JPS6020681A - Positive-negative conversion picture signal processing method - Google Patents

Abstract

PURPOSE:To improve work efficiency by converting a positive density signal on the sensitized material of desired final print to a density signal corresponding to negative image on the output sensitized material necessary for realizing said density. CONSTITUTION:An input signal obtained by photoelectric scanning of a negative original mounted on an input drum 1 is converted to a density signal by a logarithmic conversion circuit 2 and converted to a digital signal by an A/D converter 3 and inputted to an input signal processing section 4. The output of the input signal processing section 4 is color processed, the gradation processed and the sharpness processed by a color processing section 5 and converted to a signal corresponding to the negative image on the output sensitized material for realizing target density on the sensitized material of a print by an output signal processing section 6. Further, the signal is inputted to a modulator 8 through a D/A converter 7 to modulate a laser beam outputted from a light source 9 and to reproduce desired picture on an output drum 10.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for converting a positive image equivalent density signal into a negative image equivalent density signal when reproducing a negative image on an output sensitive material in an image output device such as a color scanner, laser color printer, or inkjet. Conventionally, for example, in a color scanner, image processing is generally performed in which an input positive original is photoelectrically scanned and then a three-color separated monochrome negative image signal is output. When outputting a signal, the scanner operator calculates back from the target density on the final print sensitive material based on his own experience and determines the density equivalent to the negative image for use in internegatives, etc. In order to express the density equivalent to a negative image,
The operator operates a conversion curve that is a standard for converting an input density signal equivalent to a positive image into a density signal equivalent to a negative image. Therefore, a certain degree of skill is required of the operator.
In addition, there was a problem in that the reproduced images inevitably varied among the operators, and the work efficiency was also poor.

For example, when obtaining a reproduced image by photoelectrically scanning an image document with a high-precision scanner such as a layout scanner or laser color printer, a signal processing section is installed in the middle of the process to correct the color of the input density signal. (Special application 1986-6212
5) Signal processing such as sharpness enhancement (Japanese Patent Application No. 57-57743) or gradation setting (Japanese Patent Application No. 57-72781) may be performed. However, there are two types of image originals, a positive original and a negative original, and there are two types of desired reproduced images, a positive image and a negative image, and each combination of positive and negative types of original and reproduced image. Providing separate signal processing sections for each signal processing unit has the disadvantage of increasing the system scale.

In such a case, for example, one signal processing section
It would be very convenient if signal processing related to all of the above combinations could be performed.

However, for this purpose, it is necessary to be able to reproduce either a positive image or a negative image using density signals subjected to signal processing in the same signal processing section. However, when performing signal processing in this processing section, it is easier to handle a density signal equivalent to a positive image, so this processing section uses a density signal equivalent to a positive image, and if a positive image is desired as a reproduced image. When a negative image is desired as a reproduced image, the positive density signal from this processing section is output as is, and when a negative image is desired as a reproduced image, the positive density signal from this processing section is realized on the final printed photosensitive material. This m
It is desirable to output the signal after converting it into a density signal equivalent to a W-fold signal negative image.

The present invention was developed in order to solve the above problems, and for example to provide the above-mentioned uses.
To provide a method for converting in real time, when a positive density signal corresponding to a density desired to be realized on a final print sensitive material is given, into a negative density signal corresponding to an inter-negative for accurately realizing that density. The first purpose is to

Furthermore, a second object of the present invention is to provide a positive/negative conversion processing method that can be used for various purposes. These various uses include, for example, color negative film (intra-negative film) or color transparent film other than color negative film (reversal film,
For example, a color negative image may be output on a duplex film (duplex film, etc.), or a three-color separated monochrome negative image may be output on a black and white film. Incidentally, when outputting a negative image to the above-mentioned color transmission film, it is necessary to also calculate the density of the orange mask as seen in the negative film in order to eliminate incorrect absorption of the dye of the output sensitive material.

In the positive/negative conversion image signal processing method according to the present invention, when a positive density signal corresponding to a positive image desired to be realized on the final printed photosensitive material is given, this positive density signal is converted into a final target positive image on the final printed photosensitive material. It is characterized by converting it into a negative density signal that can realize an image. In addition, the above-mentioned positive density is a color scanner.

A high-precision scanner such as a laser color printer photoelectrically scans an image document and reads the image signal, which may then be given as an image signal that has undergone some signal processing, or a frame of a scene photographed with a television camera. It is also conceivable that the memory may be provided as something converted into a density signal.

