JPH03247163A - Picture processing unit - Google Patents

Abstract

PURPOSE:To discriminate a line picture such as a character synthesized onto a picture by providing a 1st processing means identifying a kind of picture data of plural different kinds, classifying the picture data depending on the kind and processing a color picture data and a 2nd processing means processing other picture data than the color picture data. CONSTITUTION:A character picture data string signal includes 1st line of character string data C10, C11, C12... in succession to a head identification code ITOP of one picture. An end code IEND of a character picture is inserted to a line next to a final line of the character picture to identify the end of the character image data. Upon the receipt of the IEND code, the end of the character picture is identified and one pattern of the picture is stored in a character code buffer 10. A character code picture in a specific area read from the character code buffer 10 is converted into a dot data by a character generator 9 and stored in a designated area to be printed out in the image memory 8. Each color picture is stored respectively in buffer memories 28-1, 28-2, 28-3 in response to R, G, B color identification signals 104. Then the area designation of the part to be printed out in an intermediate tone picture stored in the buffer memory is implemented by using a signal 107 fed from an external device similarly in the case of the readout from the character code buffer 10.

Description

[Detailed description of the invention]

[0001]

[Industrial application field]

The present invention relates to an image processing apparatus that processes image data such as halftone images and line images such as characters, or code data such as compressed codes. [0002]

[Conventional technology]

2. Description of the Related Art Conventionally, as image processing apparatuses configured to reproduce halftones using dot images, apparatuses based on an inkjet printer, a thermal transfer printer, a laser beam printer, and the like are known. In order to reproduce halftones, such devices use a dither method, a density pattern method, etc. in which halftones are reproduced by modulating dots within a small area. In particular, color laser beam printers mainly reproduce halftones using a dither method or the like. [0003]

[Problem to be solved by the invention]

Incidentally, image data sent from a color video camera, an image file, etc. to the above-mentioned color printer is once stored in a buffer memory within the color printer and then printed out. At this time, the color printer performs dither processing and converts the image in order to print out a dot image according to the density data of the transferred image, but one type of image buffer memory Since halftone images and halftone images are mixed together, there is a drawback that the character image loses its sharpness due to such dithering processing. In particular, for images with clear contrast, such as characters or lines, there is a drawback that dithering causes edges to become blurred or the density of solid areas to decrease, resulting in a loss of sharpness. [0004] Conventionally, when superimposing characters on a halftone image,
For example, a halftone image is copied using a well-known copying machine, and the resulting copy paper is then used as printer paper in a printer capable of hardcopying characters to create a halftone image. The characters were superimposed. However, these methods are not only time consuming, but also have many complicated problems such as difficulty in aligning the image and text.
Not practical. [0005] On the other hand, a composite electrophotographic copying apparatus is known, as shown in FIG. 1, which is a combination of a conventional copying apparatus and a line printer (for example, a laser beam printer). Figure 1
In this device, a copy image of a document placed on a document table 150 and a printer character output inputted from an external device (for example, a host computer) via a signal line 163 are superimposed and printed on copy paper 161. It is something that is out. The document table 150 is exposed to light by an exposure lamp 151, and the reflected light from the document table 150 forms an image on the surface of the photosensitive drum 159 via mirrors 152 to 155 and a lens 156.
An electrostatic latent image corresponding to the original is formed. On the other hand, character information input to the interface control circuit 162 from an external device (not shown) is converted into dot data within the control circuit 162, and the laser light from the semiconductor laser 164 is modulated and output. 157 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 159, superimposed on the electrostatic latent image of the original image. Thereafter, a final copy image in which a halftone image and characters are superimposed is obtained by a process similar to that of ordinary electrophotography, including development and constant transfer. However, with this device, halftone images and character images are formed and printed out completely independently, so even if characters are superimposed on an image with many black areas, the characters cannot be distinguished as shown in Figure 2. The problem arises that it is difficult to In particular, characters superimposed on solid areas cannot be distinguished. [0006] It is an object of the present invention to eliminate the above-mentioned drawbacks. [0007] Another object of the present invention is to enable good reproduction of the halftone image without losing the sharpness of the line image such as the text when composing a line image such as a character with a halftone image such as a photograph. An object of the present invention is to provide an image processing system configured as described above. [0008] A further object of the present invention is to provide an image processing device that allows line drawings such as characters to be synthesized into an image to be clearly distinguished. [0009] Another object of the present invention is to provide an image processing device in which line drawings such as characters to be combined into an image can always be clearly distinguished regardless of the background color. [0010] Another object of the present invention is to provide an image processing device that can synthesize line images such as characters and halftone images to obtain a desired color reproduced image. [0011] A further object of the present invention is to provide an image processing device that can reproduce line images such as characters or halftone images in desired colors. [0012] The present invention also resides in an image processing system capable of synthesizing a clear character image at a desired position of a reproduced image having halftones. [0013] Another object of the present invention is to provide a versatile image processing system that can be connected to other devices. [0014] A further object of the present invention is to improve the input form of image data (for example, halftone dot data, character code, compression encoding code, etc.)
An object of the present invention is to provide an image processing system that can appropriately process them even if they are different. [0015]

