JPH07203134A - Method and device for converting color picture signal - Google Patents

Abstract

PURPOSE:To provide the method and device for converting a color picture signal in which a color mixture component of a spectral sensitivity of a photometry element is estimated to correct an original photometry signal so as to obtain a signal with high color purity without use of a special optical filter. CONSTITUTION:In the method for converting a color picture signal, where an original picture recorded on a color photo film F is lighted by a light source, a transmission light or a reflected light is separated and measured by a photometry element provided with a mosaic filter and an obtained color picture signal is converted into a coloring density of a color element of a color sensing material P, a setup filter and optical filters 11a-11c transmitting selectively lights of primary colors B, G, R in each wavelength region are inserted respectively between the light source 2 and the photometry element. A correction function correcting incorrect sensitivity of the photometry element is calculated based on an output signal of the photometry element obtained through each optical filter is calculated and the correction function is used to convert the color picture signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image signal conversion method and conversion apparatus, and more particularly, to an image signal read from an original image such as a photographic film in a photographic printing apparatus according to the characteristics of an image copying medium such as photographic printing paper. The present invention relates to a conversion method and a conversion device for performing conversion.

[0002]

2. Description of the Related Art Conventionally, a photographic original image recorded on a color photographic film is printed on a color photosensitive material such as photographic printing paper by irradiating the original image with illumination light from a light source. There is known a photographic printing method and apparatus in which the amount of transmitted light (or the amount of reflected light) of the entire area is measured by a photometric element and the amount of light applied to photographic paper is controlled based on the obtained photometric value. More recently, as this type of photometric element,
Method and apparatus for more appropriately controlling the amount of light applied to photographic paper based on a photometric value (pixel data) obtained by dividing and photometrically measuring an original image using a CCD (charge-coupled device), a photodiode array, or the like Has been applied.

By the way, in these methods of determining the exposure amount given to the photographic paper based on the photometric value obtained by the photometric element, the spectral sensitivity of the photometric system and the spectral sensitivity of the photographic paper are closer to each other. preferable. However, when a single-plate color CCD is used for the photometric system, the spectral characteristic of the mosaic filter arranged immediately before the CCD image plane and the spectral sensitivity characteristic of the printing paper are significantly different.

That is, the characteristics on the CCD side are that the color mixture of red light and green light and the mixture of green light and blue light are many, and the sensitivity peak of red light is on the short-wave side as compared with that of photographic paper. Therefore, the spectral characteristics of the three primary colors of the image picked up by the CCD and the image printed on the photographic paper are different, and C
When the exposure amount is determined based on the photometric value of DD, the color reproducibility of the printed image becomes poor. In addition, the degree of influence due to the difference between the spectral sensitivity of this photometric system and the spectral sensitivity of photographic paper differs depending on the type of photographic film that is the target, so the color reproducibility of printing differs depending on the type of film, which causes a print level difference. Has become.

In order to solve this problem, for example, in Japanese Patent Laid-Open Nos. 51-113627 and 53-64037,
A method has been described in which an optical filter that blocks light components in the color mixing range is inserted in the optical path between the light source and the photometric element to ensure color separation and improve color reproducibility of the print. Also,
In Japanese Patent Laid-Open No. 63-82183, there is a method of introducing the above-mentioned optical filter and analytically deriving a relational expression between the photometric density of the CCD camera and the photometric density of the photographic paper, and correcting the relational expression. Stated.

[0006]

In the above-mentioned conventional method and apparatus, the difference in the spectral sensitivity between the photometric element and the photographic paper is corrected,
In order to reduce the color difference between the original image and the image to be reproduced, a special optical filter with the property of cutting the light components in the color mixture range is used, but this type of optical filter is extremely accurate. However, there is a drawback that it requires very high spectral characteristics and becomes very expensive.

