JPH07273968A - Image processor - Google Patents

Abstract

PURPOSE:To perform processing matching character data by making the edge part of a character part high in resolution at the time of character composition into image data, preventing the gradations of the center part of the character part from being spoiled, and regarding resolution or gradations as important for the formation of the character data according to an area or the input source of the character data. CONSTITUTION:Image data read out by an image read part 27 are put by an external image composition part 3 together with image data from an external device 28, and the character data, etc., included in the image data read by the image read part 27 are colored by a character coloring part 5 through an outline and shade generation part 10 and composed as image data. A line number signal 18 is outputted from the character coloring part 5, area by area, and an image formation part 11 imposes pulse-width modulation for laser driving according to the line number signal 18 to adjust the resolution of the image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus, and for example, to an image processing apparatus for synthesizing a character signal and an image signal to form an image.

[0002]

2. Description of the Related Art In recent years, an image processing apparatus has been commercialized which forms an image by synthesizing a character signal and an image signal according to the value of the character signal.

The combining process of the conventional image processing apparatus as described above will be described with reference to FIG.

FIG. 10 is a diagram conceptually showing an image forming process of a conventional image processing apparatus. In FIG. 10, 201
Is a full-color image in which the original image is read by the scanner unit, and 202 is a character image in which the binary data original image is read in advance by the scanner unit and stored in the character memory. The conventional image processing apparatus uses the full-color image 2 described above.
01 and the character image 202 are combined to obtain the target combined image 2
It has a character synthesizing function to get 03.

Each pixel constituting the full-color image 201 shown in FIG. 10 has 8 bits for each of four color components of cyan (C), magenta (M), yellow (Y), and black (K), for a total of 32 bits. It is composed of. On the other hand, each pixel forming the character image 202 is composed of 1 bit, and the character portion has a value of "1" and the others have a value of "0". In the image synthesizing process in the conventional image processing apparatus, in the character image 202, the full-color image 201 is selected in the portion where the pixel is “0”, while the character image 20 is selected.
The portion where the 2nd pixel is "1" is colored by applying a predetermined color.

Further, the conventional image processing apparatus is a laser-type color electrophotographic apparatus for performing image formation on a plurality of output color components cyan (C), magenta (M), yellow (Y) and black (K) in a frame sequential manner. An image is formed by the method, and a halftone is realized by driving a laser with a signal obtained by pulse-width-modulating a combined image signal.

The above-described conventional image processing apparatus has, as a method for performing pulse width modulation, a first method for performing pulse width modulation in pixel units and a second method for performing pulse width modulation in units of a plurality of pixels. is doing. In the first method, since a pulse is output for each pixel, high resolution can be obtained. on the other hand,
In the second method, the resolution is low because a pulse is output for each of a plurality of pixels, but the amount of the pulse width that changes with changes in image data is larger than that in the first method.
It becomes easy to faithfully reproduce changes in image data. That is, high gradation can be obtained.

When the conventional image processing apparatus has a resolution of 400 dpi, the first method for performing pulse width modulation has a resolution of 40 dpi.
Since the resolution of 0 dpi is obtained, the first method is "40
It is called "0 line". On the other hand, in the second method of performing pulse width modulation, pulse width modulation is performed for every two pixels, so 200
A resolution of dpi is obtained. Therefore, the second method is "2
00 line ".

In the conventional image processing apparatus described above, FIG.
In the composite image 203 shown in (1), the character image portion is formed with 400 lines with emphasis on resolution, while the full-color image portion is formed with 200 lines with emphasis on gradation.

[0010]

In the above-described conventional example, when character composition is performed, all character parts are assumed to be 40, assuming thin line characters.
It was formed by the 0 line.

However, in the above-mentioned conventional example, since the character portion is formed by 400 lines, there is a drawback that the gradation of the character portion becomes poor. This low gradation is particularly noticeable for large characters.

Further, when a graphic such as a circle is supplied as the character data in place of a character and it is attempted to be colored, there is a problem that the intended color is not obtained because the gradation is low.

[0013]

The present invention has been made to solve the above-mentioned problems, and has the following constitution in order to solve the above-mentioned problems.

That is, a character signal input means for inputting a character signal, an image signal input means for inputting an image signal, a composite image signal by combining the image signal and the character signal according to the value of the character signal. An image processing device having a composite image signal generating means for generating a signal and an image forming means for forming an image from the composite image signal and outputting the image signal, and a first modulating means for performing pulse width modulation of the image signal in pixel units. Second modulation means for performing pulse width modulation of the image signal in units of a plurality of pixels, and the image forming means and the pulse width modulation signal modulated by the first modulation means and the second modulation means. Image formation is performed by using the pulse width modulation signal modulated by, and the image forming means modulates only the edge portion of the character signal by the first modulation method, and the center portion of the character signal is Characterized by modulating by the second modulation method.

