JP3034081B2 - Photo printing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographic printing apparatus capable of properly performing reprinting and reprinting.

[0002]

2. Description of the Related Art In general photographing, a subject B (blue), green (G), red (R) (hereinafter simply referred to as B,
It is known as an empirical rule that the average reflectances of the three primary colors (described as G and R) are substantially constant. Therefore, in a conventional photographic printing apparatus, the average transmission density (L
ATD) is measured, and the exposure in photographic printing is determined based on the measured average transmission density, thereby controlling the exposure to be applied to the B, G, and R photosensitive layers of the photographic paper to a constant value, thereby achieving color balance. Try to create good photographic prints. In this case, there is a disadvantage that it is difficult to obtain a proper photographic print when the luminance distribution and the color distribution are uneven in the subject. These photographic original images are called subject feria. In particular, when the brightness distribution of the subject is biased, the density is feria, and when the color distribution is biased, the color is feria.

[0003] As a known technique for automatically adjusting the exposure amount with respect to density feria,
The following technology disclosed in Japanese Patent Publication No. 56-2691 can be mentioned. That is, an original image on a photographic film is scanned, a characteristic value is obtained for each image region from the image density obtained by this scanning, classification is performed based on this characteristic value, and a characteristic value determined in advance for each classification is obtained. The function adjusts the exposure amount for the original image.

[0004] As a known technique for adjusting the exposure amount for color feria, there is known a low-speed correction. Generally, exposure is adjusted according to LATD for a photographic original photographing a standard subject,
Full correction, which makes the exposure amount given to each color photosensitive layer of photographic paper constant, is effective, and no correction, in which subject feria with proper exposure is exposed with a constant light flux or exposure time regardless of LATD, is effective. However, in practice, a compromise is that low-speed collection, an intermediate control method between the two, is appropriate, and the optimal collection level should be selected based on the overall quality of the photographic print. . 2. Description of the Related Art In recent years, photographic printing apparatuses are generally equipped with selectable collection levels of several levels.

However, in a photographic printing apparatus of the LATD control system, a change in the density of each of the B, G, and R colors of the photographic original image is usually caused by a difference between the tone reproduction characteristic of the photographic film and the color distribution of the subject. Cannot be identified automatically. For this reason, exposure conditions are set in advance for each type of photographic film, and the exposure conditions set according to the type of photographic film to be printed are switched. However, with the recent increase in the types of photographic films, the necessity of setting and switching the exposure conditions as described above is a major factor that hinders the rationalization of the photographic printing process. Furthermore, even in the case of photographic films of the same type, photographic prints with an appropriate color balance cannot be obtained under the set exposure conditions in many cases due to deterioration in characteristics due to the state of storage of the latent image. This is a major obstacle in producing stable and efficient photographic prints of a certain quality.

In order to solve such a problem, the applicant of the present invention disclosed in a patent application “Method for determining the amount of exposure for photographic printing” filed on Feb. 2, 1991, in which the average transmission density of an original image formed on a photographic film was determined. In a method of measuring and determining an exposure amount for an original based on this density, scanning a plurality of originals formed on a photographic film before measuring the average transmission density,
A predetermined statistic is obtained from the image information of a plurality of original images obtained as described above, an image characteristic value is further calculated from the image information of each original image, and then a correction amount is obtained from the statistic and the image characteristic value. A method of correcting the exposure amount by the correction amount has been proposed.

[0007] By these techniques, each original image formed on a photographic film is given an appropriate exposure amount, and at the time of the first printing (simultaneous printing), a photographic print of a certain quality can be stably obtained. .

[0008]

In these examples, an image processing system comprising a scanning section for scanning an original image on a photographic film and an information processing section for determining an exposure correction amount based on obtained image information. And a photographic printing apparatus having an exposure control system for adjusting the exposure amount for the original image based on the exposure correction amount output from the image processing system. However, depending on the original image, similarly to the determination of the exposure correction amount by a skilled technician, the exposure correction amount obtained by the image processing system as described above is inappropriate, so that the resulting photographic print becomes defective and cannot be shipped. Sometimes. The original image corresponding to the defective photographic print is reprinted. Additional printing at the request of the customer is performed on a daily basis. In the case of reprinting or reheating performed in this way, the conventional technology faces a serious problem.

In the case of reprinting or reprinting, since it is a prerequisite for printing that a photographic print equivalent to the photographic print obtained in the first printing is obtained, printing is not performed by the photographic printing apparatus used for the first printing. It is considered appropriate to process the photographic original to be corrected. In this case, a method in which the original image is scanned again by the same image processing system used for the first printing to obtain an exposure correction amount is considered to be effective. However, in the image processing system, since the same image information is not always obtained from the same photographic original image, the output exposure correction amount may be different from that at the time of the first printing. Therefore, there is a problem that a photographic print equivalent to the photographic print obtained in the first printing is not necessarily obtained in the case of no additional printing or reprinting.

[0010] In addition, at the time of the first printing, a plurality of photographic films immediately after development are bonded and processed in a lump while they are long, and in the case of reprinting or reprinting, the photographic films are usually cut into short lengths. Therefore, there is a case where the photographic processing step is configured by providing a dedicated photographic printing apparatus suitable for such an embodiment. In such a case, the above problem is not solved yet, and there is a problem that it is hardly expected that the same processing will be performed on an original image on a photographic film due to a different image processing system.

Further, in a photographic processing step constituted by a plurality of photographic printing apparatuses, when reprinting or reprinting is performed by a photographic printing apparatus different from the first printing, the above image processing system is generally expensive and equipped. In many cases, such printing is not performed, and the printing process using the above-described image processing system is often not performed during additional printing or reprinting. In this case, the additional printing or the reprinting process is performed irrespective of the information of the first printing, so that it is extremely difficult to obtain a photographic print equivalent to the photographic print obtained in the first printing. The same applies to the case where the same photographic printing apparatus performs printing processing without using the above-described image processing system or its output.