Further, these optical filters are usually manufactured by forming a metal coating on a raw glass by vapor deposition or the like. However, while maintaining the accuracy, there is no variation among products, and It is practically very difficult to obtain a uniform and stable product. Further, for the color difference that cannot be completely corrected by the characteristics of these optical filters, it is possible to obtain the relational expression by an analytical method and correct it, but the calculation is complicated, and individual differences in the characteristics of the filter and photometric The current situation is that it is not possible to obtain a correction that also takes into account individual differences in device characteristics.

In view of the above points, the present invention estimates a mixed color component of spectral sensitivity of a photometric element, corrects an original photometric signal, and obtains a signal with high color purity without using a special optical filter. Has an aim.

[0009]

In order to achieve the above object, a method of converting a color image signal according to claim 1 is such that an original image recorded on a color photographic film is illuminated with a light source, and the transmitted light or reflected light thereof is used. Is color-separated by a photometric element equipped with a mosaic filter, and the obtained color image signal is converted into a color density of the dye of the color photosensitive material. A setup filter is inserted in the optical path, and an optical filter capable of selectively transmitting light of each wavelength region of primary colors B, G, and R is inserted, and the output signal of the photometric element obtained through each optical filter is inserted. Based on this, a correction function for correcting the incorrect sensitivity of the photometric element is calculated, and the color image signal is converted by the correction function.

A method of converting a color image signal according to claim 2 is
A coefficient for the correction function to linearly linearly convert an original photometric vector having B, G, and R outputs obtained through the mosaic filter as components and a color mixture vector having components of the output of the photometric element obtained through the optical filter. It was a line.

A color image signal converting apparatus according to a third aspect of the present invention is
A means for illuminating an original image recorded on a color photographic film with a light source, a means for color-separating and measuring transmitted light or reflected light with a photometric element having a mosaic filter, and the obtained color image signal as a dye of a color photosensitive material. A color image signal conversion device comprising an exposure control filter, which is provided in the optical path between the light source and the color photosensitive material, and which has an exposure control filter capable of controlling the exposure amount for the color photosensitive material. , A setup filter is inserted in the optical path between the light source and the photometric element, and an optical filter capable of selectively transmitting light in each wavelength region of the primary colors B, G, and R is inserted, and each optical filter is inserted. Means for obtaining an output signal of the photometric element that has passed through, and means for calculating a correction function for correcting the incorrect sensitivity of the photometric element based on the obtained output signal. And configured to include a means for converting the color image signal by the correction function.

According to a fourth aspect of the present invention, there is provided a color image signal converting apparatus.
The optical filter is composed of a combination of one or more types of the exposure control filters. 6. The color image signal conversion method according to claim 5, wherein the correction function includes an original photometric vector having B, G, and R outputs obtained through the mosaic filter as components, and an output of the photometric element obtained through the optical filter as components. The color-mixture component vector is a coefficient matrix for linear linear transformation.

[0013]

The transmitted or reflected light of the original image of the color photographic film illuminated by the light source is color-separated and photometrically measured by the photometric device having the mosaic filter and converted into a color image signal.
Then, the obtained color image signal is converted into the coloring density of the dye of the color photosensitive material. Here, in order to correct the color image signal, a setup filter is inserted in the optical path between the light source and the photometric element, and light in each wavelength region of the primary colors B, G, and R can be selectively transmitted. Insert different optical filters. Then, based on the output signal of the photometric element obtained through each optical filter, a correction function for correcting the incorrect sensitivity of the photometric element is calculated. The color image signal is corrected and converted by this correction function. Since the calculation of the function for this correction can be calculated individually according to the photometric system, it is possible to perform correction that absorbs individual differences of the photometric system.

The correction function includes an original photometric vector having the B, G, and R outputs obtained through the mosaic filter as components, and a color-mixture vector having the output of the photometric element obtained through the optical filter as a component. , Is a coefficient matrix for linear linear transformation, the correction is executed by a simple data transformation process.

