JPH0584969A - Method and apparatus for image processing - Google Patents

Abstract

PURPOSE:To express an image in detail by performing printing of high image quality by smoothing a character or figure and also enabling printing of high image quality even with respect to a picture image expressed by binarized contrast medium and especially detecting scattered isolated dots (300 dpi) to subject the same to scattering processing in 600 dpi. CONSTITUTION:The dot data corresponding to first recording dot density are formed and the formed dot data corresponding to two or more lines are stored in line memories 6, 12 and subjected to interpolation processing according to the interpolation method selected according to the line in a main scanning direction or in a sub-scanning direction to form the dot data corresponding to second recording dot density.

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 converting image data output to a laser beam printer or the like. More specifically, the present invention relates to an image processing method and apparatus for converting the dot density when the dot density of the input image data and the recording dot density of the printer engine are different.

[0002]

2. Description of the Related Art In recent years, laser beam printers have been widely used as output devices for computers. In particular, low-density (for example, 300 dpi) laser beam printers are rapidly becoming popular due to their low price, compact size, and advantages.

For example, a laser beam printer for recording at a recording density of 300 dpi (dot per inch) comprises a printer engine section 51 and a printer controller 52 as shown in FIG. Printer engine section 51
Actually records on the photosensitive drum based on the dot data. Further, the printer controller 52 is connected to the printer engine unit 51, and is connected to the external host computer 5
4 receives the code data sent from 4 and generates page information consisting of dot data based on this code data,
The dot data is sequentially transmitted to the printer engine unit 51. The host computer 54 activates the application software by a program loaded from the floppy disk 55 having the application software, and functions as, for example, a word processor.

Many types of application software are currently created and used. Using these application software, users create and store a lot of data.

On the other hand, the printer engine section aims to perform higher quality recording, and the recording density has been increased, and a printer engine having a recording density of 600 dpi or higher has been announced in recent years. The printer controller connected to these high density printer engines (600 dpi) has a data memory having a capacity corresponding to each recording density (600 dpi). (Eg 600d
In the case of pi, it has 4 times the memory of 300 dpi).
Also, many application softwares are made exclusively for low-density printers, and these application softwares cannot be used as they are for high-density printers.

For example, in FIG. 2, the recording density is 300 dpi.
FIG. 3 is a diagram showing a dot configuration of the alphabet "G" for use with the same, and FIG. 3 is a diagram showing a dot configuration of the alphabet "t" for the same 300 dpi. If these characters are recorded with the dot structure as it is at a recording density of 600 dpi, the size of the characters becomes half in the vertical and horizontal directions.

Therefore, as one data interpolation method, the dot configuration is simply doubled in both the vertical direction and the horizontal direction.
There is a method of applying a dot configuration of 0 dpi to 600 dpi. When the conversion of the dot configuration is executed by this method, the size of the character does not have to be reduced as shown in FIGS. However, with this method, 300 dp
In comparison between the case of recording at i and the case of recording at 600 dpi, the jaggedness at the outline portion of the character is not improved. Therefore, it is not possible to realize the recording quality of characters that makes full use of the capabilities of the 600 dpi printer engine.

As another data interpolation method, there is known a smoothing technique for detecting a step in an image and smoothing the step.

According to the above-mentioned smoothing technique, the image quality can be improved for the recording in which at least two dots are continuously arranged in characters or figures. However, there is a drawback that the picture quality cannot be improved for the picture image, that is, the image by the dither method, the error diffusion method, or the like.

[0010]

Generally, in an image by a binary halftone method such as a dither method or an error diffusion method,
The image quality of the low-density portion and the high-density portion is lower than that of the medium-density portion. In the low density area, black dots smaller than one dot size (300 dpi in a 300 dpi engine) cannot be recorded, and in the high density area, it is also smaller than the one dot size. This is because it is not possible to record small white dots.