In a photographic printing apparatus, it is customary that illumination light for an original photographic image in an exposure system fluctuates due to a temporal change of an illumination light source and an illumination optical system. Because there is a considerable time gap between the reprinting stage and the fluctuation of the exposure system that occurred during this time, it is not possible to obtain a photographic print equivalent to the photographic print obtained in the first printing at the time of reprinting or reprinting due to the fluctuation of the exposure system. It will be difficult.

The present invention has been made in view of the above problems, and in the case of no additional printing or reprinting, a photographic print equivalent to the photographic print obtained in the first printing is easily and stably obtained. It is an object of the present invention to provide a photographic printing apparatus capable of appropriately and easily correcting a reprint.

[0014]

In order to achieve this object, a photographic printing apparatus according to the present invention has a measuring means for measuring an average transmission density of an original on a photographic film, and a photographic printing apparatus based on the measured average transmission density. Exposure control means for calculating and controlling the exposure amount for the original image; input means for inputting correction information for the exposure amount; scanning means for scanning the original image to obtain image information; Image information processing means for outputting a correction amount for an amount, and the image information processing means
Data corresponding to the correction amount output from the original image
Recording means for recording on the obtained photographic paper;
Reading means for reading data corresponding to the correction amount from
Data corresponding to the correction amount read by the reading unit
Is used as the correction information input by the input means.
Steps are provided to easily and properly perform reprinting and reprinting.

[0015] Further, the recording means has a printing portion for attaching a character to the surface of the photographic print.

Further, the recording means has a printing section for applying a bar code to the surface of the photographic print.

Further, the recording means has an auxiliary storage medium input / output unit such as a magnetic storage.

Further, the input means has an optical code reader.

Further, the input means has an auxiliary storage medium input / output unit such as a magnetic storage.

[0020]

In the photographic printing apparatus according to the present invention, the average transmission density of the original on the photographic film is measured by the measuring means, and the exposure amount is calculated based on the average transmission density measured by the exposure control means. The exposure system is controlled. Here, since it is sufficient to measure the average transmission density of the entire area of the original image for each color of B, G, and R, a photometric element having a large light receiving area is used. As a result, a sufficient dynamic range can be obtained in photometry, and the density of an image formed on a photographic film capable of recording an image over a wide range of densities can be accurately and stably measured. The exposure amount for the original image is determined. The input means is, for example, a correction key, by which artificial correction to the exposure amount is added as needed. Further, in the photographic printing apparatus of the present invention, the original image on the photographic film is scanned by the scanning means, image information corresponding to the original image is obtained, the image information is processed by the image information processing means, and a correction amount for the exposure amount is calculated. Output to exposure control means. As a scanning unit for scanning the original image, an image pickup device represented by, for example, a CCD is used. In the exposure control means, the exposure amount is corrected by the correction amount, and the correction amount is sent to the conversion means and converted into correction information in the input means. Further, this result is sent to a recording means, and is replaced with information readable by a visual or optical code reader, for example, a symbol such as a character or a bar code, and is recorded on the surface of a photographic print in a printing unit. Alternatively, the correction information is written to an information storage medium such as a magnetic storage in an auxiliary storage input / output unit included in the recording unit.

Therefore, when the same original image is to be printed again, the correction information recorded on the surface of the photographic print is visually read and input from a correction key provided on the input means. Alternatively, the correction information recorded on the surface of the photographic print is read and input by an optical code reader provided in the input means. Alternatively, magnetic storage information or the like written on the information storage medium is read and input by an auxiliary storage input / output unit provided in the input unit. At this time, it is not necessary to scan the original image to be printed by the scanning unit and determine the correction amount by the image information processing unit. Further, even when scanning is performed, it is not necessary to use the correction amount output from the image information processing means. The exposure amount is determined based on the average transmission density of the original image measured at the time of exposure, and the fluctuation of the illumination light in the exposure system is compensated. Therefore, the amount of light applied to each color photosensitive layer of the photographic paper can be the same as at the time of the first printing, and the same exposure amount can be corrected as at the time of the first printing by inputting the correction information by the input means. . In this way, in the case of no additional printing or reprinting, a photographic print equivalent to the photographic print obtained in the first printing is obtained. In the case of reprinting, a necessary correction can be obtained by observing a defective photographic print. Information on this correction is input from a correction key or the like provided in the input means. In this way, it is possible to appropriately and easily perform the rework correction.

By the way, in a photographic processing step constituted by a plurality of photographic printing apparatuses, when reprinting or reprinting is performed by a photographic printing apparatus different from the first printing, the photographic printing apparatus is required to correspond to the correction amount based on the correction information. In the photographic printing apparatus of the present invention, the conversion formula to the correction information in the conversion means is adjusted according to the photographic printing apparatus used for additional printing or reprinting. This adjustment depends on the setting of constants and the like. Similarly, by setting constants and the like, conversion into a plurality of types of correction information is performed during the burning process, and a plurality of types of correction information are recorded.
By using such correction information, reprinting and reprinting can be appropriately and easily performed by a plurality of types of photoprinting apparatuses in the processing process.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a photographic printing apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of a 135 photographic film subjected to a printing process.

In the figure, a plurality of photographic films F on which an original image (group) G has been formed by development are joined by a splice 10 to form a roll. A notch (group) 12 indicating the center position of the original image is formed on the side of the rolled photographic film F in a notch step preceding the photographic printing step. A well-known perforation (group) P is formed on this side in advance. The notch 12 is detected, and control such as positioning of the photographic film F in the subsequent steps is performed. As shown in the figure, the photographic film F has a bar code 14 indicating its type.
Is attached. The photographic film F of this example is 13
5. Regardless of the photographic film, other photographic films may be used.

The roll-shaped photographic film F thus processed is subjected to printing processing in a photographic printing apparatus.

FIG. 2 shows the configuration of a photographic printing apparatus.

