JP2963573B2 - Photographic printing apparatus and exposure condition determination method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure condition determining method and a photographic printing apparatus to which the exposure condition determining method is applied.

[0002]

2. Description of the Related Art Images recorded on a color negative film are B
(Blue), G (green), and R (red) are transmitted.
It is empirically known that the transmission ratios of these three color components are generally approximately equal or constant. Therefore, the photographic printing apparatus determines the exposure condition based on the following equation.

LogEj = Kj + Dj (1) where logE is the logarithm of the exposure, K is a constant, D is the integrated transmission density (LATD) of the image measured by the photometric system, and j is the R, G, B Any color light. In addition, the above (1)
When an image is printed with a photographic printing device under the exposure conditions determined based on the formula, the prints from the underexposed image have a higher overall density than the prints from the properly exposed image, and the overexposed image is printed. Prints from have lower density. For this reason, slope control is performed to correct Dj in equation (1) and determine the exposure conditions.
However, the characteristics such as sensitivity and density of the three photosensitive layers of the film are different for each film type classified according to the manufacturer and the sensitivity, and the film types differ depending on the exposure conditions determined as described above. Prints under the same exposure conditions cannot provide a print with a constant and good finish.

[0004] Therefore, as a method of correcting the film type difference and printing properly, a method and apparatus for specifying the amount of light for copying a color original (Japanese Patent Laid-Open No.
-46741) has already been proposed. In this light amount defining method, a plurality of image frames recorded on one film to be printed are measured, and a color density difference characteristic curve relating to an average density is created to obtain a film characteristic value representing the characteristics of the film. The photometric value (original eigenvalue) is corrected with the film eigenvalue to obtain the Dj, thereby determining the exposure condition.

The photometric value of an image frame recorded on a film is affected by the characteristics of the film and the like, and the film specific value obtained by the above method reflects the characteristics of each film. Therefore, by using this film unique value, an exposure condition in which the film type difference is corrected can be obtained. Further, when the image frame is discolored due to the aging of the film, it is desirable to change the exposure amount from the standard exposure amount and print according to the degree of the aging deterioration. The photometric value changes in accordance with the change in the film characteristics due to the above-mentioned factors, and the film-specific value changes. As a result, a good print in which the influence of the deterioration over time is corrected can be obtained. In addition, when almost all of the image frames recorded on the film are photographed using different types of light sources other than sunlight, good results can be obtained as in the case of deterioration over time.

However, the above-described light amount defining method has a drawback that good results cannot be obtained when many of the image frames recorded on one film are image frames in which color fear is likely to occur. Do you get it. That is, an image frame in which a large number of color feria tend to occur continuously in one film, for example, an image frame in which green or summer blue sky and the sea such as trees and flowers are taken as an object, or an image shot on a lawn in a park or the like. It has been found that it is difficult to accurately determine the film unique value in an image frame or the like obtained by shooting a frame, a sports scene in a ground under bright sunlight, or the like.

[0007] Since image frames in which color fear is likely to occur are deviated from image frames in which a general subject has a high integrated transmission density of a specific color and a general color balance, many image frames in which color fear is likely to occur are recorded. This is because the film intrinsic value of the film thus obtained changes under the influence of color feria and does not sufficiently reflect the characteristics of the film. When the image frames are printed under the exposure conditions determined using the film-specific values, the main subject is printed out of an appropriate color balance. this is,
For example, about half of the image frames of one film are also affected by a case where color fear is likely to occur, so that the above-mentioned problem frequently occurs.

As another means for correcting the difference in film type and printing properly, a code indicating the film type recorded on the film is read, and the image density is classified by film type based on the code to determine the image density. A photographic printing exposure amount determining device (e.g., Japanese Patent Application Laid-Open No.
No. 93448). Further, the photometric data is classified by judging to which of the plurality of divided color regions on the color coordinates the three-color photometric data of the film belongs, and the colorimetric data belonging to the color region having a small color difference or color ratio from the reference value is classified. An exposure determining method for an image copying apparatus that determines an exposure based on a representative value or a reference value of the first image data and the first image data (JP-A-2-90140) has also been proposed.

[0009] In the above, based on the idea that films of the same film type have similar characteristics of the film and have the same tendency in the color balance and the like of the recorded image frames, a large number of films are formed over a long period of time. Is stored for each film type, and the exposure condition is determined based on the data for each film type and the data of the image frame to be printed. Thus, even when there are a large number of image frames on which a color fear is likely to occur among the image frames recorded on the film to be printed, the influence of the color feria can be almost eliminated. However, when compared with the above-described light amount defining method, for example, even if the film has deteriorated with time, a change in the characteristics of the film due to the deterioration with time is less likely to be reflected in the exposure conditions, and a good print result cannot be obtained. I found it. The same applies to the case of printing an image frame shot with a different light source.

The present invention has been made in consideration of the above facts, and can eliminate the influence of color feria and always obtain high-quality prints regardless of changes in film characteristics due to aging or the like. It is an object to obtain a photographic printing apparatus and a method for determining exposure conditions that can be performed.

