JP3482666B2 - Field analysis device and exposure calculation device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention patterns an object scene.
The present invention relates to a field analysis device that analyzes the light and dark states of the field.
It Further, the present invention relates to an exposure calculation device used in a camera or the like, and more particularly to an exposure calculation device that calculates exposure by patterning a field.

[0002]

2. Description of the Related Art Conventionally, as an exposure calculation device for patterning a field and calculating exposure, for example, Japanese Patent Application Laid-Open No. 1-225 is known.
The one disclosed in Japanese Patent No. 927 is known.

The exposure calculation device disclosed in this publication binarizes a plurality of photometric outputs, compares the data with a prestored image pattern P as shown in FIG. 11, and finds a match. The processing is performed by recognizing the main subject.

[0004]

However, the conventional exposure calculation device has a problem that it is very difficult to binarize the photometric output.

That is, although the object scene may have a simple composition as shown in FIG. 12, for example, FIG.
When the composition becomes a little complicated as shown in (1), it becomes extremely difficult to binarize the scene, and it becomes difficult to pattern the scene.

Further, since the patterning of the object scene depends on the image patterns stored in advance, the stored image patterns can be patterned, but the unstored patterns can be patterned. There is a problem that the pattern cannot be formed and the subject cannot be recognized.

Therefore, if a large number of types of patterning are to be performed, the number of types of image patterns to be stored will increase proportionately, which may impose a burden on the memory and the calculation time.

The present invention has been made to solve such a conventional problem, and can be applied to any scene of a scene.
Easily pattern the scene and use it to capture the scene
A subject that can easily and reliably analyze the bright and dark states of the field
An object is to provide a field analysis device. It is another object of the present invention to provide an exposure calculation device capable of easily patterning an object scene in any object scene and providing an accurate and proper exposure based on the pattern.

[0009]

According to another aspect of the present invention, there is provided an exposure calculation device which uses a photometric means for dividing a field into a plurality of areas for photometry (for example, the photometric section 10 in FIG. 1) and an output of the photometry means. Spectrum analysis means for performing spectrum analysis of the object scene (for example, spectrum analysis section 13 in FIG. 1), and exposure calculation means for calculating appropriate exposure based on outputs from the photometric means and the spectrum analysis means ( For example, the exposure calculation unit 15) of FIG. 1 is provided, and the spectrum analysis unit pre-determines the array of the brightness values divided by the photometry unit .
Spectral decomposition into multiple predetermined luminance patterns
From a plurality of obtained spectrum values , a predetermined number of spectrum values p on the low frequency side and the high frequency side selected in advance
The spectrum analysis of the object scene is performed using (i, j).

According to a second aspect of the present invention, in the exposure calculation apparatus according to the first aspect, the photometric means performs photometry with a storage type photometric element. The exposure calculation device according to claim 3 is the exposure calculation device according to claim 1.
Alternatively, in 2, the photometric means divides the field into a matrix to perform photometry.

According to a fourth aspect of the present invention, in the third aspect of the present invention, in the third aspect , the photometric means is a power of 2 which is a division number of at least one of a horizontal direction and a vertical direction of the field divided into the matrix. It is what

According to a fifth aspect of the present invention, in the exposure calculation apparatus according to the first to fourth aspects, the spectrum analysis means performs spectrum analysis based on a two-dimensional discrete Walsh transform.

In the exposure calculation device according to a sixth aspect of the present invention, in the first to fifth aspects, the specific number of spectral values p (i, j) preselected by the spectrum analyzing means are mainly low frequency side spectral values. There is something. Subject field analyzing apparatus according to claim 7, the photometry means for metering by dividing the object field into a plurality (e.g., photometric unit 10 of FIG. 1), contact the photometric means
The array of brightness values obtained by divided
Spectrum analysis means for calculating a spectrum value p (i, j) of the object field by spectrally decomposing into a number of luminance patterns (for example, a plurality of light-dark patterns in FIG. 8); For each of the brightness patterns,
Prepare a calculation formula (for example, formula (9)) for calculating the exposure for the brightness value , and correspond each calculated value of the calculation formula.
Weighted according to the spectral value of the luminance pattern
And pattern analysis means for calculating the proper exposure .

[0014]

According to another aspect of the present invention, the exposure calculation device calculates the spectrum values of the low frequency side and high frequency side characteristic constants selected in advance by the spectrum analysis means, and the exposure calculation is performed based on these spectrum values. Since the appropriate exposure is calculated by the means, it is possible to quickly and accurately calculate the appropriate exposure value in correspondence with all patterns of the object scene.

