JPS60206363A - Correcting circuit provided with hue signal level indicator - Google Patents

Abstract

PURPOSE:To discriminate easily the color of an original picture by constituting a titled circuit so that the level of a hue signal can be displayed by an indicator. CONSTITUTION:Each color signal (M+...V+) and (M-...V-) being the output of a hue separating circuit 2 is inputted to an indicator 5 (for instance, voltage indicator) through a differential amplifier 6. Each edition signal level is also inputted to an indicator 7. An operator confirms the color of an original picture from the deflection of a pointer of the indicator 5 first, and subsequently, rotates a knob, while obsorving a display of the indicator 5 and the indicator 7 of the signal level of outputs Y (yellow), M (magenta), C (cyan), and K (India ink), and adjusts it to a level corresponding to a requested color.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color correction circuit in an image scanning recording device, and particularly to a color correction circuit in which a hue signal amount is displayed on a display needle so that an operator can confirm the signal board and adjustment amount of each hue in each color plate. Concerning color correction circuits.

Y (yellow) is generally used for color printed matter.

By using eight primary color inks of M (magenta) and 0 (cyan), six hues of primary colors and secondary colors can be obtained by combining them as shown in the cuff chart of FIG.

Among these, Y (yellow), 0 M (magenta), and 0 (cyan) are primary colors, and V (violet) 0 (orange) and G (green) are obtained by combining two of the above primary colors. It is a secondary color.

Furthermore, by combining these colors, intermediate colors can also be obtained, and by combining eight colors of ink, it is also possible to obtain octagonal colors. It is not shown in Figure 1.

Furthermore, since it is often not possible to sufficiently reproduce dark tones using only the basic eight colors of Y, M, and O, printed materials also include
Usually K (black ink) is used.

Note that W is the base color of the paper.

By the way, B (bp-) is obtained when a color original is photoelectrically converted using an image scanning recording device.

The color separation signals of G (green) and R (red) cannot be used as color separation signals of Y ink, M ink, and 0 ink, respectively.

For example, when the original image is a color chart as shown in Figure 1, the B, G, and R signals obtained will be transparent as shown in Figure 2 (a) because the ink used does not have the ideal hue and saturation. rate distribution (absorption rate distribution for Y, M, and 0 signals).

Therefore, these signals as they are Y i, i M , 0
(If used as a name, for example, the printing result with a separation plate for Y ink will include Y ink in hue areas other than O, Y, and G hues, resulting in cloudiness in that area. Also, separation for M ink) Printing results with the plate produce cloudiness in hue areas other than V, M, and 0 hues, and furthermore, printing results with a separation plate for C ink produce cloudiness in hue areas other than G, O, and V hues. Therefore, in order to obtain an ideal printed matter, K is as shown above, and the G and R signals are modified and the second
With transmittance distribution as shown in figure (C), Y2. M30
It is necessary to obtain two signals.

Above Y2. In order to obtain the M, , O, signals, the applicant of the present application has proposed the following method in Japanese Patent Publication No. 14845/1983. That is, first, it is disclosed that the basic color correction for ink defects is expressed as OB = RaaG - βcB M1 = G - αmB - β Yl = B - αyG - βyG, which will be explained later. In the figure, the basic correction circuit 1 performs the correction. Then, as shown in Fig. 2, etc., each of the B, G, and R signals is modified, and the M, 0. Y, G, 0. V
The aim is to make the hue direction width (the width between the intersection points of each curve in the hue direction) constant and increase the number of hues to further enhance the correction effect, and Yl, Ml, 01
Get a signal.

Next, the y10Ml, ol signals are divided into hues to create signals such as M, O, Y, G, O, Vf) as shown in FIG.
Use these for more advanced color correction. By adjusting the color number 16 quantity and modifying the yl, Ml, and o1 signals, ideal transmittance characteristics as shown in FIG. 2 (0) or transmittance characteristics as required are obtained.

FIG. 4 shows an outline of a circuit for implementing the above method, in which the basic correction circuit 1 performs the Y1. M1. o, l signals are obtained, and color signals V± are divided as shown in FIG. 8 by the hue division circuit 2 based on the Yl 6M1 and O1 signals.

M±, 0±, Y±, G±, C±tl−, and further adjust the level of the divided color signals M±, O±, G±, C±, ■” by the 14 rectifier circuit 8. The adjustment signals Yc, Ma, and Oa obtained by the 1/4 adjustment circuit 8 are input to an arithmetic circuit 4, and the arithmetic circuit 4 adjusts Yl obtained by the basic correction circuit.