[Means and operations for solving the problems] In order to solve the above problems, an image processing device of the present invention inputs a plurality of different types of image data and identification data for identifying the types of the image data. and separation means for separating the image data according to type based on the identification data;
The apparatus is characterized by comprising a first processing means for processing color image data among the image data separated by the image separation means, and a second processing means for processing image data other than the color image data. [0016] (Example) Hereinafter, the present invention will be described in detail with reference to the drawings. [0017] Fig. 3 is a block diagram of a color image recording apparatus showing an entire example of the present invention. Color image recording devices include
Character code string signals as shown in FIG. 4 are used as character image data 101, and color identification signals 104 of R (red), G (green), and B (blue) as shown in FIG. Horizontal synchronization signal 106V, 1
06H and an image signal 105 are supplied from an external device such as a host computer. Further, image trimming position designation signals 102, 103, 107° 108 are also provided from external equipment. Note that the numerical values on each line in FIG. 3 represent the number of bits. Further, 12.29 inputs character image data and halftone image data to the character code decoder 11. This is an interface circuit for inputting data to the image buffer memory 28. [0018] FIG. 4 shows a character image data string signal, in which - following the image head identification code ITOP, the character string data C in the first line is
Contains C, C... Also, each row 10'
A RET code is inserted after the last character of 11 12. Therefore, the receiving side (i.e., the color image recording device side)
If a RET code is detected in , a line break is performed. [0019] In FIG. 4, R is the RET code on the first line, and R2 is the RET code on the second line. A character image end code IEND is inserted next to the last line in the character image to mark the end of the character image data. This color image recording apparatus identifies the end of a character image by receiving this IEND code. [0020] The character image data 101 supplied as described above is stored in the character code buffer 10 for one screen. At this time,
The above-mentioned special codes (eg, ITOP code, RET code, IEND code) are decoded by the character code decoder 11, and a storage start/line feed command signal 109 and a storage end signal 110 for storing character images are sent out. In response to this storage start/line feed command signal 109, the write address generator 19 sequentially generates addresses. [0021] FIG. 6 shows an example of a character screen stored in this manner. Here, each character AB,...a, b, c,...
. . . is represented by, for example, an 8-bit ASCII code. Since this color image recording apparatus employs a laser beam method that expresses a reproduced image as a dot image, 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. A normal character generator is provided with a character part CP and a margin part WP, as shown in FIG. 7(a). Therefore, for example, if the character "A°" is dot-converted according to the figure, the inside of the 9×9 pixels will become as shown in the figure (b). Also, an area information signal 1 indicating which area of a single character image should be printed out is supplied from an external device.
02 (that is, information specifying the row and column of the character code image) is given from the external device. [0022] For example, in the character code image shown in FIG. 6, the printout start character and end character are (mn) to (R2,R
2), the area 1'1 within the thick line shown in the figure is read out from the character code buffer 10. That is, in response to the printout designation information (ml, nl), (m2.n2) included in the area information signal 1O2, the read position designation circuit 17 and the read address generator 18 generate a read address for the designated area. [0023] On the other hand, area designation as to which area of the print image should be printed out the character image area designated as described above is performed using the designation signal 103. The writing area for printout is given by the pixel number of the writing start position, the scanning line mark (m1.n), and the same number (mn) of the writing end position, and A write address for image memory 8 is generated by image memory address generator 14 . [0024] The character code image in the specific area read out from the character code buffer 10 in this way is converted into dot data by the character generator 9, and stored in the designated area to be printed out in the image memory 8. . This situation is shown in FIGS. 7A and 7B. [0025] Next, processing of a hull halftone image supplied as density data of each color of R, G, and B will be described. As shown in FIG. 5, this hull halftone image includes R, G, and B color identification signals 104,
It is composed of vertical and horizontal synchronizing signals 106V, 106H and 8-bit density data (ie, image signal) 105 for each pixel of the image. In this embodiment, the density data is sent to each pixel in 8-bit parallel fashion, but it is also possible to send the density data serially. Each color image is R, G, B
Buffer memory 2 for each color according to the color identification signal 104 of
8-1.28-2.28-3 respectively. [0026] The synchronization signals 106v and 106H are supplied to the storage address generator 32, and the address selector 30 outputs the necessary address to the image buffer memory 28-1.2.
8-2.28-3. Thus, each color image is stored in the image buffer memory 28-1.28-2.28-3.