According to another aspect of the exposure calculation device, photometry is performed by the accumulation type photometric element. In the exposure calculation device according to the third aspect, photometry is performed by dividing the field into a matrix.

According to another aspect of the exposure calculation device, the number of divisions of at least one of the horizontal and vertical directions of the field divided into a matrix is a power of two. In the exposure calculation device according to the fifth aspect, the spectrum analysis is performed based on the two-dimensional discrete Walsh transform.

In the exposure calculation device according to the sixth aspect, the low-frequency side spectrum value is mainly selected as the specific number of spectrum values. In the field analysis apparatus according to claim 7, an array of luminance values obtained by dividing and metering the field by the spectrum analysis means.
To a plurality of predetermined brightness patterns
By solving, the spectral value is calculated. Then, the divided photometry is performed for each of the plurality of luminance patterns.
Prepared in advance an arithmetic expression for calculating the exposure for the brightness value obtained by the pattern analysis means .
Weighted according to the spectral value of the corresponding luminance pattern
Calculate the appropriate exposure.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a block diagram of an embodiment of an exposure calculation device of the present invention, and FIG. 2 shows an optical system of a single-lens reflex camera to which this embodiment is applied.

In the optical system shown in FIG. 2, the light flux that has passed through the taking lens 1 passes through the quick return mirror 2, the diffusing screen 3, the condenser lens 4, the pentaprism 5, and the eyepiece lens 6 and reaches the eyes of the photographer. .

On the other hand, a part of the light flux diffused by the diffusing screen 3 reaches the accumulation type photometric element 9 through the condenser lens 4, the pentaprism 5, the photometric prism 7 and the photometric lens 8.

As shown in FIG. 1, the exposure calculation apparatus of this embodiment comprises a photometry section 10 for photometry of a field and a microprocessor 11 housed in a camera.

The photometry section 10 has the optical system shown in FIG. 2, and divides the object field into a matrix into 64 areas of vertical 8 divisions and horizontal 8 divisions for photometry, and the respective photometric data and outputs to the luminance calculation unit 1 2.

FIG. 3 is a view showing the state of photometry division of the photometry section 10 in comparison with the field of view. The field of view is divided into a matrix of 64 regions of vertical 8 divisions and horizontal 8 divisions. ing.

The microprocessor 11 controls all of the inside of the camera by the program written therein, and the brightness calculating section 12 and the spectrum analyzing section 1
3, the pattern brightness calculation unit 14 and the exposure calculation unit 15,
All are realized by a program in the microprocessor 11.

The brightness calculation unit 12 inputs the photometric data of each area obtained by the photometric unit 10, converts the 64 photometric data into brightness values, and outputs bv (h, v) (where h = 0 to 0). 7,
Substitute v = 0 to 7).

Here, bv (0,0) represents the upper left luminance value in FIG. 3, and bv (7,7) represents the lower right luminance value. The spectrum analysis unit 13 includes the brightness calculation unit 12
Based on the output of, the spectral analysis of the field is performed using the method of the two-dimensional discrete Walsh transform.

Now, the two-dimensional discrete Walsh transform will be described. Generally, the two-dimensional discrete Walsh transform is defined as an extension of the one-dimensional discrete Walsh transform, is applied to two-dimensional data such as image data, and is used for pattern recognition, image analysis and the like.

Here, for simplicity, it will be simply referred to as a two-dimensional Walsh transform. Two-dimensional Walsh transform is 1
It is defined using the dimensional Walsh function WAL (m, n).

Here, the one-dimensional Walsh function WAL
(M, n) is the power of 2 when the number of data N is
N is a one-dimensional functional system with N as the period, and m,
The values taken by n are as in equations (1) and (2), respectively.

[0030]

[Equation 1]

[0031]

[Equation 2]

For example, when N = 8, 8 as shown in FIG.
One one-dimensional Walsh function WAL (m, n) corresponds, and this one-dimensional Walsh function WAL (m, n) is
Generally, it is defined by the following formulas (3) to (6).

[0033]

[Equation 3]

[0034]

[Equation 4]

[0035]

[Equation 5]

[0036]

[Equation 6]

Here, int (x) is a function for obtaining an integer of x. And two one-dimensional Walsh functions W
A two-dimensional Walsh function Wmq (n, k) is defined as a mathematical expression (7) using AL (m, n) and WAL (q, k).

