Image processing apparatus, method, non-transitory computer-readable storage medium storing program, and program product

Abstract

The invention discloses an image processing apparatus, an image processing method, a non-transitory computer-readable storage medium storing a program, and a program product. The printing unit includes a first printing unit configured to be able to print dots in a first region of each pixel of the object, and a second printing unit configured to be able to print dots in a second region of each pixel of the object. As a result of the processing by the point arrangement unit, in a first edge pixel in a first edge portion of the object, a ratio at which the points are arranged in the second region is lower than a ratio at which the points are arranged in the first region, and in a second edge pixel in a second edge portion of the object different from the first edge portion, a ratio at which the points are arranged in the second region is lower than a ratio at which the points are arranged in the second region. The ratio at which the points are arranged in the first region is lower than the ratio at which the points are arranged in the second region.

Description

Technical Field

[0001] The present invention relates to an image processing device, a method, a non-transitory computer-readable storage medium storing a program, and a program product. Background Art

[0002] As is well known, in a printing device for printing color materials on a printing medium, a printing process is changed by detecting the edge of an image to improve the clarity of printed characters or lines (hereinafter referred to as edge processing). Japanese Patent Laid-Open No. 2020-52872 discloses a technology for changing the printing point inside the edge pixel in an inkjet printing device to reduce image quality degradation caused by bleeding of the printing ink on the printing medium. Summary of the invention

[0003] There is a need to further improve the image quality in the edge portion of an object.

[0004] The present invention provides an image processing device, a method, a non-transitory computer-readable storage medium storing a program, and a program product for further improving the image quality of an edge portion of an object.

[0005] The present invention, in its first aspect, provides an image processing device, comprising: a printing unit configured to print dots at a resolution higher than the resolution of image data; a quantization unit configured to perform quantization processing based on image data including an object; and a dot arrangement unit configured to arrange dots in pixels using a dot arrangement pattern corresponding to a quantization value that has undergone the quantization processing, wherein the printing unit comprises a first printing unit configured to print dots in a first zone of each pixel of the object, and a second printing unit configured to print dots in a second zone of each pixel of the object, and as a result of the processing of the dot arrangement unit, in a first edge pixel in a first edge portion of the object, a ratio of dots arranged in the second zone is lower than a ratio of dots arranged in the first zone, and in a second edge pixel in a second edge portion of the object different from the first edge portion, a ratio of dots arranged in the first zone is lower than a ratio of dots arranged in the second zone.

[0006] In its second aspect, the present invention provides a method performed by an image processing device, the method comprising: performing a quantization process based on image data including an object; and performing a process of arranging dots in pixels using a dot arrangement pattern corresponding to a quantization value that has undergone the quantization process, wherein a printing unit arranged in the image processing device and configured to be able to print dots at a resolution higher than the resolution of the image data comprises a first printing unit and a second printing unit, the first printing unit being configured to be able to print dots in a first area of ​​each pixel of the object, the second printing unit being configured to be able to print dots in a second area of ​​each pixel of the object, and as a result of the process in the dot arrangement, in a first edge pixel in a first edge portion of the object, a ratio of arranging dots in the second area is lower than a ratio of arranging dots in the first area, and in a second edge pixel in a second edge portion of the object different from the first edge portion, a ratio of arranging dots in the first area is lower than a ratio of arranging dots in the second area.

[0007] In its third aspect, the present invention provides a non-transitory computer-readable storage medium storing a program that enables a computer to: perform quantization processing based on image data including an object; and perform processing of arranging dots in pixels using a dot arrangement pattern corresponding to a quantization value that has undergone the quantization processing, wherein a printing unit configured to be able to print dots at a resolution higher than the resolution of the image data includes a first printing unit and a second printing unit, the first printing unit being configured to be able to print dots in a first area of ​​each pixel of the object, the second printing unit being configured to be able to print dots in a second area of ​​each pixel of the object, and as a result of the processing in the dot arrangement, in a first edge pixel in a first edge portion of the object, a ratio of arranging dots in the second area is lower than a ratio of arranging dots in the first area, and in a second edge pixel in a second edge portion of the object different from the first edge portion, a ratio of arranging dots in the first area is lower than a ratio of arranging dots in the second area.

[0008] In its fourth aspect, the present invention provides a program product storing a program that enables a computer to: perform quantization processing based on image data including an object; and perform processing of arranging dots in pixels using a dot arrangement pattern corresponding to a quantization value that has undergone the quantization processing, wherein a printing unit configured to be able to print dots at a resolution higher than the resolution of the image data includes a first printing unit and a second printing unit, the first printing unit being configured to be able to print dots in a first area of ​​each pixel of the object, the second printing unit being configured to be able to print dots in a second area of ​​each pixel of the object, and as a result of the processing in the dot arrangement, in a first edge pixel in a first edge portion of the object, a ratio of arranging dots in the second area is lower than a ratio of arranging dots in the first area, and in a second edge pixel in a second edge portion of the object different from the first edge portion, a ratio of arranging dots in the first area is lower than a ratio of arranging dots in the second area.

[0009] In its fifth aspect, the present invention provides an image processing device, which includes: an acquisition unit, which is configured to acquire image data including an object; a detection unit, which is configured to detect a first edge pixel in a first edge portion of the object and a second edge pixel in a second edge portion different from the first edge portion from the image data acquired by the acquisition unit; and a printing unit, which is configured to be able to print dots at a resolution higher than the resolution of the image data acquired by the acquisition unit, wherein the printing unit includes a first printing unit configured to be able to print dots in a first area of ​​each pixel of the object, and a second printing unit configured to be able to print dots in a second area of ​​each pixel of the object, the detection unit detects the first edge pixel and the second edge pixel by pattern matching by using a filter and a lookup table, and detects each of the first edge pixel and the second edge pixel in at least one of a nozzle array direction of the printing unit and a scanning direction of the printing unit different from the nozzle array direction.

[0010] According to the present invention, the image quality in the edge portion of the object can be further improved.

[0011] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a diagram showing the configuration of a printing apparatus;

[0013] Figure 2A and Figure 2B are diagrams and block diagrams showing a configuration including an image processing apparatus;

[0014] Figure 3A and Figure 3B is a flowchart showing the processing of the image processing unit;

[0015] FIG. 4A to FIG. 4C is a diagram for explaining edge pattern detection;

[0016] Figure 5 is a diagram used to illustrate pattern matching;

[0017] Figure 6 is a flowchart showing the processing of the image processing unit;

[0018] 7A to 7C are flowcharts, tables, and graphs illustrating processing of an image processing unit;

[0019] FIG. 8A to FIG. 8D is a diagram for explaining index expansion processing;

[0020] 9A to 9C is a diagram showing the configuration of a print head;

[0021] FIG. 10A to FIG. 10G is a diagram for explaining data that has undergone various processes by an image processing unit;

[0022] FIG. 11A to FIG. 11E is a diagram for explaining data that has undergone various processes by an image processing unit;

[0023] FIG. 12A to FIG. 12D are a flowchart and a diagram showing the processing of the image processing unit;

[0024] FIG. 13A to FIG. 13E is a diagram for explaining data that has undergone various processes by an image processing unit;

[0025] FIG. 14A to FIG. 14H is a diagram for explaining data that has undergone various processes by an image processing unit;

[0026] FIG. 15A to FIG. 15G is a diagram for explaining data that has undergone various processes by an image processing unit;

[0027] FIG. 16A to FIG. 16C are a flowchart and a diagram showing the processing of the image processing unit;

[0028] Fig.17A and Fig. 17B is a flowchart showing the processing of the image processing unit;

[0029] 18A to 18C are graphs and diagrams for explaining data that have undergone various processes by the image processing unit;

[0030] FIG. 19A to FIG. 19Fis a diagram for explaining data that has undergone various processes by an image processing unit;

[0031] FIG. 20A to FIG. 20C are graphs and diagrams for explaining data that have undergone various processes by the image processing unit;

[0032] FIG. 21A to FIG. 21D is a diagram for explaining index expansion processing;

[0033] Fig.22A and Fig. 22B is a diagram for explaining index expansion processing;

[0034] FIG. 23A to FIG. 23D is a diagram for explaining index expansion processing;

[0035] FIG. 24A to FIG. 24F is a diagram for explaining data that has undergone various processes by an image processing unit;

[0036] FIG. 25A to FIG. 25C is a diagram for explaining index expansion processing;

[0037] Fig.26A and Fig.26B is a flowchart showing the processing of the image processing unit;

[0038] FIG. 27A to FIG. 27F is a diagram for explaining data that has undergone various processes by an image processing unit;

[0039] FIG. 28A to FIG. 28D is a diagram for explaining data that has undergone various processes by an image processing unit;

[0040] Fig.29A and Fig.29B is a flowchart showing the processing of the image processing unit;

[0041] FIG. 30A to FIG. 30C is a diagram for explaining data that has undergone various processes by an image processing unit;

[0042] Fig.31A and Fig.31B is a flowchart showing the processing of the image processing unit;

[0043] FIG. 32A to FIG. 32D is a diagram for explaining data that has undergone various processes by an image processing unit;

[0044] FIG. 33A to FIG. 33C are block diagrams and tables showing a configuration including an image processing apparatus;

[0045] FIG. 34A to FIG. 34C are flowcharts and tables showing processing of an image processing unit;

[0046] FIG. 35A to FIG. 35D is a diagram for explaining the configuration of an image processing unit;

[0047] FIG. 36A to FIG. 36C are tables and diagrams for explaining the configuration of the image processing unit;

[0048] FIG. 37A to FIG. 37D is a diagram for explaining the configuration of an image processing unit; and

[0049] Fig.38A and Fig.38B is a diagram showing end pixel groups. DETAILED DESCRIPTION

[0050] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments are not intended to limit the scope of the claimed invention. A plurality of features are described in the embodiments, but are not limited to inventions requiring all such features, and a plurality of such features may be appropriately combined. In addition, in the accompanying drawings, the same reference numerals are given to the same or similar configurations, and redundant descriptions thereof are omitted.

[0051] [First embodiment]

[0052] <Structure of Printing Device>

[0053] The following will refer to Figure 1 The structure of the printing apparatus according to the present embodiment is described. Figure 1 1 is a perspective view showing an overview of a printing unit in a printing device 2 (hereinafter also referred to as a printing device or a printer). The printing medium P (hereinafter also referred to as a printing medium) fed to the printing unit is transported in the -Y direction (sub-scanning direction) by the roller gap portion between the conveying roller 101 arranged on the conveying path and the pinch roller 102 linked to the conveying roller 101, along with the rotation of the conveying roller 101. The platen 103 is set at a printing position facing the surface (nozzle surface) where the nozzles of the print head H using the inkjet printing method are formed, and the distance between the front of the printing medium P and the nozzle surface of the print head H is maintained constant by supporting the back of the printing medium P from below. The printing medium P in the printing area on the platen 103 is transported in the -Y direction along with the rotation of the discharge roller 105 while being clamped by the discharge roller 105 and the gear 106 linked to the discharge roller 105, and then discharged to the discharge tray 107.

[0054] The print head H is detachably mounted on the carriage 108 in a posture where the nozzle surface faces the platen 103 or the print medium. The carriage 108 reciprocates in the X direction, which is the main scanning direction, along two guide rails 109 and 110 by the driving force of a carriage motor (not shown). In the moving process, the print head H performs a discharge operation according to a discharge signal. The ±X directions in which the carriage 108 moves are directions orthogonal to the -Y direction in which the print medium is conveyed, and are referred to as the main scanning directions. Conversely, the -Y direction in which the print medium is conveyed is referred to as the sub-scanning direction. By alternately repeating the main scanning (movement together with the discharge operation) of the carriage 108 and the print head H and the conveying (sub-scanning) of the print medium, an image is gradually formed on the print medium P. The contents of the structure of the printing device according to the present embodiment are described.

