JPH05196858A - Camera - Google Patents

Abstract

PURPOSE:To finish the face parts of a person. etc., with an optimum density by detecting the main objects of the person, etc., without having a focus locking operation. CONSTITUTION:A large number of range-finding points and photometric areas are two-dimensionally set in a photographic scene. The range-finding of an object on each range-finding point is executed. The brightness of the object of each photometric area, is metered. In the range-finding point, an area having the shortest distance measurement data and distance measurement data within a constant range from the shortest distance measurement data, is set as a main object candidate area. Etching processing is executed with brightness data in the main object candidate area and the brightness data of a main object pattern stored in advance, to determine the main object. An exposure is controlled based on the brightness data of the main object.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera, and more particularly to a camera that automatically detects a main subject and controls exposure based on the detected main subject.

[0002]

2. Description of the Related Art In a conventional camera in which the distance measuring point is set to only one point in the center of the viewfinder screen, the focus lock is set when the main subject is photographed in a composition shifted from the center of the photographing screen. There is a need to do. Further, even in a multi-point distance measuring camera, there are at most about five distance measuring points, and these distance measuring points are arranged only in the horizontal direction and only in the vicinity of the center.
Therefore, in the composition in which the main subject is positioned at a position deviated from these distance measurement points, focus lock needs to be performed as in the above. Also, there is a method in which the image area sensor is installed in the camera and the correlation between in-focus time and release time is calculated from this signal to detect the position of the main subject. There is a need to do.

[0003]

Therefore, in any of the above cameras, when the main subject is photographed at a position off the target mark, the main subject is aligned with the target mark in the center of the viewfinder screen. After that, the release button is half-pressed to enter the focus lock state, and in this state, the direction of the camera is changed to determine the composition, and then the release operation is performed. For this reason, a troublesome operation of focus lock is required, and there is a possibility that a chance to take a shutter is missed. In a multi-point distance measuring camera, the main subject is often located at an object closest to the camera among the distance measuring points, and thus the object is closest to the camera and is set in advance.
Therefore, if there is another object in front of the main subject,
There is an inconvenience that the main subject becomes out of focus because it is in focus. Further, there is also a disadvantage that the exposure control is performed according to the brightness of the object erroneously recognized as the main subject.

The present invention is intended to solve the above-mentioned problems, and enables the user to take a picture under any composition without worrying about the position of the main subject in the screen and without focus lock. Moreover, it is an object of the present invention to provide a camera capable of producing a high-quality printed photograph by performing focus control and exposure control suitable for a main subject.

The present invention is intended to solve the above-mentioned problems, and it is possible to take a photograph under free composition without focusing on the position of the main subject in the screen and without focus lock. Moreover, it is an object of the present invention to provide a camera capable of producing a high-quality printed photograph by performing focus control and exposure control suitable for a main subject.

[0006]

In order to achieve the above object, the present invention sets a plurality of distance measuring points and a plurality of two-dimensionally arranged photometric areas in a photographing scene, and sets each distance measuring point at each distance measuring point. Means for measuring the distance to the object located and measuring the object located in each photometry area, means for storing the main object pattern in advance, and the shortest distance measurement data and the shortest distance measurement of the distance measurement data at each distance measurement point A means for extracting a point having ranging data within a certain range from the data as a main subject candidate area, a means for calculating a photographing magnification corresponding to the ranging data, and an image of the main subject pattern according to the photographing magnification. Compress and expand the data,
A means for performing pattern matching from this image data and the photometric data of the main subject candidate area to extract the main subject, and the result of the pattern matching, if the patterns are not similar, the next shortest distance measurement data and this measurement Means for extracting a point having distance measurement data within a certain range from the distance data as a main subject candidate area for pattern matching and extracting the main subject; and means for controlling exposure based on the extracted image data of the main subject. , Means for performing focusing control based on the extracted distance measurement data of the main subject.

