JPH01172827A - Exposure control method for auto printer - Google Patents

Abstract

PURPOSE:To utilize the test result of a color video analyzer by providing a channel where a slope coefficient becomes zero, converting an exposure time and a filter value which are outputted by a color video analyzer into the number of key steps, and using this conversion data. CONSTITUTION:When the test result of the color video analyzer is utilized, the channel for the analyzer is selected. In this channel, data based upon zero as slope coefficients of respective colors are stored in the channel, so an automatic exposure control function does not operate substantially. The exposure time and filter value which are outputted by the color video analyzer, on the other hand, are converted into the number of steps of a color key 74 and a density key 75 and it is inputted to the auto printer. The auto printer performs exposure control according to a manual correction quantity inputted in the form of the number of steps. Consequently, the test result of the color video analyzer can be utilized.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an exposure control method for an auto-print system equipped with an automatic exposure control function. The present invention relates to an exposure control method in which the

[Conventional technology]

A color video analyzer has already been put into use that captures an image of a negative to be printed (hereinafter referred to as a print negative) with a television camera and displays a positive image of the print negative on a color monitor.

This color video analyzer has a density key.

Color keys are provided, and when these are operated, the density and color balance of the positive image displayed on the color monitor change. Therefore, the operator may operate the density key and color key while observing the color monitor so that the density and color balance are appropriate. When the verification is completed, the color video printer outputs the exposure time and filter value.

Further, an automatic printer is known which is equipped with an automatic exposure control function, measures the three-color density of a print negative, and controls the exposure amount of the three colors according to the three-color density and the slope coefficient. This auto printer is equipped with density keys and color keys for inputting manual correction amounts. By operating these keys, you can increase or decrease the automatically calculated exposure amount for each color and print photos. It is now possible to modify the density and color balance of the image.

[Problem that the invention seeks to solve]

The color video analyzer described above is intended for printers that perform timer printing, and therefore outputs exposure time and filter values. On the other hand, in automatic printers, the exposure amount is manually determined by the number of key steps, so it was not possible to utilize the verification results of color video analyzers, which have excellent verification accuracy.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an exposure control method for an autoprinter that can utilize the test results of a color video analyzer.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an analyzer channel in which the slope coefficient is zero for each color by giving a constant exposure time regardless of the density of the print negative. Convert the exposure time and filter value obtained by verifying the print negative with a color video analyzer into the number of steps for the color key and density key, enter the number of steps for the color key and density key, and input the number of steps for the analyzer. Exposure control is performed by selecting a channel.

[Effect]

When using the test results of a color video analyzer, select the analyzer channel. Since this channel stores data that sets the slope coefficients of each color to zero, the automatic exposure control function becomes virtually inoperable. On the other hand, the exposure time and filter value output from the color video analyzer are converted into the number of color key and density key steps, and these are input to the autoprinter.

The auto printer controls exposure according to the manual correction amount input by the number of key steps.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

〔Example] FIG. 2 shows a color video analyzer.

The light source lamp 10 is supplied with power from the lamp stabilizing power source 11 and emits light. The amount of white light emitted from the light source lamp 10 is adjusted by the N01M optical filter 12. The ND light control filter 12 includes two ND filters 12a and 12b, and when a density lever (described later) is operated, the ND light control filter 12 is moved in opposite directions by a filter adjustment section 13 to adjust the amount of light. After the white light whose light amount has been adjusted is sufficiently diffused by the mirror box 14,
The negative film 15 is illuminated.

The negative film 15 is imaged by a CCD camera 18 through a mirror 17 and converted into red, green, and blue video signals. These video signals are each sent to a density conversion section 19, where they are logarithmically transformed and converted into approximate density signals.

The red, green, and blue density signals are sent to the gradation converter 20, where they are subjected to spectral correction and gradation correction. This spectral correction is for correcting the spectral characteristics of the CCD camera 18, and is performed by executing a 3×3 matrix calculation formula. Furthermore, gradation correction is to correct the light emitting characteristics of a color monitor, and negative/positive conversion is performed at the same time.

The video signal output from the gradation converter 20 is sent to a color monitor 21, and a positive image of the print negative is displayed as a test image 22 on its display surface. Also, positive image 2
2, a reference image 24 read from the reference image memory 23 is displayed.

