JPH02283169A - Picture processor - Google Patents

Abstract

PURPOSE:To discriminate clearly a character or the like to be synthesized on a picture independently of background by replacing an half tone picture and a character data as to the picture element to superimpose the character data when the half tone picture and the character are superimposed. CONSTITUTION:A dot data 115 of a character picture read from a characteristic image memory 8 and a dot data 116 of a half tone picture read by a half tone picture image memory 21 act respectively each other exclusively. That is, in the case of printing out a character, the data 115 goes to logical 1 and the level of the background, that is, the value to the same picture element read from a dark tone memory 36 is logical 1, then the output of an AND gate 37 goes to 0 and a character of white level on a black background is outputted. When the background level is white or light color, the output of a gate 37 goes to 1 and the character is printed out. On the other hand, in the case of printing out the half tone picture, when the level of the data 115 is logical 1, since the output of an AND gate 38 is logical 0 independently of the data 116, no picture appears where there is any character. Thus, the character with white level on the black level background is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an image processing apparatus for synthesizing line images such as images and characters.

Prior Art Conventionally, when text is superimposed on a halftone image, for example, the halftone image is copied using a well-known copying machine, and the resulting copy paper is then used as printer paper to print the text. Use with printer devices that can print hard copies.
Text was superimposed on a halftone image. However, such a method not only takes time and effort twice, but also has many complicated problems such as difficulty in aligning the image and characters, and is not practical.In contrast, the conventional method shown in Figure 1 2. Description of the Related Art A composite type copying apparatus that combines a copying apparatus and a line printer (for example, a laser beam printer) is known. 1st
In the illustrated apparatus, a copy image of a document placed on a document table 50 and a printer character output input from an external device (for example, a host computer) (not shown) via a signal line 63 are superimposed on a copy paper 61. It is to be printed out. The document table 50 is exposed to light by an exposure lamp 51, and the reflected light from the document table 50 is reflected by the mirrors 51 to 55 and the lens 5.
6, the image is formed on the surface of the photosensitive drum 59, and an electrostatic latent image corresponding to the original is formed.

On the other hand, character information input to the interface control circuit 62 from an external device (not shown) is processed within the control circuit 62.
The data is converted into dot data, and the laser light from the semiconductor laser 64 is modulated and output.

57 is a rotating polygon mirror for horizontally scanning the laser beam.

By modulating and scanning the laser beam in this manner, an electrostatic latent image of a character image is formed on the surface of the photosensitive drum 59, superimposing the electrostatic latent image described above, in the same manner as described above. After that, development → transfer →
The final,
A copy image in which a halftone image and characters are superimposed is obtained. However.

With this device, halftone images and single character images are processed and printed out independently, so even if characters are superimposed on an image with a lot of black, for example, the characters are difficult to distinguish, as shown in Figure 2. A problem arises. In particular, characters superimposed on solid areas cannot be distinguished.

Purpose of the Invention The present invention has been made in view of the drawbacks of the prior art, and it is an object of the present invention to provide a novel image processing device that can always clearly distinguish line drawings such as characters that are synthesized into an image regardless of the background. .

Example The present invention will be described in detail below with reference to one drawing.

Figure 13 is a block diagram showing the entire embodiment of the present invention.The image processing device shown in Figure 6 has one character image data lot.
As color code string signals as shown in FIG. 4, as color image data, R, G, H color identification signals 104 and vertical and horizontal synchronizing signals 106V as shown in FIG.
An image signal 105 accompanied by 106H is supplied from the outside. Furthermore, image trimming position designation signals 102 and 103
.

107 and 108 are also supplied from outside.

FIG. 4 shows a character image data string signal, which includes the first line of character string data CIo, Ctt, C+1 following the initial identification code ITOP of the image. Further, a RET code is inserted after the last character of each line. Therefore, when a RET code is detected on the receiving side (that is, on the single image processing device side),
In Figure 4, R is RET in the first line.
The code R3 is the RET code on the second line. After the last line in a one-character image, insert the one-character image end code IEND to mark the end of one-character image data.
This image processing apparatus identifies the end of a single character image by receiving this IEND code.