FIG. 6 shows an example of a spiral gray scale pattern. Further, FIG. 7 shows a case where a low density halftone is recorded using this gray scale pattern, and FIG. 8 shows a case where a high density halftone is recorded using the same pattern. As can be seen from these figures, isolated dots are represented as dots, and even if recorded at high print density,
It is recorded only as a dot having a size of 00 dpi, and cannot be said to have high image quality even for the purpose of expressing halftone.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and an object of the present invention is to convert characters recorded in a low recording density into a dot structure used in a high recording density. In addition to smoothing and recording high-quality images and graphics, it is also possible to record high-quality images even for picture images expressed by the binarized halftone method. In particular, the present invention has a low recording density (for example, 300 dp
An image processing method and apparatus capable of finely expressing the texture of an image by detecting a predetermined pattern scattered in the pattern data of i) and scattering the predetermined pattern in a high recording density dot configuration (for example, 600 dpi) The purpose is to provide.

[0013]

An image processing apparatus according to the present invention for achieving the above object has the following configuration.
That is, the storage means for storing the first image information having the first information amount for a plurality of lines, and the second information larger than the first information based on the image information of the plurality of lines stored in the storage means. When converting to the second image information having the information amount,
Pixel interpolation means for determining an interpolation pixel corresponding to a pixel position of the second image information, and based on the image information of a plurality of lines stored in the storage means when the interpolation pixel is determined by the pixel interpolation means. Detects a given pattern,
And a predetermined pattern dispersion means for determining the value of the interpolation pixel so that the predetermined pattern is scattered in the second image information when the predetermined pattern is detected.

The image processing method according to the present invention for achieving the above object has the following configuration. That is, the first
A storage step of storing a plurality of lines of the first image information having the information amount of, and a second information amount larger than the first information based on the image information of the plurality of lines stored in the storage step. A pixel interpolation step of determining an interpolation pixel corresponding to a pixel position of the second image information when converting into the second image information, and a memory step of storing when determining an interpolation pixel in the pixel interpolation step. A predetermined pattern is detected based on the image information of a plurality of lines that have been generated, and when the predetermined pattern is detected, the predetermined pattern is detected as a second pattern.
And a predetermined pattern dispersion process for determining the values of the interpolation pixels so as to be scattered in the image information.

[0015]

According to the above arrangement, the first image information having the first information amount is stored for a plurality of lines. Then, in order to generate the second image information having the second information amount, the second image information based on the plurality of lines of image information stored in the storage unit is generated.
The value of the pixel corresponding to the pixel position of the image information is determined by interpolation. At this time, when a predetermined pattern is detected in the first image information, pixel interpolation is performed so that the predetermined pattern is dispersedly arranged in the second image information. Then, this image processing device
By dispersing a predetermined pattern, the quality of a halftone image is improved.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

(First Embodiment) In this embodiment, a data conversion circuit for converting the dot density shown in FIG. 9 is provided between the printer controller 52 and the printer engine section 51 as shown in FIG. The inserted image recording device will be described. Therefore, in this example, the printer is configured as a part of the printer engine unit 51, but it may of course be part of the printer controller. Further, in this embodiment, the printer controller 52 sends out an image signal for 300 dpi, and the printer engine section 51 shows a data conversion circuit in the case of 600 dpi as an example. As is well known, the printer engine unit 51 includes a laser driver that modulates a laser beam based on an image signal (dot information), a scanner for scanning the beam, a photosensitive drum, and the like.

The printer controller 52 responds to the horizontal synchronizing signal HSYNC output from the horizontal synchronizing signal generating circuit 4 of the data conversion circuit, and outputs the image signal V for 300 dpi.
The DO and the image clock VCLK are sent to the data conversion circuit. The horizontal synchronizing signal generation circuit 4 sends a horizontal synchronizing signal based on a well-known BD signal which is a synchronizing signal in the main scanning direction output from the printer engine unit 51.

The printer engine section 51 uses a data conversion circuit to generate the image signal VDO for the recording density of 300 dpi.
And the recording density 60 generated from the image clock VCLK
Input a laser drive signal LD for 0 dpi, and record density 6
Recording is performed at 00 dpi.