[0011]

According to a first aspect of the present invention, there is provided a photometric device which divides an image frame recorded on a film into a plurality of photometric units, and performs photometry by the photometric unit. Selecting means for selecting photometric data necessary for exposure condition determination among a large number of obtained photometric data,
First storage means for storing data obtained by the photometry over a large number of films, and storing data obtained by the photometry for an image frame of a single film on which an image frame to be printed is recorded. Second storage means;
And selecting data of an image frame baking selected by the selection means, the first data obtained from the data stored in said first storage means is determined from the data stored in said second storage means Weighting factor setting means for setting a weighting factor to be given to each of the second data; and exposure based on a value obtained by adding each of the data to the weighting factor set by the weighting factor setting means. And exposure condition determining means for determining conditions.

The first storage means and the second storage means store photometric data or an average value for each density of the photometric data as the data obtained by the photometry. Density data corresponding to the density of the selected data obtained from the data stored in the storage means and the second storage means can be used.

Preferably, the selection means selects data necessary for determining an exposure condition based on the data stored in the first storage means.

It is preferable that the weighting factor setting means changes a weighting factor assigned to each of the data according to the color balance bias of the selected data.

According to a fifth aspect of the present invention, an image frame to be printed is divided into a large number of pieces, photometry is performed, photometric data necessary for determining exposure conditions is selected, and the selected photometric data and a plurality of films are applied. the first was determined from data obtained by photometry Te
And first data, the second data obtained from the photometric-obtained data to the image frames of a single film image frame is recorded baking, each weighting factor to be applied to the set, An exposure condition is determined based on a value obtained by adding the weight coefficient to each of the data.

[0016]

According to the first aspect of the present invention, the data obtained by photometry is stored in the first storage means over a large number of films, and the image frames to be printed are recorded on a single film frame. The data obtained by photometry is
In the storage means. In addition, as the data obtained by the photometry, photometry data, selected data selected from the photometry data necessary for determining the exposure condition, and the average value of each of the photometry data or the selected data classified and classified by density. The result of the calculation can be adopted.
First data by the weighting coefficient setting means includes a selection data selected photometric data necessary for exposure condition determination of the plurality of photometric data of image frames baking, obtained from the data stored in the first storage means If, sets the weighting factor to be applied and a second data obtained from the data stored in the second storage means, each of.

Note that data (first data ) obtained from the data stored in the first storage means and the second storage means is used.
As the second data, it is preferable to adopt data of a density corresponding to the density of the selected data. Generally, the stored data has a three-color balance depending on the density. Therefore, it is necessary to use data having a three-color balance at the same density as the image frame. Further, since the balance of these three colors differs depending on the film type, it is necessary to obtain the balance from the stored data. In the data obtained by photometry over a large number of films, the hue obtained by integrating the densities of the three colors is gray or a constant hue close to gray. On the other hand, the data obtained by photometry on the image frame of a single film on which the image frame to be printed is recorded is the color balance obtained by integrating the densities of the three colors. The characteristics of the film (e.g., three-color sensitivity balance, three-color gradation balance, three-color density balance, etc.) including changes due to aging are reflected.

[0018] Thus, the selection data, the first data from the first storage means, a second data <br/> data from the second storage means, with respect to, for example, from the first storage means When the weighting factor is set so that the weight of the first data becomes large, the value obtained by adding the weighting factor to each of the data sets the selected data to the gray hue. This corresponds to the result of correcting the image frame of the image frame so as to be close to the photometry data obtained by photometry. Therefore, from the photometric data of the image frame in which the color fear is likely to occur, it is possible to obtain the exposure condition excluding the influence of the color feria based on the value added with the weight coefficient.

When the weighting factor is set so that the weight of the second data from the second storage means is increased, the value added with the weighting factor records the selected data on the film. This corresponds to the result of correction so as to reflect the tendency of the overall color balance of the changed image frame and the change in film characteristics. Therefore, when the film characteristics are changed due to, for example, aging, the exposure condition corrected according to the degree of the change in the characteristics is obtained. Further, for example, in a case where only the image frame to be printed is an image frame captured by a different light source, if a weighting factor is set so that the weight to the selected data is increased, the light source may differ from other image frames. Appropriate exposure conditions can be obtained without being affected by differences in color balance and the like.

As described above, by appropriately setting the weighting factors to be assigned to the respective data, the influence of color feria can be eliminated, and high quality prints can be obtained regardless of changes in film characteristics due to aging or the like. Can be obtained.

Preferably, the selection means selects data necessary for determining the exposure condition based on the data stored in the first storage means. As described above, the data obtained by photometry over a number of films is stored in the first storage means because the hue obtained by integrating the densities of the three colors is gray or a constant hue close to gray. If the photometric data is selected based on the data, the influence of the subject color on the selected data can be reduced. If the selected data thus selected is stored in the first storage means and the second storage means, more appropriate exposure conditions can be obtained based on the data.

