JPH09174882A - Recording equipment and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable output of an image of a desired reduced size by a method wherein original image data are divided into a plurality of blocks on the basis of a set scale factor, pattern data on a reduced image are held for densities which the blocks in a plurality can take, and a pixel density on the reduced image corresponding to each block is determined. SOLUTION: On the occasion of a data conversion processing, first a reference area is determined in a determining part 35 on the basis of information on a set scale factor set by a scale factor setting part 26 and information on resolution of image data inputted by an image data input part 22. Next, image data corresponding to the reference area of the image data stored in a first memory 32 is extracted in an image extracting part 36. Besides, the number of ON dots wherein storage pixels are present is discriminated in a dot number discriminating part 37 and a mask pattern corresponding to the image data is selected from a table group 25a, in a mask pattern setting part 39. In a data conversion processing part 38, thereafter, a data conversion processing of the image data is executed with the mask pattern used and recording in a recording part 30 is controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus and method for reducing image data to record a reduced image.

[0002]

2. Description of the Related Art Generally, in a recording apparatus which is connected to a host computer or the like to record and output an image, image data consisting of bitmap information of pseudo halftone image by binarization or character code information is used. The character image data was received and the image was output.

Image image data is a method of pseudo representation of a halftone image by a binarized signal. For example, a threshold value of 16 gradations is pseudo-randomized and arranged on a 4 × 4 two-dimensional plane by the dither method or the like. Then, the multi-valued image signal is converted into a binary signal that determines the on / off state of the dots forming the pixels of the recorded image using the dither matrix in which the threshold value is arranged. As a result, it was possible to reproduce a halftone image with a pseudo gradation pattern even with a binary signal.

On the other hand, in the character image data, a character code is transferred to a recording device, and the recording device converts a character pattern corresponding to the character code inside the device and outputs a character image. Further, as a resolution conversion processing method of binarized image data, a method of simply thinning out pixels of an original image and a method of performing thinning processing by complementation using logical operation processing are known. Was there.

[0005]

However, when the above method is applied to the character image data having no gradation, only the disappearance of the fine line is taken into consideration, so that the above processing method causes much deterioration. I didn't. However, if the reduction ratio increases when applied to the image data, the pseudo gradation pattern that reproduces the gradation of the halftone and the thinning pattern are likely to match, and the data is missing and the gradation of the halftone image is lost. The sex was impaired. In addition, there was a problem that the image disappeared completely or was crushed.

For example, when the reduction processing of 1/2 is taken as an example, when the reduction processing is performed by simply thinning out the pixels of the original image corresponding to the hatched portion in FIG.
In the case of (a), the data of the on-dot portion is completely lost as shown in FIG. 20 (b). That is, the image becomes image data of only the off-dot portion, and the image has disappeared. On the other hand, when the original image is as shown in FIG. 20 (c), as shown in FIG. 20 (d), all the data in the off-dot portion disappears, and only the on-dot portion becomes image data, and the image is crushed.

Further, there is a problem that the color tone of the color image after data conversion is completely different from that of the original image. Further, according to the method disclosed in Japanese Patent Laid-Open No. 62-164368, a halftone image density value is estimated from the number of white pixels and the number of black pixels in a predetermined area of the original image, and dithering is performed again to reduce the reduced image. There is a way to get. However, in order to preserve the gradation of the original image, it is necessary to secure a large storage area for obtaining the halftone image density value, which causes a problem that the processing load increases.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a recording apparatus and a method thereof capable of outputting an image of a desired reduced size while maintaining the reproducibility of a halftone image. There is. Another object of the present invention is to provide a recording apparatus and method capable of outputting an image of a desired size while maintaining the color tone of an original image in color recording.

[0009]

The recording apparatus according to the present invention for achieving the above object has the following arrangement. That is, a recording device for reducing the image data to record a reduced image, the original image data having a predetermined number of pixels based on the setting means for setting a desired magnification and the magnification set by the setting means. Dividing means for dividing into a plurality of blocks, holding means for holding the pattern data on the reduced image for each of the densities that the plurality of blocks can have, and calculating means for calculating the density for one of the plurality of blocks. And an acquisition unit that acquires the pixel density on the reduced image corresponding to the block with the pixel density at the position corresponding to the block on the pattern data corresponding to the density obtained by the calculation unit.

Further, preferably, an error between the density of the block processed by the calculating means of the original image data and the density of the block having a predetermined number of pixels on the reduced image corresponding to the block is not processed. A distribution means for distributing the blocks to the data is further provided, and the density of the block of the original image data obtained by distributing the error is calculated as the density of the block of the original image data. This is because the density is saved by distributing the error and using the distributed density as the calculated density.

Further, preferably, the distribution means adds the error to a block adjacent to a block of the original image data processed by the calculation means. Further, preferably, the distribution unit multiplies the error by a predetermined amount according to a distribution destination and distributes the error to blocks around the block processed by the calculation unit of the original image data.