FIG. 9 is a block diagram showing the configuration of the data conversion circuit of the first embodiment of the image recording apparatus according to the present invention. In the figure, reference numeral 1 is a frequency multiplication circuit, which multiplies the frequency of the image clock VCLK to obtain a clock VCLK 'having a doubled frequency. 5 is an oscillation circuit,
A clock L having a frequency four times that of the image clock VCLK
Generate CLK. 2 is a demultiplexer, which selects one of the line memory 6, line memory 7, line memory 8, line memory 9, and line memory 10,
It has a function of supplying the image signal VDO to the selected line memory. 4 is a horizontal synchronizing signal generating circuit,
The beam detect signal (BD signal) is counted, and the horizontal synchronizing signal HSYNC is generated once for the BD signal output twice.
Is output. The line memories 6 to 10 are controlled by the device control circuit 3 line by line based on the BD signal. That is, the image signal VDO is stored in one line memory.
Is written in synchronization with the clock VCLK ', image data is read from the other four line memories in synchronization with the clock LCLK. Further, while writing the image data to one line memory, the image data is read twice from the other four line memories. Writing and reading operations to this line memory are sequentially performed as follows. When the line memory 6 is writing, the line memories 7, 8, 9 and 10 execute a read operation. Further, at the next timing, the line memory 7 becomes a write operation and the line memories 8, 9, 10, 6 become a read operation. Further, at the next timing, the line memory 8 becomes a write operation and the line memories 9, 10, 6, 7 become a read operation.

The line memories 6 to 10 are 300d.
It has a memory capacity twice as large as the data in the main scanning direction of pi, that is, a data memory capacity in the main scanning direction corresponding to 600 dpi. Then, since the writing of the image data into each line memory is executed in synchronization with the clock VCLK ′ having a frequency twice the image clock VCLK, 30
The dot information of 0 dpi is doubled in the main scanning direction and written in these line memories. Therefore, 300d
The dot information of pi becomes the dot information of 600 dpi in the main scanning direction and is stored in the line memory. The signals read from the line memories 6, 7, 8, 9, and 10 are D1, D2, D3, D4, and D5, respectively.

A data selector 13 selects four line memories in the read operation among the read signals D1 to D5 of the line memories 6 to 10 and distributes them to predetermined outputs DS1 to DS4. Reference numeral 14 denotes a 4-bit demultiplexer, which alternately outputs the four output signals DS1 to DS4 from the data selector 13 to the discrimination circuits 1 and 2 described later for each BD signal. 1
Numerals 5 and 16 are discrimination circuits, which compare and discriminate the input image data of four lines and output the output signals Q1 and Q2, respectively, according to the result. The line memory 11 receives the output signal Q1 and the line memory 12 receives the output signal Q.
2 is a line memory for storing the same, and has the same memory capacity as the line memories 6 to 10. The writing and reading clocks of the line memories 11 and 12 are LC
LK is used. A data selector 17 selects either the signal D6 read from the line memory 11 or the signal D7 read from the line memory 12 and outputs it as a laser drive signal LD.

Control of writing and reading operations of the line memories 6 to 10 and the line memories 11 and 12, the demultiplexers 2 and 14 and the data selectors 13 and 1 are performed.
The control of selection of 7 is performed by the device control circuit 3. SEL is a logic selection signal (SEL signal) input to the determination circuits 15 and 16. This SEL signal can be used as follows, for example. That is, the external host computer 54 uses the SE depending on the type of image data.
The logic for interpolation is switched by setting the L signal.

The operation in the configuration of FIG. 9 described above will be described below with reference to the timing chart shown in FIG.

As described above, when the line memory 6 is selected by the demultiplexer 2, the line memory 6 performs a write operation (in FIG. 10, the line memories 6 to 10 selected by the demultiplexer 2 are LINE. M
Represented by EMORY 6-10). While the image signal data for one line is being written to the line memory 6 by the clock VCLK ′, the data for one line already stored from the line memories 7 to 10 are read out in synchronization with the clock LCLK. Is done once. At this time, the outputs DS1 to DS4 of the data selector 13 become D5, D4, D3 and D2 in order. The first read data DS1 to DS4 are input to the determination circuit 15 by the demultiplexer 14, and after predetermined processing, written in the line memory 11 as data Q1 (in FIG. 10, the determination circuit 15 selected by the demultiplexer 14). , 16 are represented by DCT15 and DCT16 respectively). Line memories 11 and 12
Writing and reading are performed alternately, and line memory 1
When 1 is a write operation, the line memory 12 is a read operation. The data D7 read from the line memory 12 is output as the laser drive signal LD by the data selector 17.

On the other hand, at the time of the second read operation of the line memories 7 to 10, the demultiplexer 14 inputs the data DS1 to DS4 to the discriminating circuit 16 and, after a predetermined process, writes the data DS2 to the line memory. Be done.

