JP2603458B2 - Image processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an image processing apparatus.

[0002]

2. Description of the Related Art Conventionally, a color document image is optically read by a photosensor, converted into an electric signal, processed, and printed out.

[0003]

However, conventionally,
It has not been considered to automatically determine whether an input image is a color image or a monochrome image and to perform processing appropriate for each of the images.

[0004] Particularly, in an apparatus that can handle both an image signal read by a photosensor and an image signal from a host computer, such a rational process has not been considered.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described conventional example, and has been made in consideration of the above-described circumstances. An image processing apparatus that processes color component signals from a plurality of input means can efficiently process a color image and a monochrome image. The purpose is to.

[0006]

In order to solve the above-mentioned problems, an image processing apparatus according to the present invention comprises a first input means for inputting a plurality of color component signals generated by scanning an original, and a host computer comprising: Second input means for inputting the plurality of color component signals, and whether the image represented by the plurality of color component signals input by the first or second input means is a monochrome image or a color image Determining means for determining, and according to the determination result by the determining means,
Processing means for processing a plurality of color component signals input by the first or second input means.

[0007]

FIG. 1 is an example of an image processing system to which the present invention can be applied, which is a color system capable of reading a color document and reproducing a color image. A document 1 is placed on a transparent plate 2 of a document table and fixed by a document mat 3. Photosensitive drum 24, transfer drum 53
Rotates in the direction of the arrow to execute the color process. 12
Is a spectral dichroic mirror, and 14, 16, and 18 are CCDs that generate spectral signals B, G, and R by sensing spectral light. The lamp 8 and the mirrors 9 and 10 reciprocate to scan the original 1 and simultaneously output color signals B, G and R from each CCD to produce a Y signal for reproduction, and then reciprocate again to output an M signal. , The above scanning is repeated four times, and Y, M, C, and BK are sequentially performed.
Signals are formed, and a laser is controlled by the signals to form latent images of respective colors on the drum 24 in sequence. The latent images of the respective colors are sequentially developed by the developing units 36 to 39, and the transfer drum 53
The developed image is transferred to the upper paper, and the drum 53 is rotated four times, and is repeatedly transferred to the upper paper, thereby obtaining a full-color copy having halftones and intermediate colors.

The optical system emits light from the illumination lamps 5 and 6 and irradiates the original with light in combination with the light from the reflecting mirrors 7 and 8, and the reflected light is reflected by the moving reflecting mirrors 9 and 10. It passes through the lens 11 and passes through 12 dichroic filters. Here, the light is separated into light having a blue wavelength, light having a green wavelength, and light having a red wavelength. The decomposed light having the blue wavelength among the decomposed lights is received by the solid-state imaging device 14 through the blue filter 13. Similarly, light of a green wavelength passes through a green filter 15 and is received by a solid-state imaging device 16. The light of the red wavelength is received by the solid-state imaging device 18 through the red filter 17. That is, the original 3 is maintained while maintaining the optical path length by the movable reflecting mirror 9 moving integrally with the illumination lamps 5 and 6 and the movable reflecting mirror 10 moving in the same direction at a moving speed of 1/2 of the moving reflective mirror 9. Scanned,
Further, the image light scanned and color-separated through the lens 11 and the dichroic filter 12 is applied to the solid-state imaging device 1 of each color.
Images are formed on 4, 18, and 16. Each solid-state image sensor 14, 1
The outputs of 6 and 18 are subjected to signal processing through an image processing unit 27 to be described later.
Is output as a light output to irradiate the photosensitive member. Since the polygon mirror 22 is rotated by the scanner motor 23, the laser light is scanned perpendicularly to the rotation direction of the photosensitive drum 24. Further, a photosensor 64 is provided at a position 11 mm before the start of scanning of the laser beam on the drum, and when the laser beam hits the photosensor 64, a BD (beam detection) signal is generated. The BD determines the writing timing of one line by the laser, and also determines the output timing of one line of image data of the line memory.

The photosensitive drum 24 is negatively charged by a negative charger 25 supplied with a negative high voltage current from a high voltage power supply 25. Subsequently, when the document 1 reaches the exposure unit 26, the document 1 on the transparent plate 2 of the document table is illuminated by the illumination lamps 5 and 6, reaches the dichroic filter 12 via the movable reflecting mirrors 9 and 10 and the lens 11, and the blue filter 13 ,
The light is decomposed by the green filter 15 and the red filter 17 to form an image on solid-state imaging devices (CCD) 14, 16, and 18. The image output from these CCDs passes through the shading unit 104 for each color by the image processing circuit of FIG. 2 or FIG.
Gradation corrected, masking processing unit 109, UCR
The color processing is performed by the processing unit 119, the halftone reproduction processing is performed by the dither processing unit 124 and the multi-value processing unit 125, and the laser driver unit 126
Is output to the laser 21, and the laser light is imaged on the photosensitive drum 24. There, an electrostatic latent image is formed, enters the four color developing units 36, 37, 38, and 39 and is developed. Here, three colors are separated by one exposure scan, and the above-described processing is performed. The output of the UCR corresponding to each of B, G, R, and BK is B,
It is sequentially selected for each of G, R, and black BK scans.
Timing signals from the main unit control unit 69 (each UCR
The one-color-separated light signal in the image processing unit 27 is selected by the E signal to each gate corresponding to the output. Then, the developing device corresponding thereto is selected. The developing device selected there is performed by powder development using a magnetic blade method, and the electrostatic latent image is visualized. Then, a ghost mini lamp 40 for erasing the electrostatic latent image
Then, the negative latent image is erased by the negative post electrode 41 supplied from the negative voltage power supply 25 to erase the electrostatic latent image.