Further, preferably, the distribution means has a plurality of distribution destinations of the error and a plurality of patterns of a predetermined amount corresponding to the distribution destinations, and selects one of the plurality of patterns based on the original image data. A selection means is further provided. This is because gradation reproducibility can be further improved by selecting the optimum pattern for the original image data.

A recording method according to the present invention for achieving the above object has the following configuration. That is, a recording method of reducing image data to record a reduced image, the original image data having a predetermined number of pixels based on a setting step of setting a desired magnification and a magnification set in the setting step. A dividing step of dividing into a plurality of blocks, a holding step of holding pattern data on a reduced image for each of the possible densities of the plurality of blocks, and a calculating step of calculating a density of one of the plurality of blocks And an acquisition step of acquiring the pixel density on the reduced image corresponding to the block with the pixel density at the position corresponding to the block on the pattern data corresponding to the density obtained by the calculation step.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the drawings. <First Embodiment> FIG. 1 is a block diagram showing the arrangement of a recording apparatus according to the first embodiment. An image data input unit 22 inputs image data from a host computer or the like via the interface 21. 23 is a CPU, R
The entire device is controlled according to the program group 25c stored in the OM 25. 24 is a RAM and a ROM 25
It is used as a work area of the program group 25c stored in, a temporary save area for error processing, and a temporary storage area for image data.

Reference numeral 25 denotes a ROM, which includes a mask pattern table group 25a used for data conversion processing described later, a character pattern table group 25b for developing a character pattern in accordance with a character code of character image data, a control program, an error processing program, which will be described later. A program group 25c such as a program for processing image data according to the flowchart of FIG.

Reference numeral 26 is a magnification setting section, which is an operation panel 27.
The image magnification is set according to the magnification specified from. An address designating unit 28 designates addresses in the RAM 24 and the ROM 25 in accordance with information from the address management circuit 29. A recording unit 30 records and outputs input image data. Reference numeral 310 is a data bus line. Reference numeral 320 denotes a processing unit that performs magnification conversion processing of input image data and calculation and distribution of errors generated by the magnification conversion processing.

The recording unit 30 of the above recording apparatus uses a serial scan type color ink jet recording apparatus as shown in FIG. FIG. 2 is a perspective view showing the main configuration of the recording unit according to the first embodiment. A recording head 1Y for ejecting yellow color ink, a recording head 1M for ejecting magenta color ink, a recording head 1C for ejecting cyan color ink,
The recording head 1K that ejects black color ink is arranged at a predetermined distance on the carriage 201. A recording material made of paper, a plastic thin plate, or the like is sandwiched between paper ejection rollers 2 and 3 via a conveyance roller (not shown), and is fed in the direction of arrow C when a conveyance motor (not shown) is driven.

The carriage 201 is guided and supported by the guide shaft 4 and the encoder 5. The carriage 201 includes a carriage motor 8 via drive belts 6 and 7.
Is driven to reciprocate along the guide shaft 4. A plurality of ejection openings are provided on the surface (ejection opening formation surface) of the recording head 1 facing the recording material, and heat is generated inside each ejection opening (liquid path) to generate thermal energy for ink ejection. An element (electrical / thermal energy converter) is provided.

In accordance with the reading timing of the encoder 5, the heating element is driven based on the recording signal, and black,
An image can be formed by ejecting and adhering ink on the recording material in the order of cyan, magenta, and yellow. At the home position of the carriage 201 selected outside the recording area, a recovery unit 400 having a cap portion 420 having four caps described later is arranged. When recording is not performed, the carriage 201 is moved to the home position, the ejection port forming surface of each corresponding recording head 1 is sealed by each cap of the cap unit 420, and ink sticking or dust due to evaporation of the ink solvent is caused. Prevents clogging of the discharge port due to foreign matter. Further, a blade 540 and a wiping member 541 are provided adjacent to the cap portion 420, and are used for cleaning the ejection port forming surface of the recording head 1. Ink is supplied to the recording head 1 by the carriage 20.
1 through each of the ink tanks 10Y through the ink tubes 9 through the sub tanks (not shown).
(Yellow), ink tank 10M (magenta), ink tank 10C (cyan), and ink tank 10K (black).

Next, the processing unit 320 for performing the data conversion according to the first embodiment will be described with reference to FIG. FIG. 3 is a block diagram showing the configuration of the processing unit that performs the data conversion processing according to the first embodiment. An image data input unit 22 receives image data sent from a host computer or the like. At this time, the image data sent from the host computer or the like is 2
It is possible to mix image data consisting of binarized bit map information. In this case, if the data discriminating unit is provided, the discrimination between the character image data and the image image data can be easily discriminated based on the form of the control command and the content of the signal contained in the image data. Further, in the case of image image data, it is possible to determine the image resolution. Here, only the conversion of image data will be described. Further, it is assumed that the image image data handled in the first embodiment has the same resolution as that of the recording device.