are stored in each. [0027] Thereafter, in the same way as when reading from the character code buffer 10, a region of the halftone image stored in the buffer memory to be printed out is designated by a signal 107 supplied from an external device. This is given by the printout start point, pixel number, and scanning line number, and the corresponding address of the image memory 28-1.28-2.28-3 is generated from the read address generator 31. [0028] When reading, the yellow (Y) image buffer memory (stores the B signal) 28-1. Magenta (
Image buffer memory for 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, for example, take the complement of each signal of B, G, and R, and
. A writing start position is specified by a signal 108 supplied from an external device (not shown) so that the image area specified in is printed out at the specified position. In response to this, the image memory write position designating circuit 23 and the image memory address generator 22 generate an address of the image memory 21 corresponding to the designated position. This operation is similar to that for the character image data described above. This situation is shown in FIGS. 8C and 8D. [0029] Note that the 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 (density conversion) in accordance with the characteristics of this color image recording device in the gamma correction circuit 27, and is further subjected to masking processing well known in the field of printing technology. is received by the masking processing circuit 26 and further subjected to UCR processing (undercolor removal processing).
is received by the UCR processing circuit 25 and then redithered by the dither processing circuit 24, and then the dot data (
It is stored as binary data of "1", "o"). As is well known, dither processing refers to electrical processing that determines recording dots to be output by comparing density data for each image with a threshold value in order to reproduce halftones. Further, in this example, a process of determining a recording dot by comparing one pixel with a plurality of threshold values (for example, a process based on density pattern determination) may be performed, and this process is also referred to as dither processing. Alternatively, the dither processing circuit 24 may be constructed of a memory such as a ROM, and the memory may be directly accessed using the density data as an address to perform dither processing (dither conversion). [0030] This color image recording device first records a yellow image,
The second is the magenta image, the third is the cyan image,
Since a black image is sequentially formed on the photoreceptor 1 at the fourth position, and a full color image is obtained by overlapping each color image on the transfer paper, the storage capacity of the image memory 21 is sufficient for one image. Each time an image of each color is formed on the photoreceptor 1, the above-mentioned color processing and each color density data (Y, M, C,
Bk) is transferred to the image memory 21. [0031] In order to read data from the character image image memory 8 and the halftone color image image memory 21 and send it to the laser light modulation circuit 5, these image data are stored as dot data in the image memories 8 and 21, respectively. and the same address is assigned to the same pixel. In this embodiment, addressing of both image memories 8 and 21 is controlled by an image memory address generator 14. That is, a read address is generated at the time when images are stored in both image memories 8 and 21, and the dot data of characters and halftone images corresponding to the same pixel are sent out. [0032] The dot data read from the image memories 8 and 21 are superimposed by the OR gate 7 and input to the line buffer 6. The dot data output from the line buffer 6 is input to the laser light modulation circuit 5, and the laser light modulation circuit drives the laser 4 according to the dot data. The laser beam modulated according to the dot data is scanned by a rotating polygon mirror 3 and forms an electrostatic latent image on the photosensitive drum 1 via a lens 2. The process of creating a print image is
Same as normal laser beam printer, Y, M, C
, Bk (black), four types of developers (all not shown) are selectively used. Further, the signal 113 is a horizontal synchronization signal (BD
This signal is a double signal and causes image data to be read out from the image memories 8 and 21 in synchronization. [0033] FIG. 3120 shows a 4-bit signal that specifies the color of a character image. This signal may be a signal from an external device such as a host computer or may be a signal from a switch within the color image recording apparatus. Here, the 4-bit color designation signal Co~
Each bit of C3 corresponds to Y, M, C, and Bk in order. Signal 1 when forming a latent image of the color corresponding to the specified bit
By controlling the character image output using 12, a character image of a desired color can be obtained. For example (Co, C1
, C2, C3) = (1, 1, 0, O), the character image is output from the image memory 8 when the latent images of Y and M are formed, and the character becomes a red image. [0034] Normally, when a character image is synthesized with black Bk, the character image appears more clearly in the halftone image more effectively. In this case, the color designation signals (Co, C1, C2, C3) are (0°0.
0.1). 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 monochrome or composite color image. [0035] FIG. 8 shows an example in which designated areas of a character image and a halftone image are individually moved, and these two images are combined. That is, the area is moved for each of input images A and C, and the resulting images B and D are combined to obtain image B+D. [0036] FIG. 9 shows a detailed diagram of the control circuit 16 in FIG. 3. Control circuit 16
is roughly divided into two parts: an input/output port 43 controlled by a CPU 40 such as a microcomputer, and an address timing generator 44. 41 is CP