Further, there is an area designating means for designating an image area, and a modulation method selecting means for selecting the first modulating means and the second modulating means according to the image area designated by the area designating means. The modulation method selecting means selects a modulation method by generating a signal for selecting a modulation signal, and the image forming means is modulated by the first modulating means selected by the modulation method selecting means. An image is formed using the pulse width modulated signal and the pulse width modulated signal modulated by the second modulating means.

Further, at least two character signal inputting means, and a modulation method selecting means for selecting the first modulating means and the second modulating means according to which character signal inputting means the character signal is inputted from. And the image forming means outputs the pulse width modulated signal modulated by the first modulating means and the pulse width modulated signal modulated by the second modulating means selected by the modulation method selecting means. It is characterized in that an image is formed by using it.

For example, it has a character signal generating means for generating a character signal, the image signal input means inputs an image signal by reading an image or by receiving it from an external device, and the character signal generating means causes the image signal to be input. A character signal is generated from the image signal input by the signal input means, and the character signal input means inputs the character signal generated by the character signal generation means.

Further, there is provided a character signal holding means for holding the character signal generated by the character signal generating means, and an image signal holding means for holding the image signal input by the image signal input means, The character signal inputting means reads out and inputs the character signal held in the character signal holding means, and the character signal generating means generates a character signal from the image signal held in the image signal holding means. .

Further, the character signal includes, in the reference character signal, a contour signal representing the contour portion and a shadow signal representing the shadow portion, and the composite image signal generating means performs coloring in accordance with the value of the character signal. Is characterized by.

[0020]

With the above structure, it is possible to provide an image processing apparatus in which the edge portion of the character portion has high resolution and the gradation of the central portion of the character portion is not impaired. Further, depending on the region or the input source of the character data, by selecting whether to form the character data with emphasis on resolution or with emphasis on gradation, it is possible to perform processing suitable for that character data. It is possible to provide the image processing device thus configured.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described in detail below with reference to the drawings.

<First Embodiment> FIG. 1 shows a block diagram of a full-color copying machine which is an image processing apparatus in this embodiment.

In FIG. 1, reference numeral 1 denotes an image processing apparatus main body, which is connected to an external device 28 via a cable 29.

In the image processing apparatus 1 of this embodiment, CC
The image reading unit 27 including D and the like reads a document image on a document table (not shown) to generate digital full-color image data 13. The image data 13 generated by the image reading unit 27 is sent to the external image combining unit 3. on the other hand,
The external device interface 2, which controls the interface with the external device 28, receives the digital full-color image data 14 sent from the external device 28 via the cable 29, and sends it to the external image synthesizing unit 3.

The external image synthesizing section 3 synthesizes both the above-mentioned image data and outputs them to the image processing section 4. In the external image synthesizing unit 3, depending on the character to be processed, only the image read by the image reading unit 27 is output to the subsequent stage, or
On the contrary, it is selectively executed whether to output only the image input from the external device 28 to the subsequent stage, or to output the image in which both are weighted and added and watermark-synthesized to the subsequent stage. . The external image synthesizing unit 3 switches these processes to be executed according to the area code 300 supplied from the area code generating unit 6. The image data 15 output from the external image synthesis unit 3 is an RGB signal, and each pixel is represented by 8 bits for each color component. The image processing unit 4, which has received the processed data from the external image synthesizing unit 3, converts the RGB signal into C
Image processing such as conversion into MYK signals is performed.

The CMYK signals output from the image processing unit 4 are output data 22 of the contour / shadow generation unit 10 which will be described later.
Via the delay unit 27 in order to synchronize with 23 and 24,
It is input to the character coloring unit 5. Then, the image data is subjected to a character area synthesizing process, which will be described later, in the character coloring unit 5, and is sent to the image forming unit 11 as the combined image data 17 to form an image for output.

The area code generator 6 is an area code 30 for identifying a plurality of areas in one page.
0 is output in synchronization with the image data 13 and 14.
The area is designated by using a known digitizer or the like, or by receiving area information represented by a command from the external device 28 or an external device (not shown). The area code output from the area code generating unit 6 is the external image synthesizing unit 3, the image processing unit 4, and the character coloring unit 5.
Is referred to by each processing unit, and each processing unit switches the type of processing to be executed according to this area code. That is, different processing is performed for each area.

Further, in the present embodiment, the image forming section 11
Is an electrophotographic color printer which forms an image sequentially on a plurality of output color components C, M, Y, and K.
Depending on which color component is formed by the image processing device 11,
One of the CMYK data is output from the image processing unit 4.

The multi-valued image data 13 read by the image reading unit 27 is also sent to the binarization unit 7 and converted into the corresponding binary data 19 by the binarization unit 7, and the selector 9 and the character / graphics. It is sent to the memory 8. The character / graphic memory 8 is 400 dp for the maximum document size (A3 in this embodiment).
It is a memory having a sufficient capacity to store 1-bit binary data of each pixel at a resolution of i.

