JP2005125713A - Device for generating thinned-out mask pattern, recording device equipped with this device for generating thinned-out mask pattern, method for generating mask pattern, program and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To save a memory cost by reducing the capacity of a thinned-out mask pattern without deteriorating the quality level of an image recorded by a multi-pass process. <P>SOLUTION: In this device for generating a thinned-out mask pattern, the following constituent parts are provided: a thinned-out mask development region 3 consisting of the number of lines equivalent to E; a thinned-out mask species pattern 1 with the number of lines which is equivalent to the value obtained by dividing the number of the lines E of the thinned-out mask development region 3 by a thinned-out mask compression ratio R; a developed line table 2 wherein the values of 0 to (E-1) appear without repetition of the respective values; a species line pointer 4 which indicates the internal lines of the thinned-out mask species pattern; a reference pointer 5 which indicates the internal factors of the developed line table 2; and a duplicating device which duplicates the total number of lines indicated by the species line pointer 4 in the thinned-out mask species pattern 1, in the lines indicated by the values stored in the developed line table 2 indicated by the reference pointer 5 inside the thinned-out mask development region 3. In addition, under control, the procedures to duplicate the lines using the duplicating device and allow the reference point 5 to proceed to the following factor, are repeated "E" times and the species line pointer 4 is allowed to proceed to the following factor each time the duplication of the line is repeated "R" times. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention uses a recording head in which a plurality of nozzle groups each having a plurality of nozzles are arranged, performs main scanning a plurality of times with different nozzle groups for the same main scanning region in a recording medium, and performs a thinning mask pattern by each main scanning. A technique for reducing the storage capacity of a memory for storing the thinning mask pattern used in a recording apparatus employing a so-called multi-pass method that forms a thinned image in accordance with the above and completes the image of the same main scanning region It is about.

  In a serial scan type ink jet recording apparatus, a recording head mounted on a carriage is scanned in a main scanning direction orthogonal to the nozzle arrangement direction, and droplets are ejected from the nozzles to form an image for one scan on a recording medium. Then, a predetermined amount of the recording medium is conveyed in the sub scanning direction orthogonal to the main scanning direction. An image is formed by repeating this procedure.

  In general, in an inkjet recording apparatus, image defects such as white streaks and uneven density occur due to unevenness in the ejection amount and ejection direction of each nozzle of the recording head. To make this inconspicuous, the multipass recording method Is used. In this method, the print head is divided into a plurality of nozzle groups consisting of a plurality of nozzles, and the same main scanning region is subjected to a plurality of main scans using different nozzle groups, and a thinned image is formed according to a thinning mask pattern in each main scan. The image of the same main scanning area is completed. As a result, nozzle variations are dispersed on the image, making it difficult to perceive image defects.

The thinning mask pattern has a height equal to the number of nozzles of the head, and is assigned 1 (data indicating that dot recording is possible) or 0 (data indicating that dot recording is not possible). It is a bitmap. If this is overlapped for each divided path, it will be recorded without excess or deficiency. The configuration of an ink jet recording apparatus using a thinning mask pattern is disclosed in Patent Document 1.
JP 7-52390 A

  In the above conventional example, the thinning mask pattern capacity is proportional to the number of nozzles (vertical width of the pattern) × pattern horizontal width (width of the pattern in the main scanning direction) × number of types of patterns. For example, if the number of nozzles = 640, pattern width = 1024, pattern type = 4 (for 2 passes, 4 passes, 8 passes, 16 passes), the memory capacity is 640 × 1024 × 4 ÷ 8 = 320 KB. This necessitates an increase in the cost of read-only memory.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to reduce the capacity of a thinning mask pattern without reducing the image quality of multipass printing, thereby reducing the memory cost.

  In order to solve the above-described problems and achieve the object, a thinning mask pattern generation apparatus according to the present invention is a thinning mask pattern generation apparatus for generating a thinning mask pattern having the number of columns E, and the thinning mask pattern generation apparatus includes: A storage unit storing a thinning mask pattern having a column number C smaller than the column number E of the mask pattern, and each column of the thinning mask pattern of the column number C is copied a plurality of times, and the number of columns including the copied column Generating means for generating a thinning mask pattern of E, wherein the generating means arranges the copied E columns so as to be different from the arrangement of the thinning mask pattern of the number of columns C, and A thinning mask pattern is generated.