Further, in a color image signal conversion device comprising an exposure control filter capable of controlling the exposure amount for the color photosensitive material in the optical path between the light source and the color photosensitive material, the optical filter is the exposure device. By using a configuration in which one or more types of control filters are combined, it is not necessary to separately provide an optical filter, and the device configuration is simplified. In particular, it is practically preferable when the present invention is applied to a photo printing apparatus or the like.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a color image signal converting method and a converting apparatus according to the present invention will be described below with reference to the drawings.
Although the present invention can be applied to a color copying machine or the like, the case of being applied to a photo printing apparatus will be described here as an example. First, the structure of a color photographic film recording an original image to be printed on a color light-sensitive material will be described.

FIG. 1 shows the structure of a 135 photographic film which has been developed. In the figure, the photographic film F on which the developed original image (group) I is formed is provided with an identification code (for example, a DX code) X indicating its type. Further, a well-known perforation (group) PF is previously arranged at this side edge portion. Note that the photographic film F in this example is not limited to the 135 photographic film, but may be another photographic film (for example, 110 film). The photographic film F is printed in a photographic printing apparatus described later.

Next, the structure of the photographic printing apparatus will be described. In FIG. 2 showing the structure of the photo printing apparatus, the exposure unit 1
The original image I of the photographic film F positioned at is irradiated with the light emitted from the light source 2 and uniformized by the lens barrel 3. The illumination light transmitted through the original image I is further imaged by the lens L on the surface of the photographic printing paper P and is exposed. At this time, the average transmitted light of each color B, G, R of the original image I passes through the photometric filters 4a, 4b, 4c corresponding to each color of B, G, R, and the photodiode 5a installed in the vicinity of the exposure unit 1, The light is received by 5b and 5c. The photometric signals of B, G, and R colors obtained by photoelectrically converting the received light amount are supplied to and amplified by the signal processing unit 6, and further A
After being D / D converted, it is sent to the exposure controller 7. And
The exposure amount for printing is determined based on the average photometric value of each of B, G, and R colors obtained by the exposure control unit 7.

In the exposing section 1, the original image I formed on the photographic film F is subjected to B, G, R by the image pickup means 8.
The color separation is scanned for each color. Then, the image signals of each color of B, G, and R obtained by the image pickup means 8 are sent to the image processing section 9 and then A / D (analog / digital) converted to obtain image density information of a predetermined format. Is shaped into In the image processing unit 9, an optimum exposure correction amount is calculated from the image density information obtained in this way, and the obtained exposure correction amount is transmitted to the exposure control unit 7.

Between the exposure control unit 7 and the operator,
An operation unit 10 is provided, and an operator manually inputs an exposure correction amount according to the number of prints and a special condition of the original image I (subject feria, different light source, etc.) from the operation unit 10. These input information are sent to the exposure controller 7. In the exposure controller 7, the image processor 9
The exposure amount based on the above-described average photometric value is corrected based on the exposure correction value transmitted from the control unit 10 and the exposure correction amount transmitted from the operation unit 10. In addition, the exposure control unit 7 calculates the exposure time of the color light of each color from the exposure amount thus obtained, and further calculates this exposure time and the mechanical operation delay time of the cut filter and the dark shutter stored in advance inside. Considering this, the yellow (Y), magenta (M), and cyan (C) cut filters 11a, 1 arranged above the exposure unit 7
1b, 11c and the operating time of the dark shutter S arranged below the exposure unit 1 are determined.

A drive signal is sent to the cut filter drive unit 12 and the shutter drive unit 13 in accordance with the operating time, and the cut filters 11a, 1 are driven by this drive signal.
1b and 11c and the dark shutter S are inserted in the exposure light path, and the exposure amount for each color photosensitive layer of the photographic printing paper P is adjusted. After completion of this exposure, the photographic printing paper P is transported by a predetermined distance in preparation for the next exposure, and the photographic film F is transported to set the original image I to be printed next in the exposure section 1. The original image I formed on the photographic film F is sequentially subjected to printing processing by such a series of processes.