This is a ROM for storing programs for U40, and 42 is for the CPU.
40 is a RAM for data storage, and 43 is an input/output port. The following signal lines controlled by the CPU 40 and program ROM 41 are connected to the input/output port 43. First, a character buffer enable signal (hereinafter referred to as CBE) 122, which is an enable signal for writing to and reading from the character code buffer 10, and a character buffer enable signal (hereinafter referred to as CBE) 122, which is an enable signal for writing to and reading from the character image memory 8. An image memory enable signal (hereinafter referred to as CME) 112, a color image memory enable signal (hereinafter referred to as CLME) 121, which is an enable signal for writing to and reading from the halftone image image memory 21, and a character code. Character buffer address select signal (hereinafter referred to as CBAS) 123, which is an address switching signal for writing to and reading from the buffer 10, and character buffer read, which is a start signal for writing to and reading from the character code buffer 10. /Write control signal (hereinafter referred to as CBRWC) 124, writing to character image memory 8 and image memory 8.
The character image memory read/write control signal (hereinafter CM
It is called RWC. ) 125 and a signal line for sending out a color image memory write control signal (hereinafter referred to as CLMWC) 126 which is a write start signal to the image memory 21 for halftone images are connected. Each of the above signals is output from the output port. Note that when the memory enable signal becomes 1', reading or writing from the memory becomes possible. The input port also has a color designation signal 120 that designates the color of the character image to be printed.
, the 1-page storage end signal 110, which is the detection signal of the 1-page end code IEND of the character code, and the print format (for example, only a character image, a combination of a character image and a halftone image, or a print type). A print control signal (command) 127 is input for controlling general operations such as starting or stopping printing. The address timing generation circuit 44 also generates a character code read timing signal (hereinafter referred to as CCRT) 129 and a character dot timing signal (hereinafter referred to as CDWT) 1.
30, and the CCRT 129 serves as the count signal and read timing signal of the address generation counter in the read address generator 18, and also as the CDWTI
30 is used as a count signal to an address generation counter in the image memory address generator 14 and a timing signal for writing or reading. Additionally, the CCRTI 29 and CDWT 130 are each input to an address generator 18.14 (not shown in FIG. 3). Transfer of image data (for example, character code images and halftone color images), storage in memory, printout, etc. are all controlled by the CPU 40 in the control circuit 16 in accordance with data control commands given from external equipment on the host side. As shown in FIG. 10, the data control command includes a command to print out a character image or a color image, and a command to start transferring image data from an external device serving as a host. The operation of the CPU 40 after receiving the data control command will be explained according to the flowchart of FIG. 12. [0037] First, in steps 8200 to 5204, data control commands (see FIG. 10) are interpreted, and processes A to E corresponding to each command are performed. Command=001 (step 52
00) is a character print command, so process A
Then, CME (Character Image Memory Enable) 112 is set to ``1'' (step 5205) to make the character image memory 8 accessible, while making the color halftone image memory 21 inaccessible (disabled). CLME121='“
O'' (step 5206). Then, in order to generate an address to the character image memory 8, the CMRWC
125="1" (step 5207). Further, since the address generation circuit 14 is used both when writing to and reading from the image memory 8, the memory read mode is specified in this case. Through the above operations, character image data is read out in synchronization with the image read synchronization signal 113 and with an image transfer lock (not shown). This image data is synchronized with the printer in the line buffer 6, modulates the laser beam, and contributes to image formation. Further, when it is determined that the command=010 in step 5201, it means that only a halftone image is to be printed out, and processing B
Move to. [0038] In process B, in step 5208 CLME121="
'1゛°, the color halftone image memory 21 is made accessible, and in step 5209 CMEII2
= ``''O''' to make the character image memory 8 inaccessible. Then, an address should be generated to the color halftone image memory 21 (CMRWC = ``1'').
'° (step 5210). Then, as in process A, the address generation circuit 14 is designated to the memory read mode. [0039] Furthermore, in the composite printout of the character image and halftone image (command=011, step 5202, process C), both the character image memory 8 and the color halftone image memory 21 are enabled, and the image output is (Steps 8211-5213). In this embodiment, character images can be printed out in predetermined colors of Y, M, C, and Bk, or colors obtained by a combination of these colors.This color designation is a color sent from an external device such as a host computer. given by the designated signal 120 to print out (develop) a predetermined color of the color printer;
Sometimes, processing A or C is performed to print out in desired colors. [0040] Next, the image transfer start command will be explained. Before an external device such as a host computer transfers image data to the color image recording apparatus, it is necessary to send either a character code transfer start command or a color image transfer start command. For example, in the case of a character code, when command=101 is received by this device, processing is performed from step 5203. That is, CBE (character buffer enable) = "1" (step 52