Note that it is preferable that the conversion means of the present invention is formed by two conversion sections as described below.
a first converting the output signal from the reading means into a printing density signal for the final printed photosensitive material; A converting section (using a memory table) and a second converting section converting the printing density signal outputted from the first converting section into a signal corresponding to a negative image that realizes the printing density. Note that the density signal may be not only a logarithmic signal such as density, but also a linear signal such as brightness.

According to the present invention, when a density signal equivalent to a positive image desired to be realized on the final printed photosensitive material is given, an output photosensitive material that can realize a positive image with that density as the final target on the final printed photosensitive material is provided. Since a positive/negative signal conversion means is provided that automatically converts to a negative density signal equivalent to the density above, the color processing conditions (gradation setting, sharpness emphasis, 9 color corrections, 1 copy) that the scanner operator must set are final. Only the conditions for printing on the target printing sensitive material are sufficient. In other words, in the past, a certain amount of experience was required for an operator to back-calculate the color processing conditions on the output photosensitive material from the desired color processing conditions on the final print photosensitive material, but with the present invention, There's no need for it.

Further, since it is possible to save the effort of manually calculating the color processing conditions in reverse, work efficiency can be improved.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an example of the flow of density signals when the present invention is used in a color scanner.

An input signal obtained by photoelectrically scanning a negative original loaded on the input drum 1 is converted into a density signal by a logarithmic conversion circuit 2, and then passed through an AD converter 3 and converted into a digital signal. After that, the input signal processing unit 4 (converting the input density signal, which is an integrated density component, into an analytical density, and the negative/positive conversion process when the input document is negative), as well as the color processing unit, which can be called the heart of this system. 5 and color processing 2
Gradation processing.

and sharpness processing, etc. Thereafter, the density signal outputted by the color processing section 5 is input to the output signal processing section 6, where it is converted into a signal corresponding to a negative image on the output sensitive material in order to realize the target density on the printing sensitive material. Furthermore, the laser beam inputted to the modulator 8 via the DA converter 7 and outputted from the light source 9 is modulated to reproduce a desired image on the output drum 10. Note that normally, in an apparatus such as the one shown in this embodiment, the density signal after photoelectrically scanning a document is
By performing processing such as color processing and two-tone conversion processing, the signal is converted into a density signal corresponding to the density desired to be realized on the output sensitive material.

FIG. 2 is a block diagram showing in detail the portions of FIG. 1 that are related to the present invention.

In FIG. 2, the density signal that has passed through the color processing section 5 (density signal corresponding to the density desired to be realized on the printing sensitive material) is converted by a printing density conversion table 11 into a printing density for the printing sensitive material. Next, this printing signal is sent to a positive/negative calculation circuit 12 (multiplier/accumulator), and is converted into a density signal equivalent to a negative image on the output sensitive material in order to achieve a desired density on the printing sensitive material. Note that this arithmetic circuit 1
2 performs the calculation shown below.

Di = aoi -1-as iIYl-aziPM
+a3iPc+a4! PyPM+asiPMPc+
a6iPcPy tena71Py2+a 81PM2+a9
1pc 2----・S(i2Y, M, C) Here, Di is a signal equivalent to a negative image on the output sensitive material.

aoi, axi ++a9i are coefficients.

Thereafter, the density signal output from the arithmetic circuit 12 is converted by the sight control signal conversion table 13 into a control signal for controlling the amount of laser light.

Next, the coefficients (aoi
+L+i...as1) settings will be explained in detail.

First, in setting the memory table, it is sufficient to simply set the inverse relationship of the characteristic curve of the final printed photosensitive material in the conversion table 11 in the form of digital memory. Here, the characteristic curve is a curve representing the characteristics of a photographic light-sensitive material, with the horizontal axis representing the common logarithm of exposure iE and the vertical axis representing photographic density.

Next, when setting the coefficients (aoi, ali - a9i) in the first equation, if the printing conditions that cause burn-in on the print sensitive material are known, the density on the output photosensitive material under those conditions can be used to Integral calculations are performed to calculate the printing density of several hundred output sensitive materials (DY, DM, DC).
The coefficients (ao
i+a+i...+"9+) can be determined.

The integral formula used for the above-mentioned integral calculation is shown below.

λ: Wave length Sλniblint sensitive material fractional sensitivity Jλ: Spectral intensity of printer light source Tλ: Output sensitive material spectral transmittance (However, if the output sensitive material spectral density is Dλ, When Tλ = 10-Dλ) TB, λ: Output sensitive material base spectral transmittance The above makes it possible to execute this embodiment.