Next, details of the image pickup means 8 and the image processing section 9 will be described with reference to FIG. In FIG. 3, reference numeral 30 denotes an image pickup section of the image pickup means 8, and the image pickup section 30 comprises a two-dimensional image sensor 31 and a signal processing section 32 attached thereto. An image of the original image I illuminated by the light source 2 in FIG. 2 can be formed on the image sensor 31 via the diaphragm S ′ and the lens L ′. Mosaic filters of B, G, and R are arranged on the light receiving surface of the image sensor 31, and each photoelectric conversion element arranged under each color filter can output an electric charge proportional to the amount of received light. ing. For example, a CCD is used as the two-dimensional image sensor 31.

FIG. 4 shows the two-dimensional image sensor 31B,
An example of the arrangement of the G and R mosaic filters MF is shown.
Each color filter is mounted corresponding to each photoelectric conversion element (pixel) of the image sensor 31. Of these, FIG. 4A shows a three-color stripe type filter configuration, and FIG. 4B shows a filter in which G and R appear alternately and a filter in which G and B appear alternately for each scanning line. It has a configuration in which is arranged alternately. In either configuration, the scanning of one line is performed in the direction of the arrow in the figure, and when the scanning of one line is completed, the scanning of the next line is performed.

In the signal processing unit 32 of FIG. 3, the image signals mixed with B, G, and R output from the image sensor 31 are separated for each color, and the separated signals are sample-held and amplified to B, G. , R image signal outputs 32a, 32
b and 32c are separately output. Reference numeral 33 denotes a drive control unit of the image sensor 31, which instructs the image sensor 31 with a clock signal to control reading of pixel data on the photoelectric conversion element, and sends a timing signal to the signal processing unit 32. The output separation of the signals 32a, 32b, 32c for each primary color is appropriately controlled. Further, the drive control unit 33, when reading image data from the image sensor 31, a vertical synchronizing signal 33a which is a screen switching timing signal, a horizontal synchronizing signal 33b which is a scanning line switching timing signal, and an image reading clock signal. 33c and the like can be generated respectively.

Reference numeral 34 denotes an analog switch, which outputs 3 for each primary color according to a command output from a scanning position decoder 40 which will be described later.
2a, 32b, 32c are configured to be selectively output to the A / D converter 35 in the subsequent stage. In the embodiment (FIG. 3), the signal converted into a digital value by the A / D converter 35 is input to the data conversion unit 36 and converted into a predetermined data form (for example, LOG value). The data conversion unit 36 will be described in detail separately. The data conversion unit 3
The output of 6 is recorded in the image memory 37 in the subsequent stage.

Next, a method of correcting the color mixture of the photometric element spectral characteristics will be described. B, G, and R mosaic filters MF provided immediately in front of the light receiving surface of the image sensor 31.
As shown in FIG. 5, the spectral sensitivity characteristic of FIG. 4 is often designed to substantially match the human visual sensitivity characteristic (the relative sensitivity of B, G, and R is substantially constant). In contrast,
The spectral sensitivity of color printing paper generally has a spectral sensitivity characteristic in which the relative sensitivity decreases in the order of B → G → R, as shown in FIG. Comparing the spectral sensitivity characteristics of both,
The color separation purities of B, G, and R are different, and in the case of the mosaic filter MF, the color mixture ratio of B and R with respect to the main wavelength region of G is particularly large. Moreover, the sensitivity peak points of R are remarkably different between the two, and it is understood that accurate photometry according to the characteristics of the printing paper is difficult.

In order to solve the problem caused by such a phenomenon, for example, in the above-mentioned Japanese Patent Laid-Open No. 51-113627, an optical filter having the characteristics shown in FIG. 7 is arranged in the optical path between the light source and the photometric element. A method has been proposed in which the color purity of photometry is increased and, as a result, the spectral sensitivity of photographic paper is approached. As can be understood from FIG. 7, the optical filter for such a purpose blocks light in the wavelength range around 500 nm and 600 nm, that is, in the wavelength range in which the sensitivities of B, G, and R overlap, and cuts the light in other wavelength ranges. Has the property of transmitting. However, even when this optical filter is adopted, the overlap of B and R with respect to the G region cannot be completely removed, and therefore the color reproduction of the printed image cannot be sufficiently ensured.