FIG. 11 shows the discrimination circuit 15 (1 of the first embodiment.
It is a block diagram which shows the structure of 6). In the figure, 1
Each of 8 to 21 is a 7-bit shift register, which inputs and shifts input signals DS1 to DS4, respectively. 22 (23) is a logic circuit which takes in the image data output from the shift registers 18 to 21 and performs a logical operation. That is, the input signals DS1 to DS4 are input to the shift registers 18 to 21, respectively, and the shift outputs of the shift registers 18 to 21 are the logic circuits 22.
The signal is input to (23), subjected to a predetermined process described later, and then output as an output signal Q1 (Q2). The processing in the logic circuit 22 (23) is different between the discrimination circuit 15 and the discrimination circuit 16, and the processing contents in the discrimination circuits 15 and 16 will be described below.

12 to 14 and FIGS. 15 and 16 are diagrams for explaining a logical operation method by the logic circuit 22 (23) of the first embodiment.

As shown in FIGS. 13 and 14, the logic circuit 22
When the SEL signal input to (23) is SEL = “0”, <logical expression 1> (FIG. 13) is selected as the logical expression of the discrimination circuit 15, and when SEL = “1”, <Logical expression 2> (FIG. 14) is selected as the logical expression of the determination circuit 15.

Further, in the case of this embodiment, the discrimination circuit 1
As the logical expression in the logic circuit 23 of No. 6, the logical expression of FIG. 16 is selected regardless of the SEL signal. In the discrimination circuit 15,
When SEL = “0”, the step difference of the image is detected, and the interpolation data for smoothing this is generated. SEL =
The interpolation operation in the case of "0" will be described.

FIG. 12 is a diagram showing the positional relationship between the pixel of interest and peripheral pixels. The number of each pixel in FIG. 12 (1A,
1B, ..., 4G) correspond to the numbers used in the logical expression in FIG. Therefore, these FIGS.
3 clearly shows the correspondence between the reference pixel and the logical expression when the data of a certain pixel of interest is interpolated. Further, each pixel has a value of "1" or "0", a pixel having a value of "1" is black, and a pixel having a value of "0" is white. Figure 1
5 and FIG. 16, the correspondence between the reference pixel and the logical expression is clearly shown, as described above.

In the discriminating circuit 16, the output signal Q is set according to the logical expression shown in FIG. 16, and interpolation data in the sub-scanning direction is created. That is, the pixels between the lines of the image data for 300 dpi (pixels at the positions sandwiched between 2D and 3D) are interpolated. Further, in the discrimination circuit 15, <logical expression 1 in FIG.
Pixel data at the 3D position is newly set in accordance with the logical expression shown in <>, and interpolation data in the main scanning direction is created.

These logics will be described below.

First, the processing for the horizontal step will be described. In FIG. 17A, 2G and 3B-3
If F is black recording information (“1”) and 2A is white recording information (“0”), it is determined that the pattern has a step and the pixel of interest Q is set to smooth the step. Black (“1”). A logical expression corresponding to this processing is shown in FIG.
And (B).

Similarly, in FIGS. 18A and 19A as well, it is determined that there is a step, and the target pixel Q is set to black ("1"). Further, logical expressions corresponding to the interpolation processes shown in (A) of FIG. 18 and (A) of FIG. 19 are shown in (B) of FIG. 18 and (B) of FIG. 16, respectively. By combining these logics, a dot configuration for 300 dpi having a step as shown in FIG. 20A becomes smooth as shown in FIG. 20B.

By combining the above-mentioned steps and the steps which are symmetrical to the left, right, up, and down, the same logical expressions as described above are combined to form a logical expression for interpolating a smooth image for the horizontal steps.

Next, in the vertical direction, this is also similar to FIG.
4A and 1E, 2E, and 3E are black recording information (“1”) and 1C is white recording information (“0”), it is determined that there is a vertical step. Then, the target pixel Q is set to black (“1”) in order to smooth the step. The logical expression corresponding to this processing is shown in FIG. Similarly, in the cases of FIG. 22A and FIG. 23A, it is determined that there is a step, and the data is interpolated in the same manner as above. 22B and FIG. 23B show logical expressions corresponding to the interpolation processes shown in FIG. 22A and FIG. 23A, respectively. Then, by combining the above-described step and the logical expressions for the left, right, up, and down symmetrical steps, the same logic is used for interpolation in the vertical direction.

