JPH11136518A - Processor and method for image processing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To convert inputted binary image data into high resolution and to output smooth multi-valued image data by performing multi-valued smoothing interpolation when a bit map of a character or figure whose resolution is given priority is outputted from external equipment. SOLUTION: When the bit map of the character or figure whose resolution is given priority is outputted from the external equipment, the multi-valued smoothing interpolation is performed. The external equipment 201 such as a personal computer is connected to a color copying machine through an external interface circuit. An image signal of the bit map outputted by the external equipment 201 is inputted to a pattern matching circuit 202 and pattern matching is performed. Then it is sent to a smoothing circuit 203 to smooth and interpolate jagged patterns of the outline part of the character or figure with data of doubled resolution. A color printer part 204 forms an image by a density reproducing method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image processing apparatus and method for inputting binary image data from an external device and outputting multi-valued image data subjected to smoothing interpolation.

[0002]

2. Description of the Related Art The resolution of a color copying machine for characters is generally 400 dpi, and printing is performed in units of 63.5 μm.

[0003]

However, when using the above-described color copying machine to output characters and graphics created by a personal computer (PC) or the like,
When rasterizing a vector image such as Postscript (PS), it was inevitable that there was a jagged feeling.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. An image processing for converting input binary image data to high resolution by smoothing interpolation and outputting smooth multi-valued image data. It is an object to provide an apparatus and a method.

[0005]

According to the present invention, there is provided an image processing apparatus for inputting binary image data from an external device and outputting multi-valued image data subjected to smoothing interpolation. Input means for inputting binary image data from an external device, pattern matching means for performing pattern matching on the image data input from the input means, and smoothing interpolation in accordance with the result of the pattern matching means. A conversion means for converting the binary image data into multi-valued image data; and an output means for outputting multi-valued image data subjected to smoothing interpolation by the conversion means.

Preferably, the conversion means converts the binary image data into multi-valued image data of N times resolution by performing smoothing interpolation when the pattern matching means matches a predetermined pattern. It is characterized by doing.

[0007] More preferably, there is further provided recording means for recording the multi-valued image data output from the output means.

According to another aspect of the present invention, there is provided an image processing method for inputting binary image data from an external device and outputting multi-valued image data subjected to smoothing interpolation. Input binary image data,
Performs pattern matching of the input image data, performs smoothing interpolation according to the result of the pattern matching, converts the binary image data into multivalued image data, and converts the smoothed interpolated multivalued image data. Outputting each step.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, an outline of the structure and operation of the color copying machine according to the present embodiment will be described.

FIG. 1 is a sectional view showing the structure of a color copying machine according to this embodiment. In FIG. 1, reference numeral 101 denotes an image scanner, which reads a document and performs digital signal processing. Reference numeral 100 denotes a color printer unit which prints out an image corresponding to the original image read by the image scanner unit 101 on a sheet in full color.

In an image scanner section 101, an original pressure plate 102 and an original platen glass (hereinafter, platen) 103
The document 104 placed between them is irradiated with the light of the halogen lamp 105. Then, the reflected light from the document 104 is guided to mirrors 106 and 107, converged by a lens 108, and an image is formed on a three-line sensor (hereinafter, referred to as a CCD) 110. Further, the lens 108 is provided with an infrared cut filter 131.

The CCD 110 separates light information from a document by full color information red (R), green (G), and blue (B) color sensor reading sensor arrays 110-1 to 110-3 and reads each color component. , Signal processing unit 1
09. Each color component reading sensor array 110
Each of -1 to 110-3 is composed of 5000 pixels. As a result, the shortest direction 2 of the A3 size document which is the maximum size among the documents placed on the platen glass 103
97 mm can be read at a resolution of 400 dpi.

The halogen lamp 105 and the mirror 106
Is the speed v and the mirror 107 is １ ／ v, the CCD 11
By mechanically moving in a direction (hereinafter, sub-scanning direction) perpendicular to an electrical scanning direction of 0 (hereinafter, main scanning direction),
The entire surface of the document is scanned.