Reference numeral 32 denotes a first memory, which temporarily stores the image data received by the image data input unit 22. A decision unit 35 is used for the conversion bit number of the image image data and the data conversion process according to the magnification setting information from the magnification setting unit 26 and the resolution information of the image image data according to the image output magnification designated by the operation panel 27. Determine the reference area. The reference area here is
For example, when the image output magnification is ½ reduction and the 2 × 2 pixels are converted into one pixel (2 bits × 2 bits is 1 bit), the reference area is 2 × 2.

Reference numeral 36 denotes an image extraction unit, which is the first memory 32.
The image data corresponding to the reference area of the input image image data stored in is extracted. A dot number determination unit 37 determines the number of on-dots in which a recording pixel is present when the bit state of the image data in the reference area is 1 after the image in the reference area is extracted by the image extraction unit 36. To do.

Reference numeral 39 is a mask pattern setting unit, which selects and sets a mask pattern corresponding to image data from the mask pattern table group 25a. The mask pattern set here is predetermined according to the conversion ratio of the image data, the number of on-dots determined by the dot number determination unit 37, and the position where the input image image data is referred to by the reference area. Then, according to the mask pattern information, the pixel (bit) information at the corresponding position in the image data after the conversion process is determined to be an on dot or an off dot (1 or 0).

Reference numeral 38 denotes a data conversion processing unit, which uses the mask pattern set by the mask pattern setting unit 39 to perform data conversion processing of the input image image data.
The mask pattern and the reference position of the reference area move according to the designation information from the address designating section 42. The input image image data subjected to the data conversion processing in the data conversion processing unit 38 is stored in the second memory 41 after the error value generated in the data conversion processing is calculated in the error calculation unit 45, and recorded in the sequential recording unit 30. Is output.

Reference numeral 45 denotes an error calculation unit, which obtains an error value generated by the data conversion processing of the data conversion processing unit 38 and stores it in the third memory 44. 46 is an error distribution unit,
The error value calculated by the error calculation unit 45 is calculated by the dot number determination unit 3
The pixels determined in 7 are added and distributed to the necessary pixel portion. still,
The error calculation method and the error distribution method according to the first embodiment will be described in detail later.

Although the on-dot (bit state is 1) is used to determine the number of dots of the input image image data of the dot-number discriminating section 37 of the first embodiment, this is off-dot (bit state is 0). It is also possible to easily discriminate by using. Next, the magnification conversion process according to the first embodiment will be described. FIG. 4 is a flowchart showing the magnification conversion processing of the first embodiment.

In step S400, the image data input unit 2
Image data is input to 2. Step S401
Then, the magnification setting unit 26 sets the magnification designated by the operation panel 27. In step S402, the number of bits of image image data to be converted according to the set magnification and the area to be referred to (M rows × N columns: M, N is a positive integer)
Is determined by the determining unit 35. In step S403, the image extraction unit 36 extracts the image data in the reference area. In step S404, the on-dot state of the image data in the reference area is discriminated and counted by the dot number discriminating unit 37, and the on-dot pixel number X (X is a real number) is obtained. In step S405, the new on-dot pixel number X to which the error value E generated by the data conversion processing in the error distribution unit 46 is added
Is calculated.

In step S406, it is determined whether X calculated in step S405 satisfies 0 <X / (M × N) <1. If X is 0 <X / (M × N) <1 (YES in step S406), step S4
At 12, the mask pattern setting unit 39 sets the mask pattern table according to the image data. In step S413, if the corresponding position of the mask pattern is the on-dot designated portion (YES in step S413),
In step S414, the bit state of the corresponding pixel of the image data to be converted is set to 1. Then, step S4
At 17, X / (M × N) −1 is calculated as the error value E. When the corresponding position of the mask pattern is the off-dot designated portion (NO in step S413), step S415
Then, the bit state of the corresponding pixel of the image image data to be converted is set to 0. Then, in step S417, X / (M ×
N) is calculated as the error value E.

In step S406, X is 0 <X / (M ×
N) <1 is not satisfied (N in step S406)
O), the process proceeds to step S407, and X is X / (M × N)>
It is determined whether it is 1. In step S407,
If X / (M × N)> 1 (YES in step S407), the bit state of the corresponding pixel of the image image data to be converted is set to 1 in step S414. Step S
If X / (M × N)> 1 is not satisfied at 407 (NO at step S407), the process proceeds to step S408, where X is X /
It is determined whether or not (M × N) <0.

In step S408, X / (M × N) <0
If (YES in step S408), the bit state of the corresponding pixel of the image image data to be converted is set to 0 in step S415. In step S408, X / (M
× N) <0 (NO in step S408),
In step S409, it is determined whether X is X / (M × N) = 0.

In step S409, X / (M × N) = 0
If (YES in step S409), the bit state of the corresponding pixel of the image image data to be converted is set to 0 in step S411. In step S409, X / (M
× N) = 0 (NO in step S409),
In step S410, the bit state of the corresponding pixel of the image image data to be converted is set to 1 in step S410.

