JPH0595471A - Method and device for processing picture - Google Patents

Abstract

PURPOSE:To revise a density of binary picture data by adopting plural picture elements for inputted binary picture data. CONSTITUTION:Reception information is entirely stored once to a memory 1 and picture data 101 in the information are expanded into bit data 102 by an expansion circuit 4 and also resolution data 104 are fed to a recording mode setting section 3 and the recording mode 106 is set together with the density data from a density setting section 2. A recording picture element generating section 5 extracts a picture element of the data 102 in the unit of a prescribed matrix including a noted picture element of the data 102 to be inputted and its surrounding picture elements to decide the magnification of the extracted noted picture element in the main scanning direction and in the subscanning direction based on the recording mode 106. Thus, the picture elements of the picture data outputted are decided depending on the state of the picture elements adjacent to the noted picture element according to the decided magnification and outputted to a printer 6. Thus, the density of the binary picture data is revised.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing method and apparatus for inputting binary image data, converting it into image data of a predetermined density and outputting it.

[0002]

2. Description of the Related Art Conventionally, when image information is printed based on binary image information such as a facsimile received image, the binary image is directly changed to black and white in correspondence with image data of "1" or "0". If they are recorded in correspondence with each other, they can be recorded only at a predetermined image density. In order to change the image density and perform printing with a printer of such a printing method, it is conceivable to change the shape of each dot to be printed to make the printing density variable.

[0003]

However, in such a system, it is difficult to change the recording density depending on the type of printer. Furthermore, when the recording density is changed by changing the recording dot size in this way, a gap occurs between adjacent dots, or when the recording density is increased, the image appears to be crushed. However, there is a problem that the image quality is deteriorated and the sharpness of the image is lost. However, in the printer capable of varying the density, there is an optimum dot size due to the relationship of resolution. Therefore, when the dot size is changed to change the density, a gap is generated between the adjacent dots or the overlap with the adjacent dots becomes large.

The present invention has been made in view of the above conventional example, and an image processing method capable of changing the density of binary image data by forming pixels of input binary image data with a plurality of pixels. And to provide a device.

[0005]

In order to achieve the above object, the image processing apparatus of the present invention has the following configuration.
That is, an image processing apparatus for converting binary image data into image data of a predetermined density and outputting the image data, comprising density setting means for setting an output density of the image data, a target pixel of the binary image data, and Extraction means for extracting pixels of the binary image data in a predetermined matrix unit including peripheral pixels of the target pixel, density values set by the density setting means, resolution of the binary image data, and converted image data. Magnification determining means for determining the magnification in the main scanning and sub-scanning directions of the pixel of interest extracted by the extracting means based on the output resolution of the pixel, the state of the pixel adjacent to the pixel of interest in the binary image data, and Pixel generation means for determining the pixels of the image data to be output according to the magnification determined by the magnification determination means.

In order to achieve the above object, the image processing method of the present invention comprises the following steps. That is, it is an image processing method for converting binary image data into image data having a predetermined density and outputting the image data, wherein the two pixels are input in a predetermined matrix unit including a target pixel of the input binary image data and peripheral pixels of the target pixel. The step of extracting the pixels of the value image data, the main scanning and the sub scanning of the extracted target pixel based on the density value of the output image data, the resolution of the binary image data and the output resolution of the converted image data. The method includes the step of determining the magnification in the scanning direction, and the step of determining the pixel of the image data to be output based on the state of the pixel adjacent to the pixel of interest of the binary image data and the magnification determined by the magnification determining means.

[0007]

In the above structure, the pixel of the binary image data is extracted in a predetermined matrix unit including the pixel of interest of the input binary image data and the peripheral pixels of the pixel of interest,
Based on the density value of the image data to be output, the resolution of the binary image data and the output resolution of the converted image data,
The magnifications of the extracted target pixel in the main scanning direction and the sub scanning direction are determined. In this way, the pixel of the image data to be output is determined based on the determined magnification and the state of the pixel adjacent to the target pixel of the binary image data.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing the internal structure of the facsimile apparatus of this embodiment. In FIG. 1, reference numeral 1 denotes an image memory, which is composed of, for example, a hard disk (HD). Reference numeral 2 denotes a density setting unit, which is provided with a slide switch capable of switching the image density between three levels of light (L), normal (N), and dark (D). Reference numeral 3 is a recording mode setting unit, 4 is a decompression circuit for compressed image data, 5 is a recording pixel generation unit, and 6 is a printer, which may be, for example, an inkjet printer using thermal energy. In addition, here
The following description will be given as a printer having a resolution of 400 × 400 dpi.