Next, from one of the upper and lower cassettes 43 and 44 selected from the operation unit 45, the sheet feeding rollers 46 and
The copy paper 48 sent by the rotation of the roller 47 passes above and below the first registration roller 49, 50, and is transferred from the conveyance roller 51 through the second registration roller 52 to the transfer drum 53.
Wrapped around. Then, the toner on the photosensitive drum 24 is transferred to the copy paper 48 by the transfer electrode 54. The copy paper 48 is discharged from the photosensitive drum 24 on which the transfer is completed by the high voltage generator 25 and the discharging electrode 55 supplied with a high voltage.

As described above, the printing operation is started almost simultaneously with the document scanning, and the printing time is short.

In the case of a normal color original, the above operation is repeated four times for four colors, and the transfer drum is rotated four times to superimpose each color. In the case of an original of only one color black, when it is detected that the original has only one black color at the time when one optical movement is completed as described later, processes such as G, R scanning, development, and transfer are performed. Is jumped to start a black image copying operation.
That is, in the case of a color original, the operation time for four colors is required, but in the case of a black one-color original, the operation time for two or one color can be reduced.

The copy paper which has been transferred twice or four times is peeled off from the gripper 57, is attracted onto the belt 59 by the transport fan 58, is guided to the fixing unit 60, is fixed, and is sent out of the apparatus.

2 to 6 show image processing circuit diagrams.

Hereinafter, common parts will be described. The light of the original separated into three colors by the dichroic filter 12 is C
When irradiating CDs 14, 16, and 18, the output is amplified by CCD substrates 101, 102, and 103 for each color and A / A
The data is D-converted, and eight bits are sent in parallel to the next shading unit 104 as one pixel data. When the incident light quantity of the CCD is the same (white), the CCD for three colors is further added so that the output data for each bit of the CCD becomes equal.
It is the shading unit 104 that corrects the dispersion of 14, 16, and 18 to eliminate it. This is RA
M and the configuration of the operation unit.
, And the data is used to access the RAM, and an appropriate output is output from the arithmetic unit.

The gamma correction unit 105 linearizes the gradation characteristics between input and output. The gamma correction unit 105 is provided for each color, and the optimal gamma curve is switched by the switches 106, 107, and 108 in the ROM pattern. Selectable. The reason that the upper 6 bits of the 8-bit data are processed and output data is that the processing in the significant level region is sufficient.

Next, the B, G, and R signals are simultaneously processed by the masking processing unit 109 to change the mixture ratio of each color component to perform color correction. As a result, signal correction suitable for the color tone of the developing toner can be performed. This calculation is performed by a coefficient multiplication ROM and an addition / subtraction ROM. The mixing ratio of each color is determined by changing the values (coefficients) of the switches 110 to 118. The reason why the calculated value is set to the upper 4 bits is that the calculated value is narrowed down to a significant area level. Each ROM is addressed by the input data and outputs data of the operation result. Each ROM outputs simultaneously for each color.

Next, in the UCR processing unit 119,
Each comparator COMP logically compares each color signal,
The minimum signal of B, G, and R is determined by the logic of each gate MiN. A value obtained by multiplying the minimum signal output from the MiN by an arbitrary coefficient according to the value of the switch 120 is defined as a black level signal. This value, which becomes the output of UCR BK, is subtracted from the signal of each color by each UCR circuit. As a result, black can be separately processed, black signals can be removed from B, G, and R, and color reproduction without turbidity can be achieved. The signal is
In the gate circuit, the select signal 121 from the control unit 69,
The signals are selected in synchronization with the color output timing by 122 and 123, and a signal of one color is sent to the dither processing unit 124. Then, each color signal is sequentially sent to 124 for each document scan.

The dither processing unit 124 accesses the dither ROM so that each color signal refers to a table with a deep signal, for example, a 6-bit signal per pixel, and converts an input signal into a binary signal of 0 or 1 per pixel. . Alternatively, as shown in FIG. 5 or FIG. 6, for example, data of dither ROMs 135 to 137 storing data of a dither pattern of a 4 × 4 matrix and input data are compared by comparators 138 to 140 for 1
Each pixel is compared and converted into a digital signal of 1 pixel bit of 1 or 0, and a halftone is expressed by 4 × 4 pixels. This makes it easy to modulate the laser. Dither ROM 13
Pattern of 5-137 can select arbitrarily by 91 _to 93 ₃ as shown in FIG. 5. Further, as shown in FIG. 6, the dither processing can be limited by the selector.