When the amount of data stored in the second storage means is small, the data stored in the second storage means sufficiently represents the overall color balance of the image frame recorded on the film. Accuracy is low. In such a case, if the weight given to the data from the second storage means is increased, an appropriate exposure condition cannot be obtained.
In accordance with this purpose, the weighting factor setting means increases the amount of data stored in the second storage unit, the second data
It is preferable that weights for data sets the weighting factor to be relatively large. Thus, appropriate exposure conditions can be obtained regardless of the amount of data stored in the second storage means.

When the color balance of the selected data is biased, it is preferable to change the weighting factor assigned to each data. For example, when the image to be printed is an image in which color fear is likely to occur, the color balance of the selected data is biased toward a specific color, and the data in the second storage unit is also affected by this. If the weight coefficient is changed so that the weight of the first data from the means becomes large, it is possible to obtain the exposure condition excluding the influence of color feria as described above. Further, for example, even when the film characteristics of the film on which the image frame to be printed is changed due to aging or the like, the selection data and the second storage
Although bias occurs in the color balance of the second data from, by changing the weighting coefficients such weight increases to the second data from the second storage means, the change in the film properties as described above Regardless, appropriate exposure conditions can be obtained.

According to the fifth aspect of the present invention, the photometry data selected by photometry of an image frame to be printed, the first data obtained from data obtained by photometry over a large number of films, and the image to be printed. A second value obtained from data obtained by photometry on a single film image frame on which the frame is recorded .
And data, set the weight coefficient to be applied to each, to determine the exposure condition based on the value obtained by adding the weighting factors assigned to each of the respective data. Therefore, as described in the operation section of the first aspect of the present invention, by appropriately setting the weighting factors assigned to the respective data, it is possible to eliminate the influence of color feria and to prevent the film from deteriorating with time. High quality prints can always be obtained without being affected by changes in characteristics.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic configuration of a photographic printing apparatus 10 to which the present invention can be applied. The color negative film 20 set on a negative carrier (not shown) is transported to a printing position by the negative carrier. A mirror box 18 and a lamp house 12 having a halogen lamp are arranged below the printing position. A light control filter unit 60 is disposed between the mirror box 18 and the lamp house 12. The dimming filter unit 60 includes three CC filters of a Y (yellow) filter, an M (magenta) filter, and a C (cyan) filter.

Above the printing position, a lens 22, a black shutter 24, and a color paper 26 are arranged in this order. Each of the filters of the light control filter unit 60 emitted from the lamp house 12, the mirror box 18, and the negative film 20 are arranged. Are formed on the color paper 26 by the lens 22. A photometer 28 is arranged in a direction inclined with respect to the optical axis of the image forming optical system and at a position where the image density recorded on the negative film 20 can be measured. The photometer 28 is composed of a two-dimensional image sensor, a line sensor, and the like. As shown in FIG. 2, an image frame recorded on the negative film 20 is divided into a number of pixels Sn, and photometry is performed along a scanning line SL. I do. In this case, the photometry of each pixel is performed for each of the R, G, and B primary colors.

The photometer 28 is connected to an arithmetic circuit 30 composed of a microcomputer and its peripheral devices. In FIG. 1, various processes performed by the arithmetic circuit 30 are shown separately in a normalizing unit 44, a selecting unit 38, and an exposure condition determining unit 40. The arithmetic circuit 30 further includes a first storage unit 34 for storing data, A second storage unit 36 is provided. The first storage means 34 is, for example, an EEPROM (El
It is composed of a rewritable nonvolatile memory such as an ectrically erasable programmable ROM (ROM) and a RAM connected to a backup power supply, and can retain stored photometric data even when power supply is stopped. On the other hand, the second storage means 36 is a volatile memory (for example, a normal RA).
M) and the like.

The photometric data obtained by the photometer 28 is input to the normalizing means 44, where the data is standardized as described later. The selecting unit 38 selects only the photometric data necessary for determining the exposure condition from the standardized photometric data, and outputs the selected data to the first storage unit 34, the second storage unit 36, and the exposure condition determining unit 40. Exposure condition determining means 40
Sets a weighting factor for assigning data input from the selection unit 38, the first storage unit 34, and the second storage unit 36 to each of them, and based on the weighted integrated value calculated using the weighting factor. Determine the exposure conditions. The exposure condition determination means 40 is connected to the exposure control circuit 42. The exposure control circuit 42 controls the light exposure filter unit 60 based on the exposure conditions determined by the exposure condition setting means 40, thereby controlling the exposure conditions for printing on the color paper 26.

Next, the operation of the first embodiment will be described with reference to the flowchart of FIG. Note that the flowchart of FIG. 8 is executed each time one negative film 20 for printing is set in the photographic printing apparatus 10.

In step 100, the leading image frame of the negative film 20 is positioned at the printing position. Step 10
In step 2, the positioned image frame is divided into a large number of areas by the photometer 28, and each area is measured. In step 104, a large number of three-color photometric data obtained by the photometry is taken.