In the above configuration, a rough flow until the input binary image is output to the printer 6 will be described. First, the image data 100 sent through the G3 standard facsimile line has a resolution of 8 pel × 3.75 pel and 8 pel in the sub-scanning direction.
It is one of three types, x7.7pel and 8pelx15.4pel. These image data are MH or M
The received information is encoded by the R code, and all the received information is temporarily stored in the image memory 1. At this time, the resolution data 103 is also recorded in the image memory 1. The data stored in the image memory 1 is output according to an output instruction from a main control unit (not shown). Of these, the image data 101 is expanded by the expansion circuit 4 from the encoded image data 101 into bit data 102. At the same time, the resolution data 104 is sent to the recording mode setting unit 3 and the recording mode 106 is set together with the density data 105 set by the density selection slide switch of the external density setting unit 2. Thus, the expansion circuit 4
From the bit data 102 output from the recording mode setting unit 3 and the recording mode 106 output from the recording mode setting unit 3, image processing is performed by the recording pixel generation unit 5 and the recording pixels 107 form the recording pixels 107.
Is output to. The above-mentioned density selection slide switch is set by the operation of the operator.

FIG. 2 shows the setting conditions of the density mode set by the recording mode setting unit 3. Explaining the standard mode, for example, the resolution data of the received image is 8p.
When el * 7.7 pel and the density data is normal (N), the approximation mode is B _N. Further, when it is light (L), it is mode B _L , and when it is dark (D), it is mode B _D.
Thereafter, in accordance with this, a total of 9 types of respective modes are similarly determined. That is, the Arabic numeral A in each mode,
Each of B and C represents the resolution of the received image in the G3 facsimile standard, and each of the alphabets L, N, and D represents the density level of the output image made possible by the present embodiment. There are 9 types of modes.

FIG. 3 is a block diagram showing a schematic configuration of the recording pixel generating section 5 of FIG.

In FIG. 3, 7 is image dot data 10
2 is a page memory for storing one page and is composed of a dynamic RAM or the like. 8 is the page memory 7
In the bit image 108, a 3 × 3 matrix extraction unit composed of a total of 9 pixels consisting of 8 pixels around the _target processing pixel x _ij , 9 is an image processing unit, and a 3 × 3 matrix extraction unit 8
The image data 109 extracted in
0 is output. An image buffer 10 stores temporary data before outputting the recording pixels 110 recorded by the image processing unit 9 to the printer 6, and can store output image data for 64 lines.

With the above configuration, the A4 size image dot data 102 is stored in the page memory 7, and at the same time, the recording mode 106 is set in the image processing section 9. The image data in the page memory 7 is cut out by 9 pixels by the 3 × 3 matrix extraction unit 8 and output to the image processing unit 9. The data of 9 pixels input to the image processing unit 9 is processed in the recording mode, and the central pixel x _ij of the 3 × 3 matrix is converted into a recording pixel composed of a plurality of dots. By sequentially performing this operation, when all the A4 size image information is processed and output to the printer 6 and the printing of one page is completed, the image data of the next page is stored in the page memory 7 and the previous page is stored. It is processed in the same way as. The 64-line buffer 10 before outputting to the printer 6 is provided so as to be able to simultaneously output data of 64 dots in the vertical direction when outputting to a 400 dpi inkjet printer.

The image processing unit 9 processes the input 3 × 3 matrix image 109 according to the flowchart of FIG. Next, the operation of the image processing unit 9 will be described with reference to the flowchart of FIG.

First, in step S1, the recording mode is set, and then in step S2, when an output request to the printer is received, the resolution in the mode is checked and the process branches to each of the resolution modes A, B and C. (Steps S3 to S
4). In the processing routine steps S5, S6, and S7 of the resolution modes A, B, and C, the density modes L, N, and D are further processed according to the densities in the modes to generate print pixels.