[0055] <Structure of Print Head>

[0056] The following will refer to 9A to 9C The structure of the print head according to the present embodiment is described. 9A to 9C 1 is a schematic diagram of the print head H used in this embodiment when viewed from above the printing device. The print head H includes print chips 1105 and 1106, and each print chip receives a print signal from the main body of the printing device via a contact pad (not shown) and is supplied with power required to drive the print head. Fig. 9A As shown, a nozzle array 1101 (hereinafter also referred to as a black nozzle array) is arranged on a print chip 1105, in which a plurality of nozzles for discharging black ink are arranged in the Y direction. Similarly, on a print chip 1106, a nozzle array 1102 for discharging cyan ink, a nozzle array 1103 for discharging magenta ink, and a nozzle array 1104 for discharging yellow ink are arranged.

[0057] Fig. 9B This is an enlarged view of the black nozzle array 1101. Fig. 9CIt is an enlarged view of one nozzle array among nozzle arrays 1102, 1103 and 1104 (i.e., a total of three nozzle arrays of cyan, magenta and yellow). This enlarged view is common to color inks. Nozzles 1108 or 1111 for discharging ink are arranged on both sides of ink chamber 1107 or 1110. Discharge heater 1109 or 1112 is arranged directly below each nozzle (+Z direction side). When heater 1109 or 1112 is applied with voltage, heater 1109 or 1112 generates heat to generate bubbles, so that the corresponding nozzle discharges ink. 832 nozzles 1108 and 768 nozzles 1111 are arranged. Each nozzle 1108 discharges black ink, and Ev column and Od column are arranged, each of which is formed by arranging nozzle 1108 at a pitch of 600dpi in the Y direction. Ev column is arranged by shifting half a pitch in the -Y direction relative to Od column. By performing print scanning using the black nozzle array 1101 having the above configuration, printing can be performed on a print medium at a print density of 1,200 dpi. The cyan nozzle array 1102 , magenta nozzle array 1103 , and yellow nozzle array 1104 each have the same configuration as that of the black nozzle array 1101 .

[0058] Note that the print head H of the present embodiment has a configuration including a print chip having a black nozzle array and a print chip having a cyan nozzle array, a magenta nozzle array, and a yellow nozzle array, but the present invention is not limited to this configuration. More specifically, all black nozzle arrays, cyan nozzle arrays, magenta nozzle arrays, and yellow nozzle arrays may be assembled on one chip. Alternatively, a print head equipped with a print chip having a black nozzle array may be separated from a print head equipped with a print chip having a cyan nozzle array, a magenta nozzle array, and a yellow nozzle array. Alternatively, the black nozzle array, the cyan nozzle array, the magenta nozzle array, and the yellow nozzle array may be assembled on different print heads, respectively. In addition, the print head H of the present embodiment adopts a so-called bubble jet method of discharging ink by applying a voltage to a heater to generate heat, but the present invention is not limited thereto. More specifically, a configuration that uses an electrostatic actuator or a piezoelectric element to discharge ink may be used. The contents of the structure of the print head according to the present embodiment are described above.

[0059] Figure 2A 1 is a diagram showing an example of a configuration of a printing system including an image forming apparatus 10 equipped with a printing apparatus 2. As an example, Figure 2A FIG. 1 shows a cloud printing system in which a terminal device 11, a cloud printing server 12, and an image forming device 10 are connected via a network 13. The cloud printing server 12 is a server device that provides a cloud printing service. Figure 2AIn the configuration shown, the image forming device 10 is a printer that supports cloud printing. The network 13 is a wired network, a wireless network, or a network including both. For example, the Internet, a WAN, or a VPN environment is assumed as the network 13. However, the printing system is not limited to the cloud printing system. For example, the network 13 can be formed as an office LAN, or the terminal device 11 and the image forming device 10 can be directly connected without the intervention of the network 13. Figure 2A One terminal device 11 and one image forming device 10 are shown, but a plurality of terminal devices 11 and a plurality of image forming devices 10 may be provided. The cloud print server 12 may be a server system formed of a plurality of information processing devices. The printing system may be a cloud print system in which a plurality of cloud print services cooperate with each other.

[0060] The terminal device 11 is an information processing device such as a PC, a tablet, or a smartphone, and a cloud printer driver for the cloud printing service is installed in the terminal device 11. The user can execute arbitrary application software on the terminal device 11. For example, based on the image data generated on the printing application, a print job and print data are generated via the cloud printer driver. The print job and print data are transmitted to the image forming device 10 registered in the cloud printing service via the cloud printing server 12. The image forming device 10 is a device that performs printing on a printing medium such as a sheet, and prints an image on the printing medium based on the received print data.

[0061] <Control system configuration>

[0062] The following will refer to Figure 2B The configuration of the control system according to the present embodiment is described. Figure 2B 2 is a schematic block diagram of the image processing apparatus 100. This embodiment assumes that the image processing apparatus 100 is included in the image forming apparatus 10. However, the image processing apparatus 100 may be formed as a device connected to the image forming apparatus 10 including the printer 2 and the scanner 202. For example, the image processing apparatus 100 may be formed in the host computer 201. In this case, the image processing apparatus 100 does not need to include the print head control unit 213 or the scanner IF control unit 205.

[0063] The host computer 201 is, for example, an information processing device for creating a print job formed from input image data and print condition information required for printing, and communicates with, for example, Figure 2A The illustrated terminal device 11 corresponds to this. Note that the printing condition information is information on the type and size of print sheets, print quality, and the like.

[0064] The scanner 202 is a scanner device connected to the image processing apparatus 100, and converts analog data generated by optically reading a document placed on a scanner table into digital data via an A / D converter. When the host computer 201 transmits a scan job to the image processing apparatus 100, the reading of the scanner 202 is performed, but the present invention is not limited thereto. A dedicated UI device connected to the scanner 202 or the image processing apparatus 100 may replace the scanner 202.

[0065] The ROM 206 is a readable memory that stores a program for controlling the image processing apparatus 100. The CPU 203 controls the image processing apparatus 100 by executing the program stored in the ROM 206. The host IF control unit 204 communicates with the host computer 201, receives a print job and the like, and stores the print job in the RAM 207. The RAM 207 is a readable / writable memory used as a program execution area or a data storage area.

[0066] The image processing unit 208 generates printable nozzle data separated for each nozzle from the input image data stored in the RAM 207 according to the printing conditions included in the print job. The generated nozzle data is stored in the RAM 207. The image processing unit 208 includes a decoder unit 209, a scanned image correction unit 216, an image analysis unit 210, a color separation / quantization unit 211, and a nozzle separation processing unit 212.

[0067] The print head control unit 213 generates print data based on the nozzle data stored in the RAM 207, and controls the print head H within the printer 2. The shared bus 215 is connected to each of the CPU 203, the host IF control unit 204, the scanner IF control unit 205, the ROM 206, the RAM 207, and the image processing unit 208. These connected units can communicate with each other via the shared bus 215. The contents of the configuration of the control system according to the present embodiment are described above.

[0068] <Overall Process>

[0069] The procedure of edge processing according to the present embodiment will be described below. Figure 3A FIG. 2 is a flowchart showing the processing performed by the image processing unit 208 according to the present embodiment. Figure 3A By the process shown, input image data can be converted into nozzle data.

[0070] In step S301, the image processing unit 208 acquires input image data from the RAM 207. In step S302, the decoder unit 209 performs a decoding process on the acquired input image data. The storage format of the input image data is different, and a compression format such as JPEG is generally used to reduce the amount of communication between the host computer 201 and the image processing device 100. In the case where the storage format is JPEG, the decoder unit 209 decodes the JPEG and converts the JPEG into a bitmap format (an information format that records an image as a continuous pixel value). In the case where the host computer 201 communicates with the image processing device 100 via a dedicated driver or the like, a dedicated storage format can be processed. In the case of maintaining a dedicated storage format that is convenient for both the driver and the image processing device 100, the decoder unit 209 can perform a conversion to a dedicated storage format. According to the characteristics of, for example, an inkjet printing device, a storage format with different compression rates can be applied to an area where information is desired to be maintained with fine precision and other areas. If it is desired to focus on image quality rather than reducing the amount of communication, the input image data can be in a bitmap format. In this case, the decoder unit 209 only needs to output the bitmap format in its entirety as a conversion result.

[0071] In step S303, the image analysis unit 210 performs image analysis using the bitmap image as a decoding result. In the present embodiment, by performing image analysis, it is estimated whether the target pixel is paper white or is in the end of a pixel formed with ink different from the target pixel based on the features in the image. In addition, the end where the target pixel exists in a specific direction among the upper, lower, left, and right directions in the shape formed by the pixel group is estimated.

[0072] Figure 3B 2 shows the internal processing procedure of the image analysis processing performed in step S303. In step S401, the image analysis unit 210 converts the bitmap image as the decoding result into a brightness value. For example, if the bitmap image data is information of three channels of R, G and B, the bitmap image data is converted into one channel of brightness Y. Note that if the image data transmitted from the user through the application is already represented by brightness, step S401 does not need to be performed.

[0073] In step S402, the image analysis unit 210 converts the data of the brightness Y into binary data for edge detection. In the present embodiment, as an example, by using the threshold data Th pre-set corresponding to the printing mode of the printer, the image analysis unit 210 converts the data into binary data (Bin) by the following conditional expression (1). The binary data generation expression is only an example, and the design of the inequality condition and the form of the expression are not limited thereto.

[0074] If Y>Th, then Bin=0

[0075] Otherwise, Bin=1...(1)

[0076] In the present embodiment, image analysis is performed using an index of brightness. In an inkjet printing device, the tones of black ink used in color separation are limited. This is because the paper surface density of black ink relative to paper white for each drop changes greatly, and thus by frequently using black ink from a low tone, the image quality is easily deteriorated from the perspective of granularity. Therefore, it is easy to judge the generation position of black ink based on the brightness information of the input image compared with other color inks. By setting the above-mentioned threshold data Th to an appropriate value, a brightness value corresponding to the tones in which the black ink after ink separation is ejected by a predetermined amount or more can be set in the brightness information. In the present embodiment, the number and arrangement of black ink dots and the number and arrangement of other color ink dots adjacent to the black ink can be controlled, and the use of the brightness value is under this control. However, the embodiment is not limited thereto. For example, color separation can be performed in advance for analysis processing, and the pixels of black ink generated as a predetermined color component can be correctly grasped. If color separation is performed in advance, the pixels of cyan, magenta and yellow inks generated in addition to black ink and the discharge amount of ink can be grasped, so that a more detailed analysis can be performed. The input image data may be in CMYK format or the like instead of RGB format, and in the case of the input image data, information effective for analysis may be included. If the discharge amounts of cyan, magenta, and yellow inks are known, when the discharge amounts are small, the color may be considered to be equivalent to paper white, and judgments such as analysis of black ink generated in an area on the paper corresponding to paper white may be performed. In the present embodiment, the judgment is represented by threshold data Th. The threshold data Th may be appropriately updated according to the degree of consumption of each nozzle in the nozzle arrays 1101 to 1104 of the print head in the printing device.

[0077] In step S403 , the image analysis unit 210 performs edge pattern detection using binary data.

[0078] Figure 4A and Figure 4BEach shows an example of pattern information for edge pattern detection. The pattern information includes two types of information, namely, "pattern matching data generation information" and "edge pattern detection result generation information". The pattern matching data generation information is obtained by performing bit AND processing on each pixel in the rectangular area of ​​the binary data obtained in step S402. The pattern matching data obtained as a result of the bit AND processing is obtained by extracting only the information required to detect the edge pattern from the rectangular area. The edge pattern detection result generation information is information for performing pattern matching processing on the pattern matching data. If a complete match is obtained as a result of the pattern matching processing, the rectangular area is judged to be a predetermined edge pattern. The judgment result is associated with the central pixel in the rectangular area.