Next, this signal is stored in a read-write line memory for pixels of one line of a document, that is, one line of a print, and is output in synchronization with the DB. After that, the data is multi-valued by the multi-value processing unit 125, and the laser 21 is driven by the laser driver unit 126. Note that the dither processing unit is an R array having low threshold values.
It has an OM ₁ , a high array ROM ₃ , and an intermediate ROM ₂ , which compares the input signal with these ROM outputs simultaneously, places the output from each comparator into a line memory 141, latches it, and divides it into three equal pixels. . That is, one pixel data output from the ROMs _{1 to 3} is divided by the AND gate 142 by pulses having different widths of φ ₁ to φ ₃ (FIG. 13), and output corresponding to the ROM _{1 to} ROM ₃ respectively. Outputs one pixel data with different width. As a result, one beam can be represented by performing four pulse width modulations on the beam with the quaternary output. Thereby, halftone can be represented by one pixel. Note that the processing in FIGS. 2 to 6 is performed in real time (real time) almost simultaneously with the input of X, Y, and Z.
Made in. In other words, printing can be started almost simultaneously with document scanning, and color printing does not take much time. By the way, halftone reproduction by binarized dither can reproduce 16 gradations in the case of a 4 × 4 matrix. Therefore, since there are four halftone gradations by pulse width modulation,
A total of 64 gradations can be reproduced.

On the other hand, each UCR ROM corresponding to B, G, R
Are output to the black signal determination circuit 127-1 of FIG. Note that 127-1 is 12 through u, v, w in FIG.
7-2. The input here is 6BiT
Among the top 4 BiTs. This is because a color signal having a low density is ignored, and the color signal may be kept at 6 BiT.

In the memory 128-1, θ is stored at the address θθθ, and F is stored at all other addresses. For this reason 12
If there is no color signal in the UCR signal input to 7-1, θ
Is output if it is, and this is latched by the latch circuit 129-1, and the hold circuit 130-1 is synchronized with the clock.
To enter. The output _So is determined by the CPU of the control unit 69 by a program and contributes to the sequence control. This will be described with reference to the flowchart of FIG.

This flow is performed by the control unit CPU (69 in FIG. 1).
Which it has been programmed into the microcomputer, and outputs a RESET signal S _r immediately before the optical scanning for original scanning First, output to Q ₁ hold circuit 130-1 to Q
₄ is reset (step 1).

The first optical scanning completed until hold circuit if the color signals at least once during the 130-1 outputs S _o of outputs FF result OR gate 131 'to the H level.

The control circuit CPU checks this signal immediately after the completion of the optical scan (3) (4), and if it is an H level signal, performs a normal full-color copying operation (routine 5).

If the gate 131 remains at the L level, the original is determined to be a single color black, and the B, G, and R processes are omitted, and a sequence selection signal is output to complete the process only by the black copy operation (6). . Accordingly, a sequence controller (not shown) makes only the black developing device movable, forms a latent image, develops the image, and rotates the transfer drum once to release the gripper 57 and discharge the transfer paper.

In this case, when the scanning and developing processes are performed in the order of B, G, R and black BK, the process rotation for G and R is limited, so that the processing time for two colors is sufficient.

Further, a preliminary preliminary blank scan of the document is performed, and the color can be determined at the end of the scan, so that the development time for one black color is sufficient.

If the process is to be performed in the order of black, B, G, and R, the formation of the black latent image is completed at the time of color determination (at the end of scanning). Processing time for one color is sufficient.

When the input signal is other than black, B, G, R, Y,
Even if it is determined that the image is a monochrome image of either M or C, the sequence processing and the signal processing can be similarly omitted. This determination can be made by independently monitoring the outputs B, G, and R of the UCR and detecting that there is almost no output for any of the colors (described later).

In FIG. 2, reference numeral 127-2 designates a single color judgment. A part of the output of the ROM of each of the B, G, and R UCRs is input to a single color signal judgment circuit 127-2. What is input here is the upper 4 BiT out of 6 BiT. This is because a color signal having a low density is ignored, and the color signal may be kept at 6 BiT.

The OR gate 128-2 outputs L if there is no color signal in the UCR signal input to 127-2, and H if it does.
Is latched by the latch circuit 129-2, and is input to the hold circuit 130-2 in synchronization with the clock.
This output is soft-determined by the control unit CPU and contributes to sequence control.

This will be described with reference to the flowchart of FIG.

This flow is performed by the control unit CPU (69 in FIG. 1).
First, a RESET signal is output immediately before an optical scan for scanning a document.
Reset output Q ₁ to Q ₄ of the hold circuit 130-2 (step 100). Next, an optical preliminary scan is performed to expose the original (step 101).

Completion of optical preliminary scan (step 10)
2) If there is a color signal even once during that time, the hold circuit 130-2 outputs an H signal to an output terminal corresponding to the color signal. For example Q ₁ is when B color original is H, Q ₂ ~
Q ₄ becomes L.