[0038]

[Equation 7]

As shown in FIG. 5, this Wmq (n, k) gives a value at a point X = n, Y = k when the wave number in the X direction is m and the wave number in the Y direction is q. For example, if the maximum values N and K of n and k are 8 respectively,
As the two-dimensional Walsh function Wmq (n, k), 64 groups of functions W00 to W77 as shown in FIG. 6 are obtained.

In FIG. 6, the white part indicates +1 in the function of FIG. 5, and the black part indicates -1. Then, as shown in FIG.
The two-dimensional data d (n,
The two-dimensional Walsh transform is realized by performing the correlation operation between the k) and the two-dimensional Walsh function Wmq (n, k).

The two-dimensional data d (n, k) is n
Xk data, and in this embodiment, the data shown in FIG.
8 × 8 = 64 luminance values bv (h, v) correspond to.
Here, in general, if the Walsh transform spectrum for two-dimensional data d (n, k) is G (m, q), then G
(M, q) is given by Expression (8).

[0042]

[Equation 8]

The two-dimensional Walsh transform spectrum G (m, q) thus obtained is the two-dimensional data d (n,
It represents the spatial feature of k) and is widely used for pattern analysis and the like.

In the spectrum analysis unit 13, among the eight kinds of one-dimensional Walsh functions WAL (0, n) to WAL (7, n) shown in FIG. , Five types of one-dimensional Walsh functions s (0, y) to s (4, y), where y = 0 to 7 are suitable for extracting the feature of the object scene.

Here, the functions s (0, y), s
(1, y), s (2, y), s (3, y) and s
(4, y) is the one-dimensional Walsh function WAL in FIG.
(0, n), WAL (1, n), WAL (2, n), W
It corresponds to AL (3, n) and WAL (7, n) respectively, and the one-dimensional Walsh function WAL (4,4 in FIG.
n), WAL (5, n) and WAL (6, n) are excluded.

This is because the composition is relatively simple in most shooting scenes, and the features of the field are easier to extract in the low-frequency spectrum. Further, the function s (4, y) on the high frequency side is left in order to extract a relatively special fine pattern such as a sunbeam.

Then, the two-dimensional Walsh function ss (i, j, h, v) is obtained from these functions s (i, h) and s (j, v) using the equation (7). Here,
The functions s (i, h) and s (j, v) correspond to the one-dimensional Walsh functions WAL (m, n) and WAL (q, k) in the above description of the two-dimensional Walsh transform, respectively, and Dimensional Walsh function ss (i, j, h,
v) corresponds to the two-dimensional Walsh function Wmq (n, k).

In FIG. 8, the two-dimensional Walsh function ss (i,
Although j, h, v) luminance patterns are shown, they are simply described as ssij, (i = 0 to 4, j = 0 to 4) in the figure for simplicity.

The two-dimensional Walsh function s shown in FIG.
The luminance pattern of s (i, j, h, v) corresponds to 5 × 5 = 25 luminance patterns shown by the chain double-dashed line in FIG.

Further, the spectrum analysis unit 13 calculates the brightness value bv (h, v) calculated by the brightness calculation unit 12 and the two-dimensional Walsh function ss (i, j, h,) calculated above.
v) and the mathematical expression (8) from the two-dimensional Walsh transform spectrum p (i, j), (where i = 0 to 4, j = 0 to
4) is asked.

Two-dimensional Walsh transform spectrum p
(I, j) corresponds to the two-dimensional Walsh transform spectrum G (m, q) in the above description of the two-dimensional Walsh transform.

Here, what is meant by the absolute value of the two-dimensional Walsh transform spectrum p (i, j) is that the scene scene at the time of photometry is regarded as the scene scene with each spectrum pattern of FIG. It is the degree of inclusion of each luminance pattern component at the time.

The two-dimensional Walsh transform spectrum p
The sign (i, j) indicates the direction of lightness and darkness of the luminance pattern, which is positive when the directions of lightness and darkness match and becomes negative when they do not match.

That is, to explain in an easy-to-understand manner with reference to FIG. 13 described above, in the scene as shown in FIG. 13, the lightness and darkness of the object scene are clearly separated at the top and bottom, and ss (0, 1, h, It is similar to the luminance pattern ss01 of v).