[0079] Figure 4A Pattern information for judging that the target pixel is "in the left / right end of the 1-point vertical line" is shown. The pattern matching data generation information is set with a value that causes edge pattern detection to be performed on the 3×3 pixels including the target pixel. Pixels to which "0" is added in the pattern matching data generation information are regarded as pixels that are not considered in pattern matching regardless of how the binary data is formed. Next, the edge pattern detection result generation information corresponds to the above-mentioned predetermined edge pattern, and in this example is a pattern in which only the three pixels in the central vertical column are set to 1 among the 3×3 pixels. This information corresponds to the judgment of whether the three pixels in the central vertical column have low brightness and whether the remaining six pixels have high brightness. If the pattern matching data completely matches the pattern, it is found that there is a high brightness characteristic = paper white or low-concentration color ink on at least the left and right sides, and a low brightness characteristic = black ink exists in the target pixel and its upper and lower pixels.

[0080] Figure 4B Pattern information for judging that a target pixel is not only "in the left / right end of a 1-dot vertical line" but also "in a part of a 1-dot / 1 space" is shown. "1-dot / 1 space" indicates a pattern in which a plurality of 1-dot vertical lines are arranged at intervals of 1 dot. By widening the range of pattern matching data generation information to 7×3 pixels, information related to the surroundings of the 1-dot line to which the target pixel belongs can be included for judgment.

[0081] Figure 4C Show use Figure 4A or Figure 4B The result of pattern matching on binary data one by one. Figure 4A When the pattern matching data generation information and edge pattern detection result generation information shown are applied to the target binary data, the judgment result is judged to be "matching". Figure 4BWhen the pattern matching data generation information and edge pattern detection result generation information shown are applied to the target binary data, the judgment result is judged as "mismatch". Based on the two pattern detection results, it is found that the binary data is "in the left / right end of the 1-point vertical line", but "not in a part of the 1-point / 1 space".

[0082] Based on the above method, various edge patterns can be detected. In this embodiment, 7×7 pixels are set as the target of pattern matching, but this is only an example. For example, if you only need to be able to detect Figure 4A or Figure 4B , 7×3 pixels are sufficient as the target of pattern matching. On the other hand, if it is desired to detect line shapes of more than 4 point lines separately, 7×7 pixels are not enough, and a wider area can be set as the target. By widening the target range, a working memory for holding binary data to be compared and a working memory for holding pattern matching information are more needed. The working memory corresponds to RAM 207. In the case where the image analysis unit 210 is implemented as a dedicated circuit, when it is desired to process multiple pixels by performing pattern matching using a parallel clock, the number of processing registers and processing circuits increases. In addition, since it is necessary to pre-hold pattern matching information in ROM 206 of the image processing device 100, the capacity of ROM 206 is also required. If the edge pattern is confirmed finely and variously, more pattern matching information needs to be held, and thus it is necessary to design in consideration of the memory capacity and the increase in analysis time caused by the increase in the number of comparisons. Making a judgment of "0" = "not considered in pattern matching" in the pattern matching data generation information helps to reduce the memory capacity and reduce the number of comparisons. As other configurations for reducing the memory capacity, such as Figure 5 As shown, other variations of pattern matching can also be performed by processing such as rotation or phase shift. Figure 5 The upper side of Figure 4A The pattern matching information shown is rotated 90°, and the processed pattern information can be used to determine that the target pixel is "in the upper / lower end of the 1-point horizontal line". Figure 5 The lower side, Figure 4A The pattern information shown is horizontally shifted by 1 pixel, and the processed pattern matching information can be used to determine that the target pixel is a "neighboring pixel of a 1-point vertical line". Figure 5 In , variation is added by processing pattern matching information. However, variation can be added by processing binary data.

[0083] like Figure 4C As shown, it is effective to narrow down the judgment result by applying a plurality of pattern matching information one by one and obtain information unknown by a single pattern matching information. Figure 4C When it is judged as Figure 4A When the pattern shown is "matched", it may not be necessary to make judgments on more than two lines prepared in advance. Figure 4B As shown, by applying only the pattern matching information of more detailed information for judging the 1-point line, the effect of reducing the number of comparisons is obtained. Figure 4A or Figure 4B , find that the target binary data is "in the left and right ends of the 1-point vertical line" and "not in a part of the 1-point / 1 space". Not by preparing available separate pattern matching information, but by Figure 4A and Figure 4B The information is derived from the results of , achieving the effect of reducing memory capacity.

[0084] As described above, in the present embodiment, it is possible to determine whether the target pixel is a pixel to be subjected to special processing such as processing of thinning out dots or processing of changing the arrangement of dots. This processing is merely an example, and an example in the case where there are more restrictions on the memory / speed of the image processing apparatus 100 will be described later in another embodiment.

[0085] The judgment result of the image analysis process in step S303 is output in an information format suitable for the processing in the subsequent steps. For example, the judgment result can be represented by 3-bit multi-value data such as non-detection (not applicable to any detection mode) = 0, upper end detection = 1, lower end detection = 2, left end detection = 3, right end detection = 4, and adjacent to one of the ends = 5. Alternatively, the representation of the allocation of each bit within 5 bits such as non-detection = 00000, upper end detection = 00001, lower end detection = 00010, left end detection = 00100, right end detection = 01000, and adjacent to one of the ends = 10000 is also possible. The former can transmit the judgment result to the next processing with a small amount of data. The latter has the advantage of reducing the processing load because the bit processing can be used for the next processing. It is explained that five information is transmitted to the subsequent steps. However, as described in step S303, "pattern matching information can be represented in a variety of ways", more information than the control information required for the subsequent processing steps can be detected and transmitted.

[0086] Figure 6 and Fig. 7AAn example of the internal processing procedures of the color separation / quantization processing performed in step S304 and the nozzle separation processing performed in step S305 is shown. Note that the following description assumes that the bitmap image as the decoding result of step S302 includes pixels arranged at 600 dpi, and each pixel has an 8-bit 256-level brightness value for each color of R (red), G (green), and B (blue). In the end information detected in step S303, the upper end (first end), the lower end (second end), the right end (fourth end), and the left end (third end) are defined as pixels that change from 1 to 0 in Bin in the -Y direction, +Y direction, +X direction, and -X direction, respectively, and are located on the side of Bin=1. Since the nozzles of each color of the print head H are arranged at 1,200 dpi in the Y direction, each pixel is printed using the nozzles of the Ev column (hereinafter referred to as the Ev nozzle) and the nozzles of the Od column (hereinafter referred to as the Od nozzle). At this time, the nozzle located on the upper end side of each pixel is defined as an upstream side nozzle, and the nozzle located on the lower end side of each pixel is defined as a downstream side nozzle. In the present embodiment, it is assumed that the upstream side nozzle corresponds to the Ev nozzle, and the downstream side nozzle corresponds to the Od nozzle. That is, in the present embodiment, this configuration has a print resolution in the Y direction that is twice the resolution of the image data to be subjected to edge pattern detection.

[0087] In the color correction process of step S801, the color separation / quantization unit 211 converts the RGB data of each pixel into R'G'B' data expressed in a color space specific to the printing apparatus. As a detailed conversion method, for example, conversion can be performed by referring to a lookup table pre-stored in a memory.

[0088] In step S802, the color separation / quantization unit 211 performs color separation processing on the R'G'B' data. More specifically, with reference to a lookup table pre-stored in the memory, the brightness values ​​R', G' and B' of each pixel are converted into 8-bit 256-level concentration values ​​C, M, Y and K corresponding to the ink color used by the printing device. In addition, the color separation / quantization unit 211 copies the concentration value data of one or more colors of C, M, Y and K, thereby generating a total of two consistent data. For simplicity, an example of generating black data K1 and K2 will be described. Note that K1 and K2 are respectively applied to the Ev nozzle and Od nozzle of the black nozzle array 1101 through processing (to be described later).

[0089] In steps S803 to S805, the color separation / quantization unit 211 uses the density value K1 and the result of the judgment in step S303 to perform different tone correction processing based on whether the processed pixel is in the second end. In steps S806 to S808, the color separation / quantization unit 211 uses the density value K2 and the result of the judgment in step S303 to perform different tone correction processing based on whether the processed pixel is in the first end. The tone correction processing is such a correction that the input density value and the optical density represented by the print medium P have a linear relationship. This correction processing converts the 8-bit 256-level density values ​​K1 and K2 into 8-bit 256-level density values ​​K1' and K2'. If it is detected in step S303 that the pixel is in the second end, the density value K1 is converted to K1'=0 in step S805; otherwise, the density value K1 is converted to K1' by the first tone correction processing in step S804. On the other hand, if the pixel is detected in the first end portion in step S303 , the density value K2 is converted to K2 ′=0 in step S808 ; otherwise, the density value K2 is converted to K2 ′ by the first tone correction process in step S807 . Figure 7B and Figure 7C is a table and a graph showing an example of settings of the first tone correction process, in which In corresponds to density values ​​K1 and K2 and Out corresponds to density values ​​K1' and K2'. In this description, for simplicity, an example in which In and Out have a linear relationship is shown.

[0090] In step S809, the color separation / quantization unit 211 performs a predetermined quantization process on the density value K1' to convert the density value K1' into 4-bit 3-value quantized data (quantized values) of "0000", "0001" and "0010". In this example, three values ​​of low density, medium density and high density are represented. In addition, in steps S810 to S812, the color separation / quantization unit 211 uses the result of the judgment in step S303 to set the value in the most significant bit based on whether the processed pixel is in the first end, and outputs 4-bit quantized data K1". More specifically, if the pixel is detected to be in the first end, the most significant bit is set to 1 in step S812; otherwise, the most significant bit is set to 0 in step S811. Similarly, in step S813, the color separation / quantization unit 211 performs a predetermined quantization process on the concentration value K2' to convert the concentration value K2' into 4-bit 3-value quantized data of "0000", "0001" and "0010". In this example, three values ​​of low concentration, intermediate concentration and high concentration are represented. In addition, in steps S814 to S816, the color separation / quantization unit 211 uses the result of the judgment in step S303 to set the value in the most significant bit based on whether the processed pixel is in the second end, and outputs 4-bit quantized data K2". More specifically, if it is detected that the pixel is in the second end portion, the most significant bit=1 is set in step S816; otherwise, the most significant bit=0 is set in step S815.

[0091] In step S305, the nozzle separation processing unit 212 performs index expansion processing on the quantized data K1" and K2" output in step S304. In the index expansion processing of this embodiment, the 600×600 dpi quantized data K1" and K2" are converted into 600×600 dpi binary nozzle data K1p and K2p using a pre-prepared index pattern. Fig. 7A In step S817, the quantized data K1" is converted into nozzle data K1p by a first index expansion process, and in step S818, the quantized data K2" is converted into nozzle data K2p by a second index expansion process. In other words, the index pattern is a dot arrangement pattern for arranging dots in a pixel.

[0092] FIG. 8A to FIG. 8D is a diagram showing an example of a reference index pattern and a dot arrangement pattern used in index expansion processing. Fig. 8AIt is a diagram showing the dot arrangement pattern of the first index expansion processing. If the quantization data K1" of a pixel of 600dpi×600dpi indicates "0000" or "1000", dots are definitely not arranged in the pixel. If the quantization data K1" indicates "0001", a pattern A in which dots are arranged and a pattern B in which dots are not arranged are prepared. If the quantization data K1" indicates "0010", "1001" or "1010", dots are definitely arranged in the pixel. Figure 8B It is a diagram showing the dot arrangement pattern of the second index expansion processing. If the quantization data K2" of one pixel of 600dpi×600dpi indicates "0001", a pattern A without arranged dots and a pattern B with arranged dots are prepared. If the quantization data K2" indicates "0000", "1000", "0010", "1001" or "1010", the same processing as in the first index expansion processing is performed. Figure 8C 1 is a diagram showing an example of a reference index pattern. In this embodiment, different index patterns are used in the first index expansion process in step S817 and the second index expansion process in step S818, but each pattern is a reference index pattern. Figure 8C The reference index pattern shown in FIG. 2 is created. In the reference index pattern, each rectangle corresponds to a pixel area of ​​600 dpi×600 dpi, and for each pixel, it is determined which of the modes A and B is used to arrange the dots. The nozzle separation processing unit 212 generates nozzle data K1p for each pixel after the first index expansion process as data for the Ev nozzle of the black nozzle array 1101 corresponding to each pixel, and stores the data in the RAM 207. In addition, the nozzle separation processing unit 212 generates nozzle data K2p for each pixel after the second index expansion process as data for the Od nozzle of the black nozzle array 1101 corresponding to each pixel, and stores the data in the RAM 207. Fig.8D The figure shows binary data of 600 dpi in the X direction and 1,200 dpi in the Y direction after index expansion processing when the quantized data of each pixel all consistently indicate "0001" (intermediate density), and the positional relationship between the data and the nozzles of the black nozzle array 1101. Fig.8D As shown, for the 0th data, the second data, the fourth data, ..., in the data in the Y direction, dots are formed by the Ev nozzle, and for the first data, the third data, the fifth data, ..., dots are formed by the Od nozzle. Thus, for each pixel of the input image data of 600 dpi × 600 dpi, printing / non-printing of each nozzle of the black nozzle array 1101 is set, thereby setting printing / non-printing of 600 dpi × 1200 dpi. The contents of the process of edge processing according to the present embodiment are described above.