The control circuit (69 in FIG. 1) checks this signal immediately before the start of the optical scan for reproducing each color (step 103), and if the signal is H, performs reproduction processing of that color (step 104). ). For example, when the original is blue B, a sequence selection signal is output so as to omit the green G, red R, and black reproduction processing and perform only the B reproduction processing. Therefore, the sequence controller (not shown) makes only the blue developing device movable and forms a blue latent image,
The latent image is developed, the blue image is transferred to the transfer paper on the transfer drum, and when one rotation for that is completed, the gripper 57 is released and the transfer paper is discharged.

In this case, when scanning and developing in the order of B, G, R, and black, the process rotation for G, R, and black can be omitted, and the processing time for one color is sufficient.

In this case, the main scan may be performed in steps 101 and 102. When the blue monochromatic image is found at the end of the scan, the formation of the blue latent image has been completed. Processing time for one color is sufficient.

In the case of only two colors, for example, in the case of a document of only B and G, the reproduction process of red R and black is similarly omitted.

In the case of full color, all of Q _{1 to} Q ₄ become H, so that all of steps 104 to 107 are executed.

In the type in which each of the four photosensitive drums is reproduced in the respective colors, the resist is taken on one sheet of paper, and the image is sequentially transferred, after the process of the specific color is completed, the paper feeding speed can be increased and the time can be reduced. Can be.

The present invention is effective even if the input signals of B, G, and R in FIG. 2 or FIG. 4 are from a host computer. The host and the CCD reader can be switched. In this case, if a monochrome command signal or a single-color command signal is added to the head of the transmission signal from the host, this is determined and it can be regarded as a black image or a single color. Further, even for a printer of one pixel and four dots type, it is effective to reduce the time for a printer having a difference between a monochrome process, a single color process and a full color process. Further, since the full-color signal processing step can be omitted, the image quality of black or another single color can be reproduced well.

A single color image (one each of B, G, R, black, etc.)
If the color is determined, the image can be recognized as a character image, and the dither unit can be output and output, without deteriorating the resolution. In this case, in FIG. 5, a static threshold value (three levels) is set in a dither ROM in order to reproduce a slight halftone using the pulse width modulation of the laser drive signal based on the four values.
Set by the signal a ₁ ~a ₃ for _{1 ~ROM 3} can be the pulse width modulation or intensity modulation.

By judging the output from the hold circuit 130 for each line and resetting it, a single color judgment can be made for each line, and selection control of signal processing such as sequential dithering can be performed. In addition, the determination can be performed every several pixels, and the above-mentioned selection control can be partially performed by making the synchronization accurate.

As described above, by determining a specific color such as black in a color system such as a color copying machine or the like, the copying time can be reduced from about 1/2 to 1/4 for a black original. Further, it is possible to perform signal processing for increasing the resolving power for characters and the like. Since the useless color signal processing is not performed, the quality of the specific color does not deteriorate.

Further, since processes such as unnecessary charging, laser irradiation, development, transfer, and cleaning of the photosensitive drum are prohibited, the life of the machine can be extended without giving unnecessary fatigue.

Further, since the image processing is selectively controlled by judging the color, the image quality is not deteriorated. The black determination is based on whether or not all the outputs after each color UCR process are at the peak level.
The determination is made based on whether or not the maximum value of the G and R signals (the signal after γ conversion) or the minimum value of the Y, M, C and (B, G and R) signals after the masking correction exceeds a predetermined level. In addition, it is also possible to omit the dither processing by regarding the image as a line image by the black determination and prevent the resolution from being impaired. It should be noted that the black determination further determines whether the black has a line drawing or a gradation.
In the latter case, dither processing can be performed using a matrix pattern different from the color.

Next, the determination of the halftone and the control of the halftone processing based on the determination of the halftone will be described with reference to FIGS.

The other signals branched after the masking processing are sent to the halftone judging circuit 127-3. Memory 128-3,
In each of 128-4 and 128-5, θ is stored in advance from addresses θθ to θF, 1 is stored in addresses 1θ to 2E, and θ is stored in advance in addresses 2F to 3F. This is 12
This is because when the bit in which 1 is set out of the 6 bits of the data to 7 is medium, 1 is output to indicate that halftone is present. Therefore, a memory that can be accessed with 6 bits is provided, and the addresses that can be accessed with 6 bits are 64 from θθ to 3F. The presence or absence of halftone is determined. Memory B
The 6BiT signal input to the 128-3 is 64 patterns from θθ when there is much light (the density of the original is low) to 3F when there is little light (the density of the original is high) depending on the intensity of the light input to the CCD. Change.