Reference numeral 111 denotes a standard white plate, which generates correction data of the read data of the respective color component reading sensor arrays 110-1 to 110-3. The standard white plate 111 has a substantially uniform reflection characteristic with respect to visible light, and has a white color when visible. The output data of the visible sensors of the sensors 110-1 to 110-3 is corrected using the standard white plate 111.

The signal processor 109 electrically processes the read signal to separate it into magenta (M), cyan (C), yellow (Y), and black (BK) components. To the unit 100. One component of M, C, Y, and BK is sent to the color printer unit 100 by one original scan (scan) in the image scanner unit 101, and one original scan is performed by a total of four original scans. The printout is completed.

In the color printer unit 100, M, C, Y, B sent from the image scanner unit 101
The K image signal is sent to the laser driver 112. The laser driver 112 controls the semiconductor laser 1 according to an image signal.
13 is driven by modulation. As a result, the laser beam scans the photosensitive drum 117 via the polygon mirror 114, the f-θ lens 115, and the mirror 116.

Reference numerals 119 to 122 denote developing units, which are a magenta developing unit 119, a cyan developing unit 120, and a yellow developing unit 1.
21; a black developing device 122; four developing devices alternately contact the photosensitive drum 117;
The M, C, Y, and BK electrostatic latent images formed on the surface 7 are developed with corresponding toner.

Reference numeral 123 denotes a transfer drum which transfers the paper fed from the paper cassettes 124 and 125 to the transfer drum 1.
23, and the toner image developed on the photosensitive drum 117 is transferred to a sheet.

After the four colors of M, C, Y, and BK are sequentially transferred in this manner, the sheet passes through the fixing unit 126 and is discharged to the outside.

Next, the image scanner unit 101 will be described in detail. FIG. 2 shows a CCD according to this embodiment.
FIG. 2 is an external perspective view showing the external appearance of the embodiment. Where 110
-1 is a light receiving element array for reading red light (R), and 110-2 and 110-3 are light receiving element arrays for reading green light (G) and blue light (B) in order.

Each of the R, G, and B sensor rows 110-1
110-3 have openings of 10 μm in the main scanning direction and the sub-scanning direction. The three light receiving element rows having different optical characteristics are arranged in parallel with each other so that the R, G, and B sensors read the same line of the document, and are monolithically formed on the same silicon chip. ing.

By using the CCD 110 having such a configuration, an optical system such as a lens for each color separation reading is shared. This makes it possible to simplify the optical adjustment for each of the R, G, and B colors.

FIG. 3 is a sectional view of the CCD 110 shown in FIG. As shown in the figure, the CCD 110 has a photo sensor 110 for reading R on a silicon substrate 110-5.
-1 and a photosensor 1 for reading visible information of each of G and B
10-2 and 110-3 are arranged. An R filter 110-7 that transmits a red wavelength component of visible light is disposed on the R photosensor 110-1. Similarly, a G filter 11 is provided on the G photosensor 110-2.
A B filter 110-9 is disposed on the photosensor 110-3 for 0-8. Reference numeral 110-6 denotes a flattening layer formed of a transparent organic film.

FIG. 4 is an enlarged view of the light receiving element of the CCD 110 shown in FIG. R, G, B sensor rows 11
0-1 to 110-3 are 10 per pixel in the main scanning direction.
μm length, short side of A3 document (297mm)
Is composed of 5000 pixels in the main scanning direction so that can be read at a resolution of 400 dpi. The distance between the lines of the R, G, and B sensor rows 110-1 to 110-3 is 80 μm, and each line is separated by 8 lines for a sub-scanning resolution of 400 dpi.