  The thinning mask pattern generation apparatus according to the present invention is a thinning mask pattern generation apparatus for generating a thinning mask pattern having the number of columns E, and the number of columns C is smaller than the number E of columns of the thinning mask pattern. The thinning mask type pattern stored in the storage unit and each column of the thinning mask type pattern stored in the storage unit are copied (E / C) times so as to be different from the arrangement of the thinning mask type pattern. Generating means for arranging the copied E columns and generating the thinning mask pattern having the number of columns of E.

  Further, the thinning mask pattern generation apparatus according to the present invention divides the first storage means having a thinning mask development area having the number of columns E and the number E of columns of the thinning mask development area by the thinning mask compression ratio R. A decimation mask type pattern having the number of columns equal to the value, and a developed column table in which the numbers of elements are equal to the number of columns E in the decimation mask development region, and numerical values from 0 to (E-1) appear without duplication, respectively. Storage means, a seed sequence pointer indicating a column in the thinning mask seed pattern, a reference pointer indicating an element in the expanded column table, and a column of the thinning mask seed pattern, which is indicated by the seed sequence pointer Column copy for copying the entire column to the entire column indicated by the numerical value stored in the expansion column table indicated by the reference pointer, in the thinning mask expansion region After initializing the stage, the seed column pointer and the reference pointer to point to the head element, the column copy means copies the column in the mask seed pattern to the column in the expanded column table, and the reference And a development control means for controlling to advance the seed column pointer to the next element each time the sequence of advancing the pointer to the next element is repeated E times and the sequence of copying the column is repeated R times.

  In the thinning mask pattern generating apparatus according to the present invention, the development sequence table embeds numerical values from 0 to (E-1) without duplication in the array of the number of elements E, and uniform from 0 to (E-1). A number sequence generated by generating two distributed pseudo-random numbers and performing a plurality of exchanges between a pair of elements using this as a position index, and the appearance order is substantially uncorrelated. .

  In the thinning mask pattern generation apparatus according to the present invention, the second storage means is a read-only memory.

  Further, in the thinning mask pattern generation device according to the present invention, the mask pattern generation device can develop a plurality of thinning masks having at least different numbers of passes, and the thinning mask compression ratio R includes a plurality of thinning mask types. It is characterized by using at least two different values in relation.

  According to another aspect of the invention, there is provided an ink jet recording apparatus comprising: scanning means for causing a recording head for ejecting ink to scan the same main scanning region of a recording medium a plurality of times; and a thinning mask for each of the plurality of main scanning operations. And a recording control unit that forms a thinned image according to a pattern and completes an image of the same main scanning region, and the thinned mask pattern is generated by the thinned mask pattern generation device .

  Further, the thinning mask pattern generation method according to the present invention includes a first storage means having a thinning mask development area having the number of columns E, and the number of columns E of the thinning mask development area divided by a thinning mask compression ratio R. A decimation mask type pattern having the number of columns equal to the value, and a developed column table in which the numbers of elements are equal to the number of columns E in the decimation mask development region, and numerical values from 0 to (E-1) appear without duplication, respectively. Storage means, a seed sequence pointer indicating a column in the thinning mask seed pattern, a reference pointer indicating an element in the expanded column table, and a column of the thinning mask seed pattern, which is indicated by the seed sequence pointer Column copy for copying the entire column to the entire column indicated by the numerical value stored in the expansion column table indicated by the reference pointer, in the thinning mask expansion region A method for generating a thinning mask pattern using an apparatus comprising a stage, wherein after initializing the seed sequence pointer and the reference pointer to indicate a head element, the mask is copied by the sequence copy means The procedure of copying the column in the seed pattern to the column in the expanded column table and advancing the reference pointer to the next element is repeated E times, and the seed column pointer is advanced to the next element every time the copy of the column is repeated R times. It is characterized by controlling as follows.

  A program according to the present invention causes a computer to execute the above method.

  A storage medium according to the present invention stores the above-mentioned program so as to be readable by a computer.

  According to the present invention configured as described above, it is possible to reduce the capacity of the thinning mask pattern without lowering the image quality of multipass printing, thereby reducing the memory cost.