Therefore, the value of the spectrum p (0,1) with ss (0,1, h, v) becomes larger than the other spectrum values. Also, in the scene of FIG. 13, since the top side is bright and the ground side is dark, the directions of light and dark coincide with ss (0,1, h, v), and the sign of p (0,1) is positive.

The pattern brightness calculation unit 14 is the brightness calculation unit 1
By using the luminance value bv (h, v) of 2 and the two-dimensional Walsh function ss (i, j, h, v) of the spectrum analysis unit 13, the average luminance value bvw (i, j) for each luminance pattern. And bvb (i, j) are calculated.

Here, bvw (i, j) is the average of the brightness values corresponding to the white part when the brightness pattern of ss (i, j, h, v) in FIG. 8 is compared with the field. Similarly, bvb (i, j) is an average value of the brightness values of the black portion.

For example, bvw (0,1) is ss of FIG.
As can be seen from 01, it is an average luminance value of the upper half of the object scene, and bvb (0,1) is an average luminance value of the lower half of the object scene.

The details of the pattern brightness calculation section 14 will be described later with reference to FIG. The exposure calculation unit 15 outputs the two-dimensional Walsh transform spectrum p (i, j) output from the spectrum analysis unit 13 and the outputs bvw (i, j) and bvb output from the pattern brightness calculation unit 14.
Using (i, j), the proper exposure value BVans is calculated in the following order.

First, the exposure value BVpt for each luminance pattern is obtained using the following equation (9).

[0061]

[Equation 9]

Here, for simplicity, BVpt
(I, j) is abbreviated as BVpt and described. Therefore, w1 is w1 (i, j), w2 is w2 (i, j), w
3 is w3 (i, j), w4 is w4 (i, j), w5 is w
5 (i, j), bvw is bvw (i, j), bvb is b
Let vb (i, j) and bvx represent bvx (i, j), and bvn represent bvn (i, j).

Further, bvx (i, j) and bvn
(I, j) are expressed by the following equations (10) and (11), respectively, bvw (i, j) and bvb (i,
j) maximum and minimum values.

[0064]

[Equation 10]

[0065]

[Equation 11]

Further, w1 (i, j) to w in the equation (9)
4 (i, j) is the exposure value BVpt for each brightness pattern, which is the average brightness value for each brightness pattern such as bvw (i, j).
W5 is a constant indicating the degree of contribution to (i, j).
(I, j) is a constant term.

These constant values are given for each luminance pattern.
For example, it is set to an appropriate value in advance by known neuro learning or the like and described in the program. Then, using the exposure value BVpt (i, j) for each of these luminance patterns, the proper exposure value BVans is calculated as in Expression (12).

[0068]

[Equation 12]

Here, Abs (x) is a function for obtaining the absolute value of x. Next, the program in the microprocessor 11 will be described in detail with reference to the flowcharts shown in FIGS. 9 and 10.

First, the power switch of the camera is turned on by half-pressing a release button (not shown) attached to the camera, and the main algorithm shown in FIG. 9 is executed. First, the photometry of the object field is performed by the photometry unit 10, and 6
Photometric data of four areas are obtained (step S101).

Next, the brightness calculator 12 calculates the brightness values bv (h, v) from the photometric data of the 64 areas (step S102). Next, the spectrum analysis unit 13 performs spectrum analysis by the above-described method, and 25 spectrum values, that is, 25 two-dimensional Walsh transform spectra p (i, j), (i = 0 to 0).
4, j = 0 to 4) is calculated (step S103).

Next, the pattern brightness calculation unit 14
bvw (i, j), bvb (i, j), bvx (i,
j), bvn (i, j), (i = 0 to 4, j = 0 to 4)
Is calculated (step S104).

After that, the appropriate exposure value BVans is calculated by the formulas (9) to (12) using the respective values obtained in step S103 and step S104 (step S105).

Next, it is determined whether or not the release button (not shown) has been fully pressed (step S106), and when fully pressed, exposure control based on the proper exposure value BVans is performed (step S107).

On the other hand, if it is not fully pressed, it is determined whether or not the half-press timer has expired (step S108). If so, the program is terminated.

Next, the operation of the pattern brightness calculation section 14 will be described in detail with reference to the flow chart shown in FIG. By executing step S104 of the main algorithm shown in FIG. 9, the subroutine algorithm of FIG. 10 is activated and the processing is started.

First, 0 is substituted for i and j (step S201), and then 0 is substituted for h and v (step S202). Next, wsum, bsum, wn,
0 is substituted for each bn (step S203).