The keyboard 26 includes input keys 27 such as alphanumeric keys, a fader type color lever 28 and a density lever 29, and data and instructions are transferred to the microcomputer 3.
Enter 0. The output unit 32 is for outputting the test results to a recording medium, and examples of this recording medium include a floppy disk 33, thermal paper 34 . Any one of the punch tapes 35 is used.

When performing negative verification using a color video printer, a negative film 15 is set on a negative stage (shown in the drawing). This negative film 15 is illuminated with white light emitted from the light source lamp 10 and modulated by the ND dimming filter 12 . The CCD camera 18 images the negative film 15 and outputs a video signal. This video signal is density converted.

After spectral correction, two-tone correction, and negative/positive conversion are performed, the image is sent to the color monitor 21, and the test image 22 is displayed on its display surface. Along with this test image 22,
The reference image 24 read from the reference image memory 23 is displayed.

The test image 22 and the reference image 24 are compared to examine the finished color balance and density. If it is determined that the density is not good, slide the density lever 29 in the plus or minus direction. When the density lever 29 is operated, the microcomputer 30 sends a signal to the filter adjustment section 13 to adjust the ND dimming filter 12. As a result, negative film 1
Since the intensity of the illumination light 5 changes, the brightness of the test image 22 changes. Furthermore, if it is recognized that the color balance is not good, at least one of the three types of color levers 28 is slid. When this color lever 28 is operated, the gradation converter 20 is controlled, so that the color balance of the test image 22 changes.

When the density and color balance of the test image are good, if you operate the input key 27 to instruct the end of the test, the exposure time and three color filter values will be output to the output section 3 as test data.
2 and written on a set recording medium, for example, a floppy disk 33. Thereafter, negative verification can be performed on each print negative (frame) recorded on the negative film in the same manner.

In automatic printers, manual input is performed using density keys and color keys. Therefore, using the personal computer shown in FIG. 3, the test data is converted into the number of key steps. As is well known, this personal computer 40 has a keyboard 41.
2 main bodies 42. Display 43. The input test data and the number of converted key steps are displayed on a display 43. Also,
The printer 44 records the number of converted key steps on a recording paper 45.
to be printed.

FIG. 4 shows the procedure of key step conversion performed by the personal computer 40. In channel setting mode, various data used for conversion calculations are input. These input data include print channels specified in the color video analyzer.

These include the color key, rate of change per step of the color key, rate of change per step of the density key, master balance value, normal control negative exposure time, etc.

When the channel setting is completed, the screen shown in FIG. 5 is displayed, and the order Nα, frame number, exposure time, and three-color filter values are input. The exposure time of each color is calculated from this exposure time and the filter value. This is calculated from the following equation.

(50-X j /100) Tj=TXIOX 1000/MBj where each symbol is as follows.

Tj: Exposure time of each color (j represents one of cyan, magenta, or yellow) T: Exposure time output from the color video analyzer Xj: Filter value MB output from the color video analyzer: Master balance value The number of color key steps KC,'' is calculated from the calculated exposure time T, for each color.

KCJ' = l o g (Tj/NT= )/i o
gKsJ Here, each symbol is as follows.

NTJ: Normal control negative exposure time KS,
: Rate of change per row of color key (If this rate of change is 10%, it will be "1.1", and if it is 20%, it will be rl, 2J.

Among the color key step numbers KCj'' obtained in this way, the intermediate color key step number is determined and this is set as the density key step number.For example, if the yellow key step number KCV'' is the intermediate value, The number of steps KD of the density key is obtained from the following equation.

KD=j2og(Ty/NTy)/l
Og KSD Here, KSD is the rate of change per step of the density key. This step number KD is rounded off to an integer.

Next, by subtracting the number of steps KD of the density key from the number of steps KC,' of each color key, the actual number of steps KC, of the color key is obtained. Kcj = KC,
' -KD・(j!ogKSD/j2ogKsj) If there is a decimal point in the step number of this color key, it is rounded off to an integer.

The converted data is displayed on a display 43 as shown in FIG. 6, and is also printed out on recording paper by a printer 44.