[0093] <Modification of Color Separation / Quantization Unit and Nozzle Separation Processing Unit>

[0094] To implement this embodiment, the processing of the color separation / quantization unit 211 and the nozzle separation processing unit 212 is not limited to Figures 6 to 8D Example shown.

[0095] For example, Fig. 8A and Figure 8B The examples of settings of the index expansion processing shown in each example show a dot arrangement pattern and a so-called 1-bit index pattern in which the dot arrangement information is equivalent to the dot arrangement information of the nozzle data, but the present invention is not limited to this example. For example, for the dot arrangement pattern of one pixel, the pixel where no dots are arranged is set to "00". The pixel where dots are arranged can be represented by 2 bits, for example, by "01" when the most significant bit of the quantization data is "0", or by "10" when the most significant bit of the quantization data is "1". In addition, the nozzle separation processing unit 212 can generate nozzle data K1p' and K2p' equivalent to the dot arrangement condition by multiplying the nozzle data K1p and K2p generated based on the above-mentioned dot arrangement pattern by a mask pattern. The mask pattern is obtained by representing one pixel stored in the ROM 206 or the RAM 207 with 2 bits. For example, in the case where the nozzle data K1p is "00", K1p'=0 is set even for any mask pattern, and the same dot arrangement condition as in the present embodiment is obtained. In addition, when the nozzle data K1p is "01", the mask pattern "01" or "11" is used to set K1p'=1, or when K1p is "10", the mask pattern "10" or "11" is used to set K1p'=1, and a predetermined mask pattern is applied, thereby obtaining the same dot arrangement conditions as in the present embodiment. The nozzle data K2p is the same as K1p.

[0096] Figure 6 The example of processing each of the density value K1 referenced by the Ev nozzle and the density value K2 referenced by the Od nozzle is shown, but it is also possible to perform FIG. 16A to FIG. 16C Processing shown.

[0097] Fig.16A and Fig. 16B It is shown Figure 6Flowchart of a modified example of the present invention. Step S2201 is the same as step S801, and its description will be omitted. In step S2202, the color separation / quantization unit 211 performs color separation processing on the R'G'B' data to convert the R'G'B' data into concentration values ​​C, M, Y and K. The conversion method is the same as that in step S802. However, unlike step S802, the processing of copying the concentration value data is not performed. For simplicity, an example of the processing of black data K will be described.

[0098] In step S2203, the color separation / quantization unit 211 performs tone correction processing on the density value K to convert the density value K into a density value K'. The method of the tone correction processing is the same as that in step S804 or S807, and a description thereof will be omitted.

[0099] In step S2204, the color separation / quantization unit 211 performs a predetermined quantization process on the concentration value K' to convert the concentration value K' into 4-bit 3-value quantized data of "0000", "0001" and "0010". In addition, in steps S2205 to S2209, the color separation / quantization unit 211 uses the result judged in step S303 to set the value in the highest 2 bits based on the end information of the processed pixel, and outputs the 4-bit quantized data K". If the pixel is detected in the first end, the highest 2 bits are set to 01 in step S2209. If it is determined that the pixel is not in the first end but in the second end, the highest 2 bits are set to 10 in step S2208. If the pixel is detected neither in the first end nor in the second end, the highest 2 bits are set to 00 in step S2207.

[0100] In step S2210, the nozzle separation processing unit 212 performs index expansion processing on the quantized data K" output in step S304. In the index expansion processing in this example, the 600×600 dpi quantized data K" is converted into 600 dpi×600 dpi binary nozzle data K1p and K2p using a pre-prepared index pattern.

[0101] Fig. 16C is a diagram showing an example of a dot arrangement pattern used in the index expansion process. Fig. 16CThe dot arrangement pattern shown. If the quantization data K" indicates "0000", "0100" or "1000", no dots are arranged on the upper and lower sides of the pixel. If the quantization data K" indicates "0001", mode A for arranging dots on the upper side and mode B for arranging dots on the lower side are prepared. If the quantization data K" indicates "0010", dots are definitely arranged on both the upper and lower sides of the pixel. If the quantization data K" indicates "0101" or "0110", dots are definitely arranged on the upper side of the pixel, and dots are definitely not arranged on the lower side of the pixel. If the quantization data K" indicates "1001" or "1010", dots are definitely arranged on the lower side of the pixel, and dots are definitely not arranged on the upper side of the pixel. The reference index mode is the same as Figure 8C Then, the nozzle separation processing unit 212 generates data on the upper side in the arrangement information on the upper and lower sides of each pixel as data for the Ev nozzle of the black nozzle array 1101 corresponding to each pixel (which is the nozzle data K1p), and stores the data in the RAM 207. Furthermore, the nozzle separation processing unit 212 generates data on the lower side in the synthetic nozzle data Kp of each pixel as data for the Od nozzle of the black nozzle array 1101 corresponding to each pixel (which is the nozzle data K2p), and stores the data in the RAM 207.

[0102] Using the above process, Figures 6 to 8D The data printed by each nozzle is obtained as in the process shown in FIG. 1 , and the same effect can be obtained. More specifically, for example, in the case where "0110" indicates the upper end, dots are definitely not arranged on the lower side of the pixel, and in the case where "1010" indicates the lower end, dots are definitely not arranged on the upper side of the pixel. The above describes the contents related to the modified examples of the color separation / quantization unit and the nozzle separation processing unit according to the present embodiment.

[0103] <Processing When Shifting the Nozzle to Be Used>

[0104] The present embodiment illustrates an example in which the upstream side nozzle of each pixel is the Ev nozzle and the downstream side nozzle is the Od nozzle, but this is merely an example. For example, for the purpose of correcting the physical position shift in the Y direction that may occur between the black nozzle array 1101 and each of the remaining color nozzle arrays 1102 to 1104, the black nozzle may be shifted by 1200dpi×odd number in the Y direction relative to the input image, thereby performing printing. In this case, the Ev nozzle and the Od nozzle to be used may be interchangeable. In step S305, the nozzle separation processing unit 212 generates nozzle data K1p as data for the Od nozzle of the black nozzle array 1101, and generates K2p as data for the Ev nozzle of the black nozzle array 1101, so that the same effect can be obtained. The above describes the content of the processing when the nozzle to be used is shifted according to the present embodiment.

[0105] <Processing of Nozzle Arrays Other Than Black Nozzle Array>

[0106] This embodiment illustrates the processing of step S803 and subsequent steps only for black data. However, in step S802, data other than black data, i.e., density value data of cyan, magenta, and yellow, are also output. The same processing as that of the black data is performed on these data. Alternatively, as will be described below, a processing different from that of the black data may be used.

[0107] Fig. 12A and Fig. 12B An example of the internal processing procedures of the color separation / quantization processing performed in step S304 and the nozzle separation processing performed in step S305 is shown. Steps S4701 and S4702 are the same as steps S801 and S802, respectively. In addition, steps S4703 and S4704 are the same as steps S804 and S809, respectively, and their description will be omitted.

[0108] In step S4705, the color separation / quantization unit 211 uses the result of the judgment in step S303 to output 4-bit quantized data C", M", and Y". Based on whether the processed pixel is a pixel adjacent to a specific end, the specific end is, for example, the first end or the second end. More specifically, if it is detected that the pixel is a pixel adjacent to a specific end, the most significant bit of the quantized data is set to 1 in step S4707; otherwise, the most significant bit of the quantized data is set to 0 in step S4706.

[0109] In step S4708, the nozzle separation processing unit 212 performs index expansion processing on each of the quantized data C", M", and Y" output in step S304. In the index expansion processing in this example, the 600dpi×600dpi quantized data C", M", and Y" are converted into 600dpi×600dpi binary nozzle data C1p, C2p, M1p, M2p, Y1p, and Y2p using a pre-prepared index pattern.

[0110] Fig. 12C and Fig.12D are diagrams each showing an example of a dot arrangement pattern used in index expansion processing. Fig. 12C shows a Y" arrangement pattern, and Fig.12D The arrangement patterns of C" and M" are shown. Fig. 12C and Fig.12D The dot arrangement patterns shown are each obtained by vertically connecting arrangement information of 600dpi×1200dpi. When "0000" or "1000" is indicated for each of the quantized data C", M", and Y", dots of the corresponding color are not arranged on the upper side or the lower side of the pixel. When "0001" is indicated for each of the quantized data C", M", and Y", a pattern A in which dots of the corresponding color are arranged on the upper side and a pattern B in which dots of the corresponding color are arranged on the lower side are prepared. In the case where "0010" is indicated for each of the quantized data C", M", and Y", the dots of the corresponding color are definitely arranged on each of the upper and lower sides of the pixel. For each of the quantized data C" and M", even in the case where "1010" is indicated, the dots of the corresponding color are definitely arranged on each of the upper and lower sides of the pixel. On the other hand, if "1010" is indicated for the quantized data Y", mode A for arranging the dots of the corresponding color on the upper side and mode B for arranging the dots of the corresponding color on the lower side are prepared. Reference index mode and Figure 8CThen, the nozzle separation processing unit 212 generates the data of the upper side in the arrangement information of the upper and lower sides of the cyan dot of each pixel as the data for the Ev nozzle of the cyan nozzle array 1102 corresponding to each pixel (which is the nozzle data C1p), and stores the data in the RAM 207. In addition, the nozzle separation processing unit 212 generates the data of the lower side in the arrangement information of the upper and lower sides of the cyan dot of each pixel as the data for the Od nozzle of the cyan nozzle array 1102 corresponding to each pixel (which is the nozzle data C2p), and stores the data in the RAM 207. The same applies to magenta and yellow. As described above, for cyan and magenta, the same dot arrangement is obtained regardless of whether the pixel is adjacent to a specific end, so the dot is not thinned out. On the other hand, for yellow, in the case where the pixel is adjacent to a specific end, the dot is thinned out. It is described that for yellow, the dots are thinned out in the case where the pixel is adjacent to a specific end, but it is not limited to yellow. Similarly, for cyan or magenta, the dots can be thinned out in the case where the pixel is adjacent to a specific end. The processing of nozzle arrays other than the black nozzle array is described above. Note that this description is common to all embodiments of the present invention.

[0111] <Edge processing of horizontal lines>

[0112] Will refer to FIG. 10A to FIG. 11E Based on Figure 3 to Fig.8D The process shown is used to describe an example of edge processing using this embodiment. Fig. 10A is a diagram showing an input image used in this specification, in which a horizontal line is arranged as an object of the image. The horizontal line is an image that extends uniformly in a direction intersecting with the array direction of the nozzles of the print head H. Fig. 10A In the image processing, pixels are arranged at 600 dpi, each pixel has an 8-bit 256-level brightness value for each of R, G and B, and the so-called black pixels having a brightness value of 0 for R, G and B form a line having a pixel width of four pixels in the Y direction which is the array direction of the nozzles.