Next, the interpolation in the main scanning direction will be described. The interpolation in the main scanning direction is interpolation for 3D lines. This is also black (“1”) only when a vertical step is detected by the same logic. As shown in FIG.
C, 2E, and 3E are black recording information (“1”),
When 2C is white recording information (“0”), it is determined that there is a vertical step, and the target pixel 3D is set to black (“1”) in order to smooth the step. The logical expression corresponding to this processing is shown in FIG. This also applies to all cases where the left and right sides are upside down. However, the target pixel is 3D
If the data of is black from the beginning, leave it as black. 300d by combining these logics
In the dot configuration for pi, a step having a step as shown in FIG. 25A becomes smooth as shown in FIG. 25B.

The above-mentioned <logical expression 1> of FIG. 13 and the logical expression of FIG. 14 include all the above logics. When "G" in FIG. 2 and "t" in FIG. 3 are interpolated based on this logic, the arc portion becomes smooth as shown in FIGS. 26 and 27, and the characteristic of 600 dpi can be exhibited. Like As described above, according to the recording apparatus, the interpolated dot information in the main scanning direction and the sub scanning direction is generated based on the dot information around the dot position to be interpolated among the dot information of the input image data. In this way, interpolation dot information having a recording dot density that is a predetermined multiple of the recording dot density of the input image data is generated. Based on the interpolated dot information generated in this way, printing is performed by the printer engine having the printing dot density of the predetermined multiple.
As described above, even if the application software for the low recording dot density is used as it is, the dot information developed for the low recording dot density is stored in the small capacity memory.
It is possible to obtain a high-quality image due to the high recording dot density by converting into dot information for a high recording dot density of a predetermined number.

Next, when SEL = "1", SEL
In addition to the logical expression of "0", the logic for detecting and distributing the isolated black dots is OR-synthesized. This logical expression is shown in <logical expression 2> of FIG. That is, SEL = “1”
In the case of, the logic for smoothing acts on data having continuous dots such as text and graphics.
Also, an isolated dot (300 dpi) is detected by the halftone expression by the dither method or the error diffusion method.
It has the effect of being scattered in the dots of pi. However, S
A logic for erasing isolated dots is added to the smoothing logical expression when EL = “0”.

For example, when an image by the dither method having the dot configuration of 300 dpi shown in FIG. 7 is processed by the above logical expression and converted into a dot configuration of 600 dpi, 300 dpi isolated dots are scattered as shown in FIG. .. In this way, the size of isolated dots, which is noticeable as a halftone, is reduced and scattered, so that high image quality can be achieved in the low density portion.

Further, from the above description, the logic selection signal SEL
Can switch the logic for interpolation by setting the SEL signal according to the following two types of image data.

The first is a case where the character data and graphic data to be handled do not include data represented by one dot. In this case, SEL = "1" is set, and smoothing processing of characters and graphics and the dither method are performed. And so on to perform dot diffusion processing of halftone images. The second is the case where the character or graphic data to be handled includes data represented by one dot.
In this case, SEL = “0” is set, and only the smoothing process of characters and figures is performed, and the dot diffusion process of the halftone image such as dither is not performed.

(Second Embodiment) FIGS. 29 to 32 are views for explaining a logical operation method according to the second embodiment. In the second embodiment, as shown in FIGS. 29 to 32, the method of changing the logical expression when SEL = 1 in the first embodiment is used. In this case, in addition to the logic of the first embodiment,
It also has the logic to detect isolated white dots and disperse them. Therefore, the isolated white dot (300 dpi) in the high density dither pattern as shown in FIG.
Similarly, the white dots of i can be scatteredly arranged, and high image quality in the high density portion and high image quality in the low density portion can be achieved.

(Third Embodiment) FIG. 33 is a block diagram showing the construction of the third embodiment of the image recording apparatus according to the present invention, and FIG. 34 shows the construction of the discrimination circuit according to the third embodiment. It is a block diagram.