As an example, if the input data to 127 is θθ ~
When the signal of θF is a low density signal, when the signal of θ is 2 to 2E is an intermediate density, the signal of 2F to 3F is a high density signal. For example, when an intermediate density signal is input to the memory B, 1 is output, and otherwise, θ is output. This is latched by the latch circuit 129-3 and input to the hold circuit 130-3 in synchronization with the pixel clock. This hold circuit holds data until a reset signal is input. Therefore, if there is data between 1θ and 2E, the OR gate 131 outputs 1 (H). When the microcomputer of the control circuit 69 determines this, the dither processing shown in FIG. 6 is performed. If 1 (H) is not output, the dither processing is determined, the dither processing is terminated, and binarization is performed at a fixed threshold level. .

This operation will be described with reference to the flowchart of FIG. This flowchart is programmed in the ROM of the microcomputer of the control unit 69. A RESET signal Sr is output immediately before the optical scan (step 2).
00), the outputs Q _{1 to} Q ₃ of the hold circuit are reset. The operation of the mirror system is started to start the first optical scan. If there is an intermediate density signals even in that once during a scan, the hold circuit 130-3 latches 1, and its output, the output S ₁ of the result OR gate 131-3 becomes "H". When the control circuit 69 (FIG. 1) determines that the optical scan is completed (step 202), it immediately checks the signal (step 203). If the signal is an "H" signal, the control circuit 69 outputs the switching signal Sl = 0. Output to the selector, and the selectors 141 to 143
Switching to the 37 side (step 204), the dither processing is performed. If switches the selector 141 to 143 outputs Sl = 1 if S ₁ is "L" signal to the generator side of the fixed data 1F (step 205), to omit the dither processing.

Therefore, character images such as characters without halftones are not dithered, so that the resolution is not impaired.
In addition, halftone judgment is performed for all the color components, and if even one component has a halftone, dither processing is performed, so that color reproduction quality is good.

The first optical scan is not a scan directly related to the formation of a reproduced image, but is a pre-scan of an image at a high speed (no reproduction image is formed). You can keep it. The range for determining the intermediate density is 1 in the memory 128.
Not only the portion corresponding to θ to 2E but also the table can be freely determined by switching the memory of the table in which the storage pattern of 1 and θ is changed between θθ to 3F.

The circuit shown in FIG. 8 can be added to or replaced by x, y, and z in FIG. This means that a BD signal (a signal obtained by detecting the end of one-line beam scanning) from the beam detector 64 in FIG.
An appropriate count value (for example, a dither matrix of 4 ×
If 4), a RESET signal is output to the hold circuit 130 at 4. By inputting a signal S ₂ in that case the OR gate 131 directly to 144 as the switching signal Sl of FIG. 5 or FIG. 6, it is possible to perform sequential dithering if the intermediate density portion in every four lines. Therefore, the dither area value and the fixed area value can be selectively controlled for each area of every four lines.
In this case, a buffer capable of storing four lines of the gate output data of FIG. 2 or FIG. 4 is provided, and the output of this buffer is input to a dither circuit in order to perform dithering or binarization processing with a fixed range value. Thus, while scanning and printing the actual document, the halftone area and the character area can be distinguished and processed. In addition, in order to perform high-speed dither processing for other lines while determining halftone, a 4-line buffer
It can be used alternately for determination and processing.

With such a simple circuit, a document having an intermediate density or a portion thereof is subjected to dither processing to obtain a high-gradation print, and a document having no intermediate density is not subjected to dither processing to obtain a high-resolution print. be able to.

It should be noted that even if the input signals of B, G and R in FIG. 2 or FIG.
One is effective, and the connection between the host and the CCD reader can be switched as required at the X, Y, Z connection points. In this case, when a command signal without halftone is added to the head of the transmission signal from the host, the selectors 132 to 134 can be controlled to determine this and to omit the dither processing. Also, one pixel 4 bit type printer,
This example can be applied to a thermal printer and an ink jet printer.

In this embodiment, when the dither processing is to be ended, the laser drive signal is subjected to the pulse width modulation by the above four values, so that a slight halftone can be reproduced, and a low-level halftone (the dither is cut off by the parting). In some cases) can be reproduced. In addition, halftone determination can be performed for every several pixels, synchronization can be made accurate, and the above-described partial selection control can be performed.

FIG. 11 is a circuit diagram for inserting characters, numerals and the like into the above color image.

[0059] 200 is a character code generating means for generating a number as code data (e.g., the ASCII code), M ₁
Is a buffer memory for storing the code data at the same time as the code is generated. ADC ₁ is an address counter for controlling an address for writing and reading the memory. CG is a dot for characters and numerical values according to the code data read from the memory M _1. A well-known character generator that outputs as pattern image data, M ₂ outputs dot data from CG,
A buffer memory that stores the image data at the same time as the output, so that one pixel from the CG corresponds to one pixel of the image data.
That is, a dot pattern (bit pattern) for a plurality of characters and a plurality of numbers indicated by 0 and 1 is stored as a set of each character and each numerical value at a predetermined interval similar to the bit serial data of the reproduced image. You. ADC ₂ is the memory M ₂ write, the address counter for controlling an address to perform read, yet the timing of this read start, what determines taking process progression and synchronization of the color image data, on a color image Can be determined. 201
Is a signal input source for presetting its timing.
When the image processing according to FIG. 2 or FIG. 4 reaches the preset coordinates X and Y according to 1, reading from the memory M ₂ is started, and character output is performed in synchronization with the color reproduction output corresponding to the position after dither processing. That is why they are combined.