The photographic film F is set on a spool 20 and wound on a spool 21 via a predetermined transport path. A scanning unit 22 is provided in the middle of the path, where the original images recorded on the photographic film F are B, G,
Each color of R is separated and scanned. The image signals of B, G, and R colors obtained by the scanning unit 22 are sent to the image processing unit 24, A / D converted, shaped into image density information in a predetermined format, and then sent to the information processing unit 26. Can be

The image density information is processed by the information processing section 26 as described below. As a result, a correction amount for each original image is calculated, and a signal of the correction amount is transmitted to the exposure control section 30 through the communication line 28. You. The photographic film F that has passed through the scanning unit 22 is provided between the scanning unit 22 and the exposure unit 32 to absorb a difference in the transport speed of the two photographic films F and simultaneously scan a plurality of original images before exposure. The light is sent to the exposure unit 32 through the buffer unit 34. The transport path between the scanning unit 22 and the exposing unit 32 has a length corresponding to a maximum of 24 single-photographing 135 photographic films. Image density information corresponding to the original image G can be obtained prior to exposure.

Each original image formed on the photographic film F is positioned at the exposure unit 32, and the light emitted from the light source 36 is illuminated as light that has been made uniform by the diffusion unit 38.
Further, the image is optically formed on the photographic printing paper 40 by the lens 54 and is exposed.

At this time, the photometric filters 4 for the B, G, and R colors
The average transmitted light of each color of B, G, and R of the original image passes through photodiodes 44a, 44b, and 44c through 2a, 42b, and 42c.
Is received by the B, which is obtained by photoelectrically converting the amount of received light,
The photometric signals of each of the G and R colors are supplied to the exposure control unit 30 and further subjected to A / D conversion. The exposure amount is calculated based on the data obtained as a result and the correction amount supplied from the information processing unit 26. .

The exposure amount obtained here is subjected to an exposure control unit 30 to reduce the color of yellow (Y), magenta (M), and cyan (C) cut filters 50a, 50b, The operation time is converted as the operation time of the shutter 52 arranged below the exposure unit 32 and 50c. The cut filters 50a, 5a
Ob, 50c and the shutter 52 are inserted into the exposure light path, and the exposure given to each color photosensitive layer of the photographic printing paper 40 is adjusted.

After the completion of the exposure, the correction amount used for the exposure is sent to the input / output unit 35, converted into correction information according to a conversion formula described later, and a code corresponding to this information is recorded. At the time of additional printing or reprinting, correction information is input from the input / output unit 35, and constants and the like for device adjustment are also input from the input / output unit 100.

After these series of processes, the photographic printing paper 40 is transported by a predetermined distance in preparation for the next exposure, and the photographic film F is transported to position the original G to be printed next on the exposure unit 32. Is done.

The original image G thus formed on the photographic film F is sequentially printed.

FIG. 3 shows the configuration of the scanning unit 22 in detail.

In the scanning section 22, light emitted from the light source 59 is converted into substantially parallel light by the lens 60. This parallel light is supplied to color separation filters 62a, 62b, and 62c arranged in parallel along the transport direction of the photographic film F to B, G,
The color is separated into R colors.

In this manner, the photographic film F is separated into B, G, and R colors, and the light that has passed through the slit 64 is used.
Is irradiated. The light transmitted through the photographic film F is B,
Photoelectric conversion is performed by CCD line sensors 68a, 68b, 68c arranged at positions corresponding to the respective irradiation lights of the respective colors of G and R. The CCD line sensor 68a,
Each of 68b and 68c is composed of 2048 pixels, and uses a one-dimensional image sensor capable of scanning over a length of 32 mm in the width direction of the photographic film F.

Thus, the width 3 of the photographic film F in the width direction is
The main scanning is performed for 2 mm, and B,
Image signals for each of the G and R colors are supplied to the image processing unit 24. The notch 12, the splice 10, and the barcode 14 attached to the photographic film F are detected by detectors 70a, 70b, 70c, respectively, and the detection signal is supplied to the transport control circuit 72. Transport control circuit 72
Processes these detection signals and converts the result to a notch signal,
As a splice signal and a bar code signal, the image signal is transmitted to the image processing unit 24 and the information processing unit 26 via the system bus 74, and the pulse motor 75 is driven to control the conveyance of the photographic film F. It is supplied to the image processing unit 24 as a synchronization signal in sampling.

The photographic film F is a pulse motor 75
Is conveyed at a rate of 0.25 mm / pulse, and a sub-scan is performed accordingly.

FIG. 4 shows a detailed configuration of the image processing section 24. The image processing section 24 performs the following signal processing.

The image signal supplied from the scanning section 22 is amplified by an amplifier circuit 80, and a sample and hold circuit 82
, And are sampled by the A / D converter 84 and converted into digital signals. The timing control circuit 8
Reference numeral 6 denotes CCD line sensors 68a, 68
b and 68c, and controls the sampling timing. Here, the number of samplings is 128 for one scan,
A / D conversion is processed by 16 bits. The digitized image signal is converted into a density value via a look-up table (LUT) 88 composed of a ROM or the like, and stored in the image buffer 90. The LUT 88 stores a conversion table represented by Expression 1.

[0043]

Y = a × log (X + b) where X is an input to the LUT 88 and Y is its output. A is a constant relating to conversion from the photometric density determined by the spectral characteristics of imaging in the scanning unit 22 to the printing density determined by the spectral sensitivity of the photographic printing paper, and b is a constant relating to removal of the influence of dark current in imaging. is there.

The LUT 88 is provided with a plurality of conversion tables which are obtained by substituting several types of numerical values into the constants a and b of the formula 1, and is selected in advance by the CPU 92. The conversion table selected here does not necessarily have to be the same for each of the B, G, and R colors, and may be different.

As described above, 16 pixels each including 128 pixels are used.
Bit line image density information is stored in the image buffer 90. Hereinafter, this is referred to as primary line image density information Da.

Next, the internal processing (image processing) in the image processing section 24 will be described.

The CPU 92 fetches the primary line image density information Da in synchronization with the transport pulse, performs the following rounding processing, and then performs image processing in the main scanning direction for storing in the memory 94 for each scanning line.

Main scanning direction (primary line image density information Da)
The effective image area varies depending on the format of the photographic film F. Therefore, the CPU 92 sets an image area to be rounded in the main scanning direction and the number of pixels to be rounded stored in advance in accordance with the format of the photographic film F, and sets each pixel in the set image area. A rounding process is performed based on the number of pixels.

After processing into such line image density information of a predetermined number of pixels, the information is stored in the memory 94 for each scanning line. Here, the predetermined number of pixels is 16 pixels.