If the calculation result in step S409 is 0 or 1, no error occurs due to the magnification conversion process, and therefore it is not necessary to calculate the error, and the error amount becomes 0.
In step S416, it is determined whether the processing of the image data of all reference areas has been completed. If the end is not determined (NO in step S416), the process moves to the next reference area and the above process is repeated in step S418. When the processing of the image image data of all the reference areas is completed (YES in step S416), a predetermined amount of image image data is recorded in the recording unit 30 in step S419.
It is recorded and output via.

Next, a data conversion processing method using the mask pattern table will be described. Here, a case where the input image image data is reduced by a factor of 1/2 will be described. FIG. 5 is a diagram showing the relationship between the original image image data and the reference area and reduced image data according to the first embodiment.

FIG. 5A shows original image data. FIG. 5B shows an area of 2 × 2 pixels in reference area size. FIG. 5C shows reduced image data. The original image data of FIG. 5A is divided by the reference area size of FIG. For example, O
(1,1), O (1,2), and O (2,1) indicate the divided areas. After the reduction processing, the information of each area is S (1,1), S of the reduced image data of FIG.
(1,2), S (2,1).

At this time, the pixel state of the original image image data in the area divided by the reference area size is, for example,
A pixel state as shown in FIG. 6 can be considered. Black pixels shown in the figure are on-dot portions, and white pixels are off-dot portions. FIG.
In (a) of FIG. 6, when all pixels are off dots, in (b) of FIG. 6, 1/4 of pixels are on dots, and in (c) of FIG. 6D shows a case where 3/4 pixels are on dots, and FIG. 6E shows a case where all pixels are on dots.

7 to 10 show the patterns of the mask pattern table in the first embodiment, in which the shaded portions are on-dot positions and the non-shaded portions are off-dot positions. 7 to 10, P (1,1), P (1,2), P
(2,1) correspond to the positions of S (1,1), S (1,2), and S (2,1) in the reduced image data of (c) of FIG. 5, respectively.

Original image data O (1,1) or O (1,2), O in the reference area of FIG.
When the pixel state of (2,1) is all off dots as shown in (a) of FIG. 7, the reduced image data S (1,1) or S (1,) corresponding to (c) of FIG. 2), S
The bit state of (2, 1) is 0, that is, off dot regardless of the mask pattern table. In this case, no error occurs due to the data conversion process.

Original image data O (1,1) or O (1,2), O in the reference area of FIG.
When the pixel state of (2, 1) is all on dots as shown in (e) of FIG. 6, the reduced image data S (1, 1) or S (1,) corresponding to (c) of FIG. 2), S
For (2,1), the bit state is 1, that is, on-dot, regardless of the mask pattern table. In this case also, no error occurs due to the data conversion processing.

When the pixel state of the original image data O (1,1) in the reference area of FIG. 5A is 1/4 pixel is on-dot as shown in FIG. 6B. Is the reduced image data S (1,1) of FIG. 6C according to the condition of P (1,1) in the mask pattern table shown in FIG.
The bit state of is 1 or on-dot. In this case, −3/4 is calculated as the error E.

When the pixel state of the original image data O (1,2) in the reference area of FIG. 5A is 1/4 pixel is on-dot as shown in FIG. 6B. Is the reduced image data S (1,2) of FIG. 6C according to the condition of P (1,2) in the mask pattern table shown in FIG.
Bit state is 0, that is, off dot. In this case, 1/4 is calculated as the error value E.

Further, as shown in FIG. 6B, the pixel state of the original image data O (2,1) in the reference area of FIG. In this case, the mask pattern table P (2,
According to the condition 1), the reduced image data S of FIG.
The bit state of (2,1) is 0, that is, off dot. Also in this case, 1/4 is calculated as the error value E.

When the pixel state of the original image data O (1,1) in the reference area of FIG. 5 (a) is ½ pixel is on-dot as shown in FIG. 6 (c). Is the reduced image data S (1,1) of FIG. 5C according to the condition of P (1,1) in the mask pattern table shown in FIG.
The bit state of is 1 or on-dot. In this case, -1/2 is calculated as the error value E.

When the pixel state of the original image data O (1,2) in the reference area of FIG. 5 (a) is ½ pixel is on-dot as shown in FIG. 6 (c). Is the reduced image data S (1,2) of FIG. 5C according to the condition of P (1,2) in the mask pattern table shown in FIG.
Bit state is 0, that is, off dot. In this case, 1/2 is calculated as the error value E.

Further, as shown in (c) of FIG. 6, the pixel state of the original image data O (2,1) in the reference area of (a) of FIG. 5 becomes 1/2 dot. In this case, P in the data conversion mask table shown in FIG.
According to the condition (2,1), the bit state of the reduced image data S (2,1) in FIG. 5C is 0, that is, off dot. Also in this case, 1/2 is calculated as the error value.