5 and 6 show steps S5 to S7 of FIG.
5 is a flowchart for explaining the recording pixel generation process in each of the resolution modes A to C shown in FIG.
Is a flowchart showing the process, and FIG. 6 is a diagram showing the selected density pattern.

Resolution modes A (S5), B (S6), C
Within each processing routine of (S7), print pixels are generated along the flow of processing shown in FIG.

The image data entering each routine is branched according to the density modes L, N, D. First, in step S8, it is determined whether the density mode is N (normal), and N
If so, it is not necessary to change the density, so that step S2 is directly performed
7, pixel interpolation is performed to increase the main scanning direction by n times and the sub scanning direction by m times according to the resolution mode. The values of n and m in the resolution mode are as shown in FIG. 8, and the resolution of the received image γ _in × γ _im and the resolution of the output printer γ _on
× γ _om n ≈ γ _on / γ _in m ≈γ _om / γ _im where γ _in : input main scanning direction resolution γ _im : input sub-scanning direction resolution γ _on : output main scanning direction resolution γ _om : output sub It is the resolution in the scanning direction.

For example, in step S5, the resolution mode A shown in FIG. 8 is selected, and at this time γ _in ≉203.2 dpi.
(8 pel) and the printer resolution is 400 dpi (using a bubble jet printer), that is, γ _on = 400 d
pi, the main scanning direction magnification n = 400/20
3.2≈2.

Similarly, in the sub-scanning direction m, m = 4
00 / 95.25 (3.75 pel) ≈4. In other resolution modes B and C, the values shown in FIG. 8 are obtained by the same method.

Returning to the description of FIG. 5, if it is determined in step S8 that the density mode is not N (normal), the process proceeds to step S9, and it is checked whether the density mode is L (light). When the density mode is L, 3 × for the target pixel
It is determined which of the eight patterns 1 to 3 the pixel array of the matrix of 3 belongs to (steps S11 to S).
18), based on the result of the determination, recording pixels and pattern conversion are performed (steps S19 to S26). On the other hand, when the density mode is dark (D) in step S9, step S9
In step 10, the image data is inverted in black and white. Then, the process proceeds to step S11, and the same processing is performed as in the case where the density mode is L.

FIG. 6 (A) shows three pixels adjacent to the pixel of interest x _ij.
The state of the pixel matrix of × 3 is shown. FIG. 6 (A)
In the 3 × 3 matrix of, “□” is the white pixel of the received image,
“■” is the black pixel of the received image, and the pixel indicated by “X” is
The white or black pixels of the received image are shown. In addition, FIG.
In the recording pixels of (B) to (D), “□” indicates pixels that are not recorded by the printer 6, and “■” indicates pixels that are recorded by the printer 6. Note that when the density mode is D (dark), the white pixels and the black pixels are inverted as described above, so that “□” in the 3 × 3 matrix of FIG. 6A is used.
Indicates a black pixel of the received image, and "■" indicates a white pixel (pixel that is not recorded) of the received image. 6 (B) to (D)
The “□” in the above means a pixel recorded by the printer 6, and the “■” means a pixel not recorded by the printer 6.

FIGS. 6B, 6C and 6D show output pixels to the printer 6 corresponding to the resolution modes A, B and C, respectively. For example, when the target pixel x _ij is in the matrix state shown by (A) in FIG. _6A , the resolution mode A, that is, the pixel pattern shown by 53 in FIG. 6B is selected. This will be described in more detail. In the resolution mode A, as described with reference to FIG.
Since the magnification conversion of 4 times in the sub-scanning direction is executed,
The _target pixel x _ij indicated by (A) is 53 in FIG. 6 (B).
Then, it is converted into 2 dots in the main scanning direction and 4 dots in the sub scanning direction, that is, into a 2 × 4 matrix (x _{ij1 to} x _ij8 ). Moreover, the on / off state of the dots in the matrix indicated by 53 in FIG. 6B is determined by the on / off states of the peripheral pixels of the pixel of interest, and the dot on / off that does not make the peripheral pixel state feel uncomfortable. It is considered as much as possible.

