JP2003198934A - Photometric operation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an influence of objects other than a main subject in the case of the existence of an object much different in brightness from the main subject in a picture. <P>SOLUTION: A mesh photometric frame is divided to perform light measurement for evaluation, and the position of a center photometric frame is determined in accordance with the result, and such control is performed that the object much different in brightness may be out of the center photometric frame. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device such as a video camera capable of taking an image.

[0002]

2. Description of the Related Art FIG. 1 shows the structure of an image pickup device. Lens 1
The subject image incident from 01 is formed by the CCD 103, photoelectrically converted, and output as a video signal. Video signal is C
A / D converter 10 after being amplified by DS / AGC 104
5, converted into a digital signal, and the camera signal processing unit 106
Digital signal processing is performed by. For control of exposure, a gate frame (photometric frame) for the screen area is set in the camera signal processing unit 106, the image signal is integrated in each gate frame, and the integrated value in each gate frame is set by the camera control unit. 109, which is internally processed to generate photometric values,
According to the photometric value, the camera control unit 109 causes the diaphragm 102,
Exposure control is performed by controlling the AGC 104 and TG 110.

Further, as a conventional means for subject photometry,
As shown in FIG. 2, a photometric frame for measuring the entire screen area (overall photometric frame) and a photometric frame for mainly measuring the central part of the screen area (central photometric frame) are provided. Ordinary photometry uses these two photometric frames. Use to measure light. (Center-weighted metering) The method of calculating the photometric value is to set the luminance integrated value in the entire metering frame to Y _all , the central metering frame luminance integrated value to Y _center , and the calculated metering value to Y _s ,

[Outer 1]

Is calculated as (Α and β are respective photometric weighting ratios) Exposure control is performed so that Y _s calculated here becomes equal to the proper exposure value Y _ref . Normally, exposure control is performed using only this center-weighted metering.

Further, a screen area as shown in FIG.
Equipped with a mesh-shaped photometric frame divided into (mesh photometric frame), this frame performs evaluation photometry so that the brightness integral value of the frame with the highest brightness integral value in the mesh frame becomes the specified value, and It is used for the purpose of controlling the exposure by changing the appropriate exposure value Y _ref according to the result, and is applied only to a special shooting mode.

[0006]

However, the normal photometry means does not perform the evaluation photometry using the mesh photometry frame, but only the center-weighted photometry using the whole-surface photometry frame and the central photometry frame. Therefore, when the main subject is present in the central portion of the screen where the central metering frame is arranged, suitable exposure control is performed, but the main subject does not exist at the position of the central metering frame, and it is larger than the main subject. When there is a subject such as the sky with different brightness, the obtained photometric value does not become a photometric value suitable for exposure control for the main subject, and if the exposure control is performed based on this, the main subject There is a problem in that it may not be properly exposed due to blackout or white highlights.

[0007]

According to a first aspect of the present invention, a photometric frame in which a screen area is divided into a plurality of areas, and a range of a predetermined portion of the screen area which is wider than a single range of the divided photometric frame are measured. And a narrow area photometric frame, wherein the brightness distribution is obtained based on the photometric values in the plurality of photometric frames, and the position of the narrow area photometric frame is determined.

According to a second aspect of the present invention, there are provided a photometry frame in which the screen area is divided into a plurality of areas, and a narrow area photometry frame for performing photometry in a predetermined portion of the screen area which is wider than a single range of the divided photometry frame. In the photometric calculation device having the above, the plurality of photometric frames are divided into a plurality of regions, and the position of the narrow area photometric frame is determined according to the result of comparison of the calculated values of the photometric values in the respective regions. And

According to a third aspect of the present invention, there are provided a photometry frame in which the screen area is divided into a plurality of areas, and a narrow-area photometry frame which is a predetermined part of the screen area and which performs photometry in a range wider than the divided single area of the photometry frame. In the photometric calculation device including the above, the plurality of photometric frames are divided into upper and lower regions, and the position of the narrow range photometric frame is moved up and down according to the result of comparison of the calculated values of the photometric values in the respective regions. It is characterized by doing.