205 indicates that the output of the comparator 206 is "L".
(White, halftone), the CG dot output is set to “H”.
A gate that outputs (black) 204 is an inverter that outputs L (white) when the output of the comparator is “H” (black). The comparator 206 output A of the black component of FIG. 2 or FIG. 4, output is "H", when the following "L" at a certain level L ₁ or more. Therefore, a signal of the above level is output as a character image signal B in order to make the character image from CG white from the background color when the image has a dark background color, and to make the character image black when the tone is bright. This signal B is input to the OR gate 210 in FIG. 6, and is synthesized so as to overlap with the image data after the dither processing. In this case, since the inserted characters are not dithered, the resolution is not lost.

[0061] R / W signal writing, a read signal, the read signal of the memory M ₂ is black scans in synchronization with the black process, is applied to the black process, which is output as to form a black as a character. If the color image is a blue monochromatic image, and a character is to be inserted in red, the read signal is synchronized with the red processing so that the red signal is further executed and the B signal is output only during that step. Assigned to ₂ .

The address counter ADC ₂ counts the number of dots (CLK) and the number of lines in the image data processing in order to determine the read start timing of the memory M ₂ , and when the count value reaches preset X, Y by 201, in synchronism with the clock CLK to initiate reading of the memory M _2. The count of dots (pixels) is represented by bits (= C
LK) starts counting for each one-line end signal. The line counting starts with a beam detection signal BD in the laser scanner indicating the end of one line scan or an end signal obtained by counting bits for one line each time color data processing is started. 5 and 6 are also performed in real time (real time). In other words, the characters can be identified and the characters can be synthesized while the document scan and the print are executed substantially simultaneously.

[0063] The copying machine to attach a key or the transmission line 1 as shown in FIG. 12, when the code "1984" to the memory M ₁ is stored, CG converts it into a dot pattern in the memory M ₂ Store. After that, the above-described color data processing becomes possible (in this example, the original document can be scanned by the optical system. Unless there is a command input indicating that there is no insertion data, the original document scanning is prohibited until then). color data processing was started and preset coordinates X and black scan (fourth document scanning) the number of dots and the number of lines in the process of 201, reaches the Y, the B signal of the character to start the reading of the memory M ₂ C
The data is sequentially output in synchronization with the LK, input to the gate 210 in FIG. 6, is combined with the data before the multi-value processing after the dither processing,
A latent image of a black character is formed on a drum, and is transferred and synthesized with the previous color image to obtain a color print with characters. If necessary, it can be inserted in other color characters such as red and blue as described above.

However, a partly dark color (black) as shown in FIG.
When a character is added to a position having a background as a background, the background is automatically determined from the signal A, and a character signal without white is formed and output as a signal B as described above. This processing is based on a circuit configuration in which the synchronization relationship is accurately adjusted so that the color image processing can be achieved in real time. Note that the preset data 201 can be made by the key of the copying machine shown in FIG. 1 or transmitted code data. 200 may be a memory ROM storing a format having characters, key lines, and the like.

In the case where the background color is repeated in a short range, such as a stripe pattern, it may be rather unsightly if white blanks are processed in accordance therewith, and a delay circuit is provided at point W in FIG. Thus, whitening can be performed only when the base of the predetermined range is dark.

[0066] Incidentally, when adding a whole character in the white, it is necessary to determine the read timing of the memory M ₂ to allow the treatment in four colors each color image processing steps of the time for each color.

FIG. 14 shows a case where the combined image data after the binarization processing is transmitted to another printer without multi-value conversion.

In the figure, the selector 132 and the dither ROM 13
5, comparator 138, OR gate 210, latch,
The line memory 141 is the same as in FIG. However, the dither ROM 135 has a different dither pattern from that of FIG. It is selected by signal a. a is generated by a data transmission command from the key input unit in FIG. a
Is not a pattern dedicated to multi-valued conversion but a pattern dedicated to binarization.
This is a pattern in which halftone can be reproduced without the processing of B6, 137.

Therefore, by transmitting only the composite data of the output of the comparator 138 and the character signal B, it is possible to sufficiently transmit and reproduce a halftone color composite image.

FIG. 14 is a block diagram of the dither ROM 13 shown in FIG.
5 is set as described above, and a transmission circuit is added for the line memory 141 for storing data having a high density level.