When the pixel state of the original image data in the reference area is 1/2 of the on-dots as shown in FIG. 6C, the mask pattern table shown in FIG. 9 may be used. good. When the pixel state of the original image image data O (1,1) in the reference area of FIG. 5A is 3/4 of the pixels are on-dots as shown in FIG. P of the mask pattern table shown in FIG.
According to the condition (1,1), the bit state of the reduced image data S (1,1) in FIG. 5C is 1 or on-dot. In this case, -1/4 is calculated as the error value E.

When the pixel state of the original image data O (1,2) in the reference area of FIG. 5 (a) is 3/4 pixel is on-dot as shown in FIG. 6 (d). According to the condition P (1,2) in the mask pattern table shown in FIG. 10, the reduced image data S (1,
The bit state of 2) is 0, that is, off dot. In this case, 3/4 is calculated as the error value E.

In addition, as shown in (d) of FIG. 6, the pixel state of the original image data O (2,1) in the reference area of (a) of FIG. In this case, P in the mask pattern table shown in FIG.
According to the condition (2,1), the bit state of the reduced image data S (2,1) in FIG. 5C is 1 or on-dot. In this case, -1/4 is calculated as the error value E.

In calculating the error, the pixel of the mask pattern table corresponding to the pixel of the original image data at an arbitrary position is, for example, an image of x row and y column (x, y: positive integer) of the original image data. The pixel of the data, that is, the pixel of the original image data located at (x, y) corresponds to the pixel of the mask pattern table located at (x, y). Next, a method of distributing the error caused by the data conversion process will be described.

In the first embodiment, the error is additionally distributed to the adjacent reference areas as shown in FIG. 11 (a) or (b). In the case of FIG. 11A, the error generated during the magnification conversion processing of the original image image data O (1,1) in the reference area is the original image data O (1,2) in the reference area which is the next processing area. ). In the case of FIG. 11B, the original image data O in the reference area
The error generated during the magnification conversion processing of (1,1) is added and distributed to the original image data O (2,1) in the reference area which is the processing area of the next line.

Next, the process of adding and distributing the error between the signal in the reference area and the signal after the magnification conversion process to the adjacent reference area will be described with reference to FIG. FIG. 12 is a block diagram showing a process of addition and distribution of errors according to the first embodiment.
The input correction unit 131 calculates the error Exy as Ixy (= X / (M
× N)), and the correction value I′xy is obtained.
The correction value I′xy is compared by the comparator 135 with the comparison signal 134 based on the ON / OFF condition of the mask pattern table corresponding to I′xy. Then, the error Exy from the correction value I′xy at this time is obtained by the difference calculation unit 132 and becomes Exy = I′xy−Pxy.

Here, when the mask pattern table is on dots, Pxy = 1, and when the mask pattern table is off dots, Pxy = 0.

The image data obtained by distributing the error is stored in the memory 136 according to the address signal 133, and is sequentially output to the recording unit 30. The method of distributing the above error may be performed by a hard circuit or may be performed by software. As described above, according to the first embodiment, it is possible to reproduce a halftone image without completely losing or destroying the information of the original image data despite the high reduction ratio. Further, since the bit state of the reduced image can be variably specified in more detail according to the pixel state of the original image image in the reference area, the gradation reproducibility of the halftone image is also excellent. Further, by introducing the error generated by the data conversion processing into the adjacent pixels, the gradation of the original image is preserved even in the reduced image.

In order to better reproduce the halftone gradation reproducibility of the original image data, if the proportion of on-dots in the pixel state of the original image data in the reference area is Z, the corresponding portion It is preferable to set the conditions of the mask pattern table so that the frequency with which the bit state of the reduced image data becomes 1 is equal to Z. Although the method of converting 2 × 2 pixels into 1 pixel has been described in the first embodiment, the present invention is not limited to this, and M × N pixels in the reference area are reduced images m × n (M> m, N> n). The same method can be used for conversion into pixels. However,
In the case of reducing by m × n / M × N times,
When the mask pattern table is set, the determination of the on-dot portion in step S413 determines the position of the on-dot arranged in the m × n block of the corresponding mask pattern table, and then proceeds to the next step.

<Second Embodiment> In the first embodiment, the error distribution is distributed to adjacent pixels as shown in FIG.
In the second embodiment, the error distribution shown in FIG. 14 is performed. The flow of magnification conversion processing according to the second embodiment will be described with reference to FIG. FIG. 13 is a flowchart of the magnification conversion process according to the second embodiment.

In step S500, the image data input unit 2
Image data is input to 2. Step S501
Then, the magnification setting unit 26 sets the magnification designated by the operation panel 27. In step S502, the number of bits of image image data to be converted according to the set magnification and the area to be referred to (M rows × N columns: M, N is a positive integer)
Is determined by the determining unit 35. In step S503, the error E calculated in advance is distributed to the predetermined reference area. In step S504, the image extraction unit 36 extracts the image data in the reference area. In step S505, the on-dot state of the image data in the reference area is determined and counted by the dot number determination unit 37, and the on-dot pixel number X (X
Is a real number). In step S505, the error distribution unit 4
In step 6, a new on-dot pixel number X is calculated by adding the error value E generated by the data conversion process.