Another aspect of the present invention is to set a plurality of distance measuring points and a large number of two-dimensionally arranged light measuring areas in a photographic scene, measure the distance to an object located at each distance measuring point, and measure each light measuring area. Means for three-color separated photometry of a subject located at, and means for storing a main subject pattern in advance,
A means for designating and inputting a specific color is used to determine the color of each photometric area from the three-color separated photometric data, and this color is compared with the designated and input specific color to determine a color area similar to the specific color. Means for extracting as a subject candidate area, means for calculating a photographing magnification corresponding to distance measurement data of a distance measuring point corresponding to the main subject candidate area, and image data of the main subject pattern is compressed according to the photographing magnification. Enlargement processing is performed to perform pattern matching from the image data and the photometric data of the main subject candidate area to extract a main subject, a means for controlling exposure based on the extracted image data of the main subject, and an extracted main subject. The focus control means is provided based on the distance measurement data of the subject.

[0008] Another invention is the above camera,
The image data of the main subject pattern and the main subject candidate area is luminance data, luminance difference data with adjacent pixels, luminance difference data between the luminance average value of the main subject candidate area and each pixel, or frequency component data after orthogonal transformation. Is used. In another invention, a plurality of main subject patterns are stored and search image data is selected from these patterns.

[0009]

FIG. 2 shows a camera for performing focus control and exposure control based on multipoint distance measurement information and photometric information. The light projecting unit 11 is a light source unit 12 that generates spot-like infrared light.
Is equipped with. When the release button 13 is pressed halfway,
The controller 14 controls the light source unit 12 and the two-dimensional scanning unit 15 to project the irradiation light 16 toward the shooting scene 10. The light source unit 12 emits light intermittently and sequentially illuminates the distance measuring points SP1 to SP15 in the shooting scene 10. Figure 3
Shows an example of the arrangement of distance measuring points, and 5 × 3 matrix distance measuring points SP1 to SP15 are set in the vicinity of the center of the shooting scene 10. Also,
The photometric area is configured by dividing a shooting scene into a 60 × 40 matrix. The total number of these photometric areas and photometric points may be increased or decreased as appropriate.

During the intermittent irradiation of the irradiation light 16, the reflected light 18 reflected by the object 17 passes through the lens 19 and enters the image area sensor 20 which is the incident position detecting means. The presence or absence of the subject 17 is detected depending on whether or not the reflected light 18 is incident on the image area sensor 20, and the position and distance of the subject 17 are determined from the scanning position of the irradiation light and the incident position of the reflected light at the time of detecting the subject. To be detected.

The two-dimensional scanning unit 15 scans the light source 12 in the two-dimensional direction, and intermittently causes the light source 12 to emit light when it is located at each of the distance measuring points SP1 to SP15. Controller 1
A pulse counter 4 counts the drive pulses sent to the scanning unit 15 to detect the scanning position of the light source 12 with respect to the shooting scene 10, that is, the position on the shooting screen. This screen position signal is sent to the position / distance detection circuit 26. The light source 12 may be made to intermittently emit light and be intermittently scanned at a constant pitch, or the light source 12 may be made to continuously emit light to scan the shooting scene in a line.

The position / distance detection circuit 26 obtains the position where the reflected light 18 is incident from the time-series signal of the image area sensor 20, and from the relationship between this incident position and the screen position,
The position and distance of the subject on each of the distance measuring points SP1 to SP15 are detected, and signals of the subject position and distance (hereinafter,
Called distance measurement data) dn (n indicates each distance measurement point,
The main subject candidate area extraction unit 3
Send to 0. The main subject candidate area extraction unit 30 selects, as the main subject candidate, the distance measuring point having the shortest distance data and the distance measuring points within a certain range from the shortest distance data among the distance measuring data of the respective distance measuring points SP1 to SP15. Then, the focus control of the photographing lens 31 is performed based on the distance measurement data of these points. That is, each distance measuring point S
When the shortest distance data in P1 to SP15 is dmin and (dn−dmin) <ε, the distance measuring point n is determined to be a main subject candidate. However, ε is a certain threshold value.

