processing such as fitting to the upper part of the main subject, that is, near the face if the main subject is human, or to the closest part in the main subject area if the human is not human (in the case of a car, etc.). However, the photographer can obtain a photograph in which the main subject is properly focused only by focusing on the composition without being conscious of the position and type of the main subject.

The above is an example in which attention is paid to the contour shape as the characteristic of the main subject area. On the other hand, it is also possible to configure a case where attention is paid to the distance distribution information and the actual size of the main subject as described above.

First, when attention is paid to the distance distribution information, an algorithm that prioritizes an area having a small change in distance (the same or substantially the same block of distance information) within the main subject area is used. It is considered effective to obtain the closest priority or the average distance, or to give the region having the highest contrast the highest priority.

On the other hand, when attention is paid to the actual size of the main subject, for example, if the main subject is of a human size, the above-described near-priority priority algorithm giving priority to the upper part of the area. It is conceivable to adopt the closest priority algorithm in the above.

Further, by selecting not only the above-mentioned contour shape but also the distance distribution information in the recognized contour shape, an algorithm for setting the focus adjustment distance is selected. It is possible to obtain a photograph in which the main subject is properly focused.

(Second Embodiment) A second embodiment of the present invention will be described.
As an example, an automatic focusing camera that selects a focusing distance determination algorithm according to a shooting mode will be described as an example.

Since the basic configuration of the camera is the same as that of the first embodiment, only the components necessary for the description will be mainly described.

FIG. 15 shows a photographing mode setting dial 61 of the camera according to the second embodiment. This is one of the switches SWS in FIG. 6, and the change in the dial is transmitted to the PRS by the switch detection circuit DDR.

In FIG. 15, the photographing mode setting dial 61 is set to the "L" mark (lock mark) (relative to the index 62), and each mark engraved in a clockwise area from this position can be changed. Shows the most appropriate shooting mode.
Therefore, the shooting mode setting dial 6 is
By rotating 1 counterclockwise from the position of the "L" mark to an arbitrary mark, a desired photographing mode can be selected.

In FIG. 15, the “□” mark on the right of the “L” mark is a so-called fully automatic mark, which is a mode in which a general subject can be easily taken. The following pictogram modes are "portrait", "landscape", "close-up", and "sports" shooting modes. In each mode, the optimum setting can be easily made by expressing the object suitable for the mode, that is, a subject suitable for the mode by pictograms.

FIG. 16 is a flowchart for explaining the overall processing flow of the camera according to the second embodiment.

Steps (700) to (702) correspond to FIG.
Are exactly the same as steps (100) to (102).

In step (703), the selection mode is determined, that is, the mode corresponding to the index 62 in FIG. 15 is determined. Then, from this result, step (704)
Perform algorithm selection in. In this case, the determination and selection are only performed by switching the focal length determination subroutine in accordance with the set mode, so that these are actually the same condition determination flow.

FIG. 17 shows the process from the above-described selection photographing mode determination and algorithm selection to focus adjustment distance determination, that is, FIG.
5 is a flowchart illustrating steps (703) to (705) in FIG.

In step (801), it is determined whether the set photographing mode is the portrait mode. As a result, if the mode is the portrait mode, the focus adjustment distance determination algorithm after step (802) is selected and executed. Here, in the portrait mode, the step (60) in FIG.
An aggressive algorithm, which is performed in 2) to (605), in which the upper part of the main subject area is prioritized and the closest priority is given, is adopted.

On the other hand, if the portrait mode is not set in step (801), the flow advances to step (806).
Here, it is determined whether the mode is the landscape mode. If the mode is the landscape mode, the subject is relatively large in a relatively distant view, so that an area with high contrast in the main subject area is prioritized, and an algorithm for calculating and using an average distance thereof for further improvement in accuracy is used. Has adopted. Steps (807) to (810) are the parts implementing the above contents.

If the mode is not the landscape mode in step (806), the flow advances to step (811) to determine whether the mode is the close-up mode.

If the mode is the close-up mode, an algorithm is used in which the central portion of the main subject is prioritized and the closest distance is prioritized. This is conscious of micro photography, and this content is implemented in steps (812) to (815).

If the mode is not the close-up mode in step (811), the flow advances to step (816) to determine whether the mode is the sports mode.

If the mode is the sports mode, an algorithm that gives priority to an area with high contrast in the main subject area, and gives priority to the nearest area is adopted here. Considering that the subject is not relatively large and often moves, the processing is performed in steps (817) to (820).