The binary data written in the character / image memory 8 is separately read and supplied to the selector 9. On the other hand, the binary data 21 is also supplied from the external device 28 to the selector 9 via the external device interface 2. The selector 9 selects one of the above three signals according to the area code information from the area code generator 6 and outputs it to the contour / shadow generator 10.

A CPU bus 31 from a CPU 30 is connected to the character / graphics memory 8 so that the CPU 30 can control reading / writing of the contents of the character / graphics memory 8. Therefore, the content of the character / graphics memory 8 has a function of temporarily holding the image data read by the image reading unit 27, and also writes character data or graphic data input from an external device (not shown) by the CPU 30. Further, it is also possible to read it out and perform character combination in the character coloring unit 5 in the subsequent stage.

The character data developed by the CPU 30 in the character / graphic memory 8 is stored as a phone and data in a program ROM (not shown) in the form of a character code, for example, and the CPU 30 refers to this font data to generate raster data. And write it in the character / graphic memory 8. Similarly, for the graphic data expanded by the CPU 30 in the character / graphic memory 8, for example, when a circle is taken as an example, data of center coordinates and radius are held in a program ROM (not shown), and the CPU 30 calculates coordinates. While developing it into raster data, it is written in the character / graphic memory 8.

It should be noted that the original character data / graphic data to be expanded is input by the operator through an operation unit (not shown),
It is received as a command from the external device 28 via the external device I / F. The so-called PDL (Page Description Lang) is used as the character / graphic data received from the outside.
uage) Data may be handled. Further, in the present embodiment, the development is performed by the CPU 30, but this CPU 30
Alternatively, a dedicated drawing controller may be used.

The area code 300 supplied from the above area code generator 6 is delayed according to the delay of the image signal in each block to become 301 to 303. The area code 302 is the lookup table (LUT) 25.
Is converted into a selection signal to the selector 9. LUT
The selection signal output to the selector 9 in each area is stored in advance in the area 25, and is read under the control of the CPU 30 during operation and supplied to the selector 9.

In the contour / shadow generation unit 10, the binary signal (reference character signal) selected and output by the selector 9 is input,
A character signal, a contour signal, and a shadow signal, which will be described later, are generated. The generated characters, contours, and shadow signals are supplied to the character coloring unit 5, and the character combination described later is performed.

Next, referring to FIG. 2, the area code generator 6
2 for explaining the area code output from
A case where different processing is performed for the area 52 and the area 53 for the image data 51 of the page will be described. In this case, the area code generator 6 outputs the area code “1” for the area 52, the area code “2” for the area 53, and the area code “0” for the other areas. For example, if the area code is composed of n bits, the area code generator 6 has a page memory of n bits for each pixel, and the CPU 30 or the like controls writing / reading of the area code.

Next, the above-mentioned external image synthesizing unit 3 in FIG. 1 will be described in detail with reference to FIG.

FIG. 3 is a block diagram showing a detailed configuration example of the external image synthesizing section 3 in FIG. 1 described above. In FIG. 3, the input area code 300 is supplied to the LUT 61 and converted into a synthesis rate n. The LUT 61 stores in advance the combination rate in each area, and CP is used during operation.
The LUT 61 is read out by U30 and supplied to the multiplier 63 and the like. The multiplier 63 multiplies the image data 13 from the image reading unit 27 by the synthesis rate n obtained from the LUT 61 according to the area code 300.

On the other hand, the multiplier 64 multiplies the image data 14 input from the external device 28 by 1-n which is the complement of the synthesis rate n obtained by the complement unit 62. Multiplier 63
And the multiplication results in 64 are added in the adder 65, and the combined signal 15 is obtained.

In the present embodiment, the synthesis rate n is theoretically 0≤n≤1, and the synthesis signal 15 is: signal 15 = signal 13 × n + signal 14 × (1-n) In the circuit of m = 128 × n, that is, 0 ≦
As m ≦ 128, signal 15 = (signal 13 × m + signal 14 × (128−
m)) / 128.

Then, when only the image data 13 read by the image reading unit 27 is output as the combined signal 15, the combination rate n = 1 is set in the LUT 61. On the other hand, when only the image data 14 from the external device is output as the composite signal 15, the composite ratio n = 0 is set in the LUT 61. Further, in the case where both the signals 13 and 14 are watermark-synthesized by 50%, the synthesis rate n = 0.5 is LUT61.
Is set to.

As described above, since the composition rate n changes according to the area code, it is possible to arbitrarily change the image composition rate depending on the area to be processed. For example, in FIG. 2 described above, the area code “0” portion outputs only the image data 13 from the image reading unit 27, and the area code “1” portion outputs only the image data 14 from the external device 28. The area code “2” is the image data 13 from the image reading unit 27 and the image data 1 from the external device 28.
4 to output a 50% watermark composite image.
The UT 61 can be set.