Luminance data for each photometric area is input to the main subject candidate area extraction section 30 and the exposure control section 32. The brightness data is detected by the photometric unit 35 including the lens 33 and the image area sensor 34, and stored in the image data memory 36. The main subject candidate area extraction unit 30 selects, from among the brightness data for each photometric area,
The main subject candidate area is extracted and sent to the pattern matching unit 35. Pattern matching unit 35
Image data indicating the main subject pattern is input from the main subject pattern memory 37. As shown in FIG. 4, the main subject pattern 50 is a standard human face photographed, and the image data of the main subject pattern 50 and the photographing magnification at that time are the patterns formed by an IC memory when the camera is manufactured. It is recorded in the memory 37 in advance. The resolution of the image data at this time is m × n. The user may directly photograph the person who is the main subject, or photograph a plurality of types of prepared pattern diagrams, and input again. Further, it may be recorded in an IC card and set in the camera.

Further, the photographing magnification calculation unit 38 sends the photographing magnification to the pattern matching unit 35. The photographing magnification calculator 38 calculates the photographing magnification based on the shortest distance measurement data from the position / distance detection circuit 26 by a well-known arithmetic expression.
The pattern matching unit 35 compresses or expands the image data (m × n) of the main subject pattern in accordance with the shooting magnification, and the image data (m ′) having almost the same size as the face of the main subject in the shooting scene. Xn '). In this compression / expansion process, first, the image data of the main subject pattern is smoothed by applying a two-dimensional space filter. Next, the smoothed data is sampled according to the object magnification to obtain processed image data of resolution m ′ × n ′.

The pattern matching section 35 compares the image data (m ′ × n ′) of the main subject pattern enlarged or reduced according to the photographing magnification with the image data of the main subject candidate area to calculate the similarity. .. The calculation of the degree of similarity is performed by cutting out the image data of the main subject candidate area in the size of the image data (m ′ × n ′) of the main subject pattern. Further, the similarity D of each cutout area is calculated while moving the cutout area in the main subject candidate area in the two-dimensional direction. The similarity D is calculated by X = {x1, x2, ...
L}, the image data of the cut-out area is Y = {y1, y
2, ... yL}, it can be calculated by the following mathematical formula. However, L = m ′ × n ′, i = 1 to L
And

## EQU1 ## D = Σ (xi-yi) ² The similarity D may be calculated by the following equation.

## EQU00002 ## D = .SIGMA. | Xi-yi |

After calculating the degree of similarity, the pattern matching section 35 determines, based on the degree of similarity, the cut-out area having the highest degree of similarity (the area where the above D is the minimum) as the main subject, and the photometry of this cut-out area is performed. Data exposure control unit 3
Send to 2. Further, the distance measurement data of the cut-out area determined as the main subject is sent to the lens setting unit 39. If the degree of similarity is low, it is determined that the main subject does not exist in the distance measurement data, and the determination result is sent to the position / distance detection circuit 26. Based on this determination signal, the position / distance detection circuit 26 sends to the main subject candidate area extraction unit 30 the photometric area corresponding to the photometric point having the shortest ranging data next to the shortest ranging data in the ranging data. The main subject candidate area extraction unit 30 extracts the next main subject candidate area based on this distance measurement data, reads the luminance data of this area from the image data memory 36, and sends this to the pattern matching unit 35. The pattern matching unit 35 performs pattern matching with the main subject pattern in the same manner as in the case of the shortest distance measurement data, and extracts the main subject.

The exposure control unit 32 calculates the exposure amount based on the subject brightness of the main subject area. A film sensitivity signal is input to the exposure control unit 32, and a light value (LV) is calculated based on the film sensitivity signal and the main subject brightness signal, and the diaphragm drive unit 40 and the shutter drive unit 41 are program-controlled. Further, the exposure control unit 32 includes a subject brightness determination circuit as is well known, and when the subject brightness in the main subject area is low, the strobe device 43 is synchronized with the shutter mechanism 42.
Flashes automatically. It should be noted that when the subject brightness of the main subject area is obtained, the image data of the background portion is excluded from the cut-out area, whereby more accurate exposure control can be performed.