Lastly, if the mode is not the sports mode in step (816), the mode is the fully automatic mode. Therefore, general-purpose data such as the average distance of the center of the main subject performed in steps (606) to (609) in FIG. Algorithm is adopted. This is performed in steps (821) to (824).

Returning to the description of FIG. 16, step (706)
Steps (106) to (107) in FIG.
Has done the same.

In the above, the embodiment in which the algorithm for determining the focus adjustment distance is switched according to the shooting mode of the camera has been described as an example. It is also effective to switch according to the posture of the camera, such as shooting at a position.

For example, in the case of the vertical position, an upper region of the main subject region is prioritized, and in the case of the horizontal position, an algorithm for achieving a good balance between the left and right is adopted.

As described above, the algorithm for determining the focus adjustment distance for the main subject area is selected in accordance with the shooting mode of the camera, and the focus for the main subject area is determined in accordance with the vertical / horizontal position of the camera. Since the adjustment distance determination algorithm is selected, it is possible to determine the final focus adjustment distance according to each state of the camera.

For example, the camera changes the algorithm for determining the final focus adjustment distance for the main subject area depending on the vertical position or the horizontal position, or changes the main subject area according to a shooting mode such as a portrait shooting mode or a landscape shooting mode. It is possible to change the algorithm for determining the final focus adjustment distance for, so that optimum focus adjustment can be performed.

(Modification) In the above embodiment,
Although an example in which the present invention is applied to a focus adjusting device of a single-lens flexible camera is described, the present invention is not limited to this, and application to a focus adjusting device of a camera such as a video camera or an electronic still camera is also possible. Further, to an optical device having a focus adjustment function other than a camera, or a device for detecting a feature point of an object (the detected feature point is used for focus adjustment as described above). Is also possible.

In addition to the focus adjusting device, the present invention is also applicable to an exposure control device for detecting a characteristic point (upper part, ie, near a face in the case of a person) of the main subject area and performing optimal exposure control on the detected portion. Applicable. Also in this case, the present invention is not necessarily limited to a camera, and may be applied to an optical device having an exposure control function other than the camera or an apparatus for detecting a characteristic point of an object.

[0136]

As described above, according to the present invention,
For example, based on the actual shape of the object from the contour shape of the object region, the distance distribution of the object, or the distance distribution and the outline of the object region, the feature points of the object are detected. It is possible to provide an object feature point detection device capable of detecting feature points of the object, which is necessary for performing optimal processing on various objects.

Further, according to the present invention, the contour shape of the object region such as the main subject, the distance distribution of the object region such as the main subject, or the distance distribution and the contour of the object region such as the main subject can be used as the object. Focus adjustment device that can perform appropriate focus adjustment for various objects and main subjects because the algorithm for determining the focus adjustment distance is selected from among a plurality of algorithms according to the actual size of Can be provided.

Further, according to the present invention, the contour shape of the object area such as the main subject, the distance distribution of the object area such as the main subject, or the distance distribution and the contour of the object area such as the main subject can be used as the object. Depending on the actual size of the lens, the algorithm for determining the photometric value for exposure control is selected from among multiple types, so that appropriate exposure control can be performed for various objects and main subjects. It is possible to provide an exposure control device that can perform the control.

Further, according to the present invention, one of a plurality of algorithms for determining the focal length is determined according to the detected posture (vertical position, horizontal position) of the camera and the detected current shooting mode. Since the focus adjustment distance is determined by selecting an algorithm, it is possible to provide a camera capable of performing appropriate focus adjustment for various objects and main subjects.

Further, according to the present invention, according to the detection result of the posture detecting means for detecting the posture (vertical position, horizontal position) of the camera, or according to the photographing mode detected by the photographing mode detecting means, Provides a camera that can perform appropriate exposure control for various objects and main subjects because one of the algorithms for determining the photometric value is selected to determine the photometric value. You can do it.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a camera according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating a schematic operation of the camera according to the first embodiment of the present invention.

FIG. 3 is a diagram schematically illustrating an arrangement of an optical system of the camera according to the first embodiment of the present invention.

FIG. 4 is a perspective view showing an arrangement of an optical system of the camera according to the first embodiment of the present invention.

5 is a diagram of the optical system of FIG. 4 as viewed from above.

FIG. 6 is a block diagram showing an internal configuration of the camera according to the first embodiment of the present invention.