[0113] After the image processing unit 208 acquires the input image in step S301, the decoder unit 209 performs decoding processing on the input image in step S302. For simplicity, it is assumed that the image that has undergone the decoding processing is the same as Fig. 10A For the image that has undergone the decoding process, in step S303, the image analysis unit 210 detects a specific end portion to which each pixel corresponds. Fig. 10B : is a diagram showing the data of the brightness Y after the brightness conversion in step S401. Fig. 10C 3 is a diagram showing binary data obtained by binarizing the data of luminance Y by setting Th=50 in step S402 . Fig. 10D FIG. 4 is a diagram showing the result of edge determination for the above binary data. Fig. 10D , “0” indicates non-detection, “1” indicates the upper end, and “2” indicates the lower end.

[0114] Next, in step S304 , the color separation / quantization unit 211 performs color separation / quantization processing on the image that has undergone the decoding processing in step S302 based on the edge end detection result in step S303 . Fig. 10E : is a diagram showing density values ​​K1 and K2 after the color separation process is performed in step S802. Fig.10F is a diagram showing the density value K1′ after the tone correction processing in steps S803 to S805, but shows an example in which the second end is determined to be the lower end in step S803. Fig. 10D The pixel indicated by “2” in FIG. 1 (ie, the lower pixel) has a density value of 0. Figure 10G is a diagram showing the density value K2' after the tone correction processing in steps S806 to S808, but shows an example in which the first end is determined to be the upper end in step S806. Fig. 10D The pixel indicated by “1” in FIG. 1 (ie, the upper pixel) has a density value of 0. Fig.11A is a diagram showing quantized data K1" that has undergone steps S809 to S812, and Fig. 11B is a diagram showing quantized data K2″ that has undergone steps S813 to S816. An example is shown in which the density value 128 is quantized to “0001” and the density value 255 is quantized to “0010” in both steps S809 and S813. The definitions of the first end and the second end in steps S810 and S814 are the same as those in steps S803 and S806, respectively. Therefore, as Fig.11A As shown, in Fig.10F In the pixel with K1'=255, Fig. 10D The pixel indicated by "1" (i.e., the upper pixel) has quantized data "1010" and the remaining pixels have "0010". Fig. 11B As shown, in Figure 10G In the pixel with K2'=255, Fig. 10D The pixel indicated by "2" in FIG. 1 (ie, the lower pixel) has the quantized data "1010" and the remaining pixels have "0010".

[0115] Next, in step S305 , the image quantized in step S304 is subjected to index expansion processing by the nozzle separation processing unit 212 . Fig. 11C and Fig.11D ] are diagrams showing nozzle data K1p and K2p after the index expansion processing in steps S817 and S818, respectively. Fig.11E is a diagram showing dot arrangement when the print head H performs printing at 600 dpi×1200 dpi based on the nozzle data K1p and K2p. Fig. 10A , Fig. 10D and Fig.11E , found: Fig. 10A Among the pixels with brightness value 0 in Fig. 10D In each pixel that is not at the upper or lower end, Fig.11E The dots are arranged in each area of ​​600dpi×1200dpi in the image. Then, it is found that: Fig. 10A Among the pixels with brightness value 0 in Fig. 10D In the pixels judged to be in the upper end, only for the upstream nozzle (ie, Fig.11E In addition, it is found that: Fig. 10A Among the pixels with brightness value 0 in Fig. 10D In the pixels judged to be in the lower end, only for the downstream nozzle (ie, Fig.11E Od nozzle) arrangement point in the.

[0116] As described above, in the present embodiment, in an apparatus configuration capable of printing dots at a high resolution in the Y direction compared to the image data to be subjected to edge detection, the upper end pixel and the lower end pixel are detected as edge pixels on the object side of two opposite sides (one side and the other side) of the edge portion of the object in the image data. Then, by changing the dot arrangement by judging whether each edge pixel is an upper end pixel or a lower end pixel, the dots in the area closer to the inner side of the object (hereinafter referred to as the non-end side) are eliminated, and the dots in the area closer to the end side of the object (hereinafter referred to as the end side) are not eliminated. That is, such a dot arrangement is used that the ratio of forming dots on the non-end side is lower than the ratio of forming dots on the end side, and the magnitude relationship between these ratios is equal between the upper end edge pixel and the lower end edge pixel. This dot arrangement can reduce the deterioration of image quality caused by bleeding of printing ink on the printing medium. In addition, since edge detection can be performed using an apparatus configuration (that is, image data with a resolution lower than the resolution in the nozzle array direction of the print head H), the load of image processing can be reduced.

[0117] [Second embodiment]

[0118] <Edge processing of two pixels or less in width>

[0119] The second embodiment will be described below with regard to points different from the first embodiment. The first embodiment explains processing in the case where a horizontal line having a width of four pixels is an object of an input image. Fig.13AThe following figure shows that pixels are arranged at 600 dpi, each pixel has an 8-bit 256-level brightness value for each of R, G and B, and the so-called black pixels having a brightness value of 0 for R, G and B indicate a horizontal line having a width of two pixels in the Y direction (hereinafter referred to as a 2-point horizontal line). Fig. 13B FIG. 4 shows the edge detection result when the processing of the first embodiment is applied to a 2-point horizontal line. Fig. 13B As shown, the pixel for indicating the upper end "1" and the pixel for indicating the lower end "2" are adjacent to each other in the Y direction. Fig. 13C is a diagram showing the arrangement of points after processing is performed based on the above-mentioned edge detection result and index expansion processing is performed in step S305. Fig. 13C As shown in FIG. 1 , the thinned-out regions are adjacent to each other in the Y direction. In this case, the thinned-out regions are easily visually perceived, and a visual mismatch between the input image and the printed image may occur. Fig.13A Note that steps S301 and S302 are the same as those in the first embodiment, and description thereof will be omitted.

[0120] In the image analysis processing performed in step S303, the image analysis unit 210 detects a 2-dot horizontal line at the time of edge detection in step S403. Then, as a result of the detection, "1" is output for the upper end pixel, and "0" is output as non-detection for the lower end pixel, similarly to the first embodiment. Note that "0" is output for the lower end pixel only in the case of a 2-dot width horizontal line. That is, in the case of detecting a horizontal line having a width of three or more pixels, "2" is output similarly to the first embodiment. Fig.13D 304 and 305 are the same as those in the first embodiment, and description thereof will be omitted.

[0121] Fig.13E 2 is a diagram showing the dot arrangement of a 2-dot horizontal line when printing is performed after the index expansion process is performed in step S305 of the present embodiment. Fig.13E As shown, since the upper pixel has the same edge detection result as the edge detection result of the upper pixel in the first embodiment, the dots are thinned out similarly to the first embodiment. On the other hand, since the lower pixel is not detected as an edge pixel, the same processing as the processing of the pixel not detected as an edge pixel in the first embodiment is performed, and the dots are not thinned out. As described above, by changing only the edge judgment for the lower pixel of the 2-dot horizontal line so that the thinned-out areas are not adjacent to each other in the Y direction, the possibility of visual mismatch between the input image and the printed image can be reduced.

[0122] Note that in this embodiment, in step S403, the lower pixel is processed as non-detection, but this is only an example. For example, for the upper pixel of the detected 2-point horizontal line, "0" can be output as non-detection, and similarly to the first embodiment, for the lower pixel, "2" can be output. In this case as well, the thinned-out areas are not adjacent to each other in the Y direction, so the same effect can be obtained.

[0123] In addition, for a horizontal line having a width of one pixel (hereinafter referred to as a 1-dot horizontal line), if the same processing as in the first embodiment is performed, the number of dots on the print medium is halved. Also in this case, the density change caused by the spacing elimination is easily perceived visually, and a visual mismatch between the input image and the printed image may occur. In order to reduce the possibility of such a mismatch, during edge detection in step S403, a 1-dot horizontal line can be detected, a non-detection "0" can be output for the pixel, and spacing elimination may not be performed in subsequent processing. Note that for the same reason, for a vertical line having a width of one pixel (1-dot vertical line) or a pixel surrounded by pixels with Bin=0 on the upper, lower, left, and right sides, a non-detection can be output in step S403, and spacing elimination may not be performed in subsequent processing.

[0124] [Third embodiment]

[0125] <Edge processing of solid images>

[0126] The third embodiment will be described below with regard to points different from the first and second embodiments. The first embodiment explains processing in the case where a horizontal line having a width of four pixels is an object of an input image. Fig.14A : is a diagram showing an input image in which pixels are arranged at 600 dpi, each pixel has an 8-bit 256-level brightness value for each of R, G, and B, so-called black pixels having a brightness value of 0 for R, G, and B are arranged, and an object including a left end pixel and a right end pixel is included. The above-mentioned image having a rectangular shape will hereinafter be referred to as a solid image. Fig. 14B 3 is a diagram showing a dot arrangement after the same processing as in the first embodiment is applied to a solid image and index expansion processing is performed in step S305. Fig. 14B As shown, some dots are not thinned out in the left and right end pixels. At the left and right ends of the printed image, in order to reduce the degradation of image quality caused by the bleeding of the printing ink on the printing medium, it is preferred to thin out the dots in the left and right end pixels. This embodiment will describe Fig.14ANote that steps S301 and S302 are the same as those in the first embodiment, and description thereof will be omitted.

[0127] In the image analysis processing performed in step S303, at the time of edge detection in step S403, the image analysis unit 210 outputs "1" for the left end pixel, similarly to the case where "1" is output for the upper end pixel as in the first embodiment. Also, "2" is output for the right end pixel, similarly to the case where "2" is output for the lower end pixel as in the first embodiment. Fig. 14C 303 is a diagram showing the edge detection result in step S303 of the present embodiment. Note that in the present embodiment, "1" is output for the lower left pixel in the left end and lower end, and "2" is output for the upper right pixel in the right end and upper end. This is just an example, and other settings are possible. Steps S304 and S305 thereafter are the same as in the first embodiment.

[0128] Fig.14D 1 is a diagram showing the dot arrangement of a solid image when printing is performed after the nozzle separation processing unit 212 performs index expansion processing in step S305 of the present embodiment. Fig.14D As shown, the left end pixel has the same dot arrangement as the upper end pixel, and the right end pixel has the same dot arrangement as the lower end pixel. That is, it is found that dots are thinned out for the left end pixel and the right end pixel.

[0129] As described above, in this embodiment, in addition to the upper and lower end pixels of the edge pixels of the two opposite sides of the object, the left and right end pixels are also detected and judged. By changing the point arrangement according to the judgment result, the points in the left and right end portions are eliminated, so that the degradation of the image quality in these portions can be reduced.

[0130] Note that in the present embodiment, in step S403, "1" and "2" are output for the left end pixel and the right end pixel, respectively. However, this is merely an example, and other combinations may be used. Even if "1" and "1", "2" and "1", or "2" and "2" are output, dots in the left end pixel and the right end pixel are thinned out, and thus the same effect may be obtained.

[0131] Note that in this embodiment, in step S403, "1" and "2" are output for the left end pixel and the right end pixel, respectively, but "3" and "4" may be output to identify these pixels. Then, in step S806 or S810, the first end is determined by determining whether "1" or "3" is detected, and in step S803 or S814, the second end is determined by determining whether "2" or "4" is detected. Thus, the same effect can be obtained.

[0132] On the other hand, for a vertical line having a width of two pixels (hereinafter referred to as a 2-dot vertical line), if the same processing as in the present embodiment is performed, the number of dots on the print medium is halved. Similar to the second embodiment, in this case as well, the density change caused by the spacing elimination is easily visually perceived, and a visual mismatch between the input image and the printed image may occur. In order to reduce the possibility of such a mismatch, similar to the 2-dot horizontal line in the second embodiment, the 2-dot vertical line may be detected during edge detection in step S403, a non-detection "0" may be output for the left end pixel or the right end pixel, and the dots may not be spaced out in subsequent processing.

[0133] [Fourth embodiment]

[0134] <Edge Processing of Intermediate Density Solid Images>

[0135] The fourth embodiment will be described below with respect to the differences from the first to third embodiments. The first to third embodiments each explain the processing in the case where an object in an input image has a brightness value of 0 for R, G, and B (i.e., a so-called black pixel). Of course, the present invention is not limited to black pixels. Fig.14E As shown, an example of edge processing of an intermediate density solid image will be described below by exemplifying a case where the brightness value of an object is 128 for R, G, and B. Note that all processing of steps S301 to S305 is the same as in the third embodiment, and description thereof will be omitted.