Next, the two-dimensional Walsh function ss (i,
It is determined whether or not j, h, v) is 1 (step S204), and if it is 1, the process according to the following equation (13) is performed (step S205), and then wn is set. 1 is added (step S206).

[0079]

[Equation 13]

Two-dimensional Walsh function ss (i, j, h,
When v) is not 1, that is, when it is -1, the processing of the mathematical expression (14) described below is performed (step S20).
7) Next, 1 is added to bn (step S20).
8).

[0081]

[Equation 14]

Then, 1 is added to h (step S209), and then it is determined whether h is greater than 7 (step S210). If not, the process proceeds to step S204. Returned, if positive, h is 0
Is cleared (step S211).

Next, 1 is added to v (step S21).
2) Then, it is determined whether v is greater than 7 (step S213). If not, step 20
Returning to step 4, if affirmative, v is cleared to 0 (step S214).

Next, the average luminance value bvw for each luminance pattern is calculated by the following equations (15) and (16).
(I, j) and bvb (i, j) are calculated (step S215).

[0085]

[Equation 15]

[0086]

[Equation 16]

Here, in the case of the luminance pattern of ss00 in FIG. 8, since wn is 64 and bn is 0, bvb (i, j) is 0. Next, bvx (i,
j) and bvn (i, j) are calculated (step S
216).

Thereafter, 1 is added to i (step S2
17) Next, it is determined whether i is greater than 4 (step S218), and if negative, step 203
Returning to the processing of (1), if affirmative, i is cleared to 0 (step S219).

Next, 1 is added to j (step S22).
0) and thereafter, it is determined whether j is larger than 4 (step S221). If negative, the process returns to step 203, and if affirmative, the process ends.

Thus, in the above-described exposure calculation device, the spectrum analysis unit 13 calculates a specific number of spectral values selected in advance, and the exposure calculation unit 15 calculates the proper exposure based on these spectrum values. Therefore, it is possible to easily pattern the object scene in any object scene, and to provide accurate and proper exposure quickly based on the pattern.

Further, since photometry is performed by the accumulation type photometric device 9, the number of photometric divisions can be increased. Further, since the object field is divided into a matrix and photometry is performed, spectrum analysis becomes easy.

Further, since the number of divisions in the horizontal direction and the vertical direction of the object field divided in a matrix is a power of 2, spectrum analysis becomes easy. Furthermore, since the spectrum analysis is performed based on the two-dimensional discrete Walsh transform, the spectrum analysis can be performed at high speed.

In the exposure calculation apparatus described above, the spectrum value on the low frequency side is mainly selected as the specific number of spectrum values, so that the feature of the object scene can be efficiently extracted.

In the above-described embodiment, an example in which the spectrum calculation is performed based on the two-dimensional Walsh transform method has been described. However, the present invention is not limited to this embodiment, and for example, two-dimensional It goes without saying that the spectrum calculation may be performed using a method such as Fourier transform, discrete cosine transform, discrete sine transform, or the like.

For example, when using the two-dimensional discrete Fourier transform, instead of the equation (8), the following equation (1
7) may be used.

[0096]

[Equation 17]

Since the solution of Expression (17) is a complex number, the power spectrum value which is the sum of squares of the real number part and the imaginary number part or the amplitude spectrum value which is the square root thereof is used as the spectrum value.

As an expression corresponding to ss (i, j, h, v), the following expression (1) obtained by expanding expression (17) is used.
8) can be applied.

[0099]

[Equation 18]

In this equation, θ is given by the following equation (19).

[0101]

[Formula 19]

Here, H and V are the numbers of divisions of the photometric element 9 in the horizontal and vertical directions.

[0103]

As described above, in the exposure calculation device according to the first aspect of the present invention, the low- light preselected by the spectrum analysis means is used.
A specific number of spectrum values on the high-frequency side and the high-frequency side are calculated, and the proper exposure is calculated by the exposure calculation means based on these spectrum values, so that it is easy to pattern the scene in any scene. And an accurate and proper exposure can be quickly given based on the above.

In the exposure calculation device of the second aspect, since the photometry is performed by the accumulation type photometry element, the number of photometry divisions can be increased. In the exposure calculation device according to the third aspect, the photometry is performed by dividing the object field into a matrix shape, and therefore spectrum analysis is facilitated.

In the exposure calculation device according to the fourth aspect, since the number of divisions of at least one of the horizontal and vertical directions of the field divided into the matrix is a power of 2, spectrum analysis becomes easy.