  Hereinafter, a preferred embodiment of the present invention will be described.

  First, an outline of the present embodiment will be described.

  In this embodiment, the thinning mask pattern is compressed using human visual characteristics. The thinning mask pattern is generated using pseudo random numbers in order to reduce autocorrelation, and the compression rate in the LZ method or the like is low. On the other hand, due to human visual characteristics, it reacts sensitively when the pattern repetition period is small, but even if the correlation between the columns slightly increases, it does not stand out so much. As a result of this consideration, the present inventor has come up with a method of “randomly replacing columns of patterns copied and expanded in the column direction” in order to generate a random mask pattern.

  Specifically, the thinning mask pattern generation device divides the thinning mask development area formed in the rewritable memory by the thinning mask compression ratio R and the thinning mask development area formed in the rewritable memory and the thinning mask development area. A thinning mask type pattern formed in the read-only memory having the same number of columns and a number of elements equal to the number E of columns in the thinning mask development area appear from 0 to (E-1) without duplication. An expanded column table formed in the read-only memory, a seed column pointer indicating a column in the decimation mask type pattern, a reference pointer indicating an element in the expanded column table, and a column of the decimation mask type pattern The entire column indicated by the seed column pointer is stored in the expansion column table which is a column of the thinning mask expansion area and indicated by the reference pointer. A column copy unit that copies the entire column indicated by the numerical value, and the seed column pointer and the reference pointer are initialized so as to indicate a head element, and then the column copy unit sets one column of the mask seed pattern. The procedure of copying to the thinning mask development area and moving the reference pointer to the next element is repeated E times, and the operation of copying one column of the mask seed pattern to the thinning mask development area is repeated R times. And deployment control means configured to proceed to the next element.

  The expansion sequence table embeds numerical values from 0 to (E-1) without duplication in a one-dimensional array of element number E, generates two uniform pseudorandom numbers from 0 to (E-1), It is a numerical sequence generated by exchanging a pair of elements as an index a plurality of times, and the appearance order is generally uncorrelated.

  Preferably, the mask type pattern and the developed column table are generated in advance and held in a read-only memory. When a plurality of thinning masks having different numbers of passes are provided, the thinning mask compression ratio R may be configured to use at least two different values in relation to the thinning mask type.

  Hereinafter, specific embodiments will be described in detail with reference to the accompanying drawings.

  The present invention is characterized by a generation method of a thinning mask pattern used in the above-described printing apparatus capable of printing by the multi-pass method. Before explaining this, the inkjet printing apparatus and thinning-out method applicable to the present invention are characterized. The mask pattern will be briefly described. The recording apparatus applicable in the present invention includes a scanning unit that causes a recording head for ejecting ink to scan the same main scanning region of a recording medium a plurality of times, and a thinning mask pattern for each of the plurality of main scannings. And a recording control unit that completes the image of the same main scanning area according to the above, and uses a thinning pattern generated by a thinning mask pattern generation device to be described later as the thinning mask pattern. It has become.

  A thinning mask pattern suitably used in the present invention is a thinning mask pattern as shown in FIG. FIG. 1 is a diagram illustrating an example of a random thinning mask pattern. In FIG. 1, a thinning mask pattern 20 is a pattern that causes ink to be ejected to the position of a black frame and prevents ink from being ejected to the position of a white frame. The illustrated mask pattern 20 is for printing an image for one scan by four scans (passes) of the inkjet head 30 so that a black frame for ejecting ink with a duty of 25% appears. It is configured. When an image is formed by four scans, a different 25% duty mask pattern is used for each scan, and the ink jet head 30 is shifted in the nozzle row direction for each scan so that different ink ejection nozzles are used. To form an image. By doing so, nozzle variations are dispersed on the image, and image defects are hardly perceived.

  This embodiment is for reducing the memory capacity when such a random thinning pattern is generated.

(First embodiment)
FIG. 2 is a block diagram showing a configuration of a mask pattern generation apparatus for generating a thinning mask pattern used in the ink jet recording apparatus of the present invention.