The present invention provides a method for improving the color separation performance of a photometric system by measuring the remaining overlap and correcting the output signal of the original photometric element by an electric circuit or numerical calculation. It is provided. The output signals Bi, Gi, Ri of B, G, R picked up by the image sensor 31 of FIG. 3 can be considered as the sum of three signals, as shown in FIG. 9A.

This can be expressed by the following equation. Bi = Bbi + Bgi + Bri Gi = Gbi + Ggi + Gri Ri = Rbi + Rgi + Rri (1) where Bi is an output signal for light in the blue wavelength range based on the B sensitivity of the image sensor 31 Bgi: Output signal Bri for the light in the green wavelength region based on the B sensitivity of the image sensor 31 Bri: The sum of three signals of the output signals for the light in the red wavelength region based on the B sensitivity of the image sensor 31. The same applies to Gi and Ri.

Here, the equation (1) can be expressed as a matrix as follows. t = C · m (2) where t = (Bi, Gi, Ri) ^T

[Equation 1] m = (Bbi, Ggi, Rri) ^T

Here, since the vector m corresponds to an output signal without color mixing, if the matrix C can be measured, its inverse matrix C ^-1 is used as a correction function to obtain the correction signal m as shown in the following equation (3). Can be calculated. m = C ^-1 · t (3)

FIG. 8B shows a function C ^-1 for measuring the overlap of the remaining photometric sensitivity and correcting the original photometric data.
It is a flowchart which shows the process which calculates. First, in step 80, a setup filter serving as a calculation reference of a correction function is inserted in the optical path between the light source and the image sensor 31. It is desirable that the setup filter is an optical filter having a color balance substantially the same as that of the base portion of the photographic film or a filter having uniform characteristics over the entire surface.

Next, in step 81a, the light source 2 is further
A filter having the characteristics shown in FIG. 9B is provided in the optical path between the image sensor 31 and the image sensor 31. That is, an optical filter having a spectral characteristic that transmits only the blue wavelength range (from about 400 nm to about 520 nm) and blocks other wavelength ranges is inserted. In order to insert this optical filter into the optical path, the exposure control unit 7 is used as in the cut filter shown in FIG.
It is desirable to be controlled by the signal of.

The cut filter 11a, 11b, 11c shown in FIG. 2 is also used as the cut filter, and the M cut filter and the C cut filter are simultaneously inserted in the optical path, whereby the filter shown in FIG. It may be possible to obtain the same effect as in a more practical method. In step 81b, an image is taken by the image sensor 31 in a state where each of the filters is inserted in the optical path, A / D conversion is performed by the above-mentioned predetermined processing, and in step 81c, each pixel of B, G, and R is processed. Average output value B
After calculating bi, Gbi, and Rbi, these are stored in a memory such as a RAM.

Next, in step 82a, the green wavelength range as shown in FIG.
An optical filter having a spectral characteristic of transmitting only (about 0 nm) and blocking other wavelength regions is inserted. As described above, the Y-cut filter and the C-cut filter shown in FIG. 2 may be simultaneously inserted in the optical path instead of this filter. In steps 82b and 82c, the same processes as in steps 81b and 81c are performed, and Bgi,
Ggi and Rgi are stored.

In step 83a, the red wavelength range (near 600 nm to around 750 nm) as shown in FIG. 9D is obtained.
An optical filter having a spectral characteristic that transmits only light and blocks other wavelength regions is inserted. Instead of this filter,
The Y cut filter and the M cut filter shown in FIG. 2 may be simultaneously inserted in the optical path. Steps 83b and 83c
Performs the same processing as steps 81b and 81c, respectively, and stores Bri, Gri, and Rri.