In addition, if you simply round off the number of color key steps,
The color balance changes accordingly, so when performing high-precision exposure control, check the balance below the decimal point,
Accordingly, it is better to increase or decrease the color key by ro and 5J, and then round the value to the nearest whole number. Furthermore, the number of key steps that can be entered differs depending on the auto printer. Therefore, the maximum and minimum values that can be entered are entered at the time of channel setting, and if these values are exceeded, the master balance value must be changed, since manual input is not possible.

In the above explanation, the exposure time and filter value are entered by operating the keyboard, but if the verification data is recorded on the floppy disk 33, by setting it in the personal computer 40, the verification data will be automatically input. can be entered.

FIG. 7 shows an example of an autoprinter according to the present invention. The white light emitted from the light source lamp 50 is transmitted to the diffusion box 5.
1, the negative film 15 is illuminated. The print negative recorded on this negative film 15 is printed onto color paper 53 by a printing lens 52. This color paper 53 is pulled out from a supply reel 54 and sent to an exposure position located behind a paper mask 55, and the exposed color paper 53 is wound onto a take-up reel 56.

A cyan filter 58 for terminating red exposure is provided between the printing lens 52 and the color paper 53. Magenta filter 59 for terminating green exposure. Yellow filters 60 for terminating blue exposure are arranged respectively, and a printing optical path 62 is controlled by a filter drive unit 61.
inserted into.

Furthermore, when the exposure of all colors is completed, the shutter drive unit 6
3, the black shutter 64 is inserted into the printing optical path 62.

In order to perform three-color separation photometry of the print negative of the negative film 15, a red sensor 68. Green sensor 69. A blue sensor 70 is provided.

The signals output from these sensors 68 to 70 are A
The signal is converted into a digital signal by the /D converter 71 and then taken into the controller 72.

The keyboard 73 has color keys 74 . It is provided with a density key 75, a numeric key 76, and a print key 77, and data is input into the controller 72. The FD driver 79 reads data from or writes data to the floppy disk 80. The conversion data can be easily input by loading the floppy disk 80 into the personal computer 40, writing the key conversion data onto it, and setting the floppy disk 80 into the FD driver 79. Note that the reference numeral 81 is a memory, and the reference numeral 82 is a memory.
is a display for displaying input data and print data.

FIG. 1 shows the functions of the controller 72. A part of the memory 81 is used as channels 81a to BIn, and each channel is written with data of three color density values of four types of control negative prepared for each type of negative film and exposure time of each color. There is. Among these, the channel 81n is used as an analyzer channel, and data is written in which the exposure time is constant so that the slope coefficient is zero for all control negatives. Here, "U" is under control negative, "N" is normal control negative,
"O" is an overcontrol negative. Also, “S
O” is a super over control negative.

The channel selection section 85 selects a channel according to the film type, and sends the read data to the slope coefficient setting section 8.
6 to calculate the slope coefficient α. This film type can be specified by operating the keyboard 73.

The exposure calculation unit 87 calculates the slope coefficient αi (t represents any one of red, green, or blue) and the density value D N of the normal control negative read from the channel.
s, the photometric data D obtained by averaging photometry with the sensors 68 to 70, and the number of key steps KCJ and KD input from the keyboard 73, the exposure time T is calculated from the following formula.
Calculate i for each color.

1ogTi=(ri(Dt-DNA)) Here, each symbol is as follows.

FIJ: Paper balance value F2j: Lens balance value F3j: Color balance value The exposure time T calculated by the exposure calculation section 87 is sent to a timer section 88 to control the filter drive section 61.

Next, the operation of the auto blink shown in FIG. 7 will be briefly explained. When using the test results obtained by the color video analyzer, the user operates the keyboard 73 to select the channel 81n. After this channel selection, the negative film 15 is set on a negative carrier (not shown). The sensors 68 to 70 perform average photometry for each color of the print negative recorded on the negative film 15 to measure the density Di.

Next, the conversion data (KC,,K
D) is input from the keyboard 73. After inputting this conversion data, by operating the print key 77, the above-mentioned exposure calculation formula is executed and the exposure time T is calculated. At this time, in the analyzer channel 81n, since the slope coefficient α is zero, the first
The term "αi (D, -DN,)J becomes zero. This term is for automatic exposure control, so if analyzer channel 81n is selected, the automatic exposure control function will not work. The exposure time T is calculated based on the conversion data (KC, KD) input from the keyboard 73.