  In FIG. 2, reference numeral 1 is a thinning mask seed pattern, reference numeral 2 is a development column table, reference numeral 3 is a thinning mask development area, reference numeral 4 is a seed string pointer, reference numeral 5 is a reference pointer, reference numeral 6 is a column copy section, and reference numeral 7 is an expansion. It is a control unit. The number of columns of the thinning mask seed pattern 1 is C, and the number of columns of the thinning mask development area 3 is E. Here, R and C are determined so that E = R · C, where R is the mask compression ratio. Note that the heights of the thinning mask seed pattern 1 and the thinning mask development region 3 are equal to H, and coincide with the number of nozzles in the sub-scanning direction used in one scan of the inkjet head 30.

  The development control unit 7 will be described below as being realized as a program operating on a microprocessor. The thinning mask seed pattern 1 and the developed column table 2 are written in a read-only memory connected to the microprocessor as a numerical table generated in advance. The thinning mask development area 3 is secured on a readable / writable memory connected to the microprocessor. The thinning mask seed pattern 1 and the thinning mask development area 3 are realized as a two-dimensional array, and the development column table 2 is realized as a one-dimensional array. The seed sequence pointer 4 and the reference pointer 5 are realized as an ordinal number of the array.

  FIG. 3 is a diagram schematically showing how a thinning mask pattern is generated.

  In FIG. 3, the reference numerals are the same as those in FIG. In the figure, an example of C = 8, R = 4, E = 32 is shown. In the thinning mask seed pattern 1 in FIG. 3, the ordinal number of the column is shown for convenience of explanation. The ordinal number of the column is shown below the thinning mask development area 3 for convenience of explanation. However, in practice, pattern data as shown in FIG. 4 is stored in the mask type pattern 1 and the mask development area 3. In the expanded row table 2, numbers from 0 to 31 are written in random order without duplication.

  Assume that 0 is set to the seed sequence pointer 4 and the reference pointer 5. Since the value of the element 0 of the expansion column table 2 is 25, the contents of the column 0 of the thinning mask seed pattern 1 are copied to the column 25 of the thinning mask expansion region 3. Next, 1 is added to the reference pointer 5 to point to the element 1 of the expanded sequence table 2. Then, the contents of column 0 of the thinning mask seed pattern 1 are copied to column 8 of the thinning mask development area. The next is copied to column 30 and the next to column 17. In this way, when the value of the reference pointer 5 becomes 4, 1 is also added to the seed column pointer 4, and the contents of column 1 of the thinning mask seed pattern 1 are copied to column 1 of the thinning mask development area. By repeating the above procedure, the thinning mask development area 3 is filled, and the thinning mask pattern development is completed. It should be noted that the pattern formed in the mask development area 3 becomes the thinning mask pattern as it is.

  FIG. 4 shows a specific pattern example applied to the mask type pattern 1 and the mask development area 3.

  By copying the pattern of each column of the mask seed pattern 1 to the mask development area 3 in the procedure as described above, the mask pattern is enlarged while maintaining the randomness as shown in the lower part of FIG. The

  On the other hand, when each column of the mask type pattern 1 is simply copied to the mask development area, it becomes a regular thinning mask pattern having a constant period as indicated by 3 'in FIG. 4B. The effect of dispersing the nozzle variation on the image is reduced. According to the experiment of the present inventor, when image recording was performed using this thinning mask pattern, periodic unevenness was clearly perceived.

  In the method of the present embodiment, a substantially random mask pattern as shown in the lower part of FIG. 4A is obtained, so that nozzle variations can be effectively dispersed on the image.

  Next, the operation of the deployment control unit 7 will be described using the flowchart of FIG.

  When a print control unit (not shown) receives a print start command, it selects one thinning mask type pattern and instructs the development control unit 7 to perform development (step S0). The expansion control unit 7 sets 0 to the seed sequence pointer 4 and the reference pointer 5 (step S1). The value of the element of the expansion column table 2 pointed to by the reference pointer 5 is read out and set as the expansion column pointer (step S3), and the column copy unit 6 selects the column of the thinning mask seed pattern 1 pointed to by the seed column pointer 4 Copy to the column of the thinning mask expansion area 3 indicated by the expansion column pointer (step S4). Next, the reference pointer 5 is advanced by 1 (step S5), and when the reference pointer 5 is equal to a multiple of the mask compression ratio R, the seed sequence pointer 4 is advanced by 1 (step S6, step S7). The% symbol represents a modulo operation. Steps S3 to S7 are repeated a number of times equal to the number E of columns in the thinning mask development area 3 (steps S2 and S8). Note that the value of the seed sequence pointer 4 can also be calculated by dividing the value of the reference pointer 5 by the mask compression ratio R.