In the next step 105, the R and R of the negative film 20 stored in the memory of the arithmetic circuit 30 in advance are set.
Using the average mask densities for each of G and B and the three-color photometric data captured in step 104, the three-color low-density portion photometric data MIN (R), MIN (G), and MIN are as follows.
(B) is calculated and stored in the memory 34. The average mask density is obtained by averaging the mask densities of various films or the minimum densities of various films.

From the average mask density, a predetermined value α (for example, 0
The large value is compared with the lowest density value of the three-color photometric data or the average value of the three-color photometric data, and (average mask density + α)> (lowest density value of the three-color photometric data or (The average value of the three-color photometric data), the lowest density value of the three-color photometric data or the average value of the three-color photometric data is defined as the low-density portion photometric data. On the other hand, (average mask density +
If α) <(the lowest density value of the three-color photometry data or the average value of the three-color photometry data), a value larger than the average mask density by a predetermined value α is defined as the low-density portion photometry data. Since the low-density portion photometric data is determined as described above, the low-density portion photometric data is the lowest density data of the image recording portion of the negative film 20 and the lowest density data (mask) of the non-image portion of the color film. Concentration).

As shown in FIG. 3, the lowest density value of the three-color photometry data when the photometry area 32 of the photometer 28 extends over the image frames 20A and 20B is defined as low-density portion photometry data. Is also good. In addition, before executing Step 100, the non-image portion of the negative film 20 may be measured in advance, and the low-density portion photometric data may be calculated using the photometric result. Alternatively, the mask density or the mask color may be obtained from the image photometric data using a prediction function formula. Since the mask density is compared by the color difference or the color ratio as described above, it is preferable to use the mask density as the color difference or the color ratio of the mask as described above.

In step 106, based on the data stored in the first storage means 34, the photometric data is standardized as described below. First, low-density portion photometric data MIN (R), M
The three-color corrected photometric data R, G, and B are calculated by subtracting IN (G) and MIN (B). Next, the corrected photometric data R and B are normalized (normalized) by converting them into the density of G using the normalization table shown in FIG.
The standardized photometric data for each of G and B is obtained. Negative films have different film densities and gradation balances depending on the film type and development processing, and even if the same subject is photographed, the image density and color will differ depending on the film type and development processing. The photometric data is converted so that the same subject has a constant density and color regardless of the film type and the development processing.

The standardization table is created based on the data stored in the first storage means 32.
In the first storage means 32, the selected photometric data obtained by the processing of step 108 described later from the photometric data of the image frames printed so far over a large number of negative films 20 is classified and classified by density. The result of calculating the average value for each of R, G, and B of the photometric data belonging to each group is stored (see Table 1 below as an example).

[0036]

[Table 1]

The above data is obtained by classifying photometric data based on G density and calculating an average value.
The average value may be calculated based on the B concentration. Since the average value of the photometric data is the average value of the photometric values of a large number of frames, the hue obtained by integrating the average values of the G density, R density, and B density of each group is gray or gray. A constant hue close to. The standardization table is created by plotting on a plane coordinate having the horizontal axis the G density and the vertical axis the R density and the B density as shown in FIG. , A curve indicating the relationship between the average value of the photometric data G and the average value of the photometric data R, and a curve indicating the relationship between the average value of the photometric data G and the average value of the photometric data B.

In the above description, the photometric data of all image frames is standardized using the standardization table created from the data stored in the first storage means 34. The photometric data of the image frames after the first several frames may be normalized using a standardization table created from the data stored in the second storage unit 36.

In step 106, the corrected photometric data R and B are converted into G density using the above-mentioned standardization table.
For example, in FIG. 4, the average value R ′ of the corrected photometric data of R is G
'Is converted to an average value B of the correction photometric data of B' _R are converted similarly to G _B '. At this time, the corrected photometric data G is used without conversion. As the standardization method, other than the above, JP-A-56-1039 and JP-A-6
The method described in JP-A-2-144158 can be used. By standardizing such corrected photometric data, the same color coordinates can be used even if the film type and the like are different.

In the next step 108, as shown in FIG. 5, the color coordinates having the difference RG between the normalized data R and G as the horizontal axis and the difference GB between the normalized data G and B as the vertical axis. The three-color standardized data is classified by determining which of the above-defined color regions Aa including the origin and the color region Ab other than the color region Aa belongs to the three-color standardized data. The photometric data is selected as described above. The three-color normalized data is classified based on the boundary between the color area Aa and the color area Ab, whereby the three-color normalized data is classified into data belonging to an area having a small color difference from a reference value (origin). The data is classified into data belonging to an area having a large color difference from the reference value. In step 108, photometric data in which the normalized data belongs to the color area Aa having a small color difference from the reference value is selected as photometric data used in the subsequent processing.
The following Table 2 shows an example of color areas, three-color normalized data classified for each color area, and three-color photometric data corresponding to the three-color normalized data.