According to a fourth aspect of the present invention, there are provided a photometric frame in which the screen area is divided into a plurality of areas, and a narrow area photometric frame which is a predetermined part of the screen area and which is wider than a single range of the divided photometric frame. In the photometric calculation device including the above, the plurality of photometric frames are divided into two regions, left and right, and the position of the narrow range photometric frame is moved to the left or right according to the result of comparing the calculated values of the photometric values in the respective regions. It is characterized by doing.

According to a fifth aspect of the present invention, there are provided a photometric frame in which the screen area is divided into a plurality of areas, and a narrow-area photometric frame for performing photometry in a predetermined portion of the screen area and wider than a single range of the divided photometric frame. In the photometry calculation device having the above, the plurality of photometry frames are divided into four regions of up, down, left and right, and the position of the narrow range photometry frame is moved up, down, left and right according to the result of comparison of the calculated values of the photometry values in each region. It is characterized by moving to.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) The overall structure of the apparatus in this embodiment is the same as that of the prior art and is as shown in FIG. As shown in FIG. 4, the structure of the mesh frame is horizontally divided into two regions (Area 1 and Area 2) having the same number of frames vertically. An actual control flow chart of the camera control unit 109 is shown in FIG. 7 and will be described based on this.

(701) Y ₀₀ belonging to mesh frame Area 1
From 32 to Y _37, the brightness integration values of 32 frames are averaged, and the average value Y _a1 of the brightness integration values is calculated.

(702) Y ₄₀ belonging to the mesh frame Area 2
To Y _77, the luminance integrated values of 32 frames are averaged, and the average value Y _a2 of the luminance integrated values is calculated.

(703) Average value Y of luminance integrated values of Area 1
_Using the average value Y _a2 of the integrated luminance values of _a1 and Area 2, the Y coordinate P _y of the central photometric frame arrangement position is calculated and set according to the following formula.

P _y = Po _y − ((Y _a1 −Y _a2 ) × α) * α is a predetermined coefficient, where Po _y is the Y coordinate initial position of the central photometry frame (see FIG. 2).
P).

(704) The position of the central photometry frame is moved to the calculated P _y position. The X coordinate position P _x of the central metering frame
Is fixed at the initial position Po _x .

Here, when Y _a1 > Y _a2 , the state where the central photometry frame has moved is as shown in FIG. 10.

Further, when Y _a1 <Y _a2 , the state where the central photometry frame has moved is as shown in FIG. 11.

Thereafter, the camera control unit 109 performs photometry using the whole-surface photometry frame and the moved central photometry frame as in the conventional example, and performs exposure control based on the calculated photometry value Y _s. Since the method itself is a method in which a large proportion of weight is given to the subject within the central photometry frame, it is possible to perform suitable exposure control by moving the central photometry frame according to the brightness distribution of the subject.

(Second Embodiment) The entire structure of the apparatus of this embodiment is the same as that of the prior art and is as shown in FIG.
As shown in FIG. 5, the mesh frame structure is vertically divided into two regions (Area 1 and Area 2) having the same number of frames on the left and right. An actual control flowchart of the camera control unit 109 is shown in FIG. 8 and will be described based on this.

(801) Y ₀₀ belonging to mesh frame Area 1
From 32 to Y _73, the luminance integrated values of 32 frames are averaged to calculate the average value Y _a1 of the luminance integrated values.

(802) Y ₀₄ belonging to mesh frame Area 2
To Y _77, the luminance integrated values of 32 frames are averaged, and the average value Y _a2 of the luminance integrated values is calculated.

(803) Average value Y of integrated luminance value of Area 1
_From the average value Y _a2 of the integrated luminance values of _a1 and Area 2, the position X coordinate P _x of the central photometric frame is calculated and set according to the following formula.