  When the above is conceptualized, in generating a thinning mask pattern with the number of columns E, (1) a thinning mask type pattern having a column number C smaller than the column number E of the thinning mask pattern is prepared in advance. (2) Each column of the thinning mask seed pattern is copied (E / C) times, and the copied E columns are arranged so as to be different from the arrangement of the thinning mask seed pattern, and the number of columns is E. That is, a thinning mask pattern is generated. According to this, it is possible to generate a decimation mask pattern with a column number E larger than the column number C without repeating the arrangement of the decimation mask seed pattern of the column number C, and it is possible to generate a large random mask that is not noticeable as unevenness in visual characteristics. .

  In the above description, each column of the thinning mask type pattern is copied (E / C) times, but the present invention is not limited to this. That is, if the thinning mask pattern of the number of columns C is used to generate a thinning mask pattern E having a different number of columns from the arrangement of the thinning mask type pattern, the total number of final copy columns is E. The number of copies in each column is not limited to the same number.

(Second Embodiment)
In general, an ink jet recording apparatus switches between several types of passes according to required image quality. That is, it is necessary to prepare a thinning mask pattern corresponding to the type of the number of usable paths. The smaller the number of passes, that is, the lower the quality, the more the mask compression rate is increased. However, the image quality deterioration is not noticeable. Reduction is possible. As a specific example, R = 32 for 2 paths, R = 16 for 4 to 8 paths, and R = 8 for 16 paths.

  In the above embodiment, the development control unit 7 is realized as a program by a microprocessor. However, it is of course possible to realize all by an electric circuit.

  As described above, according to the above embodiment, it is possible to reduce the capacity of the thinning mask pattern without reducing the image quality of multipass printing. In other words, the capacity of the readable / writable memory on which the thinning mask pattern is developed is not different from the conventional one, but the read-only memory does not need the capacity to store the entire thinning mask pattern unlike the conventional one, and the thinning mask Since only the capacity for storing the data of the mask type pattern 1 and the one-dimensional array expansion column table 2 that are data of 1 / R (R is the compression ratio) of the pattern is required, the capacity of the read-only memory is reduced. be able to.

  According to the experiment by the present inventor, no deterioration in image quality was perceived even at R = 16 under the conditions of resolution 600 dpi, H = 640, and E = 1024. If the pattern capacity before compression is 320 KB, the compression ratio R is 16, so compression up to 20 KB is possible, and the size of the read-only memory can be changed to one smaller by one rank. Thereby, an inkjet recording apparatus can be provided at low cost.

  In the above embodiment, the data of the mask type pattern 1 and the one-dimensional array expansion column table 2 has been described as being stored in the read-only memory. Needless to say, the capacity of the readable / writable memory can be reduced.

(Other embodiments)
In addition, an object of each embodiment is to supply a storage medium (or recording medium) on which a program code of software that realizes the functions of the above-described embodiments is recorded to a system or apparatus, and a computer (or CPU) of the system or apparatus Needless to say, this can also be achieved by reading and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an operating system (OS) running on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.

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

  When the present invention is applied to the storage medium, the storage medium stores program codes corresponding to the flowcharts described above.

It is a figure which shows an example of a random thinning-out mask pattern. It is a block diagram which shows the structure of the mask pattern production | generation part for producing | generating the thinning-out mask pattern used with the inkjet recording device of this invention. It is the figure which showed typically a mode that a thinning-out mask pattern was produced | generated. It is the figure which applied the example of the specific pattern to the mask seed | species pattern and the mask expansion | deployment area | region. It is a flowchart explaining operation | movement of an expansion | deployment control apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thinning-out mask seed | pattern 2 Expansion | deployment row | line | table table 3 Thinning-out mask expansion | deployment area | region 4 Species row | line pointer 5 Reference pointer 6 Row copy part 7 Development control part

Claims (10)