In step S506, it is determined whether X calculated in step S505 satisfies 0 <X / (M × N) <1. If X is 0 <X / (M × N) <1 (YES in step S506), step S5
At 12, the mask pattern setting unit 39 sets the mask pattern table according to the image data. In step S513, if the corresponding position of the mask pattern is the on-dot designated portion (YES in step S513),
In step S514, the bit state of the corresponding pixel of the image data to be converted is set to 1. Then, step S5
At 17, X / (M × N) −1 is calculated as the error value E. If the corresponding position of the mask pattern is the off-dot designated portion (NO in step S513), step S515.
Then, the bit state of the corresponding pixel of the image image data to be converted is set to 0. Then, in step S517, X / (M ×
N) is calculated as the error value E.

In step S506, X is 0 <X / (M ×
N) <1 is not satisfied (N in step S506
O), the process proceeds to step S507, and X is X / (M × N)>
It is determined whether it is 1. In step S507,
When X / (M × N)> 1 (YES in step S507), the bit state of the corresponding pixel of the image image data to be converted is set to 1 in step S515. When X / (M × N)> 1 is not satisfied in step S507 (NO in step S507), the process proceeds to step S508 and X /
It is determined whether or not (M × N) <0.

In step S508, X / (M × N) <0
If (YES in step S508), the bit state of the corresponding pixel of the image image data to be converted is set to 0 in step S515. In step S508, X / (M
× N) <0 (NO in step S508),
In step S509, it is determined whether X is X / (M × N) = 0.

In step S509, X / (M × N) = 0
If (YES in step S509), the bit state of the corresponding pixel of the image image data to be converted is set to 0 in step S511. In step S509, X / (M
× N) = 0 (NO in step S509),
Proceeding to step S510, the bit state of the corresponding pixel of the image image data to be converted is set to 1 in step S510.

If the calculation result in step S509 is 0 or 1, no error occurs due to the magnification conversion process, and therefore it is not necessary to calculate the error, and the error amount becomes 0.
In step S516, it is determined whether the processing of the image data of all reference areas is completed. If the end is not determined (NO in step S516), the process moves to the next reference area and the above process is repeated in step S518. If the processing of the image image data of all reference areas is completed (YES in step S516), a predetermined amount of image image data is recorded in the recording unit 30 in step S519.
It is recorded and output via.

Next, the error diffusion method for image data of the second embodiment will be described with reference to FIG. FIG.
FIG. 5 is a block diagram showing a process of addition and distribution of errors according to the second embodiment. The error diffusion process in the second embodiment is
This is to two-dimensionally settle the accumulated error between the signal in the reference area and the signal after the magnification conversion processing. In the vicinity of the signal Ixy (= X / (M × N)) in the reference area, the error distribution coefficient 154 (diffusion) based on the error diffusion matrix 154 The coefficient at the coordinates j and k in the matrix is Kjk: j and k are positive integers), and weighting is performed. As a result, when the integrated error Sxy of the following equation is obtained: Sxy = (1 / ΣKjk) ΣKjk · Ex-j, y-k Next, the integrated error Sxy is stored in the error buffer memory 152. Then, the integrated error Sxy corresponding to the position of the desired reference area is input to Ixy by the input correction unit 131,
The correction value I'xy is obtained.

The error buffer memory 152 has a capacity capable of storing data for two lines, which are columns of the reference area obtained by dividing the original image. This buffer memory capacity can be changed according to the conversion magnification. The error diffusion matrix used in the second embodiment is a matrix as shown in FIG. The figure shows that 1/3 of the image data of the coordinate O (1,1) is distributed to the coordinates in three directions.

The correction value I'xy is I'xy = Ixy
It becomes + Sxy. The correction value I′xy obtained by adding the error generated in the magnification conversion process to the image data of the peripheral reference area is compared by the comparator 135 with the comparison signal 134 based on the ON / OFF condition of the mask pattern table corresponding to the signal I′xy. Be compared. The correction value I′xy and the error Exy at this time are obtained by the difference calculation unit 132, and Exy = I′xy−Pxy.

Here, when the mask pattern table is on-dots, Pxy = 1, and when the mask pattern table is off-dots, Pxy = 0.

The image data obtained by distributing the error is stored in the memory 136 according to the address signal 133, and is sequentially output to the recording section. The method of distributing the above error may be performed by a hard circuit or may be performed by software. When the error diffusion matrix of FIG. 16 is used, the configuration is as shown in FIG. 17, and the error distribution coefficient 1 according to the error diffusion matrix of FIG.
The configuration is the same as that of FIG. 15 except for the error buffer memory 162 having the storage capacity of 64 and the image data of 3 lines, and the specific processing is the same as that described in FIG.

The error diffusion matrix and the error distribution coefficient are not limited to those described in the second embodiment, and another error diffusion matrix and error distribution may be used depending on the capacity of the memory used for the processing and the image on which the magnification conversion processing is performed. It is also possible to easily use the coefficient. As described above, in the second embodiment, a halftone image can be reproduced without completely losing or destroying the information of the original image data, despite the high reduction ratio, as in the first embodiment. Also,
Since the bit state of the reduced image can be variably specified in more detail according to the pixel state of the original image image in the reference area, the gradation reproducibility of the halftone image can be improved.