Next, the contour / shadow generation unit 10 shown in FIG. 1 will be described in detail with reference to FIG.

FIG. 4 is a diagram showing the relationship between the contour / shadow signal generated by the contour / shadow generation unit 10 and the character signal. 4A and 4B show the relationship between the character signal and the shadow signal, and FIGS. 4C and 4D show the relationship between the character signal and the contour signal.

4A and 4B, the character indicated by the reference character signal 81 input to the contour / shadow generation unit 10 is delayed in the lower right direction 83 indicated by the arrow in the figure. As a result, either the flat shadow signal 24-1 shown in FIG. 4A or the stereoscopic shadow signal 24-2 shown in FIG. 4B is generated as a shadow signal.

4C and 4D, the character indicated by the reference character signal 81 input to the contour / shadow generation unit 10 is an outer contour of the character shown in FIG. 4C. Either the outer contour signal 23-1 shown in FIG. 4 or the inner contour signal 23-2 shown in FIG. 4D, which is the inner contour, is generated as the contour signal.

Which of the shadow signal and the contour signal shown in FIG. 4 is to be generated is determined by the register setting in the contour / shadow generation unit 10 in the present embodiment. This is, for example, the LUT6 shown in FIG.
Alternatively, the number may be switched for each area, as shown in FIG. These shadow signal and contour signal can be generated by line-delaying and pixel-delaying the reference character signal 81 and outputting it as it is, or by OR / AND processing with the data before the delay.

Note that the reference character signal 81 itself is also delayed and output as the character signal 22 because a delay occurs in forming the contour signal and the shadow signal in the contour / shadow generation unit 10, but this is explained in FIG. For simplicity, the delay of the reference character signal is not reflected.

Next, the image forming section 11 shown in FIG. 1 described above.
Will be described in detail with reference to FIG.

FIG. 5 shows the image forming unit 1 shown in FIG.
2 is a diagram for explaining a pulse width modulation method in FIG.

The pulse width modulation is to modulate the pulse width of the laser for forming an image in accordance with the size of the image data value, and the pulse width of the laser is changed so that the paper is finally changed. The average density per unit area of the toner image formed above changes. In this embodiment, as a method of performing pulse width modulation, there are a first method of performing pulse width modulation in pixel units and a second method of performing pulse width modulation in units of a plurality of pixels. In the first method, since a pulse is output for each pixel, high resolution can be obtained. On the other hand, in the second method, since the pulse is output for each of a plurality of pixels, the resolution is reduced, but the amount of the pulse width that changes with a change in the image data value is larger than that in the first method, so that the image It becomes easy to faithfully reproduce changes in data, that is, high gradation characteristics can be obtained. The image processing apparatus of this embodiment has four
Since the first method has a resolution of 00 dpi, and thus the first method can obtain a resolution of 400 dpi, the first method is called 400 lines. On the other hand, in the second method, since the pulse width modulation is performed for every two pixels, a resolution of 200 dpi can be obtained. Therefore, the second method is called 200 lines.

In the image forming section shown in FIG. 5, the image data 17 sent from the character coloring section 5 in the preceding stage is first subjected to gradation correction for correcting the characteristics of the image forming section 11 by the LUT 101, and then, Is converted into an analog signal by the D / A converter 102 and input to the A terminal of the comparator 104.

On the other hand, similarly, the line number signal 18 is input from the character coloring section 5. The line number signal 18 changes for each pixel,
The pixel is pulse width modulated with 400 lines, or 200
Indicate whether to use pulse width modulation with a line. This line number signal 18
Is input to the LUT 101 as an upper address, and the gradation correction processing in the LUT 101 is switched according to the pulse width modulation method.

On the other hand, the line number signal 18 is simultaneously set to 200/4.
It is also input to the 00-line triangular wave generation unit 103, and the line number signal 18
200/400 line triangular wave generator 103 to 20
Either the 0-line triangular wave or the 400-line triangular wave is output to the comparator 104. Comparator 1
In 04, analog image data 107 and triangular wave 106
And only the section where the image data 107 is larger,
The laser lighting signal 108 is set to "1". Laser drive unit 1
In 05, a laser 408 is generated according to the laser lighting signal 108.
Is turned on, the polygon mirror 410 scans in the horizontal direction, and the photoconductor 301 is illuminated.

FIG. 6 shows a 400-line triangular wave 10 generated from the 200 / 400-line triangular wave generating section 103 shown in FIG.
6-1, 200-line triangular wave 106-2 and image data D
A / A converted signal 107 and laser lighting signal 108 (1
08-1 and 108-2).