FIG. 7 is a flowchart showing an operation of distance distribution measurement in step (101) of FIG. 2;

FIG. 8 is a flowchart showing an operation of detecting a main subject area in step (102) of FIG. 2;

FIG. 9 is a diagram for explaining a method of actually dividing an area in the operation of FIG. 8;

FIG. 10 is a diagram showing an example of a result of labeling in the operation of FIG. 8;

FIG. 11 is a flowchart showing an operation of main subject characteristics in step (103) of FIG.

FIG. 12 is a diagram for explaining an example of an aspect ratio of a main subject area in the operation of FIG. 11;

FIG. 13 is a flowchart showing an algorithm selection operation in step (104) of FIG. 2;

FIG. 14 is a flowchart showing an operation of determining a focus adjustment distance in step (105) of FIG. 2;

FIG. 15 is a diagram for explaining a shooting mode setting dial of the camera according to the second embodiment of the present invention.

FIG. 16 is a flowchart showing a schematic operation of the camera according to the second embodiment of the present invention.

FIG. 17 is a flowchart showing an algorithm selection operation in step (704) of FIG.

FIG. 18 is a diagram showing a certain shooting scene, its distance distribution measurement result, and a state in which groups are grouped for each region characteristic from the distance distribution measurement result.

[Explanation of symbols]

 Reference Signs List 51 distance distribution measuring means 52 main subject area detecting means 53 characteristic discriminating means 55 lens driving means 56 focus adjustment distance determining means 57 algorithm storing means PRS microcomputer LPRS in-lens control circuit LNS lens ICC focus detecting and photometric sensor and driving circuit

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H04N 5/235 G06F 15/62 380 15/70 365

Claims (20)