[0136] Fig.14F 4 is a diagram showing data of brightness Y after brightness conversion is performed by the image analysis unit 210 in step S401 . Figure 14G 3 is a diagram showing binary data obtained by binarizing the data of luminance Y by setting Th=50 in step S402 . Fig.14H is a diagram showing the result of edge detection from binary data. Fig.14H As shown, it is found that: even if the input image has an intermediate density, the edge end is detected by outputting "1" for the upper pixel and the left pixel and outputting "2" for the lower pixel and the right pixel. This is because the image that has undergone brightness conversion is binarized by setting Th=50 and the image is used for edge detection.

[0137] Fig.15A 1 shows the density value K1′ after the tone correction processing is performed by the color separation / quantization unit 211 in steps S803 to S805. Fig.15A As shown, in Fig.14H The pixels indicated by "2" in the figure (i.e., the lower and right pixels) have a density value of 0, and the remaining pixels of the object have a density value of Figure 7B and Figure 7C The tone correction process shown corresponds to a conversion value of 128. Fig. 15B The density value K2' after the tone correction process is performed in steps S806 to S808 is shown. Fig. 15B As shown, in Fig.14H The pixels indicated by "1" in the image (i.e., the upper and left pixels) have a density value of 0, and the remaining pixels of the object have the same density value as Figure 7B and Figure 7C The tone correction process shown corresponds to a conversion value of 128. Fig. 15C is a diagram showing quantized data K1″ obtained by performing quantization by the color separation / quantization unit 211 in step S809 and performing steps S810 to S812 under the conditions described in the first embodiment. Fig.15D 2 is a diagram showing quantized data K2″ obtained by performing quantization by the color separation / quantization unit 211 in step S813 and performing steps S814 to S816 under the conditions described in the first embodiment. Fig. 15C As shown, in Fig.15A In the pixels with K1'=128, Fig.14H The pixels indicated by "1" in the image (i.e., the upper pixel and the left pixel) have quantized data "1001" and the remaining pixels have "0001". Fig.15D As shown, in Fig. 15B In the pixels with K2'=128, Fig.14H The pixels indicated by "2" in FIG. 1 (ie, the lower end pixel and the right end pixel) have quantized data "1001" and the remaining pixels have "0001".

[0138] Fig.15E and Fig.15F 1 and 2 are diagrams showing nozzle data K1p and K2p obtained after the index expansion processing is performed by the nozzle separation processing unit 212 in steps S817 and S818, respectively. Figure 15G is a diagram showing dot arrangement when the print head H performs printing at 600 dpi×1200 dpi based on the nozzle data K1p and K2p. Figure 15G As shown, Fig.8D Similarly, pixels with quantization data K1" and K2" of "0001" (i.e., pixels not judged as end pixels) have different dot arrangements in 600dpi×600dpi. On the other hand, for the upper end pixel and the left end pixel, dots are evenly arranged only for the upstream side nozzle (i.e., the Ev nozzle). Furthermore, for the lower end pixel and the right end pixel, dots are evenly arranged only for the downstream side nozzle (i.e., the Od nozzle). That is, the dot arrangement of the end pixel is different from Fig.14D The dot arrangement in the third embodiment shown is the same. This is because Fig. 8A and Figure 8B It is shown that the same arrangement is set for the quantized data "1001" and "1010".

[0139] As described above, in this embodiment, also for the medium density object, each edge pixel of the object is detected and judged to be an upper pixel, a lower pixel, a left pixel or a right pixel, and the dot arrangement is changed accordingly. This can make the dot arrangement of the edge pixels uniform and improve the clarity of the end. In addition, for the upper and lower ends, the dots are arranged only on the end side of the edge pixels, so that the degradation of the image quality caused by the bleeding of the printing ink on the printing medium can be reduced.

[0140] [Fifth embodiment]

[0141] <Modification of Dot Arrangement of Edge Pixels by Applying Tone Correction Processing>

[0142] The fifth embodiment will be described below with respect to the differences from the first to fourth embodiments. The first to fourth embodiments each illustrate an example of an arrangement in which, when the dots of edge pixels are eliminated or the arrangement is changed, the dots are evenly arranged on the end side of the pixel, and the dots are not arranged on the non-end side. However, this example is merely an example, and the optimal dot arrangement of edge pixels may differ depending on the configuration of the printing device and the degree of bleeding of the printing ink on the printing medium, etc. For example, an arrangement in which dots are applied on the non-end side of the edge pixels or an arrangement in which dots on the end side of the edge pixels are eliminated may be preferred. This embodiment will describe an example of edge processing in which the above arrangement is achieved by applying a tone correction process performed by the color separation / quantization unit 211. Note that in the example to be described below, all steps S301 to S303 are the same as in the first embodiment, and their description will be omitted.

[0143] Fig.17A and Fig. 17BAn example of the internal processing procedure of the color separation / quantization processing performed by the color separation / quantization unit 211 in step S304 according to the present embodiment is shown. Steps S2401 and S2402 are respectively the same as steps S801 and S802, and their description will be omitted. In steps S2403 to S2407, the color separation / quantization unit 211 converts the concentration value K1 into the concentration value K1' by performing different tone correction processing using the result judged in step S303. More specifically, if the pixel is in the second end in step S303, the concentration value is converted into K1' by the third tone correction processing in step S2407. If the pixel is not in the second end but in the first end, the concentration value is converted into K1' by the second tone correction processing in step S2406. If the pixel is neither in the second end nor in the first end, the concentration value is converted into K1' by the first tone correction processing in step S2405. On the other hand, in steps S2408 to S2412, the color separation / quantization unit 211 converts the concentration value K2 into a concentration value K2' by performing different tone correction processes using the results judged in step S303. More specifically, if the pixel is in the first end in step S303, the concentration value is converted into K2' by the third tone correction process in step S2412. If the pixel is not in the first end but in the second end, the concentration value is converted into K2' by the second tone correction process in step S2411. If the pixel is neither in the first end nor in the second end, the concentration value is converted into K2' by the first tone correction process in step S2410. The first tone correction process in this embodiment is the same as the first tone correction process described in the first embodiment. The second tone correction process is a correction of the tone value of the number of points on the end side of the edge pixel for controlling the edge pixel, and the third tone correction process is a correction of the tone value of the number of points on the non-end side of the edge pixel for controlling the edge pixel. The details of these processes will be described later. In step S2413, the color separation / quantization unit 211 performs the same quantization processing as in step S809 on the concentration value K1' to convert the concentration value K1' into 4-bit 3-value quantized data. In addition, in steps S2414 to S2416, the color separation / quantization unit 211 uses the result of the judgment in step S303 to set the value in the most significant bit of the quantized data based on the end information of the processed pixel, and outputs the 4-bit quantized data K1". More specifically, if the pixel is detected to be in the first end or the second end, the most significant bit is set to 1 in step S2416; otherwise, the most significant bit of the quantized data is set to 0 in step S2415. Similarly, in step S2417, the color separation / quantization unit 211 performs the same quantization processing as in step S812 on the concentration value K2' to convert the concentration value K2' into 4-bit 3-value quantized data.In addition, in steps S2418 to S2420, the color separation / quantization unit 211 uses the result of the judgment in step S303 to set the value in the most significant bit of the quantization data based on the end information of the processed pixel, and outputs 4-bit quantization data K2". The detailed processing content is the same as that in steps S2414 to S2416. Next, in step S305, the image quantized in step S304 is subjected to index expansion processing by the nozzle separation processing unit 212. The processing content is the same as that in the first embodiment, and its description will be omitted.

[0144] Similar to the third embodiment, the following will describe a case where the first end is the upper end or the left end, the second end is the lower end or the right end, and the input image is as follows: Fig.14A An example of actual processing in the case shown.

[0145] Fig.18A An example of the setting of the second tone correction process and the third tone correction process for realizing the arrangement of the dots applied on the non-end side of the edge pixel is shown. In this example, the dot arrangement on the end side of the edge pixel is the same as in the first to fourth embodiments, and thus the second tone correction process is equivalent to the first tone correction process. On the other hand, in the third tone correction process, Out=0 is set for In≤128, Out is gradually increased for In>128, and Out=32 is set for In=255. Fig.18B and Fig. 18C Density values ​​K1' and K2' obtained by applying these setting values ​​are shown respectively. Fig.19A and Fig.19B 24 are diagrams respectively showing quantized data K1 ″ obtained by executing steps S2413 to S2416 on the density value K1 ′ and quantized data K2 ″ obtained by executing steps S2417 to S2420 on the density value K2 ′. Fig.19C 305 are diagrams showing the dot arrangement when printing is performed after the index expansion process is performed in step S305. As shown in these diagrams, since the density value K1 of the right end pixel and the lower end pixel is "32", some quantization data of the pixel may have a probability of being "1001", and the dots are arranged accordingly on the downstream side of the pixel. On the other hand, since the density value K2 of the left end pixel and the upper end pixel is "32", some quantization data of the pixel may have a probability of being "1001", and the dots are arranged accordingly on the upstream side of the pixel. That is, it is possible to implement the arrangement of applying dots on the non-end side of the upper end pixel and the lower end pixel. Note that in this specification, the maximum value of the third tone correction process is set to "32", but the present invention is not limited to this value. For example, if it is preferred to apply more dots on the non-end side of the edge pixel, a value greater than "32" can be set. On the other hand, if it is preferred to reduce the dots, a value less than "32" can be set.

[0146] Fig. 20A An example of the arrangement of the second tone correction process and the third tone correction process for realizing an arrangement in which dots on the end side of edge pixels are thinned out is shown. In this example, the dot arrangement on the non-end side of edge pixels is the same as in the first to fourth embodiments, and thus in the third tone correction process, Out=0 is set regardless of the value of In. On the other hand, in the second tone correction process, in the area where Out≤96, the relationship between In and Out is the same as in the first tone correction process, and Out=96 is set in areas other than the above-mentioned area. Fig. 20B and Fig. 20C Density values ​​K1' and K2' obtained by applying these setting values ​​are shown respectively. Fig.19D and Fig.19E 24 are diagrams respectively showing quantized data K1 ″ obtained by executing steps S2413 to S2416 on the density value K1 ′ and quantized data K2 ″ obtained by executing steps S2417 to S2420 on the density value K2 ′. Fig.19F 305 are diagrams showing the dot arrangement when printing is performed after the index expansion process is performed in step S305. As shown in these diagrams, since the concentration value K1 of the left end pixel and the upper end pixel is "96", some quantization data of the pixel may have a probability of being "0000", and the dots on the upstream side of the pixel are correspondingly spaced out. On the other hand, since the concentration value K2 of the right end pixel and the lower end pixel is "96", some quantization data of the pixel may have a probability of being "0000", and the dots on the downstream side of the pixel are correspondingly spaced out. That is, an arrangement in which dots on the end side of the upper end pixel and the lower end pixel are spaced out can be achieved. Note that in this specification, the maximum value of the second tone correction process is set to "96", but the present invention is not limited to this value. For example, if it is preferred to apply more dots to the end side of the edge pixel, a value greater than "96" can be set. On the other hand, if it is preferred to reduce the dots, a value less than "96" can be set.

[0147] As described above, in this embodiment, it is detected and judged whether each edge pixel of the object is an upper pixel, a lower pixel, a left pixel or a right pixel, and the tone correction processing is changed accordingly. Similar to the first to fourth embodiments, this can control the ratio of dots formed in the outer area and the ratio of dots formed in the inner area while making the ratio of dots formed on the non-end side lower than the ratio of dots formed on the end side.