The character image data lO1 supplied as described above is stored for one screen in the character code buffer lO. At this time, the above-mentioned special code (for example, I-cho OP code, RE
T code, IEND code), character code decoder 1
1 and sends out a storage start/line feed command signal 109 and a storage end signal 110 for storing character images.

FIG. 5 shows an example of a character screen stored in this manner, where each character A, B, ----a.

b, c, . . . 1 is, for example, 8 bit (F) AS
CII: 0 represented by I-dot In this embodiment, a laser beam method using a dot image is adopted, so it is necessary to convert the above-mentioned character code string into a dot shape. Therefore, in this embodiment, the character generator 9 is used to perform such dot conversion.

The character generator 9 is the same as a well-known one, so a description thereof will be omitted. At this time, an area information signal 102 indicating which area of the externally supplied one-character image should be printed out (that is, information specifying the row and one column of the one-character code image) is provided from the external device.

For example, in the character code image shown in FIG. 5, the printout start character and end character are (L nn1) ~
(m2+"2), the area within the thick line shown in the figure is read out from the character code buffer 10. Then, upon receiving the printout designation information ("I, nl), (m2+I+2) included in the area information signal 102, , the read position designation circuit 17 and the read address generator 18 generate a read address for the designated area.

On the other hand, a designation signal 103 is used to designate which region of the print image the character image region designated as described above should be printed out. The writing area for printout is given by the pixel number of the writing start position, the scanning line number ('I +nl'L), the same number (12+12') of the writing end position, and A write address for the image memory 8 is generated by the circuit 15 and the image memory address generator 14.

The character code image in the specific area read out from the character code/header IO in this manner is converted into dot data by the character generator 9, and stored in a designated area in the image memory 8 to be printed out.

This situation is shown in FIGS. 6A and 6B.

Next, processing of the 11JlyA image supplied as the density data of each color of R, G, and B will be described. As shown in FIG. 7, this 1/2 tone image is R, G.

B color identification signal engineer 04. Vertical and horizontal synchronization signals 106
V, 106H and density data for each pixel of the image (
In other words, it is composed of image signals) 105. Each color image is stored in the buffer memory 28-128-2, 28-3 for each color according to the R, G, and E color identification signals 104, respectively.

The synchronization signals 106v and 106H are sent to the storage address generator 32, and the address selector 30 outputs the necessary addresses to the image buffer memory 28-1.
28-2.28-3. Thus, each color image is stored in the image pack memory 28-1.28-2.28-
3.

Thereafter, in the same way as when reading from the character code buffer 10, an area in which a halftone image is to be printed out is designated by a signal 107 supplied from the outside. this is,
The printout starting point is given by the 9th element number and the scanning line number, and the corresponding image memory 28-1.28-2
．． The address 28-3 is generated from the read address generator 31.

When reading, image buffer memory for yellow (Y) (stores B signal) 28-1.

Image buffer memory for magenta (M) (stores G signal) 28-2. The same pixel is simultaneously read out as Y, M, and C components from the cyan (C) image buffer memory (stores the R signal) 28-3.

(Here, we take the complements of each signal of B, G, H, Y, M,
It is output as a C signal. ) The color signals read out in this way are finally stored in the halftone image image memory 21, but as described above, the designated image area is printed out at the designated position. By a signal 108 supplied from an external source (not shown),
The writing start position is specified.

In response to this, the image memory write position designation circuit 23
and image memory address generator 22 generates an address of image memory 21 corresponding to the designated location. This operation is similar to that for the character image data described above.

In addition, image buffer memory 28-1.28-2.2
The color density data for each pixel read out from 8-3 is subjected to gamma conversion (GA degree conversion) in accordance with the characteristics of the unprocessed image processing device in the gamma correction circuit 27, and is further subjected to masking processing well known in the field of printing technology. (see 26) and U
After being subjected to CR processing (see 25) and then dither processing (see 24), it is stored as dot data at a specified location in the image memory 21 as described in 1- above. Here, dither processing, as is well known, is electrical processing that determines recording dots to be output by comparing the density data of every two pixels with a threshold value in order to make halftones visible.