The route correction signal y is calculated by calculating with the Ml and O0 signals.
2, M, ,0□t-obtain. Also last modified 2
The signal can be obtained by calculating an adjustment signal Kc to 1 to the black signal generated by the black color forming circuit 1' based on the basic modified color signals Y10M1 and C1.

The adjustment circuit 8 and the arithmetic circuit 4 shown in FIG. 4 are separated from each other as shown in FIG. In other words, considering only the case of correcting the Y color, the variable resistor 81YM...
The valley color value numbers (M+...V+) and (M-...V-) obtained by the hue division circuit 2 are respectively applied to both terminals of 81YV.
is input, and the center of the square is used as a neutral terminal, and 14 integers ¥YO are obtained from the movable contact terminal. A similar separation is used for the colors M, O, and Mc
, Oc, and Kc can be obtained.

The variable resistors 81M...81V are attached to the frame of the color correction circuit, and the operator can perform the adjustment operation by turning an adjustment knob 82 (see FIG. 7) arranged outside the device. It looks like it can be done.

By the way, in order to be able to perform appropriate adjustment operations with the color correction circuit configured as described above, it is necessary to recognize the accurate hue of the original image.

However, conventionally, the above-mentioned hue judgment has been made based on the operator's visual sense, so when it comes to intermediate colors such as secondary colors and octagonal colors, errors in judgment occur frequently and it is difficult to perform appropriate adjustment operations.

This invention was developed in view of the above-mentioned conventional circumstances.6
Therefore, it is an object of the present invention to provide a color correction method that allows the colors of an original picture to be easily distinguished.

Its distinctive feature is that the hue (level 1) of the color to be adjusted can be checked by the operator.More specifically, the level of the hue signal can be displayed with a display needle at the dead center.

This invention will be explained in more detail. FIG. 6 shows a first embodiment of the present invention, in which each color signal (M+...V+) is output from the hue separation circuit 2 shown in FIG.
) and (M-...V-) are input to the display needle 5 (for example, voltage display t1°) via the differential amplifier 6. Each original signal level is also input to the display meter 7.

As shown in FIG. 7, this display meter 6 is arranged in correspondence with each color on the upper part of the panel on which the adjustment knobs 82 for each hue signal JPJ14 of the color correction circuit are arranged.

In the above configuration, the operator first confirms the color of the original image from the deflection of the needle on the display meter 5, and then the display on the display needle 5 and the output y2.
．． M2. o2. 2 (G) and turn the knob while looking at the display needle 7 of the bell to select the level K corresponding to the required color.
The IAI will be adjusted.

For example, if a color considered to be yellow-green is picked up, the Y and G indicators of the indicator 5 in FIG. 7 are displayed in a large size, and the Y and C indicator hands in the display 1t7 are displayed in a large size. According to this display, the operator can adjust the knob 82 at the Y-Y and Y-G intersections to increase the amount of Y ink in the yellow-green area if the customer wants to emphasize Y, for example. can be increased, and to decrease G, the knobs 82 at the O-Y and 0-G intersections can be adjusted to reduce the number of zeros displayed. Even if the hue of a color is difficult to judge, it is possible to tell which hue it is by the display on the display meter 5.

In the above example, the signal amount corresponding to the hue was obtained from the primary color-corrected color separation signal, but it is also applicable to other color correction methods in which the signal amount corresponding to the hue is obtained from the uncorrected color separation signal. It's no good.

As explained above, the present invention has the advantage that the hue of the original image can be determined by looking at the voltmeter, and color correction can be easily performed by determining the increase or decrease of valley ink.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the primary and secondary colors that appear on printed matter.
Figure 2 shows the BG multiplier signal reflectance (absorption rate of 10 signals to Y)
Distribution curve diagram, Figure 8 is a color signal diagram of primary and secondary colors, Figure 4
The figure is a schematic diagram of the color correction circuit, and Figure 6 is a circuit diagram of 1141.
Figure 6 shows 15)! of this invention! FIG. 7 is an example of the arrangement of the display t1 of the present invention. In the figure, 6.7...Display meter, 6...Amplifier. 1st m VMQVGCV WBK V M OY G CV WBK vxovcc, v 3rd to W8 Figure 5

Claims (1)

[Claims] In an image scanning recording device that performs color correction by adjusting a signal cover corresponding to a primary color and a secondary color obtained by a combination calculation of the primary color and the secondary color, the signal amount corresponding to each of the above hues. A color correction circuit with a hue signal level indicator, characterized in that an indicator for displaying the change in the color correction circuit is attached to the color correction circuit.