14) CBRWC (Character Buffer Read/Line Control) = “'1” (Step 5215
), a write address is given to the character code buffer 10, and the character code sent one character at a time from an external device such as a host is written to the character code buffer 10.
are stored sequentially. At this time, the CBAS (Character Buffer Address Select) sent from the CPU 40
In response to the signal, the address selection circuit 20 selects the write address as the address. The character code decoder detects the IEND code inserted at the end of one page and sends a character code transfer end signal 110 to the CPU 40 to notify the CPU 40 of the end of character code data transfer. [0041] Next, in the case of color halftone image transfer, it is determined in step 5204 and the process moves to processing E. In process E, an image buffer memory enable signal (CLBE) 134 is sent to the memory 28 in order to make the image buffer memory of the color specified by the color identification signal 104 of the transferred color image accessible.
Steps 8217 to 5221) Each color image data is stored in a predetermined image buffer memory. At the time of writing, an address select signal (referred to as CLBAS) 132 is output from the CPU so that a write address is given to the image buffer memory. Also CLBAS
is input to the address selection circuit 30 (not shown in FIG. 3). Also, the write address is the vertical and horizontal synchronization signal 106
V, 106H, and when the storage of a predetermined number of lines (4752 lines in this embodiment) is completed, the write address generator 30 sends a storage end signal CIEND133.
(not shown in FIG. 3) is output and notified to the CPU 40. [0042] Once the character code and color halftone image are stored in the buffer memories 10 and 28 as described above, each image data is transferred to the image memories 8 and 21 at the next stage after being subjected to predetermined processing. [0043] First, regarding reading from the character code buffer 10 and writing to the image memory 8, reading is performed in the character code buffer 10 according to the address output from the read address generation circuit 18. At this time, the reading position specifying circuit 17 specifies which area within the page should be printed out. For example, in FIG. 8A, the upper left address (Cx Cy) and the lower right address (CX2
．． Cy2) is set in the read position designation circuit 17 to generate an address to read only the area in the figure (the area surrounded by a rectangle), and the address is applied to the character code buffer 10. Similarly, in the case of a color image, in Figure 8C, the upper left address (CLX
CLyl), 1° lower right address (CL x CL y 2 ) in the read position designation circuit 33, a read address is generated so that only the area shown in FIG. 80 is read out. Next, when the read image data is stored in the image memory 8, 21, the write position designating circuit 15 or 2 determines where on the copy paper the read image should be printed.
It needs to be set to 3. For example, in FIG. 8B, the upper left address (CX1.CY), the lower right address (CX2.CY)
By setting 2) in the write position designation circuit 15, the read character image is transferred to the position shown in FIG. 8B. Also, in Figure 8D, the address (CLX CLY)
By setting (CLX2.CLY2) in the write position 1'1 designation circuit 23, the read color halftone image is transferred to the position shown in FIG. 8D. Therefore, when these transferred image data are combined, Figure 8B+
An image laid out as shown in D is formed. [0044] Note that the addresses for specifying the above-mentioned areas are given by signals 102103.107, 108 from external devices. [0045] FIG. 11 shows the data input section of this device. In this device, image data 10 transferred from an external device such as a host
0 (character image data and color halftone image data) are all supplied through the interface circuit 45 by one system of cables, so this is internally separated and divided into two data processing systems ( character code processing system and color halftone image processing system). Prior to transfer, a character code transfer start command or color image transfer command sent by an external device such as a host causes C
The PU 40 sends a data select DS signal 140 to the data selector 46 to switch the data processing system. Therefore, even when data of various types, such as compressed code strings of image data, other codes, or data of different types such as command strings, data identification signals (in this embodiment, as shown in FIG.
By having a data control command (as shown in Figure 1) and a switching circuit such as a data selector, it is possible to transmit and receive data using a single data line. For example, if the form is as shown in Figure 13,
It is possible to receive a facsimile compression code and synthesize the character image, color halftone image, and facsimile image. That is, the command shown in FIG.
If an X code identification command is added, the CPU 40 receives the identification command before sending the compressed code,
By outputting a selection signal DS255 to the data selector 250, it is possible to select and receive a facsimile compressed code, for example, an MH code. Then, the MH code is stored in the buffer memory 251 in the same manner as character image data and color halftone images. After the MH code is stored, it is read out, decoded by the MH decoder circuit 252, and stored in the next stage FAX image memory 253 while being developed into a dot image. At this time, it is also possible to designate an area and print out only or in a specific area using a method similar to that described above. Finally, by outputting the dot data to the aforementioned printer via the OR gate 254, for example, the aforementioned character image, color halftone image, and facsimile image can be synthesized, and an image as shown in FIG. 14 can be obtained. . In FIG. 14, A is a character image area, B is a color halftone image area,
