JPS63219271A - Color copying device - Google Patents

Abstract

PURPOSE:To perform copying with the most appropriate condition and to facilitate the generation of a black signal and a contour enhancing processing, by applying a processing on either one or two elements out of three elements after converting three primary color signals to hue, saturation, and lightness. CONSTITUTION:A color original 1 is read by a three color separation system 2, and is divided into the three primary color signals Y, M and C, and they are converted to three dimensional signals by the hue, the saturation, and the lightness H, S and L of a development system by a conversion table 3. On the three dimensional signals H, S and L, the incremental/decremental quantity of each signal sent out by a control part 7 is added by adders 4-6, and they are adjusted suitably for the reading condition of the original. And the lightness signal L is inputted to a signal enhancing processing part 8, then, it becomes a lightness signal L' on which the enhancing processing is applied. The saturation signal S and the lightness signal L' are inputted to a black signal generating part 9, then, the black signal B is generated, The lightness signal L', the saturation signal S, and the hue signal H are inputted to a three primary color conversion part 10, and are converted to the three primary color signals, and the copying of the original is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION 2. Field of Vane Industrial Application The present invention relates to a color copying apparatus, such as a color facsimile machine, which reads and copies images using a color sensor.

2. Description of the Related Art Conventionally, electrophotography, inkjet, thermal transfer, and the like are known as color copying devices.

Image processing techniques common to these will be described below with reference to FIG.

FIG. 3 is a block diagram of the color copying apparatus.

In Fig. 3, 32 reads a color original 31 and converts the three primary color electric signals of red, green, and blue (JG, B) into yellow, magenta, and cyan (Y, M, C) system signals (color separation). 3 color separation system, 33 is color original 3
State 1, that is, dark or light color original 31
a control unit that manually outputs a correction value according to the state of the controller;
36 is an adder that adds the output (Y, M, C) signals of the three color separation system 32 and the correction value that is the output of the control unit 33;
-: 37 is an edge enhancement processing unit that performs edge enhancement as necessary from the outputs of the adders 34 to 37; 38 is an edge enhancement processing unit 37;
A black signal generating section 39 generates a B (black) signal from the (Y, M, C) signals output by (Y.

This is a recording section that records a color head copy 30 based on M, C, B) signals.

The operation of the above configuration will be briefly explained below.

First, the three-color separation system 32 reads a color original 31 using a reading means such as a TV camera or a drum scanner, and converts the read (JG, B) series signals into (Y, M,
C) Convert to a series of signals. Next, in adders 33 to 35,
A correction value (signal) sent from the control unit 36 is added to the (Y, M, C) series signals sent from the three-color separation system 32 to perform a certain correction. Next, the contour enhancement processing section 37 corrects image deterioration caused by overlapping (Y, M, C) series signals, etc. by contour enhancement.

Then, the black signal generation unit 38 further generates a black signal from the edge-enhanced signal sequence (Y, B, C).

B) Output as a series of signals. A recording unit 39 obtains a color hard copy 30 using thermal transfer, ink, or the like.

Problems to be Solved by the Invention However, with the above-described apparatus, when a dark-colored original or a light-colored original 31 is read, it is difficult to copy the original in the recording section 39 under optimal conditions at all times. That is, the exposure conditions are changed to suit the condition of the color original 31 to achieve the optimum condition, but it is difficult to change the conditions of the three colors in the same way, and furthermore, the hue and saturation also change, so the image It affects the whole thing. Similarly, achieving optimal hue and saturation is difficult because it involves changes in the other two elements.

Furthermore, since the black signal component for black ink (black plate) is also generated by a combination of three color signals, skilled operation is required in consideration of the copying state of the original.

Furthermore, image edge enhancement processing must be performed simultaneously for three colors, which is difficult because it requires a large load and involves changes in hue, saturation, and brightness.

5. The present invention was made in order to solve the above-mentioned drawbacks of the conventional apparatus.It not only performs copying under optimal conditions, but also facilitates black signal generation and image edge enhancement processing if necessary. The present invention provides a color copying apparatus that can carry out various types of copying.

Means for Solving the Problems The present invention provides ``color separation means for reading a color original and converting it into a series signal of (red, green, blue);
A first conversion means that converts the output of the color separation means into a series signal of (hue, saturation, brightness), and each value of (hue, saturation, brightness) that is the output of the first conversion means. first, second, and third correction means for correcting; signal enhancement processing means for emphasizing the output of the first correction means; and a black signal from the outputs of the signal enhancement processing means and the second correction means. converting the outputs of the signal enhancement processing means and the second and third correction means from (hue, saturation, brightness) into (yellow, magenta, cyan, blank) series signals; The above object is achieved by providing a second converting means for converting the output of the second converting means, and a recording means for recording from the output of the second converting means.

Effect: With the above configuration, the present invention converts the three primary color signals into hue, saturation, and brightness suitable for humans to handle colors, and then processes one or two of these three elements. This makes it possible to provide a color copying device with excellent operability.

Example The concept of the present invention will be explained below.

First, several types of models have been proposed as means for converting three primary color signals into hue, saturation, and brightness.