FIG. 5 shows an example of this mode. 1
35 Primary line image density information D obtained from photographic film
In a, the image area corresponding to the width of 20 mm at the center is set as the effective area, and the value 5 obtained by dividing the number of pixels 80 corresponding to this length by the predetermined number of pixels 16 is set as the number of rounded pixels.

In the case of 110 photographic film, this 1
10 Primary line image density information D obtained from photographic film
In a, the image area corresponding to the central width of 12 mm is set as the effective area, and the numerical value 3 obtained by dividing the number of pixels 48 corresponding to this length by the predetermined number of pixels 16 is set as the number of rounded pixels.

Here, the rounding process is performed by taking the arithmetic mean of the image density information. This has the effect of reducing the influence of noise included in the image signal. However,
The rounding does not necessarily have to be performed on all the pixels in the selected image area, but may be performed by an arithmetic averaging method in which the pixels are appropriately decimated, or by decimating only a predetermined number of pixels. Is also effective in consideration of the calculation speed.

By the image processing in the main scanning direction as described above, the secondary line image density information D consisting of a predetermined number of pixels, here 16 pixels, regardless of the format of the photographic film F.
b, and the secondary line image density information Db is stored in the memory 9
Reference numeral 4 stores line image density information corresponding to a large number of scanning lines as the photographic film F is transported.

Further, the CPU 92 takes out the secondary line image density information Db stored in the memory 94, shapes it into two-dimensional image density information in a predetermined format by image processing in the next sub-scanning direction, and processes the information. To the unit 26.

Here, the management of the correspondence between the original image formed on the photographic film F and the secondary line image density information Db stored in the memory 94 becomes a problem. This management is performed based on the notch signal. As described above, notch 12
Is previously provided at the center position of the original image, and is detected by the scanning unit 22. As a result, a notch signal corresponding to the position of the original image is sent from the scanning unit 22 to the CPU 9 via the system bus 74.
2 is sent. When the CPU 92 receives the notch signal, it counts the number of transport pulses, and after reaching a predetermined processing start count value, takes out the primary line image density information Da stored in the image buffer 90 and reaches the predetermined number of scanning lines. The image processing in the main scanning direction is repeated until the above.

The address of the secondary line image density information Db stored in the memory 94 corresponds to the notch signal.
Is stored in a predetermined area. In this way, the secondary line image density information Db is managed corresponding to the position of the original image formed on the photographic film F. However, the correspondence described above is based on the CCD line sensor 6 for each color of B, G, and R.
8a, 68b, 68c. Therefore, the predetermined count value is selected and set according to the color from a constant stored in advance.

This selection can be made by a switch (not shown) provided inside the image processing section 24. As a result, the image processing unit 24 can have a common configuration for each of the B, G, and R colors, and its internal processing can be common. By operating them in parallel, an extremely high processing speed can be achieved.

The effective image area in the sub-scanning direction (the number of scanning lines) may differ depending on the format of the photographic film F. Therefore, the CPU 92 sets the number of scanning lines stored in advance according to the format of the photographic film F as the predetermined number of scanning lines. Scanning unit 22
Scan is performed once every 0.25 mm. For example, the number of scanning lines corresponding to the processing target area 32 mm of the full-size original of 135 photographic film is 128,
The number of scanning lines corresponding to the processing target area 16 mm of the half-size original image is 64. Therefore, the CPU 92 sets the number of scanning lines stored in advance according to the format of the photographic film F as the predetermined number of scanning lines. Furthermore, rounding processing is performed in the sub-scanning direction in accordance with the set number of scanning lines to process the two-dimensional image density information having a predetermined number of pixels in the sub-scanning direction.
Here, the number of pixels in the predetermined sub-scanning direction is 16.

FIG. 6 shows an example of this mode. In the figure, for the secondary line image density information Db obtained from a full-size original image, a numerical value 8 obtained by dividing the number of scanning lines 128 by the predetermined number of sub-scanning pixels 16 is set as the number of rounded scanning lines. You. For the secondary line image density information Db obtained from the half-size original image, a numerical value 4 obtained by dividing the number of scanning lines 64 by the predetermined number of sub-scanning pixels 16 is set as the number of rounded scanning lines. .

In the rounding process, the arithmetic mean of the image density information is obtained in the sub-scanning direction. This is similar to the case of the image processing in the main scanning direction. It is effective in reducing. However,
The rounding does not necessarily have to be performed on all the stored secondary line image density information Db, but is performed only by a method of taking an upper arithmetic average with appropriately thinning out, or by thinning out only a predetermined number of scanning lines. A method that does not take an arithmetic average is also effective when the calculation speed is taken into consideration.

The image processing in the main scanning direction does not need to be performed according to all the transport pulses, but may be performed intermittently. As a result, not only image processing in the main scanning direction,
Since the load on image processing in the sub-scanning direction is also reduced, the processing speed can be greatly improved. In this case, the intermittent processing cycle may be changed according to the format of the photographic film F.

By the image processing in the sub-scanning direction as described above, finally, a two-dimensional image density information consisting of a predetermined number of pixels, here 16 × 16 pixels, is obtained irrespective of the format of the photographic film F. The information is sent to the information processing section 26. Therefore, the information processing section 26 can perform common processing regardless of the format of the photographic film F.

FIG. 7 shows a detailed configuration of the information processing section 26.

The two-dimensional image density information for each color of B, G, and R sent from the image processing unit 24 is stored in the memory 102 via the system bus 74. The CPU 104 reads the two-dimensional image density information stored in the memory 102 and calculates a correction amount for each original G formed on the photographic film F.

This correction amount is sent to the exposure controller 30 via the communication line 2.
8. Further, a notch signal, a splice signal, and a barcode signal transmitted from the transport control circuit 72 (see FIG. 3) of the scanning unit 22 via the system bus 74 are also stored in the memory 102 and processed by the CPU 104. .

Next, the internal processing in the information processing section 26 will be described.

FIGS. 8 and 9 show a flowchart of this internal processing.

First, a variable L indicating the number of original pictures processed in step 1 is initialized.