In FIG. 33, circuits similar to those in FIG. 9 are assigned the same reference numerals and description thereof will be omitted, and only different circuits will be described below. Reference numerals 115 and 116 denote discriminating circuits according to the third embodiment. This discrimination circuit 115, 11
6 has a counter indicated by 51, as shown in FIG. This counter 51 has a clock signal LCL.
K is input (FIGS. 33 and 34) and clock signal LCLK is input.
Is counted N times (N is a natural number), α = 0, β
= 0 → α = 1, β = 0 → α = 0, β = 1 → α = 1, β =
The outputs α and β are controlled in the order of 1. The predetermined number N is selected to be N = 8, for example. In this case, α and β change in the above cycle every time LCLK is counted eight times. 1
Reference numerals 18 to 121 denote shift registers having the same functions as those of the shift registers 18 to 21 in FIG.
3) shows a logic circuit according to the third embodiment.

The logical expressions of the logic circuit 122 in FIG. 34 are shown in FIGS. 36 to 41. FIG. 35 is a diagram showing the relationship between the pixel of interest and the peripheral pixels. This diagram and FIGS.
The relationship with the logical expression shown in is the same as that of the first embodiment described above.

36 to 41 are diagrams for explaining the logical operation method according to the third embodiment, and FIG. 42 is a diagram for explaining the dot distribution pattern according to the third embodiment.

The logical expression in this case is basically a modification of the logical expression shown in FIGS. 13 and 14, and when SEL = 0, the same logical expression as <logical expression 1> of FIG. 13 is selected. (FIG. 36), and when SEL = 1, <logical expression 2> is selected (FIGS. 37 to 41).

When SEL = 1, smoothed data for data such as text and graphics and data in which isolated black dots are dispersed are O in the logic circuit 122.
R is synthesized. In particular, when the isolated black dots are dispersed, the values of α and β change every eight counts of the clock signal LCLK. Therefore, the logical expression of dispersion is γ1 → γ2 → γ3 → according to the values of α and β. It changes to γ4. γ
The logical expressions of 1 to γ4 are shown in FIGS. 38 to 41.

As a result, the regular dispersion pattern generated in FIG. 8 when the isolated dots are dispersed in the first embodiment can be made irregular and less obtrusive as shown in FIG. Therefore, the image quality can be further improved as compared with the first embodiment. In the third embodiment, an example of dispersion of isolated black dots has been described, but the idea described in the second embodiment is used to perform not only dispersion of isolated black dots but also dispersion of isolated white dots. Things can be easily achieved.

In the above third embodiment, the counter 51 may be reset for each scan by the main scan start point, that is, the BD signal.

In each of the above embodiments, a laser beam printer is used as an image recording device, but the invention is not limited to this.

Furthermore, in each of the above-mentioned embodiments, the isolated dot is one dot of 300 dpi, but the isolated dot is not limited to this.
It is also possible to detect an isolated dot of 2 dots of i as an isolated dot and disperse them.

As described above, according to each of the above-described embodiments, when the recording data for the low recording density is converted into the dot structure for the high recording density, the recording in which the characters and figures are smoothly expressed is performed. Not only that, but it is also possible to improve the image quality of the image by halftone expression such as the dither method.

[0056]

As described above, according to the image processing method and apparatus of the present invention, when converting the recording data for low recording density into the dot structure for high recording density, the binarized halftone is used. Even for the picture image represented by the method,
It becomes possible to record with high image quality.

[0057]

[Brief description of drawings]

FIG. 1 is a diagram showing a general image recording system.

FIG. 2 is a diagram showing a dot configuration example of an alphabet “G” having a recording density of 300 dpi.

FIG. 3 is a diagram showing a dot configuration example of alphabet “t” having a recording density of 300 dpi.

FIG. 4 is a diagram showing a dot configuration example of an alphabet “G” having a recording density of 600 dpi.

FIG. 5 is a diagram showing a dot configuration example of alphabet “t” with a recording density of 600 dpi.

FIG. 6 is a diagram showing an example of a spiral gray scale pattern.

FIG. 7 is a diagram showing a case where a low density halftone is recorded using a spiral gray scale pattern.

FIG. 8 is a diagram showing a case where a high density halftone is recorded using a spiral gray scale pattern.

FIG. 9 is a block diagram showing the configuration of the first embodiment of the image recording apparatus according to the present invention.

10 is a timing chart for explaining the operation of signals in the data conversion circuit of FIG.

FIG. 11 is a block diagram showing the configuration of the discrimination circuit of the first embodiment.