A known diaphragm mechanism 44 and shutter mechanism 42 are arranged behind the taking lens 31. Each of these mechanisms 42 and 44 operates when the release button 13 is further pressed from the half-pressed state, and exposes the negative film 45.

Next, the operation of this embodiment will be described. In FIG. 5, the solid line indicates the main subject A. When holding the camera and pressing the release button halfway, the position / distance detection circuit 26 causes the distance measuring points SP1 to SP1 of the shooting scene 10 to be detected.
Measure the distance to SP15. Main subject candidate area extraction unit 30
Of the distance measurement data, the distance measurement points SP4, SP5, SP9, SP10, SP14, having the shortest distance measurement data and the distance measurement data within a certain range from the shortest distance measurement data.
An area centered on SP15 is extracted as a main subject candidate area. Then, subject brightness data is read from the corresponding area of the image data memory 36, and this brightness data is sent to the pattern matching unit 35.

In the pattern matching section 35, the main subject pattern is enlarged or reduced based on the photographing magnification signal calculated based on the shortest distance measurement data. Then, the similarity D between the luminance data of the enlarged or reduced main subject pattern and the luminance data cut out from the main subject candidate area is calculated by the above mathematical expression 1. Then, when the degree of similarity is equal to or less than a certain value and D is minimum, the cut-out area is determined as the main subject area. Then, the signal indicating the main subject area is the exposure control unit 32.
Sent to. The exposure control unit 32 uses the image data memory 36.
The subject brightness signal is read out from the main subject area and the light value (LV) is calculated based on this and the film sensitivity. When the release button 13 is further pressed from the half-pressed state, the diaphragm drive unit 40 and the shutter drive unit 41 are operated, and the main subject A is photographed with the optimum exposure amount.

In the determination processing of the main subject area, if there is no area that can be regarded as the main subject at the distance measuring point having the shortest distance measuring data, the above-mentioned main distance is determined for the distance measuring point having the next distance measuring data. The subject area determination process is repeated. When the main subject area cannot be finally detected, an alarm is generated to prompt manual photography.

In the above embodiment, the main subject candidate area is extracted based on the distance measurement data. In addition to this, the color of the main subject is designated by key input, and the photometric area having this color is designated as the main subject candidate area. May be extracted as
Also in this case, pattern matching is performed and the main subject is extracted as in the above-described embodiment. Then, the focus control is performed based on the distance measurement data of the distance measurement points corresponding to the extracted main subject area, and the exposure control is performed based on the photometry data of the main subject area.

In the above embodiment, the brightness data is used as the image data, but in addition to this, the brightness difference data between adjacent pixels, the brightness average value of the main subject candidate area, and each pixel are also used as the image data. Luminance difference data or frequency component data after orthogonal transformation may be used. Further, in the above embodiment, one main subject pattern is stored, but in addition to this, a plurality of main subject patterns may be stored and the search image data may be selected from these patterns. ..

As the camera information at the time of shooting, the image data of the main subject pattern and the shooting magnification data are recorded in the magnetic recording layer of the film, the IC card, etc., and these information are sent to the printer side at the time of DP processing, and the printer Occasionally, the pattern matching processing is performed using the image data of the main subject pattern, the photographing magnification data, and the density data of the negative film, and the main subject is detected on the negative film by this, and more accurate exposure control is performed based on this. May be performed.

[0025]

As described above, according to the present invention,
The main subject pattern that the photographer wants to take is stored, and the main subject is extracted by performing pattern matching processing between this main subject pattern and the image data of the shooting scene. Suitable focusing control and exposure control can be performed. Thus, for example, by storing the human face portion, the face can be photographed at an appropriate density without being affected by clothes or the background when photographing a person. In addition, normally, when there is another object closer than the main subject, there is a disadvantage that the object is accidentally focused,
According to the present invention, such a focus error can be prevented without a focus lock operation.

[Brief description of drawings]

FIG. 1 is a flowchart showing an exposure control procedure of a camera of the present invention.

FIG. 2 is a schematic diagram showing a camera of the present invention.

FIG. 3 is an explanatory diagram showing an example of distance measurement points in the same camera.

FIG. 4 is an explanatory diagram showing an example of a main subject pattern.