P _x = Po _x − (Y _a1 −Y _a2 ) × β) * β is a predetermined coefficient, where Po _x is the X coordinate initial position of the central photometry frame (see FIG. 2).
P).

(804) The position of the central photometry frame is moved to the calculated P _x position. The Y coordinate position P _y of the central metering frame
Is fixed at the initial position Po _y . As a result, when Y _a1 > Y _a2 , P _x of the central metering frame shifts to the right in FIG. 5, and Y _a1 <
When it is Y _a2 , P _x of the central photometry frame shifts to the right in FIG. After that, the camera control unit 109 performs photometry using the entire surface photometry frame and the moved central photometry frame as in the conventional example, and performs exposure control based on the calculated photometry value Y _s. Since this is a method in which a large proportion of weight is given to the subject in the photometric frame, suitable exposure control can be performed by moving the central photometric frame according to the brightness distribution of the subject.

(Third Embodiment) The entire configuration of the apparatus of this embodiment is similar to that of the prior art and is as shown in FIG.

As shown in FIG. 6, the mesh frame has four areas (Area 1, Area 2, Area 3, and 4 areas) having the same number of frames in the vertical and horizontal directions.
Area 4). An actual control flowchart of the camera control unit 109 is shown in FIG. 9 and will be described based on this.

(901) Y ₀₀ belonging to the mesh frame Area 1
The average value Y _a1 of the brightness integrated values is calculated by averaging the brightness integrated values of the 16 frames from Y ₃₃ to Y ₃₃ .

(902) Y ₀₄ belonging to the mesh frame Area 2
The luminance integrated values of 16 frames from No. to Y ₃₇ are averaged, and the average value Y _a2 of the luminance integrated values is calculated.

(903) Y ₄₀ belonging to the mesh frame Area 3
The average value Y _a3 of the brightness integrated values is calculated by averaging the brightness integrated values of the 16 frames from Y ₇₃ to Y ₇₃ .

(904) Y ₄₄ belonging to the mesh frame Area 4
The average value Y _a4 of the brightness integrated values is calculated by averaging the brightness integrated values of the 16 frames from Y to Y ₇₇ .

(905) Average value Y of integrated luminance value of Area 1
Average value Y _a2 of the integrated luminance values of _a1 and Area 2 Y _upper
Is calculated.

(906) Average value Y of luminance integrated value of Area 3
Average value _Y3 of the integrated luminance value of _a3 and Area 4 Y _lower
Is calculated.

(907) From Y _upper and Y _lower , the position Y coordinate P _y of the central photometry frame is calculated and set by the following formula.

P _y = Po _y -((Y _upper -Y _lower ) × α) *
α is a predetermined coefficient Note that Po _y is the Y coordinate initial position of the central photometry frame.

(908) Average value Y of luminance integrated value of Area 1
The average value Y _left of the average value Y _a3 of the integrated luminance values of _a1 and Area 3 is calculated.

(909) Average value Y of integrated luminance value of Area 2
Average value _Y2 of the integrated luminance value of _a2 and Area 4 Y _right
Is calculated.

(910) From Y _left and Y _right , the position X coordinate P _x of the central photometry frame is calculated and set by the following formula.

P _x = P0 _x − ((Y _left −Y _right ) × β) * β is a predetermined coefficient, where Po _x is the X coordinate initial position of the central photometry frame.

(911) The position of the central photometry frame is moved to the calculated positions of P _x and P _y .

After that, the camera control unit 109 performs photometry using the whole-surface photometry frame and the moved central photometry frame as in the conventional example, and performs exposure control based on the calculated photometry value Y _s. Since the method itself is a method in which a large proportion of weight is given to the subject within the central photometry frame, it is possible to perform suitable exposure control by moving the central photometry frame according to the brightness distribution of the subject.

[0043]

According to the present invention of each claim, a more suitable exposure control is performed by calculating the brightness distribution of the screen using the mesh frame and moving the central photometry frame according to the distribution state. It becomes possible.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of a conventional example and the present invention.

