JPS60232773A - Recording method of digital color picture - Google Patents

Abstract

PURPOSE:To obtain a fine black-and-white picture by using only one picture signal out of three red, green and blue picture signals. CONSTITUTION:When an original picture is read out, a red picture signal R, a green picture signal G and a blue picture signal B are obtained from a picture reading circuit 1. These signals R, B, G are simultaneously applied to respective signal switching circuits 2r, 2b, 2r and an output driver 4. These circuits 2r, 2b output signals R, B respectively in a color picture recording mode, i.e. a mode for recording and reproducing a color picture as the color picture, but when a signal specifying a black-and-whilte recording mode is received, all signal switching circuits output green picture signals G. Consequently, the outputs R1, G1, B1 of output drivers 3-5 are the same in the black-and-white mode and cyanic, magenta and yellow pictures are superposed mutually with equal distribution to obtain a fine black-and-white picture.

Description

[Detailed description of the invention] (Technical field) The present invention relates to a digital color image recording method.

(Prior art) One original image is separated into red, green, and blue colors and read, and based on these five types of image signals, such as a red image signal, a recorded image signal, and a blue image signal, the above-mentioned A digital color image recording method for recording and reproducing a color image corresponding to an original image is known. The three types of image signals obtained by the reading section are
It is sent to a part of the printer of the same or different recording device as the reading section. A portion of the printer records and reproduces a color image corresponding to the original image based on the six types of image signals sent. That is, for example, by using the inkjet method or the electrostatic recording method, a cyan image l which is a complementary color to a red image signal, a mabinota image which is a complementary color to a recording I signal, and a yellow l! which is a complementary color to a blue image signal are produced. III statue? A color image is obtained by combining these six color images.

By the way, this type of digital color image recording method has
There were the following problems.

In other words, if the original image has a so-called black and white gap, naturally,
The reproduced recorded image should also be a black and white image source, but in reality it is often a colored image.

(Objective) Therefore, it is an object of the present invention to provide a novel digital color image recording method that effectively solves the above-mentioned problems.

(composition) The present invention will be explained below.

When a black and white image on a document is recorded using a digital color image recording method, the reason why the recorded image appears colored is as follows.

In other words, when a monochrome image is separated into red, green, and blue, the red image signal, recorded image signal, and blue image signal should originally be the same, but in reality, the filter used for color separation These six types of signals have different strengths due to differences in transmittance. For example, if the red image signal is strong, the cyan color on the recorded image is weakened, and what should be a black and white image is colored red. The result is a recorded image that looks like this.

Therefore, in the present invention, only one of the three types of image signals, red, green, and blue, is used for image recording in the monochrome recording mode.

Here, the black-and-white recording mode refers to the case where the document image is a black-and-white image and is recorded as a black-and-white image, and the case where a color image on the document is recorded as a single black-and-white image.

This will be explained below with reference to the drawings.

In the figure, numeral 1 is an image reading circuit, numerals 2r, 2g,
Reference numeral 2b indicates a signal switching circuit, and reference numeral 6.4.5 indicates an output driver.

The original image is read through (from the image reading circuit 1, the red image signal R
1 recorded image signal G and blue image signal B are obtained. For example, the red image signal R is an electrical signal obtained by color-separating an original image using a red filter.

The red image signal R is applied to the signal switching circuit 2r, the blue image signal B to the signal switching circuit 2o, and the recording 1 image signal G is applied to the signal switching circuit 2g and the output driver 4 at the same time.

The signal switching circuits 2r and 2b respectively output a red image signal R1 and a blue image signal B in a color image recording mode, that is, a mode in which a color image is recorded and reproduced in color, but output a signal specifying a monochrome recording mode. When the signal is received, the output signal is switched and each signal switching circuit outputs the recording image signal G. That is, the outputs R' and B' of the signal switching circuits 2r and 2b are the red image signal R and the blue image signal B, respectively, in the color image@recording mode, but in the monochrome recording mode, they are both the recorded image signal. G, and the outputs R1, Gl, -B1 of the output driver 6.4.5 are the same in the monochrome recording mode. Output R1, C)1. B
1 are converted into Noan, magenta, and yellow color images @f in a part of the printer, but in black and white recording mode, the outputs R1, G1 . Since the B1 power is completely the same signal, the 777 image, magenta image, and yellow image are also the same, and since they are superimposed on each other in equal distribution, a good black and white image without coloring can be obtained as a whole.

Signal switching circuits 2r, 2g, 2b and output driver 6
．． 4.5 may be provided in the reading section or may be provided in a part of the printer.

In the above example, only the recorded image signal G was used for image recording in the black and white recording mode, but it is also possible to use only the red image signal H or only the back side signal B for image recording. good.

By the way, when the original image is a color image and is recorded in black and white recording mode, if only the red image signal is used for image recording, the red image on the original image will be lost in the recorded image. .

Therefore, in order to prevent the red image in the original image from being omitted in the recorded image, it is sufficient to use only the recorded image signal or the blue image signal for recording.

From this point of view, when in monochrome recording mode, any one of the red image signal, blue image signal, and recording image signal is selected for recording. It is desirable to select the signal depending on the color of the image 1# that is not desired to be omitted on the image. When the signals are not selectable in this manner, it is preferable to use only the recording single-image signal for image recording when switching to black and white recording mode.

This is because recorded images are generally of low importance. Incidentally, when only one of the blush gap signal, the back iron signal, and the recorded image signal is used for image recording, this one type of signal may be used to drive a printer for black and white image recording.

(Effects) As described above, according to the present invention, a novel digital color image recording method can be provided. With this method, when in black and white recording mode,
Since only one of the red face signal, inter-recording signal, and blue image signal is used for image recording, no unnatural coloring occurs in the resulting black and white image.

[Brief explanation of drawings]

The figure is a block diagram for explaining the present invention.

Claims (1)

[Claims] A red image signal, a recorded image signal, and a blue image signal are obtained by color-separating the original image into red, green, and blue colors and reading them.
Based on the seed image signal, one of the above manuscript images (a color image corresponding to the elephant (in the digital color image recording method for recording and reproducing elephants, and in black-and-white recording mode, the above three types of images)) A digital color image recording method characterized in that only images are subjected to inter-plane recording.