C is a facsimile image area. [0046] In FIG. 13, the circuit for processing character codes and the circuit for processing halftone image data are the same as those in FIG. 3, and are therefore omitted. [0047] FIG. 15 is for explaining the third embodiment. Components having the same functions as those in FIG. 3 are given the same numbers, and their explanations will be omitted. Therefore, mainly the parts different from the circuit of FIG. 3 will be explained here. [0048] In the figure, 335 and 336 are a dark tone extraction circuit and a dark tone memory that stores a dark tone portion, respectively. The dark tone extraction circuit 335 is composed of comparison circuits 342, 343, 344, switches 346, 347, 348, etc., as shown in FIG. switch 3
46, 347, 348 should be determined as dark tone, Y
(yellow) Set the amount of each density component of M (magenta) and C (cyan). Comparison circuits 342, 343, 344
are the Y, M, and C components of the input image density and the switches 346, 3
47, 348, and for pixels whose input image density component amount exceeds the set value,
" is output. When the input image density of all Y, M, and C exceeds the set value, output 3 of comparison circuits 342, 343, and 344
Since pixels 42-1, 343-1, and 344-1 are all "1", this pixel is considered to be a dark part, and "1" is stored in the dark tone memory 336 shown in FIG. At this time, data is written to 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 the data is stored in the image memory 21 for the halftone image. Therefore, the dark tone memory 336 is the image memory 2.
It has the same capacity as 1. Furthermore, in this configuration, by changing the setting values of the switches 346, 347, and 348 in FIG. 16 described above, the color that is considered to be a dark tone can be freely changed. For example, if switches 346 and 347 are set to high density and switch 348 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 It is possible to set the color of [0049] In order to read data from the character image image memory 8 and the halftone image image memory 21 and send it to the laser light modulation circuit 5, these image data are transferred to the image memories 8 and 21 and the dark tone memory 336. Each pixel is stored as dot data, and the same address is assigned to the same pixel. In this embodiment, the addressing of both image memories 8.21 and the dark tone memory 336 is controlled by the image memory address generator 14. That is, a read address is generated at the time when images are stored in both 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. [0050] 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 characters, the character part is a printing dot (115 = "'1"), and the ground part,
That is, when the value for the same pixel read from the dark tone memory is 1'' (that is, the background is dark tone), the output of the AND gate 337 becomes 0, and a white character is output. Further, when the background part is 0%, that is, white or light colored, the output of the AND gate 337 becomes 1'', and characters are printed. [0051]On the other hand, when printing a halftone image , when the character part is a printed dot, that is, the signal 115 = "1", the AND gate 33
Since the output of 8 is "o" regardless of the image data 116, no image appears where there are characters. Therefore, whiteness is achieved. In other words, the halftone image data is output as follows.
This is when there is no character (115=“0”). The image output in this way is, for example, as shown in FIG. 17. 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). Reference numeral 339 is a character halftone image selector, and according to the signal 114 output from the control circuit 16, when outputting a character image, A and C are connected so that when outputting a halftone image, B and C are connected. controlled. Note that an OR gate may be used instead of the selector 39. If an OR gate is used, a character image and a halftone image can be output at the same time, and the number of transfers can be reduced. [0052] This color image recording apparatus first reads out a yellow image, for example, and forms the yellow image on the photoreceptor by operating a yellow developing device (not shown). Then, the yellow image on the photoreceptor is transferred to transfer paper wrapped around the transfer drum, thereby completing the transfer of one color. Next, in a similar process, magenta, cyan, and black are successively aligned and superimposed to obtain a full-color image of four colors. Thereafter, the selector 339 is switched to obtain a character image in a desired color. [0053] As described above, 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 monochrome or composite color image. [0054] Therefore, as described above, when printing out characters in yellow, for example, if only the switch 346 in FIG. 10 is set to high density and the other switches 347 and 348 are set to low density, only the yellow part of the halftone image It is considered as a background, and yellow characters and halftone images can be clearly distinguished. In other words, even if the yellow part of the halftone image overlaps the yellow text, the yellow text is expressed as white, so the text can be clearly recognized. [0055] FIG. 18 is for explaining the fourth embodiment. Components having the same functions as those in FIG. 3 are given the same numbers, and their explanations will be omitted. Therefore, mainly the parts different from the circuit of FIG. 3 will be explained here. [0056] In FIG. 18, 55 is a blank code generation circuit, which is used to create a white outline around characters to be output. When outputting a halftone image with a white box, a blank code is sent by the blank code generation circuit 55 to the character generator 9 via the selector 56,