In FIG. 6, the section designated by e in 700 corresponds to one pixel, and FIG. 6 shows signals for four pixels. The resolution of the image processing apparatus of this embodiment is 400 dpi.

According to FIG. 6, 400-line triangular wave 106-1
Varies in units of 1 pixel, and as a result, the laser lighting signal 108-1 also becomes a signal modulated in units of 1 pixel. The laser lighting signal 108-1 is “1” for the sections a, b, c, and d in which the image signal 107 is larger than the triangular wave 106-1 in each pixel.

On the other hand, the 200-line triangular wave 106-2 fluctuates in units of 2 pixels, and as a result, the laser lighting signal 108
-2 is also a signal modulated in units of 2 pixels. The laser lighting signal 108-2 is a section a + in which the image signal 107 is larger than the triangular wave 106-2 in each two pixels.
It is “1” for b and c + d.

Two triangular waves 106 of 400 lines and 200 lines
-1, 106-2 is output for each pixel from the 200/400 line triangular wave generation unit 103 according to whether the line number signal 18 is "1" or "0" in FIG. Comparing the laser lighting signals 108-1 and 108-2 by these two triangular waves 106-1 and 106-2, the laser lighting signal 108-1 is turned off / on for each pixel, so that the laser lighting signal 108-1 is turned on / off. The resolution of the output image is better than that of 108-2. On the other hand, the laser lighting signal 108-2 is
The amount of change in the laser lighting time with respect to the amount of change in the original image signal 107 is about twice that in the case of the laser lighting signal 108-1. Therefore, the lighting time of the laser, the development process,
Image signal 1 because the resolution such as toner particle size is limited
The change of 07 can be reproduced more faithfully and the gradation is improved.

Next, the character coloring section 5 shown in FIG. 1 described above.
Will be described in detail with reference to FIG. 7.

FIG. 7 is a block diagram showing a detailed configuration example of the character coloring unit 5 shown in FIG. In FIG. 7, the area code 303 is input to the LUT 111 and converted into each control signal 121 to 127. Each control signal 121 to 127 in each area is stored in advance in the LUT 111, and is read by the CPU 30 shown in FIG. 1 during operation and supplied to the selector 115 and the like.

First, as the character signal valid signal 127, the character signal 22 input from the contour / shadow generation unit 10 is assigned to the priority determination unit 1
It is a valid signal to be output to 13. Similarly, the contour signal valid signal 126 and the shadow signal valid signal 125 are also valid signals for outputting the contour signal 23 and the shadow signal 24, respectively, to the priority determination unit 113.

In the present embodiment, the character signal 2 output to the priority determining section 113 by each of the above-mentioned valid signals.
2. When the contour signal 23 and the shadow signal 24 are “1”,
It is shown that each area has color data to be colored, and the color data is character color data 121, outline color data 122, and shadow color data 123, respectively. Each color data is supplied to the selector 115, and only the selected data is output from the selector 115 as described later. Each of these color data is composed of 8 bits, and by rewriting according to each color component of YMCK being formed in the image forming unit 11, it is possible to color each signal in full color.

The line number control mode signal 124 is a 2-bit signal, and the character area (the area in which the character signal, the contour signal, and the shadow signal are combined) has 200 lines, 400 lines, or will be described later. Only the edge of the character area is 40
A signal for selecting 0 line and 200 line at the center.

The character signal 22, the contour signal 23, and the shadow signal 24 whose output is controlled by the gate circuits 112a, 112b, and 112c in accordance with the valid signals 125 to 127 are prioritized by the priority determining unit 1.
By being input to 13 and prioritized, only one of the three signals is processed to be “1” or all “0”. For example, the character signal 22
When the character signal 22 is "1", the contour signal 23 and the shadow signal 24 are forcibly replaced by "0" regardless of their values.

The output from the priority determining section 113 is input to the encoder 114 and coded according to the combination of the values of the three input signals. The combination of the values of the three input signals has four states in which all are “0” and only one is “1”, and “0” to “3” for each state. Is assigned.

The signal 128 encoded by the encoder 114 has 2 bits and is supplied to the selector 115 as a selection signal. Therefore, in the selector 115, all of the character signal 22, the contour signal 23, and the shadow signal 24 are "0".
In the case of, the image data 16 read by the image reading unit 27 is selected. On the other hand, when the character signal 22 is "1", the character color data 121 output from the LUT 111 is selected, and when the contour signal 23 is "1", the contour color data 1 output from the LUT 111 is selected.
If 22 is selected and the shadow signal 24 is "1", L
The shadow color data 123 output from the UT 111 is selected. Therefore, the data output from the selector 115 is a combination of the character area including the character, the contour, and the shadow, and the image data read by the image reading unit 27.

The image data subjected to the character combination by the selector 115 is output as the image data 17 to the subsequent image forming unit 11 via the delay unit 116 in order to synchronize with the line number signal 18.