On the other hand, 35 and 36 are dark tone memories that respectively store a dark tone extraction circuit and a dark tone part. As shown in FIG. 8, the dark tone extraction circuit 35 includes comparison circuits 42, 43, 44, switches 46, 47, .
It consists of 48 mag. Switches 46, 47, and 48 set the amount of each density component of Y (yellow), 1M (magenta), and C (cyan) that should be determined as a dark tone. Comparison circuit 4
2, 43, and 44 compare the Y, M, and C components of the input image density with the set values set by switches 46, 47, and 48, and for pixels whose input image density components exceed the set values, , outputs "1". Comparison circuits 42, 43, 44 when the input image density of all Y, M, C exceeds the set value
Since the outputs 42-1.43-1.44-1 are all rlJ, this pixel is regarded as a dark part and is stored in the dark tone memory 36 shown in FIG.

At this time, data is stored in the dark tone memory in accordance with the address 118 generated by the address generation circuit 22, which is specified from an external source (not shown), in the same way as storage in the image memory for halftone images. In addition, in the one-piece configuration, by changing the setting values of the switches 46, 47 and 48 shown in FIG. , when the density is set to high and the switch 48 is set to zero, the areas where Y and M are high density and C is low density, that is, the "red" part becomes a dark tone, and this is used as the "r background color". is possible.

In order to read the data from the image memory 8 for character images and the image memory 21 for halftone images and send them to the laser light modulation circuit 5, these image data are stored in the image memories 8 and 21 and the memory 36 for dark tone images, respectively. In this embodiment, the addressing of both the image memories 8 and 21 and the dark tone memory 36 is handled by the image memory address generator 14. It's in control. That is, a read address is generated when an image is stored in the single image memories 8 and 21, and the dot data of characters, halftone images, and dark tone portions corresponding to the same pixel are sent out.

The dot data of the character image read from the image memory 8 and the dot data of the halftone image read from the image memory 21 act exclusively. In other words, when outputting or printing out one character, the one character part is a printing dot (115=°"1'°), and the value for the same pixel read from the background part (dark) is When the background is 'i' (i.e. the background is dark tone), the output of the AND gate 37 is 'o' and a white character is output. Also, when the background is 'O゛', i.e. white or light color , the output of the 7nd gate 37 becomes °°l', and two characters are printed.

On the other hand, when printing a halftone image, if the character part is a printing dot, that is, the signal 115 = '"1°", the AND gate 3
Since the output of No. 8 is "0°" regardless of the image data 116, no image appears where there are two characters, and whitening is therefore achieved. In other words, halftone image data is output only when there is one character. This is the case when there is no part (115=“0°′). In this way, the output image will look like the one shown in Figure 9, for example.
As can be seen from the figure, areas with a dark tone or solid black background can be printed out with white characters, and areas with a white background can be printed out with black or other monochrome characters (described later). 3
9 is a selector for characters and halftone images; when outputting a two-character image by the signal 114 outputted from the control circuit 116, A and C are connected; when outputting a halftone image, B and C are connected. controlled in a similar manner.

The laser beam modulated by the dot data l read from the image memories 8 and 21 forms an electrostatic latent image on the photosensitive drum l.

The process of creating a print image is similar to that of a normal laser beam printer, and four types of developing devices (none of which are shown) are selectively used for Y, M, C, and BK (black). . Further, the signal 113 is generated when the laser beam detector 40 is irradiated with a laser beam.
This is a horizontal synchronizing signal sent from 0, and causes image data to be read out from the image memories 8 and 21 in synchronization.

The wood image processing device first reads a yellow image, operates a yellow developer (not shown) to obtain a yellow image, and then processes magenta, cyan, and
A four-color full-color image is obtained by sequentially aligning black and overlapping each other.

Note that the signal 112 is a signal for controlling the color of the character image, and causes the image memory 8 to output data only when a desired color is to be printed out. Similarly, when reading a halftone image from the image memory 21, it is also possible to control the reading of only a desired color image to obtain a parcel or composite color image.