Blanks are written in the image memory 8 at the positions where characters are to be printed. At the same time, the input 21 of the OR gate 54 is used for parts other than characters, that is, outside the area where the blank is written.
5 writes "1", and a white hollow image as shown in FIG. The output of the image memory 21 is connected to the output of the image memory 21. Therefore, the final image output from the AND gate 67 is
This results in a halftone image or edge image in which only the white frame portion WH in a) is removed. The next time a character is output, the selector 56 operates so that the character code buffer 10 is connected to the character generator 9. Therefore, in the character generator, the character code is converted to dot data,
Dot data of a character image to be written is written into the character image memory 8. At this time, input 2 of OR gate 54
Since 15 is '0'', only the character dot data is written into the character image memory 8.The selector 57 is connected so that the input of the AND gate 67 is 1°''. Therefore, only the character dot data read from the character image memory 8 passes through the AND gate 67.
Then, as a final image, as shown in FIG. 19(c),
(b) An image with predetermined characters written in the white frame is obtained. [00573] By the way, the blank code generation circuit 55 performs the following operation when forming an image as shown in FIG. 19(a) in the image memory 8. [0058] First, character codes are input sequentially from the character code buffer 10 (signal lines for inputting character codes are not shown). Blank codes are generated for parts other than blank codes, and input is performed for other parts. 215 sends a signal (not shown) to the control circuit 16 to write "°1°" into the image memory 8. When the control circuit 16 receives a signal from the blank code generation circuit, it starts the address generator 14. control to generate Pa1'''. [0059] In this way, an image as shown in FIG. 19(a) is formed in the image memory 8. In this embodiment, it is assumed that the character code buffer does not include control codes and stores all character codes. [0060] CR the image based on the data in memories 8 and 21 of Nangoku 3
Once display L is displayed on the T-display, the position and color of the composite character can be confirmed, and printing can be started after confirmation. [0061] This color image recording device sequentially forms a yellow image, a magenta image, a cyan image, and a black image on the photoreceptor 1, and by aligning and overlapping each image on the transfer paper, You are getting a full color image. [0062] The color of the character image can be easily selected by selecting a developing device when printing out (developing) the character image. [0063] Note that the blank code generation circuit outputs various codes with different blank sizes to the character generator,
By outputting a blank pattern according to the blank size from the character generator, it is possible to create white frames of different sizes. [0064] In this embodiment, character patterns are stored in the image memory, but other line drawing patterns may also be stored. Further, in this embodiment, a laser beam printer is used as an example of the output device, but the present invention is not limited to this, and can also be used for, for example, an inkjet printer, a thermal printer, etc. [0065] Alternatively, a disk may be used instead of the output device to file the combined image. [0066] Further, in this embodiment, the character data and the position designation signal are sent from an external device, but they can also be input using data input keys provided on the color image recording apparatus side. [0067] Furthermore, the R, G, and B color image data can also be sent from a CCD scanner or the like. [0068] It is also possible to store the combined image in memory (for example, Y, M, C, and Bk memories). [0069] As described above, according to the present invention, it is possible to synthesize a character image with a halftone image without impairing the sharpness of the character image, and moreover, it is possible to perform movement of designated areas for each of the character image and the halftone image. Since they can be performed separately, it is possible to efficiently rearrange and synthesize the character image and the halftone image. [0070] Furthermore, according to the present invention, since character images and the like can be input using, for example, code codes, connection with other devices is also possible, and a versatile image device can be obtained. [0071] Further, according to the present invention, the character image can be made into any color depending on the halftone image that is the background, and the reproducibility of the character image and the halftone image is improved. I can do it. [0072] Furthermore, according to the present invention, it is possible to receive compressed codes from, for example, facsimiles, simply by adding an input data identification command. Therefore, it is possible to synthesize various images input from various devices. [0073] Further, according to the present invention, at least one of the halftone image and the line image can be arbitrarily colored, which is suitable for office processing after printing (for example, changing the color of characters for each data). A reproduced image can be obtained. [0074] Further, according to the present invention, the color of line drawings such as characters, the tone of images,
Since line drawings such as characters can be clearly reproduced regardless of the density, it is possible to eliminate the inconvenience that, for example, characters become invisible in solid areas of an image. [0075]