Next, in step 2, B, G, R
2D image density information for each color of
_K( i, j). Where i is the pixel position in the main scanning direction
, J is the pixel position in the sub-scanning direction, K is each color of B, G, R
Is shown.

In step 3, the two-dimensional image density information D (i,
j) is calculated by equation (2).

[0071]

[Number 2] D (i, j) = { X B (i, j) + X G (i, j) + X R (i, j)} / 3 In Step 4, using the D (i, j) area Characteristic value D '
(m, n) is calculated. Here, m is, for example, the upper position, the lower position, the right position, the left position of the two-dimensional image density information,
The central position corresponds to the entire area. N is, for example,
It corresponds to the maximum value, the minimum value, and the average value in each area.

In step 5, a density correction value D ″ _L for each original image is obtained by a linear linear expression as shown in Expression 3 using the characteristic value D ′ (m, n).

[0073]

(Equation 3) Here, α (m, n) is a predetermined coefficient, and β is a constant.

In step 6, a histogram F _K (s) of two-dimensional image density information for each of B, G, and R colors is calculated. Here, s indicates the image density, and K indicates each color of B, G, and R. FIG. 10 shows an example of the histogram obtained in step 6. In this figure, the horizontal axis indicates the image density s, and the vertical axis indicates the frequency f.

Further, in step 7, the cumulative density function CDF _KL (s) of the two-dimensional image density information relating to each of the B, G, and R colors of the original image is obtained from the above-mentioned histogram according to equation (4).

[0076]

(Equation 4) FIG. 11 shows an example of the cumulative density function obtained in this way. In this figure, the horizontal axis indicates the image density s, and the vertical axis indicates the cumulative frequency CDF. As is clear from Equation 4 and the figure, this function is continuous for any s and is a monotonically increasing function.

In step 8, 1 is added to a variable L indicating the number of processed original images, and the process is ready for the next original image.

In step 9, it is evaluated whether this L is larger than a predetermined number N of original pictures.
In es), the next step 11 is executed, and when it is not large (No in the figure), the processing of step 10 is executed.
Here, the predetermined number N of the original images is a predetermined constant, and this constant relates to the transport path between the scanning unit 22 and the exposure unit 32 in FIG. 2 described above. In this example, the transport path has a length corresponding to a maximum of 24 photographic 135 photographic films, and when the number N of predetermined original images is, for example, 24, almost all of the images recorded on one 24 photographic 135 photographic film The above-mentioned cumulative density function can be obtained prior to exposure from the image density information corresponding to the original image. In addition, even when the number of original images is large, for example, in the case of a 36-photographing 135 photographic film, the above-mentioned cumulative density function is obtained prior to exposure from image density information corresponding to a sufficient number of original images to obtain statistics. You can also.

In step 10, it is identified whether or not the processed original is the last original G formed on one photographic film F. In the case of the last original (Yes in the figure), the next step 11 is executed. The processing is executed, and if it is not the last original image (No in the figure), the processing after step 2 is executed again. In the information processing unit 26, a splice signal sent from the transport control circuit 72 of the scanning unit 22 via the system bus 74 is stored in the memory 102.
4, it is possible to identify the last original image G recorded on one photographic film F by referring to this signal.
Thus, even when the number of original images is small, for example, as in the case of a 12-shot 135 photographic film, the above-described cumulative density function is exposed from the image density information corresponding to all the original images G formed on one photographic film F. Can be sought before.

In step 11, the two-dimensional image density information of each of the B, G, and R colors of the plurality of original images recorded on the photographic film F is obtained from the cumulative density function of the two-dimensional image density information corresponding to each of the original images. The cumulative density function CDFM _K (s) is obtained by Equation 5 for all s.

[0081]

(Equation 5) As described above, since the cumulative density function CDFM _K (s) shown on the right side is continuous for an arbitrary s and is a monotonically increasing function, as apparent from Equation 5, the cumulative density function CDFM KFM shown on the left side _K (s) is continuous for any s and is a monotonically increasing function.

Further, the cumulative density function CDFM _K (s) can be added very easily in this way. As described above, predetermined statistics and a cumulative density function are obtained from a plurality of originals recorded on one photographic film F.

The cumulative density function CD obtained as described above
It has been confirmed by experiments that FM _K (s) has a close correlation with the tone reproduction characteristics of the photographic film F.

Further, in step 12, the inverse function value _CK is obtained from the cumulative density function for each of the B, G, and R colors corresponding to each original image by the equation (6).

[0085]

[Formula 6] C_K = CDF^-1 _KL(Γ) (K = B, G, R) where γ is a predetermined constant,
A numerical value that does not exceed 256 pixels of degree information, for example, 128
is there. In this way, the characteristic values of the individual originals are determined.
However, this characteristic value is not limited to this example, and the two-dimensional image
The average value of the degree information may be used.

The cumulative density function obtained from the two-dimensional image density information corresponding to a plurality of original images recorded on the photographic film as described above is a statistic corresponding to the tone reproduction characteristic of the photographic film F. The image density of each color that gives a predetermined value to the function is extremely effective for estimating the neutral color recorded on the photographic film F, and can be used as a reference for color correction in determining the photographic printing exposure amount.

In step 13, density information C ′ _{K of} each color of B, G, and R, which is a reference for color correction, is calculated by equation 7 using the above characteristic values and the cumulative density functions obtained from a plurality of original images. Is done.

[0088]

C ′ _K = CDFM _K ⁻¹ (CDF (C _G )) (K = B, G, R) Since the cumulative density function is continuous at any point and is a monotonically increasing function, Such an inverse function can be obtained very easily and has the advantage that no exception handling is required due to the nature of the function.

In the following step 14, a color correction value C ″ _KL for each original image is calculated for each color of B, G, and R by using the above characteristic values and the reference density information for color correction.

[0090]

Equation 8] _{C "KL = C 'K -C} K (K = B, G, R) where C" since _K is an estimate of the neutral color which has been recorded on the photographic film, C _"KL The absolute value of takes a small value when the subject recorded in the original image is a neutral color, and takes a large value when the color distribution in the subject is biased. By using this, correction can be selectively given to color feria.