FIG. 12 is a diagram showing the relationship between a pixel of interest and peripheral pixels during interpolation processing in the main operation direction.

FIG. 13 is a diagram showing a logical expression when SEL = 0 during interpolation processing in the main operation direction.

FIG. 14 is a diagram showing a logical expression when SEL = 1 at the time of interpolation processing in the main operation direction.

FIG. 15 is a diagram showing a relationship between a pixel of interest and peripheral pixels at the time of interpolation processing in the sub-scanning direction.

FIG. 16 is a diagram showing a logical expression at the time of interpolation processing in the sub-scanning direction.

FIG. 17 is a diagram showing a detection state of a step in smoothing processing and a logical expression corresponding to the interpolation processing.

FIG. 18 is a diagram showing a detection state of a step in smoothing processing and a logical expression corresponding to the interpolation processing.

FIG. 19 is a diagram showing a detection state of a step in smoothing processing and a logical expression corresponding to the interpolation processing.

FIG. 20 is a diagram showing an interpolation result of smoothing processing.

FIG. 21 is a diagram showing a state of detecting a step in smoothing processing and a logical expression corresponding to the interpolation processing.

FIG. 22 is a diagram showing a detection state of a step in smoothing processing and a logical expression corresponding to the interpolation processing.

FIG. 23 is a diagram showing a detection state of a step in smoothing processing and a logical expression corresponding to the interpolation processing.

FIG. 24 is a diagram showing a detection state of a step in smoothing processing and a logical expression corresponding to the interpolation processing.

FIG. 25 is a diagram illustrating an interpolation result of smoothing processing.

FIG. 26 is a diagram showing an example in which the dot configuration for 300 dpi shown in FIG. 2 is interpolated for 600 dpi.

27 is a diagram showing an example in which the dot configuration for 300 dpi shown in FIG. 3 is interpolated for 600 dpi.

FIG. 28 is a diagram illustrating a dot dispersion pattern according to the second embodiment.

FIG. 29 is a diagram illustrating a logical operation method according to the second embodiment.

FIG. 30 is a diagram illustrating a logical operation method according to the second embodiment.

FIG. 31 is a diagram illustrating a logical operation method according to the second embodiment.

FIG. 32 is a diagram illustrating a logical operation method according to the second embodiment.

FIG. 33 is a block diagram showing the configuration of a third embodiment of the image recording apparatus according to the present invention.

FIG. 34 is a block diagram showing the configuration of a discrimination circuit according to the third embodiment.

FIG. 35 is a diagram showing a relationship between a pixel of interest and peripheral pixels at the time of interpolation processing in the main operation direction.

FIG. 36 is a diagram illustrating a logical operation method according to the third embodiment.

FIG. 37 is a diagram illustrating a logical operation method according to the third embodiment.

FIG. 38 is a diagram illustrating a logical operation method according to the third embodiment.

FIG. 39 is a diagram illustrating a logical operation method according to the third embodiment.

FIG. 40 is a diagram illustrating a logical operation method according to the third embodiment.

FIG. 41 is a diagram illustrating a logical operation method according to the third embodiment.

FIG. 42 is a diagram illustrating a dot dispersion pattern according to the third embodiment.

[Explanation of symbols]

 1 Multiplication circuit 2, 14 Demultiplexer 3 Device control circuit 4 Horizontal sync signal generation circuit 5 Oscillation circuit 6-12 Line memory 13, 17 Data selector 15, 16 Discrimination circuit 51 Printer engine section 52 Printer controller

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04N 1/387 101 8839-5C

Claims (13)