【Effect of the invention】

As described above, according to the present invention, it is possible to perform image synthesis according to various input image data.

[Brief explanation of drawings]

[Figure 1] FIG. 1 is a diagram showing an example of a composite copying apparatus.

[Figure 2] A diagram showing a state in which characters are superimposed on an image with many black parts.

FIG. 3 is a circuit diagram of a color image recording apparatus showing an entire embodiment of the present invention.

[Figure 4] The figure which shows an example of character image data.

[Figure 5] A diagram showing an example of color image data.

FIG. 6 is a diagram showing an example of a character screen stored in a character code buffer.

FIG. 7 is a diagram showing the state of characters input to the character generator and the state of characters converted into dots.

FIG. 8 is a diagram illustrating an example in which designated areas of a character image and a halftone image are moved separately, and the two screens are combined.

[Figure 9] A detailed diagram of the control circuit 16.

[Figure 101 Diagram for explaining various commands. [Figure 11] FIG. 3 is a diagram showing a data input section.

FIG. 12 is a flowchart of a program stored in the ROM 41.

FIG. 13 is a diagram showing a second embodiment in which compressed code data can be input.

FIG. 14 is a diagram showing an example of combining a character image, a color halftone image, and a facsimile image.

FIG. 15 is a diagram showing a color image recording device according to a third embodiment of the present invention.

[Figure 16] A specific configuration diagram of a dark tone extraction circuit.

[Figure 17] FIG. 3 is a diagram showing an image state obtained by this example.

FIG. 18 is a diagram showing a color image recording apparatus according to a fourth embodiment of the present invention.

[Figure 19] A diagram for explaining the state of an image with a white outline.

[Explanation of symbols]

7 OR gate 8.21 Image memory 9 Character generator 10 Character code buffer 16 Control circuit 24 Dither processing circuit 28-1 to 28-3 Image buffer memory 40
CPU 46.250 Data selector 251 Buffer memory 252 MH decoder circuit 253 FAX image memory

[Document base]

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Claims (1)

[Claims] 1. Input means for inputting a plurality of different types of image data, identification data for identifying the types of the image data, and separation for separating the image data according to types based on the identification data. and a first processing means for processing color image data among the image data separated by the separating means; and a second processing means for processing image data other than the color image data.
An image processing device comprising: processing means.