The 2-bit signal 128 output from the above-described encoder 114 is further OR-processed by the OR circuit 117, and the character area signal 12 indicating a character area is displayed.
It becomes 9. The character area signal 129 is "1" when any of the character signal 22, the contour signal 23, and the shadow signal 24 is "1", and is "0" otherwise. Character area signal 129
Is first input to one terminal of the AND circuit 118, and is ANDed with the 0th bit of the line number control mode signal 124 input to the other terminal, and the result 131 is the selector 120.
Entered in.

On the other hand, the character area signal 129 is also input to the edge extraction unit 119, and the edge portion of the character area is extracted and the edge signal 130 in which only the edge portion is "1" and other than that is "0" is output. , To the selector 120.
In the selector 120, the first line number control mode signal 124
Output 1 from AND circuit 118 when bit is "0"
31 is selected, and in the case of “1”, the edge signal 130 is selected and output as the line number signal 18.

Therefore, when the line number control mode signal 124 is "0", the line number signal 18 is always "0", and 200 lines are processed in all areas. When the line number control mode signal 124 is "1", the character area signal 129 becomes the line number signal 18 as it is, and the character area is 40.
The 0 line processing is performed, and the other 200 lines are processed. Further, when the line number control mode signal 124 is “2” or “3”, the edge signal 130 becomes the line number signal 18,
400 lines are processed in the edge part of the character area, and 2 in other cases.
00 line processing is performed.

An example in which images are combined in the image data 17 output from the character coloring unit 5 described above is shown in FIG.
Will be described with reference to.

FIG. 8A shows the contents represented by the character signal 22 which is a binary image input to the character coloring section 5,
This is a signal similar to the reference character signal 81 input to the contour / shadow generation unit 10. 8B shows an image obtained by coloring the image added with the contour or shadow generated by the contour / shadow generation unit 10 by the character coloring unit 5, and FIG. 8C shows the image processed by the image processing unit 4. The output color image is shown. Also,
FIG. 8D shows an image formed by combining FIG. 8B and FIG. 8C.

A hatched portion 93 in FIG.
-1 to 93-4 are character portions, the value of the character signal 22 is "1", and the other portions are "0". Corresponding to each character portion, the area 94-indicated by a broken line in FIG.
1 to 94-4 are set, and different image processing is designated for each area.

First, for example, in the area 94-1, the character coloring section 5 colors the character portion 93-1 in a predetermined manner to form an image 92-1 shown in FIG. It is combined with the color image 91 from the image processing unit 4 shown in FIG. 8C to form an image 99 shown in FIG. 8D. Further, regarding the area 94-2 shown in FIG. 8A, the contour / shadow generation unit generates the three-dimensional shadow unit 95 shown in FIG. 5
Then, different colors are added to the character portion and the three-dimensional shadow portion and are combined with the image 91 to form images 100-1 and 100-2.

For the area 94-3, the character portion 9
3-3, the contour / shadow generation unit 10 generates an outer contour portion 96, and the character coloring unit 5 generates a character portion 93-3 and an outer contour portion 9
6 is given a different color and is combined with image 91 to form image 1
01-1 and 101-2 are formed. Also, the area 94-4
Regarding the character part 93-4, the contour / shadow generation part 10
The outer contour portion 97 is generated by the above, and the character coloring portion 5 colors only the outer contour portion, and is combined with the image 91 to form the image 10
Form 2.

Incidentally, regarding the areas other than those described above,
The color image 91 from the image processing unit 4 is output as it is.

Next, how the image formation is controlled by the line number signal 18 output from the character coloring section 5 will be described.

In FIG. 9, when the line number control mode signal 124 is “2” or “3” in FIG. 7 described above, the edge portion of the character area signal 129 is processed by 400 lines, and the other is 200 lines. FIG. 4 is a diagram for explaining in detail how the processing is performed in step 1.

In FIG. 9, "1" and "0" indicate a character area signal, and "1" indicates a character area. Then, among the pixels of “1”, the pixels surrounded by the circles indicate the pixels extracted by the edge extracting unit 119 shown in FIG. 7 described above. The edge signal 130 output from the edge extraction unit 119 shown in FIG. 7 becomes “1” only for the pixels circled in FIG. 9, and as a result, only the pixels circled in these circles have 400 lines. Is processed in. On the other hand, the pixels other than the character area and the pixels other than the edge portion in the character area are processed by 200 lines.

The edge extracting unit 119 shown in FIG. 7 in this embodiment extracts only the edge in the main scanning direction as shown in FIG. 9, and it suffices to focus only on the change points of the data. It can be realized with a simple configuration.

As described above, by processing only the edge portion of the character area with 400 lines, the edge portion has a high resolution and the outline of the character is smooth.
On the other hand, by processing the central part of the character area with 200 lines, the gradation can be improved in the central part.