[0041]

[Table 2]

In the above description, the three-color standardized data is classified using the color coordinates having the axes of GB and RG, but one or three or more of the three primary colors (for example, D _x −
_Dy , _Dx / _Dy , _Dx / ( _Dx + _Dy + _Dz ), _Dx + _Dy +
_{D z, D x -K, D} x / K , etc., provided that, x, y, z are respectively expressed R, G, and different one color B, K is a constant. ), That is, a coordinate axis having a color difference or a color ratio other than the above as the axis can be used as a two-dimensional or three-dimensional color coordinate.

Further, a plurality of color regions can be determined according to the distance from the reference value. As this reference value,
Origin of color coordinates used, values related to specific colors of original image, values obtained from average value of many image frames, minimum value of photometric data, values obtained from photometric data of specific image frames, predetermined constant values Etc. can be adopted. Further, the reference value may be a value given by a function expression or a table. In this case, for example, a function expression or a table value whose reference value changes depending on the density of the image may be used. In addition,
As the specific color, a neutral color, a skin color, or a color obtained from an average value of a large number of image frames can be used. Further, as shown in FIG. 6, a color region having an irregular distance from the origin provided on coordinates having a neutral color as the origin may be used as the color region.

In step 110, the average values D1 _R , D1 _G , and D1 _B of the photometric data selected above for each of _R , _G , and _B are obtained. In the next step 112, the photometric data belonging to the color area Aa having a small color difference from the selected reference value is reflected on the data stored in the first storage means. Specifically, first, the selected photometric data is classified into a plurality of groups according to density. As described above, the average value of the photometric data for each density is stored in the first storage means 34, and the photometric data belonging to each of the classified groups and the average value of the corresponding density in the first storage means 34 are stored. And the average value of.

In this calculation, the selected photometry data belonging to a certain group is stored as D _X1 , D _X2 ,..., D _Xn1 , the number of the selected photometry data of the group is n ₁ , and the first storage means 34 is stored in the first storage means 34. Assuming that the average value of the n ₂ pieces of photometric data corresponding to the group described above is D _Y , the average value D ₀ is calculated by the following equation (2).

[0046]

(Equation 1)

The calculated average value is stored in the first storage means 34.

In step 114, the selected photometry data is reflected on the data stored in the second storage means 36 as in step 112. As described above, since the selected photometric data is the photometric data standardized and selected based on the data of the first storage unit 34, the data stored in the second storage unit is influenced by the color of the subject. And film characteristics (three-color sensitivity balance, three-color gradation balance,
3 color density balance) is accurately reflected. Therefore, even when a large number of image frames of the negative film 20 are images in which color fear is likely to occur, data in which the influence of the color feria is small and suppressed is obtained.

If no data is stored in the second storage means 36, the selected photometry data is classified into a plurality of groups according to density, and the average values of the classified data are stored in the second storage means 36. . As the process of measuring and printing the image frames is sequentially performed from the first image frame of the negative film 20 as described later, the selected metering data of each image frame is reflected in the data stored in the second storage means 36. Will be done. Therefore, as the above process proceeds,
The color balance of the data obtained by normalizing the average value approaches the tendency of the overall color balance of the image frames stored in the negative film 20.

In step 116, image data MD2j for each of R, G, and B at the same density is obtained from the first storage means 34 based on the average value of the selected photometric data. In the image data MD2j, the average value MD1G of the G density of the photometric data obtained in step 110 is defined as MD '(G), and this M
D ′ (G) is inversely transformed by interpolation or extrapolation (interpolation) using a standardization table created from the average value of the photometric values stored in the first storage means 34 to obtain an R density MD ′.
(R), B concentration MD '(B) is obtained (see FIG. 7), (3)
As shown in the equations, R, G, and B concentrations MD ′ (R), MD ′
(G) and low density part photometric data MIN for each of MD '(B).
(R), MIN (G), and MIN (B).

[0051]

(Equation 2)

In the next step 118, the above step 1
As in the case of No. 16, the second
, Image data MD3j for each of R, G, and B at the same density is obtained from the storage means 36. This image data MD3j is
The average value MD1G of the G density of the photometric data is defined as MD "(G), and the MD" (G) is determined using a standardization table created from the average photometric value stored in the second storage means 36. In the same manner as above, inverse conversion is performed by interpolation or extrapolation (interpolation) to obtain R density MD "(R) and B density MD" (B), and as shown in equation (4), R, G, B density MD "(R),
Each of MD "(G) and MD" (B) has low-density portion photometric data M
It is obtained by adding IN (R), MIN (G), and MIN (B).

[0053]

(Equation 3)

In the above description, the density of the selected photometry data is G
From the data stored in the first storage means 34 and the second storage means 36, the average value MD1
The image data at the same density as _G is obtained, but may be represented by R density or B density.
Image data at the same density as the color average density may be obtained.

In step 120, the average value MD1j of the selected photometric data and the image data M from the first storage means 34 are read.
D2j, image data MD3j from the second storage means 36
, K2, K3 for weighting
Is determined, and the exposure control amount Dij is calculated. In this embodiment, the exposure control amount Dij is calculated using the following equation (5).