Since the average reflectance of each color of most subjects is constant, the absolute value of this correction value is generally extremely small as compared with the change in exposure based on the average transmission density of the original image. It is a target. Therefore, the two-dimensional image density information for obtaining this correction value does not require high accuracy,
Therefore, an inexpensive element typified by the CCD line sensors 68a, 68b, 68c can be used in the imaging system for scanning the original image, and a simple circuit can be used for signal processing.

Further, in step 15, it is identified whether the processed original is the last original recorded on one photographic film F as done in step 10,
In the case of the last original image (Yes in the figure), the processing is terminated, and in the case of not the last original image (No in the figure), the processing after step 2 is executed again.

The density correction value D ″ obtained as described above
_{The L} and the color correction value C ″ _KL are transmitted to the exposure control unit 30 via the communication line 28, and are used for determining the photographic printing exposure amount.

Next, how the exposure control section 30 determines the photographic printing exposure amount will be described.

The photographic printing exposure amount is determined according to equation (9).

[0096]

Equation 9] _{E K = E 0K + LATD K} -LATD 0K + C '''K + D''' where, E _K is B, G, the exposure amount of each color of R (logarithmic value of the exposure time), LATD _K is Average transmitted light photometric value (logarithm) from the original image to be printed by the photodiodes 44a, 44b and 44c in the exposure unit 32, LATD
_0K is the average transmitted light photometric value (logarithm) from the standard original image,
C ′ ″ _K and D ′ ″ ″ are the correction amounts of the exposure amount shown in Expression 10.

[0097]

C ″ _K = α × C ″ _KL D ″ = β × D ″ _L where C ″ _KL is a color correction value transmitted from the information processing unit 26, and α is for adjusting the strength of color correction. , D ′ _L is a density correction value transmitted from the information processing unit 26, β is a coefficient for adjusting the intensity of the density correction, and E _0K is an exposure amount (exposure time vs. exposure time) set for the standard original image. Number), K is B,
The colors G and R, and L indicate the processing order of the original image.

In this manner, the exposure amount is determined based on the average transmitted light photometric value of the original image, and is corrected by the color correction value determined in consideration of the tone reproduction characteristics of the photographic film F. Here, the average transmitted light of the original image G is measured at the time of exposure. Therefore, a change in density due to a change in irradiation light in the exposure system or a deterioration of an image during exposure can be detected, and the exposure amount can be adjusted thereby, so that these effects are greatly reduced. Therefore, finally, the photographic film F
The optimum exposure amount can be obtained in consideration of the tone reproduction characteristics of the above, the characteristics of each original image, and various fluctuations during exposure. Further, a photometric element having a large light receiving area can be used for photometry of the average transmitted light of the original image for each of the colors B, G, and R. As a result, a sufficient dynamic range can be obtained in photometry, and the density of the image G formed on the photographic film F capable of recording an image over a wide density range can be accurately and stably measured, and high reproducibility can be obtained. Thus, the exposure amount for the photographic original image can be obtained.

Further, as shown in Expression 10, the exposure control unit 30 performs the adjustment by multiplying the correction value output from the information processing unit 26 by the coefficients α and β. The amount of correction depends on the result of this multiplication. When this adjustment is not performed, the values of α and β may be set to 1, and when these correction values are not used, these values may be set to 0. Further, a mode switching switch may be provided in the photographic printing apparatus, and a plurality of coefficient sets may be selected according to the mode selected by the switch. The correction amount thus obtained is sent to the input / output unit 35.

FIG. 12 shows a detailed configuration of the input / output unit 35.

The correction amount sent to the input / output unit 35 is
The information is converted by 20 into correction information. This conversion process will be described later in detail. The correction information obtained as a result of this conversion is printed by the printing device 121 on the back surface of the photographic printing paper 40 at the corresponding printing position. The code printed in this way can be input from the correction key 122 or the optical code reader at the time of additional printing or reprinting. FIG. 13 shows an example of the correction key 122.
The first, second and third columns are color correction keys for inputting color correction information for each of B, G and R colors, and the fourth column is a density correction key for inputting density information. The correction information is further recorded on a magnetic disk (not shown) in the magnetic disk device 123, and is read as necessary at the time of additional printing or re-printing. A display 124 and a keyboard 125 are provided, and input and output of device adjustment constants and the like are performed via an interface circuit 126. The input constants and the like are stored in the memory 127.

Next, the process of conversion into correction information in the input / output unit 35 will be described.

The correction amount output from the exposure control unit 30 is converted into correction information according to equation (11).

[0104]

CKEY _K = (C ′ ″ _K + CHALF) / CUNIT DKEY = (D ′ ″ + DHALF) / DUNIT Here, CKEY _K is color correction information related to four-color correction in a photographic printing apparatus. This is information corresponding to the correction key 122. C ′ ″ _K is a color correction amount output from the exposure control unit 30, and CUNIT is a unit correction amount, for example, a correction amount per key of a color correction key, and is usually a positive value, for example, a log exposure ratio LOG1. .1 or 0.04. DKEY is density correction information relating to density correction in the photographic printing apparatus, D "" is a density correction amount output from the exposure control unit, and DUNIT
Is a unit correction amount, for example, a correction amount per key of the density correction key, and is usually a positive value, for example, a log exposure ratio LOG1.
15 or 0.06. K is B,
G and R are shown. The unit correction amount is displayed on the display 124 and input from the keyboard 125 as needed. The input unit correction amount is stored in the memory 127. In this case, if a plurality of types of unit correction amounts are input and stored, the obtained correction information can correspond to the correction information in the plurality of types of photographic printing apparatuses.

Note that the numerical value after the decimal point resulting from the division in Equation 11 is truncated. In the process of quantizing the correction information performed in this way, it is desirable to minimize the quantization error. Therefore, Equation 11 is
A value smaller than each of CUNIT and DUNIT, for example, a half value thereof, CHALF and DHALF, is added to the correction amount C " _K , D"", and division is performed. The values of CHALF and DHALF are respectively For example, the values are 0.02 and 0.03.