In the exposure calculation device according to the fifth aspect, the spectrum analysis is performed based on the two-dimensional discrete Walsh transform, so that the spectrum analysis can be performed at high speed. In exposure calculation device according to claim 6, as the spectral value of the specific number, the spectral value of the main low-frequency side to be selected, Ru can be extracted efficiently characteristics of the object scene. Claim 7
In the field analysis device, the pattern analysis means having a plurality of arithmetic expressions corresponding to a plurality of luminance patterns changes the weights acting on the plurality of arithmetic expressions according to the spectrum value to calculate the final arithmetic result. By doing so, it is possible to easily and surely analyze the bright and dark states of the object scene.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of an exposure calculation device of the present invention.

FIG. 2 is an explanatory diagram showing an optical system of a camera to which the exposure calculation apparatus of FIG. 1 is applied.

FIG. 3 is an explanatory diagram showing a divided state of a photometric element of the exposure calculation apparatus of FIG.

FIG. 4 is an explanatory diagram showing an example of a one-dimensional Walsh function.

FIG. 5 is an explanatory diagram showing a configuration example of a two-dimensional Walsh function.

FIG. 6 is an explanatory diagram showing a two-dimensional Walsh function configured in wave number order.

7 is an explanatory diagram showing a correlation calculation function of the exposure calculation device of FIG. 1. FIG.

8 is an explanatory diagram showing the correlation calculation functions of the exposure calculation device of FIG. 1 in wave number order.

FIG. 9 is a flowchart showing a main algorithm of the exposure calculation device of FIG. 1.

10 is a flowchart showing a subroutine algorithm of step S104 of FIG.

FIG. 11 is an explanatory diagram showing an image pattern in a conventional technique.

FIG. 12 is an explanatory diagram showing a scene with a simple composition.

FIG. 13 is an explanatory diagram showing a scene with a complicated composition.

[Explanation of symbols]

1 Shooting lens 2 quick return mirror 3 diffusion screen 4 condenser lens 5 penta prism 6 eyepiece 7 Photometric prism 8 Photometric lens 9 Photometric element 10 Photometric section 11 microprocessors 12 Luminance calculation unit 13 Spectral analysis section 14 Pattern brightness calculation unit 15 Exposure calculator

Continuation of the front page (56) Reference JP-A-5-196858 (JP, A) JP-A-3-262278 (JP, A) JP-A-1-225927 (JP, A) JP-A-2-96725 (JP , A) JP-A-2-61543 (JP, A) JP-A-4-47454 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03B 7/28 G01J 1/44 G03B 7/099

Claims (7)

(57) [Claims] 1. A photometric means for dividing a field into a plurality of areas for photometry, a spectrum analysis means for performing spectrum analysis of the field using an output of the photometry means, the photometry means and the spectrum analysis means. Exposure calculation means for calculating an appropriate exposure on the basis of the output of, and the spectrum analysis means, the array of brightness values divided by the photometry means ,
Spectral decomposition into multiple predetermined brightness patterns
An exposure calculation apparatus, which performs spectral analysis of a field using a predetermined number of low-frequency side and high-frequency side spectral values selected in advance from a plurality of obtained spectral values. 2. The exposure calculation device according to claim 1, wherein the photometric means performs photometry with a storage-type photometric element. 3. The exposure calculation device according to claim 1, wherein the photometric means divides the object field into a matrix to perform photometry. 4. The photometric means sets the division number of at least one of the horizontal direction and the vertical direction of the object field divided into the matrix shape to a power of two. Exposure calculator. 5. The exposure calculation apparatus according to claim 1 , wherein the spectrum analysis unit performs spectrum analysis based on a two-dimensional discrete Walsh transform. 6. The exposure calculation according to claim 1, wherein the specific number of spectral values preselected by the spectral analysis means are mainly low-frequency spectral values. apparatus. 7. A photometric means for dividing a field into a plurality of areas for photometry, and an array of brightness values divided by the photometry means.
Spectral decomposition into multiple predetermined brightness patterns
The spectral analysis means for calculating the spectral value of the object field, and the divided photometric brightness for each of the plurality of luminance patterns.
Prepare an arithmetic expression to calculate exposure for the degree value in advance, and
Each calculated value of the arithmetic expression is the spectrum of the corresponding luminance pattern.
And a pattern analysis means for calculating a proper exposure by weighting according to the rule value .