[0148] [Sixth embodiment]

[0149] <Modification of Dot Arrangement of Edge Pixels by Applying Index Expansion Processing>

[0150] The sixth embodiment will be described below with regard to the differences from the first to fifth embodiments. The fifth embodiment illustrates an example of tone correction processing performed by the color separation / quantization unit 211 as a configuration for realizing an arrangement in which points are applied to the non-end side of edge pixels or an arrangement in which points on the end side of edge pixels are thinned out. The above arrangement can be achieved by index expansion processing performed by the nozzle separation processing unit 212. This embodiment will describe an example of edge processing. Note that in the example to be described below, all steps S301 to S303 are the same as those in the third embodiment, and their description will be omitted. Step S304 is the same as that described as a modification of the first embodiment. Fig.16A Similar to the third embodiment, it is assumed that the input image is Fig.14A Similar to the third embodiment, it is also assumed that the first end is the upper end or the left end, and the second end is the lower end or the right end.

[0151] FIG. 21A to FIG. 21C 305 is a diagram showing an example of settings of the third index expansion process performed by the nozzle separation processing unit 212 in step S305 , and settings for realizing arrangement of applying points on the non-end side of edge pixels. Fig.21A : is a diagram showing an example of a dot arrangement pattern. If the quantization data K" indicates "0000", "0100" or "1000", dots are not arranged on either the upper or lower side of the pixel. If the quantization data K" indicates "0001", modes A and C for arranging dots on the upper side and modes B and D for arranging dots on the lower side are prepared. If the quantization data K" indicates "0010", dots are definitely arranged on each of the upper and lower sides of the pixel. If the quantization data K" indicates "0101", dots are definitely arranged on the upper side of the pixel, and dots are definitely not arranged on the lower side of the pixel. If the quantization data K" indicates "0110", dots are definitely arranged on the upper side of the pixel. Then, only for mode D, dots are also arranged on the lower side. If the quantization data K" indicates "1001", dots are definitely arranged on the lower side of the pixel, and dots are definitely not arranged on the upper side of the pixel. If the quantization data K" indicates "1010", dots are definitely arranged on the lower side of the pixel. Then, only for mode D, dots are also arranged on the upper side. In addition, the nozzle separation processing unit 212 uses two reference index modes according to the quantization data. More specifically, if the quantization data K" indicates "0000", "0001", "0010", "0100" or "1000", the first reference index mode is used; otherwise, the second reference index mode is used. Fig.21B is a diagram showing a first reference index mode, and Fig. 21C is a diagram showing a second reference index pattern. Fig.21Dis a diagram of dot arrangement when the setting value is applied. As shown in these diagrams, in the left end pixel and the upper end pixel, in the pixel indicating "D" in the second reference index mode, the dot is also arranged on the downstream side. Similarly, in the right end pixel and the lower end pixel, the dot is also arranged on the upstream side. That is, it is possible to implement the arrangement of the dot applied on the non-end side of the upper end pixel and the lower end pixel.

[0152] Fig.22A 305 is a diagram showing an example of the setting of the third index expansion process executed by the nozzle separation processing unit 212 in step S305 and the setting of an arrangement for realizing thinning out dots on the end side of edge pixels. Fig.22A is a diagram showing an example of a dot arrangement pattern. If the quantization data K" indicates "0000", "0100", "1000", "0001" or "0010", the arrangement is the same as Fig.21A If the quantization data K" indicates "0101" or "0110", modes A, B, and C in which dots are arranged only on the upper side of the pixel and mode D in which dots are not arranged on the upper side or the lower side are prepared. If the quantization data K" indicates "1001" or "1010", modes A, B, and C in which dots are arranged only on the lower side of the pixel and mode D in which dots are not arranged on the upper side or the lower side are prepared. In addition, the nozzle separation processing unit 212 uses two reference index modes according to the quantization data. The relationship between the quantization data K" and the reference index mode to be used is as follows Fig.21A and the first reference index mode and the second reference index mode are respectively Fig.21B and Fig. 21C The first reference index pattern and the second reference index pattern shown in are the same. Fig. 22B is a diagram of dot arrangement when the setting value is applied. As shown in these diagrams, for the left end pixel and the upper end pixel, the dots on the upstream side of the pixel indicating "D" in the second reference index mode are eliminated. Similarly, for the right end pixel and the lower end pixel, the dots on the downstream side are eliminated. That is, an arrangement in which the dots on the end side of the upper end pixel and the lower end pixel are eliminated can be achieved.

[0153] As described above, in this embodiment, it is detected and determined whether each edge pixel of the object is an upper pixel, a lower pixel, a left pixel or a right pixel, and the index expansion processing is changed accordingly. Similar to the first to fourth embodiments, this can control the ratio of forming points on the non-end side and the ratio of forming points on the end side while making the ratio of forming points on the non-end side lower than the ratio of forming points on the end side. Note that this embodiment illustrates an example of using four point arrangement modes of mode A to mode D, but the present invention is not limited to this setting. By defining more point arrangement modes and preparing a reference index mode corresponding to the point arrangement mode, the application amount of points on the non-end side of the upper pixel and the lower pixel, or the amount of interval elimination of points on the end side can be further controlled. Although this embodiment illustrates an example of changing the reference index mode only for edge pixels, the present invention is not limited to this setting. Even if a common reference index mode is used for edge pixels and other pixels, points can be applied on the non-end side of the upper pixel and the lower pixel, or the point interval on the end side can be eliminated.

[0154] [Seventh embodiment]

[0155] <Edge Processing in the Case of Performing Printing with High Resolution in the X Direction>

[0156] The seventh embodiment will be described below with regard to the points different from the first to sixth embodiments. The first to sixth embodiments each explain edge processing in a device configuration that prints dots at a high resolution in the Y direction (i.e., the array direction of nozzles of each color) compared to image data to be subjected to edge detection. This embodiment will describe the process of edge processing in a device configuration that prints dots at a high resolution in the X direction (i.e., the main scanning direction of the print head H).

[0157] As a first process of the present embodiment, an example will be described in which at most two dots are arranged in a pixel of 600dpi×600dpi regardless of whether the pixel is an edge pixel. Steps S301 to S304 are the same as those in the third embodiment, and their description will be omitted. In step S305, the nozzle separation processing unit 212 performs index expansion processing on the quantized data K1" and K2" output in step S304. In the index expansion processing of the present embodiment, a pre-prepared index pattern is used to convert the quantized data K1" and K2" of 600dpi×600dpi into nozzle data K1p and K2p obtained by horizontally connecting the data of 1200dpi×600dpi. In step S817, the quantized data K1" is converted into nozzle data K1p by a first index expansion processing, and in step S818, the quantized data K2" is converted into nozzle data K2p by a second index expansion processing.

[0158] Fig.23A and Fig. 23B are diagrams showing examples of dot arrangement patterns of the first index expansion process and the second index expansion process, respectively. In the first index expansion process, if the quantization data K1" indicates "0000" or "1000", dots are definitely not arranged on the left or right side of the pixel. If the quantization data K1" indicates "0001", mode A for arranging dots on the left side and mode B for not arranging dots on the left or right side are prepared. If the quantization data K1" indicates "0010", "1001" or "1010", dots are definitely arranged only on the left side. In the second index expansion process, if the quantization data K2" indicates "0000" or "1000", dots are definitely not arranged on the left or right side of the pixel. If the quantization data K2" indicates "0001", mode A for arranging dots neither on the left nor on the right side and mode B for arranging dots on the left side are prepared. If the quantization data K2" indicates "0010", "1001" or "1010", dots are definitely arranged only on the right side. Baseline index pattern and Figure 8C Then, the nozzle separation processing unit 212 generates nozzle data K1p as data for the Ev nozzle of the black nozzle array 1101 corresponding to each pixel, and stores the data in the RAM 207. In addition, the nozzle separation processing unit 212 generates nozzle data K2p as data for the Od nozzle of the black nozzle array 1101 corresponding to each pixel, and stores the data in the RAM 207. When the print head H is controlled by generating the print data 214 from the nozzle data K1p and K2p, in the case where the main scanning direction of the print head H is the +X direction, the print head control unit 213 generates the nozzle data K1p and K2p in the order from the left data to the right data. On the other hand, in the case where the main scanning direction of the print head H is the -X direction, the print head control unit 213 generates the nozzle data K1p and K2p in the order from the right data to the left data.

[0159] FIG. 23C to FIG. 24F 304 is a diagram showing a processing example of the first process. Note that in step S304, the first end is the left end, and the second end is the right end. Fig.23C is a diagram showing an input image having vertical lines as objects. The vertical lines are images extending uniformly in the array direction of the nozzles of the print head H. Fig.23C In the image sensor, pixels are arranged at 600 dpi, each pixel has an 8-bit 256-level brightness value for each of R, G, and B, and so-called black pixels having a brightness value of 0 for R, G, and B form a line having a width of four pixels in the X direction. Fig.23D 3 is a diagram showing the result of edge detection performed on the input image by the image analysis unit 210 in step S303. Fig.23DAs shown, similarly to the third embodiment, the left end pixel is indicated by "1", and the right end pixel is indicated by "2". Fig.24A 1 shows the density value K1′ obtained after the color separation / quantization unit 211 performs the tone correction processing in steps S803 to S805. Fig.24A As shown, in Fig.23D The pixel indicated by “2” in FIG. 1 (ie, the right end pixel) has a density value of 0. Fig. 24B The density value K2′ obtained after the tone correction processing is performed in steps S806 to S808 is shown. Fig. 24B As shown, in Fig.23D The pixel indicated by “1” in (ie, the left end pixel) has a density value of 0. Fig.24C is a diagram showing quantized data K1″ obtained by performing quantization by the color separation / quantization unit 211 in step S809 and performing steps S810 to S812 under the conditions described in the first embodiment. Fig.24D 2 is a diagram showing quantized data K2″ obtained by performing quantization by the color separation / quantization unit 211 in step S813 and performing steps S814 to S816 under the conditions described in the first embodiment. Fig.24C As shown, in Fig.24A Among the pixels with K1'=255, Fig.23D The pixel indicated by "1" (i.e., the left end pixel) has quantized data "1010" and the remaining pixels have "0010". Fig.24D As shown, in Fig. 24B In the pixels with K2'=255, Fig.23D The pixel indicated by "2" in FIG. 1 (ie, the right end pixel) has quantized data "1010" and the remaining pixels have quantized data "0010". Fig.23A and Fig. 23B The indexing mode shown converts the quantized data K1" and K2" into nozzle data K1p and K2p. Fig.24E is a diagram showing dot arrangement when the print head H performs printing at 1200 dpi×1200 dpi based on the nozzle data K1p and K2p. Fig.24E As shown, in Fig.23C Among the pixels with brightness value 0 in Fig.23D In the pixels not judged as the left end pixel or the right end pixel, dots are arranged on each side of the left side and the right side of 1200 dpi×1200 dpi. Fig.23D Among the pixels judged as the left end pixels, Fig.24E The midpoint is only placed on the left side and Fig.23D Among the pixels judged as right end pixels, Fig.24EThe midpoints are arranged only on the right side. That is, the points on the non-end side of the left end pixel and the right end pixel are thinned out.

[0160] As described above, in an apparatus configuration that prints dots at a high resolution in the X direction compared to input image data, it is determined whether each pixel is a left end pixel or a right end pixel, and the dot arrangement is changed accordingly, thereby making it possible to implement an arrangement in which dots on the non-end side of edge pixels are thinned out. Fig.25A It shows that the input image is Fig.14A The solid image shown in FIG. 1 and the dot arrangement in the case where the first end in step S304 is the upper end or the left end and the second end is the lower end or the right end. Fig.25A As shown, similar to Fig.24E and Fig.24F , the points on the non-end side in the left and right ends are thinned out, and the points on the non-end side in the upper and lower ends are also thinned out. That is, this embodiment can realize an arrangement in which the points on the non-end side of all end pixels are thinned out.

[0161] Note that this embodiment describes the dot arrangement when printing is performed at 1200 dpi × 1200 dpi when the image resolution for edge detection is 600 dpi × 600 dpi. Note that for the resolution in the Y direction, the resolution for edge detection can be equal to the resolution for printing. As a practical example, Fig.24F The case where the Ev column and the Od column in the print head H are not shifted by half a pitch (1,200 dpi) is shown. Fig.24F It shows that in this case when Fig.23C The vertical lines shown are the point arrangements of the input image. Fig.24F As shown, similar to Fig.24E , in the left end portion and the right end portion, the points on the non-end side are thinned out, so that the same effect can be obtained.