Further, since the error can be diffused in a wide range according to the diffusion matrix, the gradation of the original image can be saved more favorably. In order to better reproduce the halftone gradation reproducibility of the original image data, if the ratio of on-dots in the pixel state of the original image data in the reference area is Z, the reduced image data of the corresponding part It is preferable to set the conditions of the mask pattern table so that the frequency with which the bit state of 1 becomes 1 is equal to Z.

<Third Embodiment> In the method of diffusing an error according to the third embodiment, similarly to the method of the second embodiment, the accumulated error between the signal in the reference area and the signal after the magnification conversion processing is calculated. A two-dimensional liquidation method is used. In the third embodiment, the error diffusion method is performed using two types of error diffusion matrices. The method will be described with reference to FIG.

The signal Ixy (= X / (M ×
N)) is multiplied by the error distribution coefficient Kjk based on the error diffusion matrix by the error distribution unit 153 and the error Exy generated at the time of magnification conversion, and weighted to obtain the integrated error Sxy of the following equation. Sxy = (1 / ΣKjk) ΣKjk · Ex-j, y-k (where j and k are coordinates in the diffusion matrix) Next, the integrated error Sxy is input to Ixy by the input correction unit 131 to obtain the correction value I′xy. obtain.

The error diffusion matrix in the third embodiment is shown in FIGS. 14 and 16. In addition, the correction value I'xy
Becomes I'xy = Ixy + Sxy. The correction value I'xy obtained by adding the error generated in the magnification conversion process to the image data of the peripheral reference area is compared by the comparator 135 with the comparison signal 134 based on the ON / OFF condition of the mask pattern table corresponding to the signal I'xy. It The error Exy at this time is obtained by the difference calculation unit 132 and becomes Exy = I′xy−Pxy.

Here, when the mask pattern table is on-dots, Pxy = 1, and when the mask pattern table is off-dots, Pxy = 0.

The error diffusion matrix is the selector 17
It can be changed by switching between 2, 175 and 177. Further, switching of the selector is switched by the selection signal S. The switching condition is controlled according to the signal value in the reference area to be processed, the data conversion ratio, the type of image data, and the like. Then, the image data obtained by distributing the error is stored in the memory 136 according to the address signal 133, and is sequentially output to the recording unit.

In the third embodiment, the error buffer memories are error buffer memory 152 and error buffer memory 162.
As described above, the error buffer memory 162 may be configured to store the error distribution coefficient 154 or the error distribution coefficient 164 according to the image data. it can. The switching between the error buffer memories 152 and 162 is switched according to the size of the error diffusion matrix determined according to the data conversion magnification and the type of image, and does not change within the same image. When changing the condition for each reference area, that is, when changing the condition within the same image, the error buffer memory 162 having a large buffer memory capacity is used and only the error distribution coefficients 154 and 164 are switched. The error diffusion matrix is not limited to that shown in the third embodiment, and the diffusion matrix size, the error distribution coefficient, the variable number, the capacity of the memory used for the processing, and the set number of the data conversion magnification are determined depending on the image to be handled. It is preferable to use the one suitable for the type. The analysis of the image type is performed using an image area separation circuit or the like.

The method of distributing the above-mentioned error may be performed by a hard circuit or may be performed by software. Further, as in the second embodiment, since the error can be diffused in a wide range according to the diffusion matrix, the gradation of the original image can be stored better. As described above, in the third embodiment, a halftone image can be reproduced without completely losing or destroying the information of the original image data despite the high reduction ratio, as in the second embodiment. Further, the gradation reproducibility of the halftone image can be improved by variably designating the bit state of the reduced image in more detail according to the pixel state of the original image image in the reference area.

Furthermore, in order to better reproduce the halftone gradation reproducibility of the original image image data, if the proportion of on-dots in the pixel state of the original image image data in the reference area is Z, It is preferable to set the conditions of the mask pattern table so that the frequency with which the bit state of the reduced image data becomes 1 is equal to Z. The present invention may be applied to a system including a plurality of devices or an apparatus including a single device. Also,
It goes without saying that the present invention can also be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0076]

As is apparent from the above description, according to the present invention, it is possible to provide a recording apparatus and method capable of outputting an image of a desired reduced size while maintaining the reproducibility of a halftone image. Further, it is possible to provide a recording apparatus and method capable of outputting an image of a desired size while reproducing and maintaining the color tone of an original image even in color recording.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a recording apparatus according to a first embodiment.

FIG. 2 is a perspective view showing a main configuration of a recording unit according to the first embodiment.

FIG. 3 is a block diagram showing a configuration of a processing unit that performs a data conversion process according to the first embodiment.

FIG. 4 is a flowchart showing a magnification conversion process according to the first embodiment.