Next, a method of reproducing the density of the color printer unit 100 according to the present embodiment will be described. In the present embodiment, the lighting time of the semiconductor laser 113 is controlled in accordance with a density signal of an image by a pulse width modulation (PWM) method well known in the art for density reproduction. As a result, an electrostatic latent image having a potential corresponding to the lighting time of the semiconductor laser 113 is formed on the photosensitive drum 117.
Then, by developing the latent image with toner in an amount corresponding to the potential of the electrostatic latent image in the developing devices 119 to 122, the density reproduction is performed.

Next, the image processing in the signal processing unit 109 will be described. FIG. 5 is a diagram for describing image processing in the present embodiment. Although FIG. 5 shows only processing related to the present invention, it goes without saying that general image processing of a color copying machine is also included.

In FIG. 5, reference numeral 201 denotes an external device such as a personal computer (personal computer), which is connected to a color copying machine via an external interface circuit (not shown). 202 is a pattern matching circuit described later,
Reference numeral 203 denotes a smoothing circuit, which is included in the signal processing unit 109 of the image scanner unit 101 shown in FIG. Reference numeral 204 denotes a color printer unit that forms an image by a density reproduction method.

First, an image signal of a bitmap output from the external device 201 is input to a pattern matching circuit 202, and pattern matching described later is performed. Then, the data is sent to a smoothing circuit 203, and smoothing interpolation is performed with double-resolution data between jagged patterns at outlines of characters and figures. The interpolation data is determined by referring to the density data of the surrounding pixels.

FIG. 6 is a diagram showing an example of an actual input image, and FIG. 7 is a diagram showing a result of smoothing.

Next, the above-described pattern matching circuit 20
2 will be described in detail. FIG. 8 is a block diagram showing a detailed configuration of the pattern matching circuit 202. In the figure, 301 is a line memory, 302 is a shift register, and 303 is a determination circuit.

Here, the image signal of 400 dpi is the image C
When the image dot data is sent from the external device 201 in synchronization with the LK, the image dot data is sequentially stored in the line memory 301 and, at the same time, of the dot data of the line memory 301, 11 dots of main scan × 9 dots of sub-scan The information is taken out to the shift register 302 as matrix information, sent to the determination circuit 303, and the feature of the dot matrix information is detected.

FIG. 9 is a diagram for explaining the pattern matching performed by the determination circuit 303 shown in FIG. Hereinafter, an algorithm for extracting the features of the dot pattern from the matrix area of 11 dots in the main scanning and 9 dots in the sub-scanning over the entire area of the matrix area and checking whether or not the dot pattern should be subjected to smoothing interpolation will be described. I do.

FIG. 9A shows a main scanning of 11 dots ×
A reference area of 9 dots in the sub-scanning direction, a, b, c, d, e, f, g, h, i, j, k in the main scanning direction, and 1, 2, 3, 3 in the sub-scanning direction. Each of the 99 pixels is represented by a matrix of 4, 5, 6, 7, 8, and 9. Here, 5f
Is a central pixel, and the central pixel 5f is a pixel to be changed for smoothing. (B) shown in FIG.
(A) is divided into 17 regions X1 to X8, Y1 to Y8, and 5f. Here, X1 is 3
d, 3e, 3f, 4d, 4e, 4f, and the area X2 is 3f,
3g, 3h, 4f, 4g, 4h, area X3 is 6d, 6
e, 6f, 7d, 7e, 7f, and likewise in the drawing.

As described above, each area is composed of 6 dots.
Area (X1 to X8), 6 areas (Y1, Y3, Y4, Y5, Y7, Y8) of 9 dots, 2 areas (Y2, Y6) of 10 dots, and a central pixel 5f can do. Here, the characteristics of each area are represented by Xn, Y
When all the dots in each area are the same, the feature of each area is set to “0”. When the dots of each area are different from each other, the feature of each area is set to “1”.