After the exposure time is calculated, the light source lamp 50 emits full light and the shutter 64 is retracted from the printing optical path 62. When the shutter 64 operates, the print negative of the negative film 15 is printed onto the color paper 53. When, for example, a red exposure time TI has elapsed from this exposure start point, the filter drive unit 61 inserts the cyan filter 58 into the printing optical path 62 and ends the red exposure. Furthermore, when the green exposure time TG has elapsed, the magenta filter 59 is inserted into the printing optical path 62, and when the blue exposure time T8 has elapsed, the yellow filter 60 is inserted into the printing optical path 62. When all of these filters 58 to 60 are inserted into the printing optical path, the black shutter 64 is inserted into the printing optical path. When the black shutter 64 is closed, the color paper 53 is moved by one frame, the unexposed portion is set at the exposure position, and the filters 58 to 60 are withdrawn from the printing optical path 62. Further, in an automatic printer equipped with a negative feed mechanism, the negative film 15 is transferred by one frame and the next print negative is set at the printing position. Thereafter, each print negative is photoprinted using the same procedure.

If the test results obtained by the color video analyzer are not used, the type of negative film is input by operating the keyboard 73. When the type of negative film is input, the corresponding channel, for example 81a, is selected. In this case, since the slope coefficient is not zero, the automatic exposure control function works effectively and the exposure time T is calculated according to the density of the print negative and the slope coefficient.

With this automatic exposure control, if there is a risk of subject feria occurring, the color key 74 and density key 7
5 to input the manual correction amount using the number of key steps.

The auto printer of the above embodiment adjusts the exposure time for each color, but instead of using a common exposure time as used for exposure control in minilabs, a light control filter is used to adjust the exposure time for each color. The present invention can also be applied to an auto printer that adjusts the amount of exposure. Furthermore, if the color video printer and auto printer are connected online, it is only necessary to transfer the negative film, so that photo printing can be carried out efficiently. Furthermore, there is a system in which the manual correction amount is recorded on a punch tape using a negative verification machine, and this is set in an automatic printer to print photographs continuously. When using the present invention in this type of auto printer,
The number of key steps converted by the computer 40 may be recorded on the punch tape.

〔Effect of the invention〕

As explained in detail above, according to the present invention, in order to substantially prevent the automatic exposure control function from operating, a channel whose slope coefficient is zero is provided, and the exposure time output from the color video analyzer is The filter value is converted to the number of key steps, and this conversion data is used to print a photo of the print negative that has been verified with a color video analyzer. It is now possible to use the test results. Additionally, the verification results obtained using a color video analyzer are superior to the automatic exposure control function of an auto printer, allowing for highly accurate exposure control.

Furthermore, the present invention makes it possible to utilize the test results of the color video analyzer without making any changes to currently operating autoprinters.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram showing exposure control of an autoprinter according to the present invention. FIG. 2 is a block diagram schematically showing a color video analyzer. FIG. 3 is a front view of a personal computer for performing key step conversion. FIG. 4 is a flowchart showing the procedure of key step conversion. FIG. 5 and FIG. 6 are explanatory diagrams showing the screen of the display of the personal computer, respectively. FIG. 7 is a schematic diagram of the autoprinter of the present invention. 15...Negative film 21...Color monitor 22...Verification image 23...Reference image 26...Keyboard 53...Color paper 68-70...Sensor 74...Color key 75...・Density key 81...Memory 81a, 81b...Automatic exposure control channel 81n...
...Analyzer channel.

Claims (1)

[Claims] (1) In an automatic printer that measures the three-color density of the print negative and controls the exposure amount of each of the three colors according to the three-color density and the slope coefficient, a constant exposure time is given regardless of the print negative density. Then, we set up an analyzer channel with a slope coefficient of zero for each color, and convert the exposure time and filter value obtained by testing the print negative with a color video analyzer into the number of steps for the color key and density key. An exposure control method for an auto printer, characterized in that exposure control is performed by inputting the number of steps of a key and a density key, and selecting an analyzer channel.