A thinning-out mask pattern generation device for generating a thinning-out mask pattern whose number of columns is E,
A storage unit storing a thinning mask pattern having a column number C smaller than the column number E of the thinning mask pattern;
A means for copying each column of the thinning mask pattern of the column number C a plurality of times and generating the thinning mask pattern of the column number E composed of the copied columns;
The generation unit arranges the copied E columns so as to be different from the arrangement of the thinning mask pattern of the number of columns C, and generates the thinning mask pattern of the number of columns E. apparatus. A thinning-out mask pattern generation device for generating a thinning-out mask pattern whose number of columns is E,
A storage unit that stores a thinning mask seed pattern having a column number C smaller than the column number E of the thinning mask pattern;
Each column of the thinning mask type pattern stored in the storage unit is copied (E / C) times, and the copied E columns are arranged so as to be different from the arrangement of the thinning mask type pattern. Generating means for generating the thinning mask pattern which is E;
Thinning mask pattern generation means characterized by comprising: First storage means having a decimation mask development area with the number of columns being E;
A decimation mask seed pattern having a number of columns equal to the value obtained by dividing the number E of columns in the decimation mask expansion region by the decimation mask compression ratio R, and the number of elements is equal to the number E of columns in the decimation mask expansion region from 0 to (E-1 A second storage means having an expanded column table in which the numerical values up to
A seed sequence pointer indicating a column in the thinning mask seed pattern;
A reference pointer indicating an element in the expanded column table;
A column of the thinning mask seed pattern and indicated by the seed row pointer is a column indicated by a numerical value stored in the development column table which is a column of the thinning mask development area and indicated by the reference pointer. Column copy means to copy to the whole,
After initializing the seed column pointer and the reference pointer to point to the head element, the column copy means copies the column in the mask seed pattern to the column in the expanded column table, and the reference pointer is An expansion control means for controlling to advance the seed sequence pointer to the next element every time the sequence of proceeding to the element is repeated E times and the copy of the sequence is repeated R times;
A thinning mask pattern generation apparatus comprising: The expansion sequence table embeds numerical values from 0 to (E-1) without duplication in an array of element number E, generates two uniform distribution pseudorandom numbers from 0 to (E-1), 4. The thinning-out mask pattern generation device according to claim 3, wherein the thinning mask pattern generation device is a numerical sequence generated by performing exchange between a pair of elements as an index a plurality of times, and the appearance order is substantially uncorrelated. 4. The thinning mask pattern generation apparatus according to claim 3, wherein the second storage unit is a read-only memory. The mask pattern generation device can develop at least a plurality of thinning masks having different numbers of passes, and the thinning mask compression ratio R uses at least two different values related to the types of the plurality of thinning masks. The thinning-out mask pattern generation device according to claim 3. A thinning image is formed in accordance with a thinning mask pattern in each of the scanning means for causing the recording head for ejecting ink to scan the same main scanning region of the recording medium a plurality of times and each of the plurality of main scanning, and the same main scanning region is formed. Recording control means for completing an image of the scanning area,
An inkjet recording apparatus, wherein the thinning mask pattern is generated by the thinning mask pattern generation apparatus according to any one of claims 1 to 6. A first storage means having a decimation mask expansion area with the number of columns being E; a decimation mask seed pattern having a number of columns equal to a value obtained by dividing the number of columns E of the decimation mask expansion area by a decimation mask compression ratio R; A second storage means having a developed column table in which a numerical value from 0 to (E-1) appears equal to the number E of columns in the decimation mask expansion region, and columns in the decimation mask seed pattern; , A reference pointer indicating an element in the expanded column table, a column of the thinning mask seed pattern, and the entire column indicated by the seed column pointer is a column of the thinning mask expansion region. A thinning mask pattern is generated using an apparatus comprising column copy means for copying the entire column indicated by the numerical value stored in the expanded column table indicated by the reference pointer. A method for,
After initializing the seed column pointer and the reference pointer to point to the head element, the column copy means copies the column in the mask seed pattern to the column in the expanded column table, and the reference pointer is A method for generating a thinning mask pattern, wherein the process of proceeding to an element is repeated E times and the seed sequence pointer is advanced to the next element every time the copy of the sequence is repeated R times. A program causing a computer to execute the method according to claim 8. A storage medium storing the program according to claim 9 in a computer-readable manner.

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