FIG. 14 shows the relationship between the density correction amount output from the exposure control unit 30 to the input / output unit 35 and the density correction amount obtained as a result of quantization. The solid line shows the case where DHALF is added, and the broken line shows the case where DHALF is not added. As shown in this figure, when DHALF is added, the quantization error can be reduced.

The unit correction amount is set independently for density correction and color correction. In particular, if the unit correction amount for color correction is set smaller than the unit correction amount for density correction,
The above-described quantization error can be further reduced. This is due to the conversion shown in Equation 12.

[0108]

CKEY _K = {C ″ _K + CHALF + MOD {(D ′ ″ + DHALF) / DUNIT} / CUNIT DKEY = (D ″ ″ + DHALF) / DUNIT where MOD (X / Y) is X The following shows a function that gives a remainder divided by Y. According to this conversion, the quantization error of the density correction amount is partially compensated for by the information of the color correction, and can be further minimized. Output unit 35
9 shows the relationship between the input density correction amount and the density correction amount obtained as a result of the quantization shown in Expression 12. The solid line indicates the case where the compensation by the color correction information is added, and the broken line indicates the case where the compensation is not added. As shown in this figure, when the compensation based on the color correction information is added, the quantization error can be further reduced.

As is clear from the above, the quantization error depends on the unit correction amount. However, for example, the correction information of the photoprinting apparatus has upper and lower limits, and it is not possible to input correction information exceeding this limit. Therefore, the unit correction amount is determined by the normally required correction amount and the range of the correction information, for example, the number of correction keys. However, the correction information output above may exceed the upper and lower limits. In this case, the processing shown in Expression 13 is performed.

[0110]

[Number 13] _{IF CKEY K> CKEYMAX THEN CKEY K} = CKEYMAX IF CKEY K <CKEYMIN THEN CKEY K = CKEYMIN IF DKEY> DKEYMAX THEN DKEY = DKEYMAX IF DKEY <DKEYMIN THEN DKEY = DKEYMIN Here CKEYMAX, CKEYMIN, DKEYMA
X and DKEYMIN indicate upper and lower limits of color correction information and density correction information, respectively.
24 and input from the keyboard 125. These numerical values are, for example, 4, -4, -4, respectively, corresponding to the number of correction keys shown in FIG. The input upper and lower limit values are stored in the memory 127. In this way, the correction information can be limited to a numerical value within a predetermined range.

The correction information obtained in this way is transmitted to the printing device 1
At 21, it is recorded on the back of the photographic print. The record may be either a character code that can be read visually or a bar code that can be read by an optical code reader, or both. This selection differs depending on the mode of the input means of the correction information of the photographic printing apparatus for performing reprinting or additional printing. further,
This correction information is recorded on a magnetic recording medium (not shown) in the magnetic disk device 123. Further, when the photographic printing process is configured by a plurality of photographic printing devices, when the unit correction amount of each photographic printing device is different, when the setting of the unit correction amount or the like for the cut film processing is changed, or when the setting is different. In the case of selecting from a plurality of types of unit correction amounts and the like, the correction information corresponding to the plurality of photographic printing apparatuses or the plurality of conditions is stored in each recording unit. Recorded together with the identification code. The setting conditions of such a recording method are displayed on the display 124 as needed, and are input from the keyboard 125. The input unit correction amount is stored in the memory 127.

Table 1 below shows an example of correction information obtained as a result of the above conversion, that is, correction information recorded as CKEY and DKEY. As shown in the figure, these may be in a format that can be replaced with each other by a predetermined procedure. Here, the values of CKEY and DKEY are recorded in association with the display of the correction key shown in FIG.

[0113]

Table 1 CKEY DKEY Correction information to be recorded BGR 00 -1 555-1 00 00 555 N 0 0 0 0 1 555 +1 -1 -1 0 444 N 1 1 1 1 1 0 1 0 N -1 FIG. 16 shows an example of correction information recorded on the back side of a photographic print in this manner. Regarding the first column, the information of the first digit is the identification code of the photographic printing device that has performed printing, the information of the second digit is the identification code of the photographic printing device that is used when reprinting or reprinting is performed, and the third and fourth digits. Is the code relating to the type of photographic film, the information of the fifth, sixth, and seventh digits is color correction information, the information of the eighth digit is density correction information, and the same applies to the second column. Therefore, by referring to the information of the second digit, it is possible to easily find correction information corresponding to the photographic printing apparatus used for additional printing or reprinting.

Next, a description will be given of a reprint or reprint process using the above correction information.

As described above, the correction information recorded on the back side of the photographic print is read visually, and the correction key 1
22. As a result, the printing exposure amount obtained is represented by Expression 14.

[0116]

Equation 14] _{E K = E 0K + LATD K} -LATD 0K + C '''' K + D '''' where, LATD _K is subjected to baking to Motasa in an exposed portion 32 photodiodes 44a, 44b, by 44c This is an average transmitted light photometric value (logarithm) from the original image, and this photometry is performed again when additional printing is not performed or when reprinting is performed, as in the first printing. As described above, since the exposure amount is determined based on the average transmitted light photometric value of the original image measured at the time of exposure, the exposure which is a problem when the time interval between the first printing and the second printing is long is long. Changes in the illumination light over time in the system are compensated. Therefore, the amount of light given to each color photosensitive layer of the photographic paper can be the same as at the time of the first printing. Here, C ′ ″ ″ _K ,
D ′ ″ ″ is the density and color correction amount obtained by Expression 15.

[0117]

Equation 15] _{C '''' K = CKEY} K × CUNIT D '''' = DKEY × DUNIT Here CKEY _K, the value of DKEY corresponds to the correction key, a correction information.

In particular, when further correction is necessary as in the case of reprinting, the correction obtained by observing the print obtained by the first printing is added to the above correction information, and the obtained color correction and density correction information are obtained. Can be easily rewritten. The input means is provided with two modes. In the first mode, correction information for the first printing is inputted, and the second mode is inputted.
In this mode, further correction information may be input. In this case, for example, in the first mode, the correction information is mechanically read by an optical code reader or a magnetic disk device 123 provided in the input means, and in the second mode, further correction is input by the correction key 122. As a result, the correction at the time of the first printing is automatically set, so that it is not necessary to calculate new correction information, so that reprinting or additional printing can be performed more easily. In addition,
In any case, the recorded correction information is associated with the correction information to be used for exposure according to a predetermined procedure.