Based on the signals thus stored, in step 84, the elements of the correction matrix C of the above equation (2) are calculated, and further, the inverse matrix C ^-1 of the above equation 3 is calculated,
Each of the elements is stored in a predetermined position on a memory such as a RAM. These series of processes are usually calculated and registered as initial data at the time of assembling and shipping the photo printing apparatus, but are periodically refreshed so as to be able to follow the temporal change of the characteristics of the image sensor. It may be configured as follows. Further, even if there are individual differences in the characteristics of the image sensor or the optical filter of FIG. 7, the correction function can be calculated individually according to the characteristics.

On the other hand, FIG. 8A shows data for correcting the original photometric data based on the correction function C ^-1 obtained in the above processing and converting it into data for calculating the exposure amount on the photographic paper. The converter is described. At step 85, as shown in FIG. 3, B, G, and
Each pixel data of R is A / D converted by the A / D converter 35.
After the conversion, it is set in a predetermined register. In step 86, the correction operation of the equation (3) is executed based on each element of the correction function stored in step 84. Further, in step 87, the calculation result is logarithmically converted by referring to the look-up table, and stored in the image memory 37 in step 88. The stored pixel data is used to determine the exposure amount given to the printing paper based on the predetermined process described in FIG.

[0039]

As described above, according to the method of converting a color image signal of claim 1, the original image recorded on the color photographic film is illuminated with a light source, and the transmitted light or reflected light thereof is measured by a mosaic filter. In the color image signal conversion method of performing color separation photometry with an element and converting the obtained color image signal into the color density of the dye of the color photosensitive material, a setup filter is inserted in the optical path between the light source and the photometric element. At the same time, an optical filter capable of selectively transmitting light in each wavelength region of the primary colors B, G, and R is inserted, and based on the output signal of the photometric element obtained through each optical filter, the illegality of the photometric element is detected. A correction function for correcting the sensitivity is calculated, the color image signal is converted by the correction function, and the correction for absorbing the individual difference of the photometric system can be performed.

A method of converting a color image signal according to claim 2 is
The correction function performs linear linear conversion of an original photometric vector having B, G, and R outputs obtained through the mosaic filter as a component, and a color mixture vector having an output of the photometric element obtained as a component through the optical filter as a component. The correction matrix can be executed by a simple calculation by using the coefficient matrix.

According to a third aspect of the present invention, there is provided a color image signal converting apparatus.
A means for illuminating an original image recorded on a color photographic film with a light source, a means for color-separating and measuring transmitted light or reflected light with a photometric element having a mosaic filter, and the obtained color image signal as a dye of a color photosensitive material. A color image signal conversion device comprising an exposure control filter, which is provided in the optical path between the light source and the color photosensitive material, and which has an exposure control filter capable of controlling the exposure amount for the color photosensitive material. , A setup filter is inserted in the optical path between the light source and the photometric element, and an optical filter capable of selectively transmitting light in each wavelength region of the primary colors B, G, and R is inserted, and each optical filter is inserted. Means for obtaining an output signal of the photometric element that has passed through, and means for calculating a correction function for correcting the incorrect sensitivity of the photometric element based on the obtained output signal. The arrangement is because having a means for converting the color image signal by the correction function, can be corrected to absorb the individual difference of the metering system.

According to a fourth aspect of the present invention, there is provided a color image signal converting apparatus.
Since the optical filter is configured by combining one or more types of the exposure control filters, it is not necessary to separately provide the optical filter, and the device configuration is simplified. In particular, when the present invention is applied to a photo printing apparatus or the like, a great effect is exerted.

A color image signal converting apparatus according to a fifth aspect of the present invention is
The correction function linearly linearly transforms an original photometric vector having B, G, and R outputs obtained through the mosaic filter as a component and a color mixture vector having an output of the photometric element obtained as a component through the optical filter as a component. Since it is a coefficient matrix, the correction can be performed by performing a simple calculation in the control unit of the exposure control filter.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the structure of a 135 photographic film that has been subjected to a development process.

FIG. 2 is a principle diagram showing a configuration of a photographic printing apparatus.

FIG. 3 is a block diagram showing details of an image pickup unit and an image processing unit.

FIG. 4 is a principle diagram showing a configuration example of B, G, and R mosaic filters arranged on a light receiving surface of a two-dimensional image sensor.