FIG. 5 is a diagram showing the relationship between the original image image data and the reference area / reduced image data according to the first embodiment.

FIG. 6 is a diagram showing a pixel state of original image image data divided by a reference area size according to the first embodiment.

FIG. 7 is a diagram showing a data conversion mask pattern table used when 1/4 pixel of original image image data in an area divided by a reference area size according to the first embodiment is an on-dot.

FIG. 8 is a diagram showing a data conversion mask pattern table used when 1/2 pixel of the original image image data in the area divided by the reference area size of the first embodiment is an on dot.

FIG. 9 is a diagram showing a data conversion mask pattern table used when 1/2 pixel of the original image image data in the area divided by the reference area size of the first embodiment is an on-dot.

FIG. 10 is a diagram showing a data conversion mask pattern table used when 3/4 pixels of original image image data in an area divided by a reference area size according to the first embodiment are on dots.

FIG. 11 is a diagram showing error distribution positions according to the first embodiment.

FIG. 12 is a block diagram showing a process of addition and distribution of errors according to the first embodiment.

FIG. 13 is a flowchart showing a magnification conversion process according to the second embodiment.

FIG. 14 is a diagram showing error distribution positions according to the second embodiment.

FIG. 15 is a block diagram showing a process of addition and distribution of errors according to the second embodiment.

FIG. 16 is a diagram showing another error distribution position according to the second embodiment.

FIG. 17 is a block diagram showing another error addition and distribution process according to the second embodiment.

FIG. 18 is a block diagram showing a process of addition and distribution of errors according to the third embodiment.

FIG. 19 is a diagram showing the thinning-out positions when the 1/2 reduction processing is performed by the thinning-out processing.

FIG. 20 is a diagram showing an original image and an image subjected to 1/2 reduction processing by thinning processing.

[Explanation of symbols]

 1 Recording Head 2, 3 Paper Ejection Roller 4 Guide Shaft 5 Encoder 6, 7 Drive Belt 8 Carriage Motor 9 Ink Tube 10 Ink Tank 400 Recovery Unit 420 Cap Unit 540 Blade 541 Wiping Member 21 Interface 22 Image Input Unit 23 CPU 24 RAM 25 ROM 25a Mask pattern table group 25b Character pattern table group 25c Program group 26 Magnification setting section 27 Operation panel 28 Address designating section 29 Address management circuit 30 Recording section 310 Bus line 320 Processing section 32 First memory 36 Image extracting section 37 Dot number determination Unit 38 data conversion processing unit 39 mask pattern setting unit 41 second memory 42 address designation unit 43 recording unit 44 third memory 45 error calculation unit 46 error distribution unit 131 input correction 132 difference calculation unit 133 the address signal 134 comparison signal 135 comparator 136 memory 152 error buffer memory 153 error distributor 154 the error distribution coefficients 162 error buffer memory 164 error distribution coefficients 172 selector 175 Selector 177 Selector

Front page continuation (72) Inventor Kazuhiko Morimura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Masafumi Matsumoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (6)

[Claims] 1. A recording apparatus for reducing image data to record a reduced image, comprising setting means for setting a desired magnification, and predetermined original image data based on the magnification set by the setting means. A dividing unit that divides into a plurality of blocks composed of the number of pixels, a holding unit that holds pattern data on a reduced image for each of the densities that the plurality of blocks can have, and a density is calculated for one of the plurality of blocks. A means for calculating, and a pixel density at a position corresponding to the block on the pattern data corresponding to the density obtained by the calculating means,
A recording device, comprising: an acquisition unit that acquires a pixel density on a reduced image corresponding to the block. 2. A block of unprocessed original image data for an error between the density of a block of original image data processed by the calculating means and the density of a block having a predetermined number of pixels on a reduced image corresponding to the block. The recording apparatus according to claim 1, further comprising: a distribution unit that distributes the error to a block of the original image data obtained by distributing the error as a density of the block of the original image data. 3. The recording apparatus according to claim 2, wherein the distribution unit adds the error to a block adjacent to a block of the original image data processed by the calculation unit. 4. The distribution unit distributes the error to blocks around a block processed by the calculation unit of the original image data by multiplying a predetermined amount according to a distribution destination. The recording device according to 1. 5. The distribution means includes a distribution destination of the error and a plurality of patterns of a predetermined amount corresponding to the distribution destination, and a selection means for selecting one of the plurality of patterns based on the original image data. The recording apparatus according to claim 4, further comprising: 6. A recording method of reducing image data to record a reduced image, comprising: a setting step of setting a desired magnification; and a step of setting original image data based on the magnification set in the setting step. A dividing step of dividing into a plurality of blocks composed of the number of pixels, a holding step of holding pattern data on a reduced image for each of the densities that the plurality of blocks can take, and a density of one of the plurality of blocks A step of calculating, and a pixel density at a position corresponding to the block on the pattern data corresponding to the density obtained by the calculating step,
An acquisition step of acquiring the pixel density on the reduced image corresponding to the block.