As described above, the characteristic of each area is X
1 to X8 and Y1 to Y8 are obtained. Then, the obtained feature is matched with a predetermined pattern, and according to the result, the smoothing circuit 203 replaces the predetermined pattern by dividing the predetermined density into two. Will be

FIG. 10 is a diagram showing an example of smoothing correction of a line of one pixel width of the rasterized density data 255. As shown in the drawing, by performing smoothing interpolation in accordance with the input pixel pattern, the target pixel is converted to double resolution, and the interpolation data is replaced with multi-valued data.

The predetermined pattern in the above-described pattern matching may be any pattern suitable for smoothing interpolation, and it goes without saying that the interpolation data to be replaced is not limited to that shown in FIG.

In the above-described embodiment, as a result of performing pattern matching according to the characteristics of the image, when converting the resolution, the density interpolation is performed at twice the resolution of reading. To remove jaggedness,
It is also possible to interpolate data at a resolution of N times (N is a natural number).

As described above, according to this embodiment, when outputting a bitmap of a character or a figure giving priority to resolution from an external device, multi-level smoothing interpolation is performed to achieve high gradation and high gradation. A high-resolution color copying machine can be provided.

[Other Embodiments] The present invention relates to a plurality of devices (for example, a host computer, an interface device,
The present invention may be applied to a system including a reader, a printer, or the like, or may be applied to an apparatus (for example, a copying machine, a facsimile machine, or the like) including one device.

Further, an object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the above-described embodiments to a system or an apparatus, and to provide a computer (CPU or MP) of the system or apparatus.
It goes without saying that U) can also be achieved by reading and executing the program code stored in the storage medium.

In this case, the program code itself read from the storage medium implements the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instructions of the program code, It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

[0046]

As described above, according to the present invention,
It is possible to convert the input binary image data to high resolution by performing smoothing interpolation and output smooth multivalued image data.

[0047]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of a color copying machine according to an embodiment.

FIG. 2 is an external perspective view showing a CCD 110 according to the embodiment.

FIG. 3 is a cross-sectional view of the CCD 110 shown in FIG.

FIG. 4 is an enlarged view of a light receiving element of the CCD 110 shown in FIG.

FIG. 5 is a diagram for describing image processing in the present embodiment.

FIG. 6 is a diagram illustrating an example of an actual input image.

FIG. 7 is a diagram showing a result of smoothing.

FIG. 8 is a block diagram showing a detailed configuration of a pattern matching circuit 202.

9 is a diagram for explaining pattern matching performed by a determination circuit 303 shown in FIG.

FIG. 10 is a diagram illustrating an example of smoothing correction of a line of one pixel width of rasterized density data 255.

Claims (5)

[Claims] An image processing apparatus for inputting binary image data from an external device and outputting multi-valued image data subjected to smoothing interpolation, comprising: input means for inputting binary image data from an external device; A pattern matching unit that performs pattern matching of image data input from the input unit; and performs smoothing interpolation according to a result of the pattern matching unit to convert the binary image data into multi-valued image data. An image processing apparatus comprising: a conversion unit; and an output unit that outputs multi-valued image data subjected to smoothing interpolation by the conversion unit. 2. The conversion means converts the binary image data into multi-valued image data of N times resolution by performing smoothing interpolation when the pattern matching means matches a predetermined pattern. The image processing apparatus according to claim 1, wherein: 3. The image processing apparatus according to claim 1, further comprising recording means for recording the multi-valued image data output from said output means. 4. An image processing method for inputting binary image data from an external device and outputting multi-valued image data subjected to smoothing interpolation, comprising the steps of: inputting binary image data from an external device; Pattern matching of the obtained image data, performing smoothing interpolation according to the result of the pattern matching, converting the binary image data into multi-valued image data, and outputting smoothed interpolated multi-valued image data. ,
An image processing method having each step. 5. The converting step converts the binary image data into multi-valued image data having an N-fold resolution by performing smoothing interpolation when the pattern matches a predetermined pattern in the pattern matching step. The image processing method according to claim 4, wherein: