SU756343A1 - Electronic colour corrector - Google Patents

Description

The invention relates to the field of printing and phototelegraphy and can be used in electronic color correctors (ETSK), color phototelegraphic apparatus, devices, 5 producing electronic color correction in the process of electron-optical analysis of color images.

A color-correcting device is known that calculates correction signals of the difference of color-separated uncorrected signals, which are used to set the color-correction mode, which contains mask modulators, 15 computer of color-correcting signals for the channel of each three-color synthesis synthesis channel using three uncorrected color-separated signals, which consist of summing and inverting amplifiers and limiters of signals, and the calculator of the correction signals is additionally equipped with a limit the readers, the inputs of which are connected to the outputs of the summing 25 amplifiers, and the outputs of the calculator of the correction signals through other limiters and inverters are connected to adjustable potentiometers, the outputs of which are connected to the inputs 30

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mask modulators [11. However, potentiometers that set color correction modes allow changing only the amplitude value of the correction signals, which is insufficient for obtaining high-quality reproductions; in addition, the set color correction mode impairs the color rendition of gray fields in unbalanced originals.

The closest to the invention to the technical entity is an electronic color corrector, which contains a scanner of the original and photoforms, a signal calculator, amplifiers, potentiometers, a channel switch, a recording unit, a subtractive device and an analyzer whose outputs are connected to the inputs of the amplifiers and simultaneously with the corresponding inputs of the subtractor, connected by outputs to the corresponding inputs of the correction signal evaluator, the outputs of which are loaded with potentiometers, a. the outputs of the amplifiers, through the switch channels connected to the input of the recording unit [2].

The device has the following disadvantages:

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- uncorrected color separations signals from unbalanced gray tones are corrected

in a general manner in accordance with the established color correction mode, which impairs their reproduction on reproduction;

- it is not possible to change not only the magnitude, but also the sign of the correction signal.

These drawbacks significantly narrow the color adjustment range.

The purpose of the invention is to enhance the functionality of color correction.

The goal is achieved by the fact that the proposed device introduced the scheme AND and limiters, connected by inputs to the corresponding outputs of the reading device, and outputs through

. And - to one of the inputs of the signal calculator, the potentiometers are made with a grounded midpoint, grouped into a number of groups and connected in parallel, the number of potentiometers in each group corresponds to the number of colors being analyzed, each group of potentiometers is connected to bipolar, outputs of the signal calculator, current-collecting potentiometer contacts are connected to the amplifiers, with the potentiometer contacts corresponding to one of the analyzed colors being connected to each amplifier.

The drawing shows the block diagram of the electronic color corrector.

The electronic color corrector contains a scanner device 1 of the original and a photoform, an analyzer 2, a recording unit 3, a subtractor 4, limiters 5-7, circuit AND 8, signal calculator '9, amplifiers 10 - 12, switch channels 13, HZ potentiometers.

The outputs of the analyzer 2 are connected simultaneously with the inputs of the subtracting device 4 and the inputs of the amplifiers 10-12, the outputs of the subtractive device 4 are connected to the inputs of the signal calculator 9 and to the inputs of threshold limiters 5-7, the outputs of which are connected to one of the signals calculator inputs 9, to the raenopolar outputs of which the extreme outlets of the potentiometers are connected Κή - in groups of three, the middle outlets of the latter are grounded, and the current collector contacts of the potentiometers

in groups of six connected to the inputs of the corresponding _{amplification ν For} 10 - 12, the output of each of which through a switch of channels 13 is connected to the input of the recording unit 3.

Electronic color corrector works as follows.

The input of the analyzer 2 receives the luminous flux reflected from the elementary area of the image attached to the analyzing drum of the scanner device 1 of the original and the photo form. In the process of scanning the original, the analyzer 2 generates color-separated electrical signals. Thus, from the output of the analyzer 2 to the input of the subtractor 4, color separated signals Ts, and ₅ , and _k are received, the amplitude of which is proportional to the effective color density of the analyzed element of the original in the corresponding spectral zone (for example, behind blue, green and red light filters). In the subtractive device 4, the differences U _s ^- ~ “ ^and c 'are formed

served simultaneously in the transmitter signals 9 and the inputs of the limiters 5-7.

If the color element of the original is analyzed, then consequently _with - and ₃ A o, and ₃ - o and and „- and ^ o.

In this case, the output of the And 8 circuit does not show a signal. The prohibiting blocking outputs of the signal transmitter 9. At the same time, correction signals are generated in the signal calculator 9 in accordance with the algorithm of its operation and the specific color original correction program implemented by the operator setting the moving potentiometer contacts

If the achromatic element of the original is analyzed, then both _c = and ₃ = and _k , and therefore _c —and ₃ = 0, and _k = 0 and

and ^ -and _c = 0. In this case, at the output of the AND circuit 8 is formed by the signal '' Disable ', outputs a blocking signal calculator 9, and amplifiers 10 - 12 receives signals only separations and _with sufficiently good

transmitting achromatic image elements for which the effect of corrective signals is not required.

If a slide is being analyzed, the color cDOs of which are unbalanced so that the achromatic parts of the color images are not gray wedge fields, but colored in various colors depending on the nature of the imbalance, i.e. have bluish, brownish or other shades, then in a known device these shades are captured and enhanced by color-correcting devices, which emphasizes the defect of the original, its quality in shades deteriorates. To prevent this from happening, limiters 5–7 are added to the device, in which limit thresholds are set, for example, a. As long as the magnitude of the difference signals does not exceed the value of a, the signal “Ban” and from the achromatic sections of the rebalanced original in usi is stored at the output of the And 8 circuit

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• drivers 10–12 correction signals are received.

From the outputs of amplifiers 10 - 12. the corrected color-separated signals of both ^, and _g , and _n enter the recording unit of 3 photoforms simultaneously (if several recording units) or alternately. The sequence is set by channel selector 13.

Thus, the introduction of threshold limiters, the And circuit and correction potentiometers, as well as the organization of links between them, extends the correction limits, which is expressed in blocking the operation of the correction signal calculator when analyzing unbalanced gray fields and affecting the correction amplifiers both positive and negative components of color correction signals.

Claims (1)

Claim Electronic color corrector containing a scanner of the original and photoforms, a signal calculator, amplifiers, potentiometers, a channel selector, a recording unit, a subtractor and an analyzer whose outputs are connected to the inputs of the amplifiers and simultaneously with the corresponding inputs of the subtractor devices connected by outputs to the corresponding inputs of the correction signal calculator whose outputs are loaded with potentiometers, and the outputs of the amplifiers are connected via a channel switch to the input of a recording unit, characterized in that, in order to enhance the functionality of color correction, an AND scheme and limiters connected inputs to the corresponding outputs of the detracting device, and outputs through the circuit AND to one of the inputs of the signal calculator, the potentiometers are made with a grounded midpoint, with grouped in a number of groups and connected in parallel, the number of potentiometers in each group corresponds to the number of analyzed colors, each group of potentiometers is connected to bipolar outputs of the signal calculator, the current collector contacts of potentiometers are connected to amplifiers, and potentiometers corresponding to one of the analyzed colors are connected to each amplifier.