Supplementary explanations will be given below regarding the case of outputting a color negative image and the case of outputting a three-color separation negative on a black-and-white photosensitive material. A detailed explanation regarding the density of burn-in can be found in '1. “he Tbe
ory of the Photographic Pr
(edited by James, Macmi l1a)
n, 1977), pp. 519-523, the explanation will be omitted.

(2) In the case of color negative image output In the second equation, when the output sensitive material is a negative sensitive material, ]゛B and λ are the spectral transmittances of the negative sensitive material orange mask. On the other hand, if the output photosensitive material is not a negative photosensitive material (for example, a duplex film shade), the density d corresponding to the orange mask,
I want to develop color using three primary colors (Y, M, C). To do this, if we give TBλ the spectral transmittance when the orange mask is expressed using the three primary colors (Y, M, C) (this is approximately equal to the base spectral transmittance of the negative photosensitive material mentioned above), we can The coefficient obtained from the sample data of ``13 ('=
The density on the output photosensitive material calculated from Or 1 ``' + '' t J =Y+M, C') is the density in which the orange mask for correcting incorrect absorption of the output photosensitive material is taken into account.

In other words, an image with an orange mask can be obtained as if it were a negative photosensitive material.

■ When outputting a three-color separation negative on a black-and-white photosensitive material, it is not necessary to generate an orange mask as in the case of outputting a color negative image. That is, the spectral transmitting portion in a state where no color is developed may be given to TB and λ in the second equation.

As mentioned above, in this example, C automatically calculates the density on the output photosensitive material, including correcting incorrect absorption of the output photosensitive material dye, so there are even more factors that are artificially determined. It is possible to improve work efficiency.

Furthermore, the conversion in this embodiment only requires the use of a memory table, a multiplier, etc., and does not require a large-capacity image memory or a circuit for performing integral calculations, making it possible to perform calculations at high speed and in real time. can.

Further, the calculation performed by the positive/negative calculation circuit 12 may be modified, for example, as follows, depending on the required precision.

That is, if high accuracy is not required, Di'=
aoi + aliDy +a2iDM+a31I)c
Correct it as ++ +・3) (i=Y, M, C).

In addition, for gifts that require even higher precision,
aoi +al iDy +a211)M+ a3iD
c10a, 1 jDyDM10as iDMDc +a61
DCDy10a7iDY2+a81DM2+a9□Dc2
10a+oiDyDMD(+aniDYL)M2+a+o
iDy2DM+...4) Correct as (i = Y, M, C).

Although all the embodiments described above are based on the premise that processing is performed by digital circuits, it goes without saying that processing may be performed by analog circuits.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of the flow of a density signal when the present invention is used in a color scanner, and FIG. 2 is a block diagram showing a part of FIG. 1 in more detail. 1... Input drum 2... Logarithmic conversion circuit ~ 3...
AD converter 4... Input signal processing section 5... Color processing section 6... Output signal processing section 7... DA converter 8... Modulator 9... Laser light source 10.
... Output drum 11 ... Burning density conversion table 12
...Positive/negative calculation circuit 13...Light amount control signal conversion table Fig. 2 (Spontaneous) Procedure 1 Official document 1, Incident display 1982 Patent application No. 128769 2, Title of invention Positive/negative conversion image signal processing method 3. Relationship with the case of the person making the amendment Patent applicant Address: 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Name: Fuji Photo Film Co., Ltd. 4 Agent: 5-2-1-5 Roppongi, Minato-ku, Tokyo Date of amendment order None 6. Number of inventions increased by amendment None 7. Subject of amendment Column 8 of "Detailed Description of the Invention" of the specification, Contents of the amendment 1) Page 4 of the specification, line 9 "Patent Application No. 1983" -57743J [Patent Application No. 57-6605]
Corrected to 3J.

Claims (1)

[Claims] (1) In the image output device, a desired final print negative image positive density signal is converted into a density signal equivalent to a negative image on the output sensitive material necessary to achieve the desired density. A positive/negative conversion image signal processing method characterized by: (2゛ The printing on the printing sensitive material converts the positive density signal into a density signal, and then this printing converts the density signal into a negative density signal on the output sensitive material necessary to achieve the density. The positive/negative conversion image signal processing method according to claim 1, characterized in that the positive/negative conversion image signal processing method is performed by converting into an image equivalent density signal. (3) The positive/negative conversion image signal processing method is performed by converting the positive density signal into an image equivalent density signal. , the burn-in is converted into a density signal, and then,
The positive-negative conversion image signal processing according to claim 1, wherein the printing is performed by converting the density signal into a density signal corresponding to the negative image by performing matrix calculation on the density signal. Method.