(For example, l-l5I-11, Comparison of various methods related to GB conversion: Proceedings of the 1st Color Engineering Conference, Fukue et al., 1984, November) and a color that converts the three primary color signals into hue, saturation, and brightness. This display method is generally referred to as a color display method, and is said to be a color representation method suitable for human senses when humans handle colors. Therefore, when reading a color original and copying it under optimal conditions, for example, if there is a problem with the shading of the original, the hue and color 71 can be fixed and the problem can be solved by only increasing or decreasing the brightness component.

In other words, assuming that the hue signal value is H1, the saturation signal value is 81, and the lightness signal value is L, the case where the shading is changed can be expressed by the following equation.

(H, S: Fixed) As shown in the above equation (1) (2. Increase/decrease the brightness signal △
By changing L, the brightness of the three primary color signal values can be increased or decreased.

Similarly, regarding the hue and saturation, the hue and saturation of the three primary color signal values are changed by increasing and decreasing the hue and saturation.

Next, generation of a black signal component for black ink recording used in printing etc. will be explained. Conventionally, in order to generate a black ink component, a black signal component was generated for a portion where the three colors of the three primary color signal values overlap, and where the signal value is at an appropriate level or higher. In the present invention, a black signal is generated using an increase/decrease in a saturation signal and a brightness signal. That is, when the saturation signal is below a certain value, a black signal component (saturation component is 0 and hue is 0) is generated as shown in Fig. This is possible by increasing the model.

s'-p(s, △L) ・・・・・・・・・
(2) Conventionally, edge enhancement processing has been performed using three primary color signals, which requires a large device and is difficult to implement, as shown in FIG. However, according to the present invention, the edge enhancement processing is an enhancement of the signal value at the edge portion (2), and basically there is no need to change the hue, and it is sufficient to perform the signal value enhancement processing on the brightness signal or the chroma signal. .

An embodiment of the present invention will be described below.

FIG. 1 is a block diagram of a color copying apparatus according to an embodiment of the present invention.

In FIG. 1, 2 reads the color original 1, R, G-
This is a three-color separation system that converts (color separation) into H three primary color electrical signals. 3 is Read-on-Memory (ROM) or Random-Access-Memo! A conversion table consisting of J-(RAM), etc. converts the (JG, B) series signals sent from the separation system 2 into hue, saturation, and lightness (H, S, L) series signals, respectively. Convert to signal and output. Reference numeral 7 denotes a control unit such as a keyboard, which manually outputs a correction value according to the state of the color original 1, that is, the state of the color original 1, which is dark or light. 4 to 6 are adders that add the output (H, S', L) series signals of the conversion table 3 and the correction value that is the output of the control section 7;
9 is an edge enhancement unit that performs edge enhancement using the brightness signal output from the adder 4; This is a black signal generating section that generates a black signal (B). 10 is the output of the adders 4, 5 and the adder 6 which are input via the signal emphasis processing section 8 and the black signal generation section 9 (H, S, L
) series signal to a (Y, M, C) series signal; 11 is a (Y, M, C, B) series sent from the three primary color signal converter 10 and the black signal generator 9; This is a recording unit that prints on the printer hard copy 12 according to a signal, and is a thermal transfer or inkjet recording device.

10 Be-7 The operation of the above configuration (2) will be explained below.

First, a color original 1 is read by a three-color separation system 2 (R, G
, B) into three primary color signals;

The color signal is expressed as the hue, saturation, and lightness (H, S) of the color developing system.

L) into a ternary signal using conversion table 3.

(The three-dimensional signal of I (, S, L) is adjusted according to the reading conditions of the document by adding the increase and decrease of each signal sent by the control unit 7 by the adder 4, 5.6. The signal is inputted to the signal enhancement processing unit 8, and becomes an enhanced brightness signal.Next, the saturation signal d and the brightness signal ml are
is input to the black signal generating section 9, which generates a black signal B. Brightness signal L' and saturation signal g after generating black signal B
and the hue signal H are input to the three primary color signal conversion section 10,
The signal is converted into three primary color signals (Y, M, C) and input to the recording unit 11 together with the black signal B, and the original is not copied.

Effects of the Invention As described above, the present invention converts the three primary color signals into hue, saturation, and brightness that are suitable for human handling of colors. By performing processing on the elements, it is possible to perform copying under optimal conditions, and if necessary, it is possible to easily generate a black signal and perform image edge enhancement processing, which is highly effective.

[Brief explanation of the drawing]

FIG. 1 is a block wiring diagram of a color copying apparatus according to an embodiment of the present invention, FIG. 2 is a conceptual diagram showing the generation of a black signal in the same apparatus, and FIG. 3 is a block wiring diagram of a conventional color copying apparatus. . DESCRIPTION OF SYMBOLS 1... Color original, 2... 3-color separation system, 3... Conversion table, 4, 5.6... Adder, 7... Control unit, 8... Contour emphasis processing unit, 9...Black signal generating section, 1
0.Record section.

Claims (1)

[Claims] Scan color originals (red, green, blue)
a three-color separation means for converting into a series signal of (hue, saturation, lightness) from the output of the three-color separation means; The first step is to correct each value (hue, saturation, lightness).
second and third correction means; signal enhancement processing means for emphasizing the output of the first correction means; and a black signal generating a black signal from the outputs of the signal enhancement processing means and the second correction means. a generating means; the signal enhancement processing means; and a second;
a second conversion means that converts the output of the third correction means (hue, saturation, brightness) into a series signal of (yellow, magenta, cyan, black); and recording from the output of the second conversion means. 1. A color copying apparatus comprising a recording means for performing.