Reference numeral 150 denotes a switch for switching between data transmission for printing and transmission, which is switched in the dotted line direction by the transmission command signal a. A run-length counter 151 counts the number of times "1" continues in the image data and a number of times "0" continues in the image data. 152 is an MH encoder that codes the image data according to the count data of the counter 151. 151 and 152 are image data. Is known in order to reduce the bit amount. A switch 153 is sequentially switched in synchronization with the document scan in FIG. 1 and the end of the encoding by 151 and 152, and is controlled by a signal b by the end of the encoding of the image data of each color component. Reference numeral 154 denotes a memory for storing each color component data coded corresponding to the switch 153 or the data of each color component sent thereto. B, G, R, and BK each have a storage amount of one page of the document. Has four memory parts. 155 transfers the data of the memory 154 to the transmission unit MO.
A switch for switching between sending to D and sending to the printing section. The switch is switched to a dotted line by a signal b due to data reception. M
OD 156 is a well-known high-frequency modulator for transmitting data to a remote place. DEMOD 157 is a known high-frequency demodulator that extracts data from the transmitted high frequency. Reference numeral 158 denotes a separator that determines the type of the transmitted data, outputs the data to the line MH when the data is an MH code, and outputs to the line AS when the data is an ASCII code (hexadecimal code). Also, MH
The code also determines whether it is a color B, G, R, or BK component, and outputs it to the corresponding line. Since the separator has command data indicating the type of data attached to the head of the transmitted data, it discriminates the command data and selects an output line. The ASCII code is character data such as characters, and is character data when a halftone image and a character image are transmitted serially at different times. Also, the MH code is such that the G-compatible code is sent after the B-compatible code is sent, and the data of each color component is sent serially. Each MH data is stored in the memory 154. 159-161 is M _1, CG in FIG. 12, the same character image generator and M _2,
Bit character image data C is output from the character code by the character generator. The character data C is combined with the transmitted halftone data by the OR gate 162 in a synchronized manner as shown in FIG. Reference numerals 163 and 164 denote a well-known MH decoder and a run-length counter for converting the transmitted MH code data into bit image data. A selector 163 determines whether data to be sent to the printing unit is decoded data or data obtained by scanning a document.

In the transmission mode, first, during the first scan of a document, the color processing signal corresponding to blue is binarized by the dither circuit 124 to be converted into 1-bit data per pixel. The combined data of this data and the character data is sent to the counter 1 via the switch 150.
51, which is sent to an MH coding circuit comprising a decoder 152, converted into an MH code of up to 36 bits, and
3 is stored in the memory B of the memory 154. Then, the high frequency is modulated by the modulator 156 using the data in the memory B and transmitted. When the transmission of the composite data for blue is completed, the document is scanned for the second time,
The color processing for red is performed, and the binarization processing and the synthesis processing are performed in the same manner as described above, stored in the memory, and transmitted.

As described above, the composite color data of the character and the scan color image is sequentially changed to B,
G, R, and BK are sent in this order. In this case, since an image having no halftone, such as a character in a scanned image, is not subjected to dither processing by the selector 132 as described above,
D can be transmitted while maintaining the resolution. Also memory 1
The 54 data can be sequentially filed on the optical disc for each color, and a plurality of pages of the document can be sequentially filed.

When it is determined in FIG. 2 and FIG. 3 that the document image is one component such as a black component, document scanning after the determination is prevented by the determination signal. Therefore, the combined data of the one-component data and the character data is only stored in the memory 154 and transmitted.

The dither ROMs 135 to 137 have different dither patterns for each color component so as not to impair the color quality. It is the gates 121 to 1 shown in FIGS.
Control signals B, G, R, and BK to port 23 E
, A 2-bit code signal K indicating a color component
Is performed by selecting a dither pattern.

Next, the received signal is sent to the data separator 1
According to 58, the data is transmitted by being divided into data lines for each color component and stored in a memory corresponding to each color. This data is sent to a decoder and a counter via the switch 155, and the code data is converted into serial dot bit data. The bit data is recombined with the character as necessary, sent to the selector 163, and stored in the line memory 141 for printing. Thereafter, laser printing is performed in the same manner as described above. Note that the character image C to be added can also be generated by a key operation in the receiving side system as shown in FIG. The character image C to be added if coming be separately sent as ascii code and MH image data, the code data is converted by the character generator CG ₂ via line AS is know as MH image by a separator 158 into a dot bit image Is done. Since the characters are transmitted as they are, the transmission efficiency is good and the time is short. As the character data and the character data in FIG. 12, there are sentence information created by word processing by key input or the like and management information such as date and time. The latter management information is printed after being added outside the area of the document image to be printed.
For this purpose, the output timing of the management information is preset in the address counter AD ₂ (FIG. 12).

If the received information is 8-bit data per pixel, which expresses a halftone by 8 bits, the separator 158
14 determines this by a command, sends it to the buffer 170, inputs the upper 6 bits of the data to A in FIG. 14, and inputs it to the dither circuit 124. Therefore, as described above, this signal is binarized by each of the dither ROMs 135 to 137 and stored in each line memory 141 as bit-serial image data. In this case, the selector 163 is set in a direction to send the scan image data to the printing unit. In this case, the character data C is synthesized via the OR gate 210. In the case of halftone data, pulse width modulation is also performed, and halftone reproduction is performed from both digital and analog data.

When the received image is full color, the address of the memory M4 is controlled so that the character data C is output in synchronization with the decoding operation of each color component code data. If a character image of a specific color is desired, the character image is output from the memory M4 in synchronization only with the decoding of the code of the specific component.