When performing additional printing or reprinting in this way, it is not necessary to scan the target original image again and determine the correction amount. Therefore, even a short photographic film can be processed without special processing such as bonding for continuous scanning and exposure. Even when the target original image is scanned again, the exposure control unit 30 does not use the color correction value and the density correction value transmitted from the information processing unit 26 or does not substantially affect each of them. A method similar to the above can be performed by assigning a numerical value, for example, 0. For example, in a photographic printing apparatus in which a scanning unit is provided in the vicinity of an optical path of an exposure unit and scanning is performed at the time of exposure as disclosed in Japanese Patent Application Laid-Open No. 1-195439, two modes are provided to an exposure control unit. In the first mode, an original image is scanned to determine a correction amount, exposure control is performed based on the correction amount, and in the second mode, a numerical value that does not employ the correction amount or has substantially no influence. May be assigned, and these may be switched by a switch.

In the present embodiment, the mode in which the scanning section and the exposure section are separated has been described. However, the present invention is not limited to this, and the scanning section is provided near the optical path of the exposure section as described above. Even in a photographic printing apparatus of a type that scans at the right time, it is possible to construct a photographic printing apparatus and obtain the effect by the same technical means, but this is included in the scope of the present invention.

[0121]

As described above, according to the photographic printing apparatus of the present invention, the correction information used for the first printing is recorded in an appropriate format according to the photographic printing process. In the case of (1), a photographic print equivalent to the photographic print obtained in the first printing can be easily obtained, and particularly, in the case of reprinting, the defective photographic print can be properly corrected.

Since the exposure amount is determined based on the average transmission density of the original image measured at the time of exposure, the fluctuation of the illumination light in the exposure system is compensated. Therefore, the amount of light applied to each color photosensitive layer of the photographic paper can be the same as in the first printing, and in the case of no additional printing or reprinting, a photographic print equivalent to the photographic printing obtained in the first printing can be easily obtained. Can be

Further, since the correction information is converted with an extremely small error from the actual exposure correction amount, the exposure correction amount used for the first printing can be reproduced with high accuracy.

Further, at the time of additional printing or reprinting,
Since the correction information used for the first printing can be automatically input, not only the work efficiency of additional printing and reprinting can be greatly improved, but also human errors can be reduced. The correction information is printed on the image.
The image is recorded on the photographic paper, and the image and the image are printed.
The correction information at the time of shading is recorded in association with the image, and the image and its
The correction information at the time of printing the image is not
There is also an effect that it is easy to specify the correct information.

As described above, the present invention can obtain extremely significant effects in photographic printing.

[Brief description of the drawings]

FIG. 1 is a block diagram of a 135 photographic film used for explaining a photographic printing exposure amount determining method of the present invention.

FIG. 2 is a schematic diagram showing a schematic configuration of a photographic printing apparatus to which the photographic printing exposure amount determining method of the present invention is applied.

FIG. 3 is a configuration diagram showing a scanning unit in FIG. 2 in detail.

FIG. 4 is a configuration diagram showing an image processing unit in FIGS. 2 and 3 in detail;

FIG. 5 is a diagram showing a part of image processing in the main scanning direction used for explaining the embodiment.

FIG. 6 is a diagram illustrating a part of image processing in the sub-scanning direction used for describing the embodiment.

FIG. 7 is a configuration diagram showing an image processing unit in FIGS. 2 and 3 in detail;

FIG. 8 is a flowchart illustrating internal processing in the information processing unit.

FIG. 9 is a flowchart showing internal processing in the information processing unit following FIG. 8;

FIG. 10 is a diagram illustrating an example of an image density histogram used for describing the embodiment.

FIG. 11 is a diagram showing an example of a cumulative density function used for describing the embodiment.

FIG. 12 is a configuration diagram showing details of an input / output unit in FIG. 2;

FIG. 13 is a diagram illustrating an example of a correction key in FIG. 12;

FIG. 14 is a diagram illustrating a relationship between a density correction amount output from an exposure control unit to an input / output unit and a density correction amount obtained as a result of quantization.

FIG. 15 is a diagram illustrating a relationship between a density correction amount output from an exposure control unit to an input / output unit and a density correction amount obtained as a result of quantization and compensation based on color correction information.

FIG. 16 is a diagram illustrating an example of correction information recorded on the back side of a photographic print.

[Explanation of symbols]

 Reference Signs List 20 spool 22 scanning unit 24 image processing unit 26 information processing unit 28 communication line 30 exposure control unit 32 exposure unit 34 buffer unit 35 input unit 38 diffusion unit 40 photographic printing paper F photographic film

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03B 27/72-27/80

Claims (6)

(57) [Claims] A measuring means for measuring an average transmission density of an original image on a photographic film; an exposure control means for calculating and controlling an exposure amount for the original image based on the measured average transmission density; and correction information for the exposure amount Input means for inputting an image, scanning means for scanning the original image to obtain image information, image information processing means for processing the obtained image information and outputting a correction amount for the exposure amount, and output by the image information processing means.
Prints the data corresponding to the corrected amount from the original image
Recording means for recording on paper, and the correction amount from the photographic paper
Reading means for reading data corresponding to
Data corresponding to the correction amount read by the input means.
A photographic printing apparatus , comprising: conversion means for converting correction information to be input by steps . 2. A photographic printing apparatus according to claim 1, wherein said recording means has a printing section for attaching a character to the surface of the photographic print. 3. The photographic printing apparatus according to claim 1, wherein said recording means has a printing unit for applying a bar code to the surface of the photographic print.
A photo printing apparatus according to item 1. 4. The photographic printing apparatus according to claim 1, wherein said recording means has an auxiliary storage medium input / output unit such as a magnetic storage. 5. A photographic printing apparatus according to claim 1, wherein said input means has an optical code reader. 6. A photographic printing apparatus according to claim 1, wherein said input means has an auxiliary storage medium input / output unit such as a magnetic storage.