Dij = K1 · MD1j + K2 · MD2j + K3 · MD3j (5) Here, j: Represents any one of R, G, and B i: Represents an individual film Weighting factors K1, K2 , K3 are set to constant values as initial values, and are changed according to various conditions so as to satisfy the relationship shown in the following equation (6).

[0057]

(Equation 4)

The above conditions are, for example, as follows.

1. Data amount stored in the second storage means 36 When the data amount stored in the second storage means 36 is small, the accuracy of the image data MD3j is low, and the data amount of the image frame recorded on the negative film 20 is low. It is not considered to represent color balance. For this reason, for example And

2. Density of Image Frames to be Printed When the density of image frames to be printed is extremely high or low, it is considered that the characteristics of each negative film greatly fluctuate, and the accuracy of photometric data, especially image data MD3j, is low. Thus, for example, And

3. Color Feria of Image Frame to be Burned If the image frame to be printed is an image frame in which color fear is likely to occur and the color balance is biased toward a specific color, the image data MD1j obtained by classifying and selecting the photometric data will be described. Also, the color balance is biased toward a specific color, and the image data MD3j is also slightly affected by the color frame (other image frames are greatly affected when the image frame is likely to cause color feria). For this reason, in the above case, for example, the value of the weighting coefficient K1 is reduced so that the main subject has an appropriate color, and the color of the entire screen of the image frame to be printed and the color of the full screen of many frames are compared. Difference <0.2: K2 = 1 0.2 ≦ Tint difference: K2 = 3. Note that the color feria is determined to be an image frame in which color feria easily occurs when, for example, the color balance is biased to a specific color and a region having a predetermined area or more of the image frame has a constant hue. it can.

4. Even if the film characteristics change due to the aging deterioration of the negative film and the image frame including the image frame to be printed is faded, the color balance of the photometric data is biased to a specific color. It is necessary to correct the exposure conditions according to the degree of deterioration over time. In such a case, the value of the weight coefficient K3 is increased so that the weight of the image data MD3j in which the influence of the film characteristics is averaged and reflected is increased. It should be noted that the time-dependent deterioration can be determined to be large when, for example, the color balance of all the image frames of the negative film is a color balance peculiar to the time-dependent deterioration.

5. Photographing light source Even when the image frame to be printed is photographed with a different light source such as a fluorescent lamp or a tungsten lamp, the color balance of the photometric data is biased to a specific color, and it is necessary to correct the exposure condition. In such a case, the value of the weighting factor K1 is increased when only the image frames to be printed are shot with different types of light sources, and when most of the image frames of the negative film are shot with different types of light sources, the value of the weighting factor K2 is increased. Increase the value. It should be noted that the determination as to whether or not the image is captured by a different kind of light source can be made based on, for example, whether or not the color balance of the photometric data is a color balance specific to the different kind of light source.

In addition to the above, the weighting factors K 1, K 2, K 2, K 2, K 1, K 2, K 3, K 2, K 3, Change the value of K3. It is preferable to empirically change the value of the weight coefficient K1 within a range of 3 to 6 according to various conditions. In the above description, the sum of the weighting factors K1, K2, and K3 is set to be "10" (see equation (6)). However, since the weighting factor is a coefficient for weighting, the sum is constant. Should be set to.

The determined weighting factor is substituted into the above equation (5), and the exposure control amount Dij is calculated. In the above description, as the weighting of each data, the exposure control amount Dij, which is a weighted integrated value of each data, is calculated according to equation (5).
The present invention is not limited to this, and a weighted average value may be calculated as the weight of each data.

In step 122, the exposure condition is determined based on the exposure control amount determined in step 120. The exposure condition is determined based on the following equation (7).

LogEj = Sj · Aj (Dij−Dφj) + Kj (7) where j is one of R, G and B logE: logarithm of exposure amount Dij: exposure control amount Dφj: standard Density of negative film Kj: Constant determined by color paper and photographic printer Sj: Slope control coefficient (= 0.5 to 2.0) Aj: Color correction coefficient (≒ 1.0) In step 124, exposure for each of R, G, and B obtained above The exposure condition comprising the quantity is set in the exposure control circuit 42, and the image frame positioned at the printing position by the exposure control circuit 42 is printed and exposed on the color paper 26 under the exposure condition. In the next step 126, it is determined whether or not printing of all the image frames of the negative film 20 set in the photographic printing apparatus 10 has been completed. If the determination in step 126 is negative, the flow returns to step 100 to position the next image frame at the printing position, and perform each process of photometry, exposure condition determination, and printing.

Steps 100 to 126
As the process is repeated, the amount of data stored in the second storage means 36 gradually increases. As a result, the overall color balance of the image frames recorded on the negative film 20 is reflected in the image data MD3j from the second storage means 36, and the accuracy is improved. For this reason,
The value of the weight coefficient K3 can be increased.

If the determination in step 126 is affirmative, the process proceeds to step 128, in which the photometric data and the average value stored in the second storage means 36 are deleted, and the process is terminated.