For example, in the case of FIG. 6A in which the pattern of the 3 × 3 matrix of mode B _L is arranged diagonally to the upper right, the pixel of interest x _ij is indicated by 51 in FIG. 6C. As described above, conversion is performed so that a recording pixel is composed of three dots of x _ij2 , x _ij3 , and x _ij4 . Therefore, x
Not only the connection between the two pixels _{i + 1, j-1} and x _{i-1, j + 1} is not broken, but also the diagonal lines are removed, resulting in a smooth line. Hereinafter, even in the case of the patterns shown in (1) to (6) of FIG. 6A and the resolution modes A and C, pixel element conversion is performed so as to remove the recording pixels on the white pixel side instead of the adjacent black pixel side. Recording is performed so that the recorded pixels are smoothly connected.

Next, as described above, step S in FIG.
If it is determined in 9 that the density mode is not L, that is, if the density is D (dark), the black and white of the image data is inverted in step S10, and the same processing as when the density mode is L is performed. Although it is performed (steps S11 to S26), the density mode is again determined to be D in step S28, the process proceeds to step S29, and the black and white inversion of the image data is performed again. By performing such scanning,
When the black pixel is adjacent to the target pixel, it means that the black pixel side is recorded black. As a result, step S
In 27, the periphery of the black pixel becomes thicker than when the pixel is simply multiplied by a certain value.

Further, in the case of patterns other than those shown in FIG. 6A, since x _ij is simply multiplied by n × m, no gap due to dot omission occurs even in the case of a black surface.

FIG. 7 shows an example of recording pixels recorded with three kinds of densities of L, N and D after the series of steps according to the present embodiment described above.

FIG. 7A shows the recording mode B _N and FIG. 7B.
_Shows the case of the recording mode B _L , and FIG. 7C shows the case of the recording mode B _D. As is clear from the figure, in FIG. 7 (B), the corners of the diagonal lines are removed and the line becomes smoother than in the case of FIG. 7 (A). In addition, the vertical line is also thin, with the pixels of the left saturation missing, resulting in a pseudo "light" image. Also, in FIG. 7C, the corners of the diagonal lines are filled and become smoothly thick, and the vertical lines also fill the pixels on the left side,
It's getting bigger, and it looks like a "dark" image. In addition, in the case of FIG. 7, the description was made assuming characters, but
Similarly, in the image of the intermediate representation, the density change can be represented by decreasing or increasing the recording pixels.

In the present embodiment, only one example of the recording pixel generation is shown, and many other embodiments can be considered within the scope not changing the gist of the present invention.

For example, although the present embodiment has been described in the case of a facsimile machine, the present invention is not limited to this.
Of course, it can be applied to image processing in various information processing apparatuses such as personal computers and workstations.

Further, it is obvious that the printer 6 is not limited to the ink jet printer of 400 dpi, and its resolution and printer system are not fixed to this.

Further, in the recording pixel generator 5, 3 ×
Although the central pixel is operated by the matrix of No. 3, it is clear that the size of the matrix and the operation algorithm can be selected according to the purpose of use. Further, it goes without saying that the recording pixel generation performed by software can be realized by hardware logic.

Further, in the density selection section 2, the three-step densities are switched by the slide switch, but it is possible to increase the number of densities to be set according to the resolution of the printer and the received image. A touch panel switch or the like can also be used.

Further, the reception image memory of the facsimile may be a memory such as a RAM or a floppy disk instead of the hard disk.

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

As described above, according to the present embodiment, not only the density change based on the binary image information which is conventionally impossible or accompanied by the image deterioration can be prevented by preventing the image deterioration but also the character conversion can be performed. The effect is that smoothing of diagonal lines, which is often the case, can be done at the same time. Therefore, for example, in a binary image received by a facsimile machine, it is possible to print out an image with a density that the receiver likes or a density that is easy to read, and many other advantages not available in the past are provided. is doing.