FIG. 2 is a layout view of a photometry frame in the center-weighted photometry method.

FIG. 3 is a layout view of a mesh photometric frame.

FIG. 4 is a division diagram of a mesh frame according to the first embodiment.

FIG. 5 is a division diagram of a mesh frame according to the second embodiment.

FIG. 6 is a division diagram of a mesh frame according to the third embodiment.

FIG. 7 is a control flowchart of a camera control unit according to the first embodiment.

FIG. 8 is a control flowchart of a camera controller according to the second embodiment.

FIG. 9 is a control flowchart of a camera control unit according to the third embodiment.

FIG. 10 is a diagram showing a result of movement of the central photometry frame according to the first embodiment.

FIG. 11 is a diagram showing another result of movement of the central photometry frame in the first embodiment.

[Explanation of symbols]

101 lens 102 aperture 103 image sensor 104 CDS / AGC 105 A / D converter 106 camera signal processing unit 107 image recording unit 108 memory 109 camera control unit 110 TG

Claims (9)

[Claims] 1. A photometric calculation comprising: a photometric frame in which a screen area is divided into a plurality of areas; and a narrow area photometric frame for photometrically measuring a predetermined part of the screen area, which is wider than a single range of the divided photometric frame. In the device, a photometric calculation device characterized by obtaining a luminance distribution based on photometric values in the plurality of photometric frames and determining a position of the narrow area photometric frame. 2. A photometric calculation comprising a photometric frame in which a screen area is divided into a plurality of areas, and a narrow area photometric frame for photometrically measuring a predetermined portion of the screen area and wider than a single range of the divided photometric frame. In the device, the plurality of photometric frames are divided into a plurality of areas, and the position of the narrow area photometric frame is determined according to the result of comparison of the calculated values of the photometric values in the respective areas. . 3. A photometric calculation provided with a photometric frame in which a screen area is divided into a plurality of areas, and a narrow area photometric frame for photometrically measuring a predetermined part of the screen area and wider than a single range of the divided photometric frame. In the device, the plurality of photometric frames are divided into upper and lower two areas, and the position of the narrow area photometric frame is moved up and down according to a result of comparison of calculated values of the photometric values in the respective areas. Photometric calculator. 4. A photometric calculation comprising a photometric frame in which a screen area is divided into a plurality of areas, and a narrow area photometric frame for photometrically measuring a predetermined part of the screen area and wider than a single range of the divided photometric frame. In the device, the plurality of photometric frames are divided into two left and right areas, and the position of the narrow area photometric frame is moved to the left or right according to a result of comparison of calculated values of photometric values in the respective areas. Photometric calculator. 5. A photometric calculation provided with a photometric frame in which a screen area is divided into a plurality of areas, and a narrow area photometric frame for photometrically measuring a predetermined portion of the screen area and wider than a single range of the divided photometric frame. In the device, the plurality of photometric frames are divided into four regions of up, down, left and right, and the position of the narrow range photometric frame is moved up, down, left and right according to the result of comparison of the calculated values of the photometric values in the respective regions. A characteristic photometric calculator. 6. The apparatus according to claim 3, wherein the device moves the position of the narrow area photometric frame based on the result of comparing the average values in the respective divided areas. Photometric calculator. 7. The photometric operation device according to claim 1, wherein the narrow-area photometric frame is a photometric frame for photometrically measuring the central portion of the screen. 8. The photometric value is determined based on the photometric value in the narrow area photometric frame.
Alternatively, the photometric calculation device described in 3 or 4 or 5 or 6 or 7. 9. A narrow-area photometric frame, comprising a wide-area photometric frame including the narrow-area photometric frame and measuring a wider range than the narrow-area photometric frame,
9. The photometric calculation device according to claim 1, wherein the photometric value is determined by calculating a photometric value with a wide area photometric frame.