[Second Embodiment] Next, a second embodiment of the present invention will be described. The same portions as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 9, the photo printing apparatus 70 of the second embodiment has a bar code reader 72. The barcode reading device 72 reads the DX code recorded on the negative film 20 itself or on the cartridge 76 containing the negative film 20. The DX code is a bar code indicating information indicating a film type such as a film maker name, a film sensitivity, and a film family.
The bar code reader 72 is connected to the film type classification means 74 of the arithmetic circuit 30.

The film type classification means 74 determines the film sensitivity, film family, manufacturer name, etc. based on the DX code read by the bar code reader 72, and determines the manufacturer, sensitivity, gradation, base density, and photosensitivity. In addition, a negative film or a film type having some common film characteristics such as a shape of a characteristic curve and the like is classified as the same film type. As a result, films to be printed can be classified mainly by film types having the same or similar printing exposure conditions.

The film type classification means 74 is connected to the first storage means 34. The first storage means 34 is shown in Table 3 below.
As shown in the figure, photometric data of many negative films
The results are obtained by classifying each photometric data obtained by photometry from the same negative film of the same film type, classifying them into groups of different densities, and calculating the average value of each group.
Therefore, a standardization table can be created for each film type from the data stored in the first storage unit 34.

[0074]

[Table 3]

Next, the operation of the second embodiment will be described with reference to the flowchart of FIG. In step 150, the bar code reader 72 reads the DX code of the negative film 20 set in the photo printer 70. In step 152, the type of the negative film 20 is determined based on the read DX code. In step 154, data corresponding to the determined film type is fetched from the first storage unit.

In the next step 156 and subsequent steps, the same processing is performed as in step 100 and the subsequent steps in the flowchart of FIG.
The mask density, which is the low-density portion photometry data for each film type, is stored in advance in the first storage means 34, and the low-density portion photometry data is stored for each film type in step 162 based on the result of determining the film type. May be determined. In step 164, a standardization table is created using the data fetched in step 154, and normalization is performed in the same manner as in step 106 of the flowchart of FIG. In step 170, the average value of the selected photometric data and the data fetched from the first storage means 34 is calculated using equation (2), and the selected photometric data is reflected on the fetched data.

In step 174, image data MD2j for each of R, G, and B at the same density is obtained from the fetched data based on the average value of the selected photometry data. As described above, since the data stored in the first storage means 34 is classified for each film type, it reflects the different film characteristics for each film type more accurately than in the first embodiment. And high accuracy. Therefore, step 178
When the weighting factor is set by the above, the value of the weighting factor K2 can be increased so that the weight of the image data MD2j is increased, and more appropriate exposure conditions can be obtained.

When the printing of the image frames on one negative film 20 is completed and the determination in step 184 is affirmative, the data stored in the second storage means 36 is deleted in step 186, and then the next step is performed. At 188, the data in the first storage means 34 is updated with the data in which the selected and selected photometric data has been reflected from the first storage means 34, and the process ends.

In the above-described embodiment, the average value stored in the first storage means 34 is updated using the selected photometry data every time photometry is performed on one image frame.
After the photometry and printing of the image frames of the negative film 20 of the book have been completed, the data stored in the first storage means 34 is used by using the data stored in the second storage means 36 as shown in FIG. May be updated, and the data stored in the second storage means 36 may be deleted.

In the above embodiment, the second image is printed after all the image frames recorded on the negative film 20 have been printed.
The data stored in the storage means 36 is erased. However, if the color or color distribution of the image frame to be printed is significantly different from the image frame that has been previously printed, for example, a certain scene It can be determined that the printing of a series of image frames in which has been photographed has been completed, and it can be inferred that the colors and color distributions of the subsequent image frames are significantly different from those of the series of image frames. In such a case, if the data is erased and the exposure condition is determined using the data stored in the first storage means 34, the print pass rate is improved. The value of the weight coefficient K3 may be reduced instead of deleting the data stored in the second storage means 36.

In the above embodiment, the first storage means 34
The second storage means 36 stores the result obtained by classifying the selected photometric data by density and calculating the average value of each of the classified photometric data. However, all the selected photometric data may be stored. Alternatively, all the photometric data and the result of classifying the photometric data by density and calculating the average value of each of the classified photometric data may be stored. In the above embodiment, the exposure condition is determined using the selected photometric data. However, the standardized photometric data, data obtained by standardizing the data stored in the first storage unit 34, and the second storage unit Using the data obtained by standardizing the stored data, an exposure correction amount for an average exposure condition obtained from the average density may be obtained to determine the exposure condition.

In the above embodiment, the processes including photometry, exposure condition determination, and printing for a specific image frame are performed in order from the first image frame of the negative film 20. After the photometry of the frame is performed, the exposure condition determination and printing may be sequentially performed.

Further, first, photometry is performed until the number of measured photoframes reaches a predetermined number, or until the number of selected photometry data reaches a predetermined number, and photometry data is stored in the second storage means 36. Next, a process including photometry, exposure condition determination, and printing may be performed on each image frame. In particular, when printing or the like is performed after performing photometry until the number of photometric image frames reaches a predetermined number, the photometry position and the printing position are set separately for the photometry portion and the printing portion separately from the predetermined number. A series of processing can be performed without rewinding the negative film 20 if the distance is equal to or longer than the distance corresponding to the longitudinal dimension of the image frame.