FIG. 5 is a characteristic diagram showing spectral sensitivities of B, G, and R mosaic filters similar to human luminosity characteristics.

FIG. 6 is a characteristic diagram showing the spectral sensitivity of color photographic paper.

FIG. 7 is a transmission characteristic diagram of an optical filter arranged in an optical path between a light source and a photometric element.

FIG. 8A is a flowchart of a data conversion unit that corrects original photometric data based on a correction function and calculates an exposure amount on photographic paper. (B) is a flowchart of a process of measuring an overlap amount of photometric sensitivity and calculating a function for correcting the original photometric data.

9A is a characteristic diagram showing signal components when the output of the CCD is regarded as the sum of three original photometric signals. FIG. (B)
This is the spectral characteristic of an optical filter that transmits only the blue wavelength range (from about 400 nm to about 520 nm) and blocks the other wavelength ranges. (C) Green wavelength range (from around 500 nm to 6
This is the spectral characteristic of an optical filter that transmits only around 20 nm) and blocks other wavelength regions. (D) Red wavelength range (6
This is a spectral characteristic of an optical filter that transmits only (from around 00 nm to around 750 nm) and blocks other wavelength regions.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 exposure part 2 light source 6 signal processing part 7 exposure control part 8 imaging means 9 image processing parts 11a, 11b, 11c cut filter (optical filter) 12 cut filter control part 13 shutter control part 30 imaging part 31 photometric device (CCD) 80 Setup B Filter insertion process 81 B output mixed color component measurement process 82 G output mixed color component measurement process 83 R output mixed color component measurement process 84 Calculation of primary conversion matrix F Color photographic film I Original image P Color photosensitive material (printing paper) MF Mosaic filter

Claims (5)

[Claims] 1. An original image recorded on a color photographic film is illuminated with a light source, and transmitted light or reflected light thereof is subjected to color separation photometry with a photometric device equipped with a mosaic filter, and the obtained color image signal is subjected to color sensitization. In a method of converting a color image signal for converting into a coloring density of a dye of a material, a setup filter is inserted in an optical path between the light source and the photometric element, and light in each wavelength region of primary colors B, G, R is selected. Optically transmitting optical filters, a correction function for correcting incorrect sensitivity of the photometric element is calculated based on the output signal of the photometric element obtained through each optical filter, and the color image is calculated by the correction function. A method for converting a color image signal, which comprises converting the signal. 2. The correction function includes an original photometric vector having B, G, and R outputs obtained through the mosaic filter as a component, and a color mixture vector having components of the output of the photometric element obtained through the optical filters. The method of converting a color image signal according to claim 1, wherein the coefficient matrix is a linearly linearly transformable coefficient matrix. 3. A means for illuminating an original image recorded on a color photographic film with a light source, a means for color-separating and measuring the transmitted light or reflected light with a photometric element having a mosaic filter, and the obtained color image signal, A color image comprising a conversion means for converting the color density of the dye of the color photosensitive material, and an exposure control filter capable of controlling the exposure amount to the color photosensitive material in the optical path between the light source and the color photosensitive material. In the signal conversion device, a setup filter is inserted in the optical path between the light source and the photometric element, and optical filters capable of selectively transmitting light in each wavelength region of the primary colors B, G, and R are inserted. Means for obtaining the output signal of the photometric element that has passed through each optical filter and a correction function for correcting the incorrect sensitivity of the photometric element based on the obtained output signal. An apparatus for converting a color image signal, comprising: a means for outputting and a means for converting the color image signal by the correction function. 4. The color image signal conversion device according to claim 3, wherein the optical filter is configured by combining one or more types of the exposure control filters. 5. The correction function includes an original photometric vector having B, G, and R outputs obtained through the mosaic filter as a component, and a color-mixture component vector having an output of the photometric element obtained through the optical filter as a component. 4. The color image signal conversion device according to claim 3, wherein the conversion device is a coefficient matrix for linear linear conversion.