The present invention brings excellent effects particularly in a recording head and a recording apparatus of a system utilizing heat energy among the ink jet recording systems. For the typical configuration and principle thereof, see, for example, US Pat.
What is carried out using the basic principle disclosed in the specification of 723129 and the specification of 4740796 is preferable. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). A thermal energy is generated in the electrothermal converter by applying at least one drive signal to the electrothermal converter, which corresponds to the recorded information and causes a rapid temperature rise exceeding nucleate boiling, to thereby generate a recording head. It is effective because the film is boiled on the heat-acting surface, and as a result, bubbles can be formed in the liquid (ink) in a one-to-one correspondence with this drive signal. Liquid (ink) is ejected through the ejection openings by the growth and contraction of the bubbles to form at least one droplet. If this drive signal has a pulse shape,
Since bubble growth and contraction are performed immediately and appropriately, it is more preferable because ejection of a liquid (ink) with excellent responsiveness can be achieved. As this pulse-shaped drive signal, US Pat.
Those described in US Pat. Nos. 4,633,359 and 4,345,262 are suitable. Incidentally, US Pat. No. 43131 of the invention relating to the rate of temperature rise of the heat acting surface
If the conditions described in the specification of No. 24 are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the discharge port, the liquid passage, and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications. US Pat. No. 4,558,333 and US Pat. No. 4, which disclose a configuration in which a heat acting portion is arranged in a bending region.
The structure using the specification of 459600 is also included in the present invention. In addition, Japanese Laid-Open Patent Publication No. 123670/1984 discloses a configuration in which a common slit is used as a discharge portion of a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy. The present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 138461/1984, which discloses a configuration in which the above is associated with the discharge portion.

[0040]

As described above, according to the present invention, the density of the binary image data can be changed by forming the pixels of the input binary image data with a plurality of pixels.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a relationship between a resolution and a recording mode in the facsimile apparatus of the embodiment.

FIG. 3 is a block diagram showing a schematic configuration of a recorded image generation unit of the facsimile apparatus of the embodiment.

FIG. 4 is a flowchart showing generation of a recorded image in the facsimile apparatus of the embodiment.

FIG. 5 is a flowchart showing generation of recording pixels for each resolution in the facsimile apparatus of the embodiment.

FIG. 6 is a diagram showing a recorded image dot array in each resolution mode corresponding to a 3 × 3 matrix pattern.

FIG. 7 is a diagram for explaining an example of a character recorded with varying density based on the recording pixel generation processing of the present embodiment.

FIG. 8 is a diagram showing a magnification of a recorded image in each resolution mode.

[Explanation of symbols]

 1 Image Memory 2 Density Setting Section 3 Recording Mode Setting Section 4 Decompression Section 5 Recording Pixel Generation Section 6 Printer 8 3 × 3 Matrix Extraction Section 9 Image Processing Section

Claims (4)

[Claims] 1. An image processing apparatus for converting binary image data into image data having a predetermined density and outputting the image data, wherein a density setting means for setting an output density of the image data, and the binary image data Extraction means for extracting pixels of the binary image data in a predetermined matrix unit including the pixel of interest and peripheral pixels of the pixel of interest, density values set by the density setting means, resolution of the binary image data, and conversion. Magnification determining means for determining magnifications in the main scanning and sub-scanning directions of the pixel of interest extracted by the extracting means based on the output resolution of the image data, and pixels adjacent to the pixel of interest in the binary image data. An image processing apparatus comprising: a pixel generation unit that determines a pixel of image data to be output according to the state and the magnification determined by the magnification determination unit. 2. A recording means for recording on a recording medium on the basis of the converted and output image data, wherein the output resolution is determined according to the recordable resolution of the recording means. The image processing apparatus according to claim 1. 3. The recording means is provided for each of a plurality of ejection ports for ejecting ink and corresponding ejection ports, and causes the ink to undergo a state change due to heat, and the ink is ejected from the ejection port based on the state change. 2. A thermal energy generating means for discharging and forming flying droplets.
The image processing device according to any one of 1 to 2. 4. An image processing method for converting binary image data into image data having a predetermined density and outputting the image data, wherein a predetermined matrix unit including a target pixel of the input binary image data and peripheral pixels of the target pixel. Based on the density value of the output image data, the resolution of the binary image data and the output resolution of the converted image data,
Image data to be output according to the step of determining the magnification of the extracted pixel of interest in the main scanning and sub-scanning directions, and the state of pixels adjacent to the pixel of interest of the binary image data and the magnification determined by the magnification determining means. And a step of determining the pixels of the image processing method.