[Claims] An object having a distance distribution measuring means for measuring a distance distribution in a screen, and an object area detecting means for detecting an area where the object is present from the distance distribution obtained by the distance distribution measuring means. In the feature point detection device, the object includes a feature portion detection unit configured to detect a characteristic portion of the object region detected by the object region detection unit based on a contour shape of the object region. Feature point detection device. 2. An object having a distance distribution measuring means for measuring a distance distribution in a screen, and an object area detecting means for detecting an area where the object is present from the distance distribution obtained by the distance distribution measuring means. In the feature point detection device, the object includes a feature portion detection unit configured to detect a characteristic portion of the object region detected by the object region detection unit based on a distance distribution of the object region. Feature point detection device. 3. An object having a distance distribution measuring means for measuring a distance distribution in a screen, and an object area detecting means for detecting an area where the object is present from the distance distribution obtained by the distance distribution measuring means. In the feature point detection device, the characteristic portion of the target object region detected by the target object region detection means, the actual size of the target object is calculated from the distance distribution and the contour shape of the target object region, An object feature point detecting device, comprising: a characteristic portion detecting means for detecting based on the detected characteristic portion. 4. A distance distribution measuring means for measuring a distance distribution or a defocus distribution in a screen, and an object area detecting means for detecting an area where an object is present from the distance distribution obtained by the distance distribution measuring means. A characteristic discriminator for discriminating a characteristic of the target area detected by the target area detector. Based on an output result of the characteristic discriminator, a final focus adjustment is performed from the distance distribution information of the target area. A focusing device having an algorithm for determining a distance. 5. A distance distribution measuring means for measuring a distance distribution or a defocus distribution in a screen, and a main subject area detecting means for detecting an area where a main subject is present from the distance distribution obtained by the distance distribution measuring means. Characteristic determining means for determining characteristics of the main subject area detected by the main subject area detecting means. Based on an output result of the characteristic determining means, final focus adjustment is performed based on distance distribution information of the main subject area. A focus adjustment device having an algorithm for determining a distance. 6. Based on an output result of the characteristic determining means,
6. The focus adjustment apparatus according to claim 5, wherein a predetermined range of the main subject area is selected, and a final focus adjustment distance is determined from the distance distribution information therein. 7. A distance distribution measuring means for measuring a distance distribution in a screen, a main subject area detecting means for detecting an area where a main subject is present from the distance distribution obtained by the distance distribution measuring means, and the distance distribution A focus adjustment distance determining means for determining one focus adjustment distance from the distance distribution information in the main subject area measured by the measurement means, and a lens for adjusting the focus by driving the lens based on the determined focus adjustment distance A focus adjustment device having a driving unit, wherein the algorithm storage unit previously stores a plurality of algorithms for determining one focus adjustment distance from the distance distribution information of the main subject region, and the algorithm is detected by the main subject region detection unit. A characteristic determining unit that determines characteristics of the main subject area, wherein the focus adjustment distance determining unit is configured to determine a characteristic of the main subject area based on an output result of the characteristic determining unit. Focusing device, characterized in that determining the focusing distance by selecting one of the algorithms from among a plurality of algorithms stored in the algorithm storage means. 8. The focus adjustment apparatus according to claim 7, wherein said characteristic determination means performs characteristic determination of said main subject area according to a contour shape of said main subject area. 9. The focus adjustment apparatus according to claim 7, wherein said characteristic determining means determines the characteristic of the main subject area according to a distance distribution of the main subject area. 10. The characteristic determining unit calculates an actual size of a subject from a distance distribution and a contour shape of the main subject region, and performs characteristic determination of the main subject region in accordance with the calculated size. The focus adjusting device according to claim 7, wherein: 11. A distance distribution measuring means for measuring a distance distribution in a screen, a main subject area detecting means for detecting an area where a main subject is present from the distance distribution obtained by the distance distribution measuring means, and the distance distribution Measured by the measuring means,
In an exposure control device including a photometric value determining unit that determines one photometric value from the distance distribution information in the main subject region, and an exposure control unit that performs exposure control based on the determined photometric value, An algorithm storage unit that stores a plurality of algorithms for determining one photometric value from the distance distribution information in advance, and a characteristic determination unit that determines characteristics of the main subject area detected by the main subject area detection unit, The photometric value determining unit selects one algorithm from a plurality of algorithms stored in the algorithm storage unit and determines a photometric value to be used for exposure control, based on a determination result of the characteristic determining unit. Exposure control device. 12. The exposure control device according to claim 11, wherein said characteristic determining means determines characteristics of the main subject area according to a contour shape of the main subject area. 13. The exposure control apparatus according to claim 11, wherein said characteristic determining means determines characteristics of the main subject area according to a distance distribution of the main subject area. 14. The characteristic determining unit calculates an actual size of a subject from a distance distribution and a contour of a main subject area,
12. The exposure control device according to claim 11, wherein the determination of the characteristic of the main subject area is performed according to the calculated size. 15. A distance distribution measuring means for measuring a distance distribution or a defocus distribution in a screen, and a main subject area detecting means for detecting an area where a main subject exists from the distance distribution obtained by the distance distribution measuring means. Focus adjustment distance determining means for determining one focus adjustment distance from the distance distribution information in the main subject area measured by the distance distribution measurement means, and driving a lens based on the determined focus adjustment distance to focus. A lens drive unit for performing adjustment, wherein the focus adjustment distance determination unit selects one of a plurality of focus adjustment distance determination algorithms according to a setting state at the time of photographing of the camera, and performs focus adjustment. A camera for determining a focus adjustment distance used for adjustment. 16. An image forming apparatus comprising: posture detecting means for detecting a posture of a camera; wherein the focus adjustment distance determining means selects one of a plurality of focus adjusting distance determining algorithms in accordance with a detection result of the posture detecting means. 16. The camera according to claim 15, wherein an algorithm is selected to determine a focus adjustment distance used for focus adjustment. 17. A photographing mode setting unit, and a photographing mode detecting unit for detecting a current photographing mode, wherein the focus adjustment distance determining unit determines a plurality of focal points in accordance with a detection result of the photographing mode detecting unit. The camera according to claim 15, wherein one of the algorithms for determining the adjustment distance is selected to determine a focus adjustment distance used for focus adjustment. 18. A distance distribution measuring means for measuring a distance distribution in a screen, a main subject area detecting means for detecting an area where a main subject is present from the distance distribution obtained by the distance distribution measuring means, and the distance distribution Measured by the measuring means,
In a camera having a photometric value determining unit that determines one photometric value from the distance distribution information in the main subject region, and an exposure control unit that performs exposure control based on the determined photometric value, the photometric value determining unit includes: A camera characterized in that one of a plurality of photometric value determination algorithms is selected according to a setting state at the time of photographing of the camera to determine a photometric value to be used for exposure control. 19. A photometric value determining means for detecting the attitude of a camera, wherein the photometric value determining means uses one of a plurality of photometric value determining algorithms in accordance with the detection result of the attitude detecting means. 19. The camera according to claim 18, wherein a photometric value used for exposure control is determined by selection. 20. A photographing mode setting means, and a photographing mode detecting means for detecting a current photographing mode, wherein the photometric value determining means includes a plurality of photometric values according to a detection result of the photographing mode detecting means. 19. The camera according to claim 18, wherein one of the determination algorithms is selected to determine a photometric value used for exposure control.