In this embodiment, as shown in FIG. 9, only the edge portion of the character area where the character area signal is "1" is 400
Although it is processed by the line, by processing the adjacent non-character region side, that is, the pixel whose character region signal is "0" by the 400 line at the same time, a higher resolution can be obtained at the edge portion. .

As described above, the character coloring unit 5 determines whether or not to perform character composition for each of the character signal, the contour signal, and the shadow signal in accordance with the area code 303, and whether or not to perform character composition for each signal. What kind of color is applied to the character area part, and the type of 400 line / 200 line switching process (200 lines, 400 lines, only the edge part is 400
Select the line) and process it.

The control of the processing of each area in the character coloring unit 5 will be described below. Each control is C
It is performed by the PU 30 based on a program stored in a ROM (not shown) or the like.

In the present embodiment, the processing setting for each area is determined by explicitly designating the processing for each area by an operator operating an operation panel (not shown) or a command from an external device. it can. For example,
When the type of the 400-line / 200-line switching process in the character coloring unit 5 is designated for each region, the character region part is processed by 200 lines in a region where graphic data such as a circle is treated as character data, Is the character area part 4
Optimal processing can be performed for each area according to the image, such as processing with 00 lines and processing only the edge portion of the character area portion with 400 lines for areas containing large characters.

Further, the character coloring section 5 for each area is made to correspond to the value of the selection signal for the selector 9 shown in FIG.
It is also possible to specify the type of the 400-line / 200-line switching process in (1) or perform automatic setting. That is, it is possible to switch the processing depending on which input source the character signal is supplied from. Then, when using the character / graphic memory 8 as a graphic memory,
By automatically setting all the areas to which the binary data is supplied from the character / graphic memory 8 to be processed by 200 lines, the operator does not need to specify each area.

As described above, according to this embodiment, the edge portion of the character portion is made to have high resolution at the time of character combination, and
There is an effect that the gradation of the central portion of the character portion can be maintained. In addition, depending on the area or the input source of the character data, it is possible to perform processing suitable for the character data by selecting whether to form the character data with emphasis on resolution or gradation. There is an effect that can be.

<Other Embodiments> In the above-described first embodiment, the edge portion of the character area signal including the character, contour and shadow signal is detected, and only the edge portion is processed by 400 lines. However, the edge part is detected for each of the character, outline, and shadow signal, and only each edge part is detected by 40
You may make it process by 0 line.

Further, in the above-described first embodiment, the image data is received from the external device such as the host computer through communication, but the image data is read from the floppy disk provided inside the image processing device. You may do it. Of course, a hard disk or the like may be used instead of the floppy disk, and image data created by an application program (not shown) may be transferred on the main memory.

Further, in the above-described first embodiment, a color scanner such as a CCD which reads an original placed on an original plate (not shown) is assumed as the image reading unit 27, but the present invention is not limited to this. , Film readers, digital video cameras, video image digitizers, image databases, hard disks, magneto-optical disks, C
Any image generation device such as a G (Computer Graphics) generation system may be used.

In the first embodiment described above, the electrophotographic color printer is assumed as the image forming unit, but an ink jet printer, a thermal transfer printer or the like may be used.

Further, in the above-described first embodiment, the image is transferred by using the so-called video interface that sends the image data in synchronization with the synchronizing signal as the external device interface 2, but this is transferred by GPIB or SCSI. You may make it transfer using general-purpose interfaces, such as. This general-purpose interface is also used when sending a print start command or the like to the image processing apparatus. In this case, generally, the transfer speed of the general-purpose interface is slower than the image forming processing speed of the image processing apparatus, so that an image memory for speed conversion is required in the image processing apparatus.

Further, in the image processing apparatus, the image forming section 11,
Although the example in which the image reading unit 27, the character / graphic memory 8 and the like are present has been described, these may be configured as an external device.

In addition, in FIG. 1 showing the configuration of the above-described first embodiment, it is possible to omit the external device interface 2, for example, and in that case, the image data read by the image reading unit 27 is used. By specifying the character area in, the gradation of the character area can be improved. If fixed character data is stored in the character / graphic memory 8 in advance, it can be combined with the image data without impairing the gradation.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0097]

As described above, according to the present invention, the edge portion of the character portion has a high resolution when the characters are combined, and
There is an effect that the gradation of the central portion of the character portion can be maintained. Further, depending on the region or the input source of the character data, by selecting whether to form the character data with emphasis on resolution or with emphasis on gradation, it is possible to perform processing suitable for that character data. There is an effect that can be done.

[0098]

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an image processing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a relationship between a region code and an image in this embodiment.

FIG. 3 is a block diagram showing a detailed configuration of an external image synthesizing unit in the present embodiment.