In the second embodiment, the DX code is read by the bar code reading device 72 to determine the type of film. However, the present invention is not limited to this. Information may be read to determine the film type. Further, the determination may be made based on the result of spectrally metering the image recorded on the film.

At the time of the first printing, the subject number and the average value of the selected photometric data (or the front part of the selected photometric data) are stored in the photoprinting apparatus 10, and the subject number is printed on the back of the print. When performing reprinting, input the subject number of the image frame to be reprinted into the photoprinting apparatus 10,
The exposure condition may be determined by taking in the stored data. It is also possible to judge whether or not the image frame has faded by comparing the newly measured light with the acquired data.

[0086]

As described above, according to the first aspect of the present invention, the first storage means selects the photometric data necessary for determining the exposure condition among the multiple photometric data of the image frame to be printed. The data obtained from the data obtained by photometry over a large number of films stored in the second storage means and the photometry obtained for the image frames of a single film recorded with the image frames to be printed stored in the second storage means. Data obtained from the obtained data, and set a weighting factor to be assigned to each of the data, so as to determine the exposure conditions based on the value obtained by adding a weighting factor to each of the data,
An excellent effect is obtained that the influence of color feria can be eliminated and high-quality prints can always be obtained irrespective of changes in film characteristics due to aging or the like.

Further, according to the present invention, photometric data obtained by photometrically selecting an image frame to be printed, data obtained from data obtained by photometry over a large number of films, and an image frame to be printed. Is set from the data obtained from the data obtained by photometry for the image frame of a single film recorded, and set a weighting factor to be given to each of the above, to the value obtained by adding a weighting factor to each of the data Since the exposure conditions are determined based on the above, the excellent effect that the influence of color feria can be eliminated and high quality prints can always be obtained regardless of changes in the film characteristics due to aging or the like. Is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a photographic printing apparatus according to a first embodiment.

FIG. 2 is a conceptual diagram illustrating a process of performing photometry by dividing a surface.

FIG. 3 is a plan view of a negative film for explaining an example of a photometric range when measuring a mask density.

FIG. 4 is a diagram showing a normalization curve.

FIG. 5 is a diagram showing color coordinates for classifying three-color normalized data.

FIG. 6 is a diagram showing other color coordinates for classifying three-color normalized data.

FIG. 7 is a diagram illustrating a process for obtaining image data using a normalized curve.

FIG. 8 is a flowchart illustrating the operation of the first embodiment.

FIG. 9 is a schematic configuration diagram of a photographic printing apparatus according to a second embodiment.

FIG. 10 is a flowchart illustrating the operation of the second embodiment.

FIG. 11 is a schematic configuration diagram showing another example of a photographic printing apparatus to which the present invention has been applied.

[Explanation of symbols]

 Reference Signs List 10 photo printing device 28 photometer 34 first storage device 36 second storage device 38 selecting device 40 exposure condition determining device 70 photo printing device

Claims (5)

(57) [Claims] 1. Photometric means for dividing an image frame recorded on a film into a large number of pieces and performing photometry; Selection means for selecting; first storage means for storing data obtained by the photometry over a large number of films; second storage means for storing data that is, the selection data of the image frame baking selected by the selection means, the first data obtained from the data stored in said first storage means, said a weighting factor setting means for setting a weight coefficient to be applied to each of the second data obtained from the data stored in the second storage means, said weighting factor setting said each of the data Photographic printing apparatus comprising an exposure condition determining means for determining an exposure condition based on the value obtained by adding bear the weight coefficients set by means. Wherein said first storage means and second storage means stores an average value for each concentration of photometric data or measurement data as data obtained by said photometric, the exposure condition determining means, said First data and the second data
As a first storage means and second photographic printing apparatus according to claim 1, characterized by using the data of the corresponding concentration to the concentration of said selected data determined from said stored data in the storage means. Wherein said selecting means, according to claim 1 or claim 2 Symbol and selects data necessary for the exposure conditions determined based on the data stored in said first storage means
Mounting of photographic printing apparatus. 4. The weighting factor setting means according to claim 1, wherein said weighting coefficient setting means sets said selected data and said second data in accordance with a color balance bias of said selected data.
Claims 1 to any one of the 3 and changes the weighting factor to be applied to the first data and the second data
The photo printing device according to the item. 5. An image frame to be printed is divided into a large number of pieces, photometry is performed, photometric data necessary for determining exposure conditions is selected, and photometry is performed on the selected photometric data over a number of films. First data obtained from the obtained data, and second data obtained from data obtained by photometry with respect to an image frame of a single film on which an image frame to be printed is recorded; An exposure condition determining method for setting an exposure condition based on a value obtained by adding a weighting factor to each of the data and setting a weighting factor to be assigned to each of the data.