Therefore, as mentioned above, when printing out characters in yellow, for example, by setting only the switch 46 in FIG. The yellow text and the halftone image can be clearly distinguished.

FIG. 6 shows an example in which the specified areas of a character image and a halftone image are moved individually, and these two images are combined. In other words, the areas are moved for each of input images A and C. , the resulting images B and D
In this embodiment, the image memory is used to store character brim patterns, but other line drawing patterns may also be stored in the image memory. Although the present invention has been described using a laser beam printer as an example, the present invention is not limited thereto, and can also be applied to, for example, an ink printer, a thermal printer, etc.

Effects As explained above, according to the present invention, line drawings such as characters can be clearly reproduced regardless of the color tone and density of the image. It is possible to eliminate the inconvenience of not being able to see the image.

Furthermore, according to the present invention, since character images can be input using code codes, connection with other devices is also possible, and a versatile image processing device can be obtained.

Further, according to the present invention, halftone images and line drawings can be colored arbitrarily, so image processing suitable for office processing after printing (for example, changing the color of characters every two pieces of data) can be performed. .

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a composite copying apparatus, FIG. 2 is a diagram showing a state in which characters are superimposed on an image with many black areas, and FIG. 3 is a diagram showing an entire configuration of an embodiment of the present invention. 4. Fig. 4 shows an example of character image data. Fig. 514 shows an example of a character screen in which the character code buffer has been stored. Fig. 6 shows the designated areas of the character image and halftone image separately. FIG. 12 is a diagram showing an example in which both screens are combined. FIG. 7 is a diagram showing an example of color image data, FIG. 8 is a diagram showing a specific configuration of a dark tone extraction circuit, and FIG. 9 is a diagram showing an image state obtained by this embodiment. 8-111 character image memory 9-111 character generator 10--1 character code buffer 11--1 character code decoder 12--Interface 14--Image memory/address generator 1
5----Image memory write position designation circuit 16-
--- Control circuit 17 --- Read position designation circuit 18 --- Read address generator 19 ---
1. Write address generator 20 --- Address selector 21 --- 1. Image memory for halftone image 22 ---
Image memory address generator 23---Image memory write position designation circuit 24---Dither circuit, 25---U CR circuit 2B-1---Masking circuit 27---Gamma correction circuit 28-1. 28-2.28-3---Image panzer memory 29----Interface 30---Address selector 31----Read address generator 32---
- Write address generator 33 - - Read position designation circuit 35 - - Dark tone extraction circuit 36 - - Dark tone memory 39 - - Selectors 42 to 44 - - Comparison circuit 1 Ω image fC1Pa bait Family name +061-1-Yamaichi--2111-11U-222Nee-2-241 Beast 91υzu -jSaraSara22221ILJllIII;Ninini■几-U-2- 22-Two Hand Ito Sales Nehosho 1) (Voluntary) Case Description Patent Application 3'F (B) 2 filed on March 16, 1990;
Name of the invention Image processing device 3, address of person making the amendment Relationship to the name case Patent applicant 3-3O-2 Shimomaruko, Ota-ku, Tokyo (tool Canon Co., Ltd. Representative Keizo Yamaji 44, agent residence 146 Tokyo 3-30-25, Shimomaruko, Ota-ku, Tokyo Description subject to amendment Details of the amendment (1) Deleting the statement on page 16, line 3 of the specification. (2) Deleting the statement on page 3, line 8 of the specification. "This device" is amended to "For example, these devices." (3) "The present invention" stated on page 16, line 4 of the specification is amended to "this embodiment". (4) "This invention" stated on page 16 of the specification, line 4. "r This invention" written in line 9 is amended to "the present embodiments." (5) "The present invention" written in line 13 of page 16 of the specification is amended to "the present embodiments." (6) Specification Insert the following between page 16, line 17 and line 18.

Claims (1)

[Claims] An image processing device characterized in that, when superimposing a halftone image and text, the halftone image and text data are replaced for pixels on which text data should be superimposed.