FIG. 4 is a diagram for explaining a relationship among a character signal, a contour signal, and a shadow signal in the present embodiment.

FIG. 5 is a diagram illustrating a detailed configuration and operation of an image forming unit according to the present exemplary embodiment.

FIG. 6 is a waveform diagram of pulse width modulation in the present embodiment.

FIG. 7 is a diagram showing a detailed configuration of a character coloring unit in the present embodiment.

FIG. 8 is a diagram for explaining image area composition in the present embodiment.

FIG. 9 is a diagram showing processing of an edge portion of a character area signal in the present embodiment.

FIG. 10 is a diagram showing a character synthesizing method in a conventional image processing apparatus.

[Explanation of symbols]

 2 external device interface 3 external image synthesizing unit 4 image processing unit 5 character coloring unit 6 region code generating unit 7 binarizing unit 8 character / graphic memory 9 selector 10 contour / shadow generating unit 11 image forming unit 25 LUT 27 delay unit 28 External device 30 CPU

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H04N 1/405 1/46 H04N 1/46 Z

Claims (9)

[Claims] 1. A character signal input unit for inputting a character signal, an image signal input unit for inputting an image signal, and a composite image signal by combining the image signal and the character signal according to the value of the character signal. An image processing device having a composite image signal generating means for generating an image, and an image forming means for forming an image from the composite image signal and outputting the first image, and a first modulating means for performing pulse width modulation of the image signal on a pixel-by-pixel basis. A second modulation means for performing pulse width modulation of an image signal in units of a plurality of pixels, wherein the image forming means and the pulse width modulation signal modulated by the first modulation means and the second modulation means. Image formation is performed using the pulse width modulation signal modulated by the image forming means, and the image forming means forms only the edge portion of the character signal in the first portion.
2. The image processing apparatus according to claim 2, wherein the central portion of the character signal is modulated by the second modulation method. 2. A character signal input means for inputting a character signal, an image signal input means for inputting an image signal, and a composite image signal by combining the image signal and the character signal according to the value of the character signal. In an image processing apparatus having a composite image signal generating means for generating a composite image signal and an image forming means for forming and outputting an image from the composite image signal, an area specifying means for specifying an image area, and a pulse of the image signal for each pixel First modulation means for performing width modulation, second modulation means for performing pulse width modulation of an image signal in units of a plurality of pixels, the first modulation means according to the image area designated by the area designating means, and the first modulation means A second modulation means and a modulation method selection means for selecting a modulation method by generating a signal for selecting a modulation signal, and the image formation means. Image formation is performed using the pulse width modulation signal modulated by the first modulation means and the pulse width modulation signal modulated by the second modulation means selected by the modulation method selection means. Image processing device. 3. At least two character signal inputting means for inputting a character signal, image signal inputting means for inputting an image signal, and combining the image signal and the character signal according to the value of the character signal. In an image processing apparatus having a composite image signal generating unit for generating a composite image signal and an image forming unit for forming and outputting an image from the composite image signal, first pulse width modulation of the image signal is performed in pixel units. Modulating means, second modulating means for performing pulse width modulation of an image signal in units of a plurality of pixels, the first modulating means and the second modulating means according to which character signal input means the character signal is input. A modulation method selecting means for selecting a modulation means, the modulation method selecting means selects a modulation method by generating a signal for selecting a modulation signal, and the image forming means is An image is formed using the pulse width modulation signal modulated by the first modulation means selected by the modulation method selection means and the pulse width modulation signal modulated by the second modulation means. Image processing device. 4. A character signal generating means for generating a character signal is provided, wherein the image signal inputting means inputs an image signal by reading an image, and the character signal generating means is inputted by the image signal inputting means. The character signal is generated from an image signal, and the character signal input means inputs the character signal generated by the character signal generation means.
4. The image processing device according to any one of 3 to 3. 5. A character signal generating means for generating a character signal is provided, wherein the image signal inputting means inputs the image signal by receiving it from an external device, and the character signal generating means inputs by the image signal inputting means. The image processing apparatus according to claim 1, wherein a character signal is generated from the generated image signal, and the character signal input means inputs the character signal generated by the character signal generation means. . 6. The character signal holding means for holding the character signal generated by the character signal generating means, wherein the character signal input means reads and inputs the character signal held by the character signal holding means. The image processing apparatus according to claim 4, wherein the image processing apparatus comprises: 7. An image signal holding means for holding the image signal input by the image signal input means, wherein the character signal generating means generates a character signal from the image signal held by the image signal holding means. The image processing apparatus according to claim 6, wherein 8. The image processing apparatus according to claim 1, wherein the character signal includes, in a reference character signal, a contour signal representing a contour portion and a shadow signal representing a shadow portion. 9. The image processing apparatus according to claim 1, wherein the composite image signal generating means colors in accordance with a value of the character signal.