The MOD 156 contains one 8-bit parallel data for one data line or lineless transmission.
DEMOD to convert to serial data of bits
157 has a converter for converting the received 1-bit serial data into 8-bit parallel data.

FIG. 15 shows a case where a bit signal of a character image to be synthesized is added before the halftone determination in FIG. This can be achieved by inserting the circuit of FIG. 14 at point P in FIG. This is the line 2F of the higher 2 bits of the higher density of the 6 bits of the image signal from the masking circuit.
(Corresponding to .about.3F) to insert a character signal B (FIG. 12). As described above, the halftone determination circuit 127-3 determines whether or not data 1 is present in the middle bits 1θ to 2E of the 6 bits. Therefore, the character signals inserted in the 2F to 3F are not regarded as halftones, and are switched by the selectors 132 to 134 to be binarized not at the dither pattern level but at a fixed threshold level for each pixel. Therefore, this character signal is not subjected to dither processing.
That is, the bit character signal B is applied to the upper two bits of the data line via the OR gates 301 and 302 in FIG. 5 or FIG. 6, so that it is possible to insert a character of a darker level. Is not damaged. Each of the latches in FIG. 2 or FIG. 4 applies a data delay of about one bit for synchronizing image processing, and B, G, and R next to the point P are also several bits to about one line. This is a latch circuit that applies a delay.

FIG. 16 shows the case where the bit signal of the character image is disabled after the multi-value processing of FIG. FIG.
This can be achieved by inserting the circuit of FIG. This is a multivalued output, that is, the pulse φ _{1 in} FIG.
Imparting bit data B of the character image into a pulse width modulated pixel data (dot data) by to [phi] _3. When synthesizing the B signal in synchronism at this time phi ₁ and the image signal is added dark characters. That is, when the switch 310 in the figure is turned on, a pulse of the basic width is output from the AND gate 303 with φ ₁ , B, 310, and the gates 306, 3
This is added to the image signal line via a line 07.
Also, when switch 308 is turned on, φ ₃ of 1/3 pulse of φ ₁
, A character signal B is added to the image signal line. Therefore, a pixel having a width of 1/3 is added, and a character having a density of 1/3 is added. Thus, the switch 30
By selecting from 8 to 310, the density of the inserted character can be selected. With this method, the resolving power of the character image is not impaired because the pulse width in one pixel is changed. As described above, since character data can be added in synchronization with the black component or in synchronization with each color component, a single-color character such as a black character or blue can be inserted, and the density of the character can be controlled.

In each of the above examples, a part of the scan image can be canceled and a character image can be inserted into the canceled part. It is each OR gate 21
A data selector is provided in place of 0, and corresponding to the combining part,
This can be achieved by controlling the time of the selector in synchronization with the address counter. In this case, when the scan image is full color, the cancel portion is set to white, and black or monochrome characters can be formed therein.

In this embodiment, as shown in FIG. 4, halftone judgment and character synthesis can be performed before the document scan is completed, and printing can be started before the scan is completed. Therefore, the reproduction time of the synthesized image can be shortened. It is particularly convenient for color image reproduction. Also, since real-time color processing is used, less memory is required.

[0084]

As described above, according to the present invention, in an image processing apparatus having a plurality of input means, both a color image and a monochrome image can be efficiently processed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a color copying machine to which the present invention can be applied.

FIG. 2 is a circuit diagram of an image processing unit.

FIG. 3 is a circuit diagram of an image processing unit.

FIG. 4 is a circuit diagram of an image processing unit.

FIG. 5 is a circuit diagram of an image processing unit.

FIG. 6 is a circuit diagram of an image processing unit.

FIG. 7 is a flowchart for black determination, single-color determination, halftone determination, and processing based on the determination.

FIG. 8 is a flowchart for black determination, single-color determination, halftone determination, and processing based thereon.

FIG. 9 is a flowchart for black determination, single-color determination, and halftone determination, and the processing based thereon;

FIG. 10 is a circuit diagram of an image processing unit.

FIG. 11 is a circuit diagram of an image processing unit.

FIG. 12 is a view illustrating a reproduced image.

FIG. 13 is a pulse waveform diagram for pulse width modulation of a laser beam.

FIG. 14 is another image processing circuit diagram.

FIG. 15 is another image processing circuit diagram.

FIG. 16 is another image processing circuit diagram.

[Explanation of symbols]

 101 to 103 CCD substrate 104 Shading correction circuit 105 γ correction circuit 109 Masking circuit 119 Base color removal circuit 127-1, 127-2 Single color detection circuit 127-3 Halftone detection circuit

Claims (1)

(57) [Claims] A first input unit for inputting a plurality of color component signals generated by scanning a document; a second input unit for inputting a plurality of color component signals from a host computer; A determination unit that determines whether an image represented by the plurality of color component signals input by the second input unit is a monochrome image or a color image; and, based on a determination result by the determination unit, Processing means for processing a plurality of color component signals input by the first or second input means.