[Claims] 1. Storage means for storing a plurality of lines of first image information having a first information amount, and more than the first information based on the plurality of lines of image information stored in the storage means. When converting into second image information having a second amount of information, a pixel interpolating unit that determines an interpolating pixel corresponding to a pixel position of the second image information, and when determining an interpolating pixel in the pixel interpolating unit. To
A predetermined pattern is detected based on the image information of a plurality of lines stored in the storage means, and when the predetermined pattern is detected, the interpolation pixel is arranged so that the predetermined pattern is scattered in the second image information. An image processing apparatus, comprising: a predetermined pattern dispersion unit that determines a value of. 2. When determining an interpolation pixel in the pixel interpolating means, a step of an image is detected based on image information of a plurality of lines stored in the storage means, and when the step is detected, the step is detected. The image processing apparatus according to claim 1, further comprising a smoothing unit that determines a value of the interpolation pixel so as to be smooth. 3. A scaling unit that scales the first image information in the main scanning direction so as to correspond to the second information amount, and the storage unit is scaled by the scaling unit. The image processing device according to claim 2, wherein the image information corresponding to a plurality of lines is stored. 4. The pixel interpolating means corresponds to the pixel position of the second image information having the second information amount by performing a predetermined logical operation on the image information of a plurality of lines stored in the storage means. The image processing apparatus according to claim 2, wherein the interpolation pixel to be determined is determined, and the interpolation in the main scanning direction and the interpolation in the sub scanning direction are executed by different logical operations. 5. The storage means comprises a plurality of line memories for storing image information in a wider range than image information in a range required for the pixel interpolating means to execute processing, and the line interpolating means stores the line information. The image processing apparatus according to claim 2, wherein the next image data is written to another line memory while the image information is being read from the memory. 6. The predetermined pattern dispersion unit detects a predetermined pattern by performing a predetermined logical operation on image information of a plurality of lines stored in the storage unit, and the predetermined pattern is detected. The image processing apparatus according to claim 2, wherein the values of the interpolation pixels are determined so that the predetermined pattern is scattered. 7. The image processing apparatus according to claim 6, wherein the predetermined pattern distribution unit has a plurality of logical expressions for executing the logical operation and changes the logical expressions in a predetermined order. 8. The counting means for counting the number of pixels interpolated by the interpolation means is further provided, and the logical expression is changed when the count value of the counting means reaches a predetermined value. Item 7. The image processing device according to item 7. 9. A selection means for selecting either a first mode in which both the predetermined pattern dispersion means and the stage smoothing means are executed, and a second mode in which only the smoothing group is executed. The image processing apparatus according to claim 2, further comprising: 10. An image processing device inserted between a printer controller and a printer engine, wherein the first image information having the first amount of information input from the printer controller is stored for a plurality of lines. Means for converting the second image information into a second image information having a second information amount larger than the first information based on the image information of a plurality of lines stored in the storage means. Pixel interpolating means for deciding the interpolating pixel corresponding to the pixel position, and when deciding the interpolating pixel in the pixel interpolating means,
A predetermined pattern is detected based on the image information of a plurality of lines stored in the storage means, and when the predetermined pattern is detected, the interpolation pixel is arranged so that the predetermined pattern is scattered in the second image information. And a predetermined pattern dispersion unit that determines the value of the second image information, and outputs the second image information generated by the pixel interpolation unit and the predetermined pattern interpolation unit to the printer engine. .. 11. A storage process for storing a plurality of lines of first image information having a first information amount, and more than the first information based on a plurality of lines of image information stored in the storage process. A pixel interpolation step of determining an interpolation pixel corresponding to a pixel position of the second image information when converting to second image information having a second information amount, and an interpolation pixel in the pixel interpolation step To
A predetermined pattern is detected based on the image information of a plurality of lines stored in the storage process, and when the predetermined pattern is detected, the interpolation pixel is arranged so as to be scattered in the second image information. And a predetermined pattern dispersion process for determining the value of the image processing method. 12. When determining an interpolation pixel in the pixel interpolation step, a step in an image is detected based on image information of a plurality of lines stored in the storage step, and when the step is detected, the step is detected. The image processing method according to claim 11, further comprising a smoothing step of determining a value of the interpolation pixel so as to be smooth. 13. An image processing method for performing data conversion between a printer controller and a printer engine, the first image information having a first information amount input from the printer controller for a plurality of lines. When converting into the second image information having the second information amount larger than the first information based on the storing process to be stored and the image information of a plurality of lines stored in the storing method, the second image information A pixel interpolation step of determining an interpolation pixel corresponding to a pixel position of image information, and when determining an interpolation pixel in the pixel interpolation means,
A predetermined pattern is detected based on the image information of a plurality of lines stored in the storage means, and when the predetermined pattern is detected, the interpolation pixel is arranged so that the predetermined pattern is scattered in the second image information. And a predetermined pattern dispersion process for determining the value of ## EQU3 ## and outputting the second image information generated by the pixel interpolation process and the predetermined pattern dispersion process to the printer engine.