FIG. 5 is an explanatory diagram showing extraction of a face portion of a main subject.

[Explanation of symbols]

 10 Shooting Scene 11 Projection Section 30 Main Subject Candidate Area Extraction Section 32 Exposure Control Section 35 Pattern Matching Section 36, 37 Memory

[Procedure amendment]

[Submission date] August 24, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

In the pattern matching section 35, the main subject pattern is enlarged or reduced based on the photographing magnification signal calculated based on the shortest distance measurement data. Then, the similarity D between the luminance data of the enlarged or reduced main subject pattern and the luminance data cut out from the main subject candidate area is calculated by the above mathematical expression 1. Then, when the degree of similarity is equal to or less than a certain value and D is minimum, the cut-out area is determined as the main subject area. Figure 5
At, the face of the person (near SP4) is the main subject area.
It is judged as a. Then, a signal indicating this main subject area is sent to the exposure control unit 32. The exposure controller 32
The subject brightness signal is read from the main subject area of the image data memory 36, and the light value (LV) is calculated based on this and the film sensitivity. When the release button 13 is further pressed from the half-pressed state, the diaphragm drive unit 40 and the shutter drive unit 41 are operated, and the main subject A is photographed with the optimum exposure amount.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction content]

Further, as the camera information at the time of photographing, the image data of the main subject pattern and the photographing magnification data are recorded in a magnetic recording layer of the film, an IC card or the like, and the information is sent to the printer side at the time of the DP processing to print. At the same time, the pattern matching process is performed using the image data of the main subject pattern, the photographing magnification data, and the density data of the negative film, and the main subject is detected on the negative film by this, and a more accurate exposure is performed based on this. You may make it control.

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Claims (4)

[Claims] 1. A plurality of distance measuring points and a large number of two-dimensionally arranged light measuring areas are set in a shooting scene to measure the distance to an object located at each distance measuring point and to detect an object located in each light measuring area. Means for photometry, means for pre-storing the main subject pattern, and for the main subject, the point having the shortest distance measurement data and the distance measurement data within a certain range from the shortest distance measurement data among the distance measurement data of each distance measurement point Means for extracting as a candidate area, means for calculating a shooting magnification corresponding to the distance measurement data, and compression and expansion processing of the image data of the main subject pattern according to the shooting magnification,
A means for performing pattern matching from this image data and the photometric data of the main subject candidate area to extract the main subject, and the result of the pattern matching, if the patterns are not similar, the next shortest distance measurement data and this measurement Means for extracting a point having distance measurement data within a certain range from the distance data as a main subject candidate area for pattern matching and extracting the main subject; and means for controlling exposure based on the extracted image data of the main subject. And a means for controlling focus based on the extracted distance measurement data of the main subject. 2. A plurality of distance measuring points and a large number of two-dimensionally arranged photometric areas are set in a photographic scene to measure the distance to an object located at each distance measuring point and to detect an object located in each light measuring area. A means for three-color separated photometry, a means for pre-storing the main subject pattern, a means for designating and inputting a specific color, and a color for each photometric area determined from the three-color-separated photometric data, and designated and inputted. Means for comparing a specific color and extracting a color area similar to the specific color as a main subject candidate area; and means for calculating a photographing magnification from the distance measurement data of the distance measuring points corresponding to the main subject candidate area. , Compressing and enlarging the image data of the main subject pattern according to the photographing magnification, and performing pattern matching from the image data and the photometric data of the main subject candidate area. A camera comprising: a means for extracting a main subject, a means for controlling exposure based on image data of the extracted main subject, and a means for controlling focus based on distance measurement data of the extracted main subject. 3. The camera according to claim 1, wherein:
The image data of the main subject pattern and the main subject candidate area is luminance data, luminance difference data with adjacent pixels, luminance difference data between the luminance average value of the main subject candidate area and each pixel, or frequency component data after orthogonal transformation. A camera characterized by using. 4. The camera according to claim 1, wherein a plurality of the main subject patterns are stored, and search image data of the main subject is selected from these patterns. camera.