[0162] <Edge Processing in the Case of Arranging Four Dots in 600 dpi×600 dpi Pixels>

[0163] Next, as a second process of the present embodiment, an example in the case where at most four dots are arranged in a pixel of 600 dpi×600 dpi will be described. Steps S301 and S302 are the same as those in the third embodiment, and description thereof will be omitted.

[0164] In the image analysis processing performed in step S303, when edge detection is performed in step S403, the image analysis unit 210 outputs "1" for the upper pixel, "2" for the lower pixel, "3" for the left pixel, and "4" for the right pixel.

[0165] Fig.26A and Fig.26B An example of the internal processing procedure of the color separation / quantization processing performed by the color separation / quantization unit 211 in step S304 according to the present embodiment is shown. Steps S3601 to S3608 are respectively the same as steps S801 to S808. In step S3609, the color separation / quantization unit 211 performs the same quantization processing on the concentration value K1' as in step S809 to convert the concentration value K1' into 4-bit 3-value quantized data. In addition, in steps S3610 to S3616, the color separation / quantization unit 211 uses the result judged in step S303 to set the value in the highest 2 bits based on the end information of the processed pixel, and outputs the 4-bit quantized data K1". More specifically, if the pixel is detected in the first end, the highest 2 bits are set to 01 in step S3616. If the pixel is detected in the third end, the highest 2 bits are set to 10 in step S3615. If the pixel is detected in the fourth end, the highest 2 bits are set to 11 in step S3614. If the pixel is detected in the fourth end, the highest 2 bits are set to 11 in step S3614. If the pixel is not in the first end, the third end or the fourth end, the highest 2 bits are set to 00 in step S3613. Similarly, in step S3617, the color separation / quantization unit 211 performs the same quantization processing on the concentration value K2' as in step S813 to convert the concentration value K2' into 4-bit 3-value quantized data. In addition, in steps S3618 to S3624, the color separation / quantization unit 211 uses the result judged in step S303 to set the value in the highest 2 bits based on the end information of the processed pixel, and outputs 4-bit quantized data K2". More specifically, if the pixel is detected in the second end, the highest 2 bits are set to 01 in step S3624. If the pixel is detected in the third end, the highest 2 bits are set to 10 in step S3623. If the pixel is detected in the fourth end, the highest 2 bits are set to 11 in step S3622. If it is detected that the pixel is not in the second end portion, the third end portion, or the fourth end portion, the highest 2 bits are set to 00 in step S3621.

[0166] Next, in step S305, the image quantized in step S304 is subjected to index expansion processing by the nozzle separation processing unit 212. The processing procedure is the same as the first procedure. Fig.25B and Fig.25CThe figures respectively show examples of dot arrangement patterns of the first index expansion process and the second index expansion process in the process. In the first index expansion process, if the quantization data K1" indicates "0000", "0100", "1000" or "1100", dots are not arranged on the left or right side of the pixel. If the quantization data K1" indicates "0001", "1001" or "1010", dots are arranged on the left side of the pixel. If the quantization data K1" indicates "0010", "0101" or "0110", dots are arranged on each of the left and right sides of the pixel. If the quantization data K1" indicates "1101" or "1110", dots are arranged on the right side of the pixel. In the second index expansion process, if the quantization data K2" indicates "0001", dots are arranged on the right side of the pixel. In other cases, the arrangement is the same as in the first index expansion process. The subsequent processing of the nozzle data K1p and K2p generated by the above setting is the same as in the first process, and its description will be omitted.

[0167] FIG. 27A to FIG. 27F It is shown that the input image is Fig.14A FIG. 1 is a diagram showing a processing example of the second process in the case of a solid image shown in FIG. Note that in this processing example, the first end is the upper end, the second end is the lower end, the third end is the left end, and the fourth end is the right end. Fig.27A 3 is a diagram showing the result of edge detection performed on the input image by the image analysis unit 210 in step S303. Fig.27A As shown, the upper end pixel is indicated by "1", the lower end pixel is indicated by "2", the left end pixel is indicated by "3", and the right end pixel is indicated by "4". Fig.27B 1 shows the density value K1′ obtained after the color separation / quantization unit 211 performs the tone correction processing in steps S3603 to S3605. Fig.27B As shown, in Fig.27A The pixel indicated by “2” in FIG. 1 (ie, the lower pixel) has a density value of 0. Fig.27C The density value K2′ obtained after the tone correction processing is performed in steps S3606 to S3608 is shown. Fig.27C As shown, in Fig.27A The pixel indicated by “1” in FIG. 1 (ie, the upper pixel) has a density value of 0. Fig.27D : is a diagram showing quantized data K1" obtained by performing quantization by the color separation / quantization unit 211 in step S3609 and performing steps S3610 to S3616 under the conditions described in the first embodiment. Fig.27E 2 is a diagram showing quantized data K2″ obtained by performing quantization by the color separation / quantization unit 211 in step S3617 and performing steps S3618 to S3624 under the conditions described in the first embodiment. Fig.27DAs shown, in Fig.27B Among the pixels with K1'=255, Fig.27A The pixel indicated by "1" in (i.e., the upper pixel) has the quantized data "0110". Similarly, Fig.27A The pixel indicated by "3" in (i.e., the left end pixel) has quantized data "1010", and Fig.27A The pixel indicated by "4" in (i.e., the right end pixel) has quantized data "1110". Fig.27A Pixels indicated by "0" in (i.e., pixels that are not any end pixels) have quantized data "0010". Fig.27E As shown, in Fig.27C In the pixels with K2'=255, Fig.27A The pixel indicated by "2" in (i.e., the lower pixel) has quantized data "0110". Fig.27A The pixels indicated by "3", "4" or "0" in have the same quantization data as K1". Fig.25B and Fig.25C The indexing mode shown converts the quantized data K1" and K2" into nozzle data K1p and K2p. Fig.27F is a diagram showing dot arrangement when the print head H performs printing at 1200 dpi×1200 dpi based on the nozzle data K1p and K2p. Fig.27F As shown, in Fig.14A Among the pixels with brightness value 0 in Fig.27A In the pixels that are not judged as the upper end pixel, the lower end pixel, the left end pixel, or the right end pixel, dots are arranged in all areas of 1200 dpi×1200 dpi. Fig.27A Among the pixels judged as upper pixels, Fig.27F The midpoint is arranged only on the upper side and Fig.27A Among the pixels judged as the lower end pixels, Fig.27F The midpoint is only arranged on the lower side. Fig.27A Among the pixels judged as the left end pixels, Fig.27F The midpoint is only placed on the left side and Fig.27A Among the pixels judged as right end pixels, Fig.27F The midpoint is arranged only on the right side. That is, this process can realize the arrangement in which the points on the non-end side of all end pixels are thinned out.

[0168] exist Fig.27FIn the step S403, a blank area A is generated in units of 1200 dpi×1200 dpi in each of the upper left pixel, the upper right pixel, the lower left pixel, and the lower right pixel. By changing the edge mode output in step S403 and the processing of steps S3610, S3616, S3618, and S3624, the blank area A can be avoided. More specifically, in step S403, the image analysis unit 210 outputs "5" for the upper left pixel in the left end and the upper end, outputs "6" for the lower left pixel in the left end and the lower end, outputs "7" for the upper right pixel in the right end and the upper end, and outputs "8" for the lower right pixel in the right end and the lower end. Fig.28D is a diagram showing the output result. Then, in step S3610, if in addition to the "1" indicating the upper pixel, a "5" indicating the upper left pixel and a "7" indicating the upper right pixel are detected, then in step S3616, the color separation / quantization unit 211 sets the highest 2 bits of the quantization data K1" = 01. Furthermore, in step S3618, if in addition to the "2" indicating the lower pixel, a "6" indicating the lower left pixel and an "8" indicating the lower right pixel are detected, then in step S3624, the color separation / quantization unit 211 sets the highest 2 bits of the quantization data K2" = 01. Fig.28A and Fig.28B The quantized data K1 ″ and K2 ″ at this time are respectively shown. This changes the quantized data of the upper left pixel, the lower left pixel, the upper right pixel, and the lower right pixel, and changes the dot arrangement to be selected in step S305 . Fig.28C is a diagram showing the dot arrangement through this process, and it is found that the generation of the blank area A can be avoided.

[0169] As described above, in the present embodiment, in the device configuration capable of printing dots with high resolution in the X direction compared to the image data to be subjected to edge detection, it is detected and judged whether each edge pixel of the object is an upper pixel, a lower pixel, a left pixel or a right pixel, and the dot arrangement is changed accordingly. This obtains the following dot arrangement: in the X direction, the ratio of forming dots on the non-end side is lower than the ratio of forming dots on the end side, and the size relationship between these ratios is equal between the edge pixel area formed by the left end pixel and the edge pixel area formed by the right end pixel. In the device configuration capable of printing dots with high resolution in the Y direction, a dot arrangement with the same characteristics is obtained for the edge pixel area formed by the upper end pixel and the edge pixel area formed by the lower end pixel. This dot arrangement can reduce the deterioration of image quality caused by the bleeding of printing ink on the printing medium. In addition, since the device configuration (i.e., the image data with a resolution lower than the resolution in the nozzle array direction of the print head H and the resolution in the main scanning direction) can be used for edge detection, the load of image processing can be reduced.

[0170] Note that this embodiment illustrates an example of processing in the case where an object in the input image has a brightness value of 0 for R, G, and B (i.e., a so-called black pixel). Of course, the present invention is not limited to black pixels. Similar to the description of the fourth embodiment, even for an intermediate density input image, if the density is converted into quantized data of "XX01" or "XX10" (XX is other than 00), the dot arrangement of the edge pixels is the same as that of the black pixels. That is, even for an intermediate density, the clarity of the end can be improved, and the degradation of the image quality caused by the bleeding of the printing ink on the printing medium can be reduced.

[0171] This embodiment illustrates an example of an arrangement in which dots are uniformly arranged on the end side of edge pixels and dots are not arranged on the non-end side. However, this example is only an example, and the optimal dot arrangement of edge pixels may differ depending on the configuration of the printing device and the degree of bleeding of the printing ink on the printing medium, etc. Therefore, similar to the description of the fifth and sixth embodiments, the settings of the tone correction processing and the index expansion processing may be changed to obtain an arrangement in which dots are applied on the non-end side of edge pixels or an arrangement in which dots on the end side of edge pixels are thinned out.

[0172] [Eighth Embodiment]

[0173] <Edge processing of dot arrangement to realize dot thinning on the end side of edge pixels>

[0174] The eighth embodiment will be described below with respect to the differences from the first to seventh embodiments. The first to seventh embodiments each illustrate an example of edge processing of an arrangement in which dots on the non-end side of edge pixels are mainly eliminated. However, depending on the characteristics required for an image printed on a print medium, an arrangement other than an arrangement in which dots on the non-end side are eliminated may be preferred. In a case where it is necessary to reduce the image width of a printed image, it may be more preferable to eliminate dots on the end side of edge pixels and to arrange dots uniformly on the non-end side. For example, in a case where a character or symbol includes a portion in which horizontal or vertical lines are densely arranged, by eliminating dots on the end side of edge pixels in such a portion and arranging dots uniformly on the non-end side, thickening of the lines can be more effectively prevented. This embodiment will describe an example of edge processing that implements such an arrangement.

[0175] Similar to the first to sixth embodiments, an example is shown in which printing is performed at high resolution in the Y direction for input image data. Regarding the process of edge processing, all steps S301 to S303 and S305 are the same as those in the third embodiment, and description thereof will be omitted. Fig.29A and Fig.29B An example of the internal processing procedure of the color separation / quantization processing performed in step S304 is shown. Fig.29A and Fig.29B as well as Figure 6 The difference between the above is that the detected end information is changed between steps S4103, S4106, S4110 and S4114 and steps S803, S806, S810 and S814. That is, the dot arrangement of edge pixels of this embodiment is obtained by interchanging the arrangement positions of the upstream side nozzle and the downstream side nozzle (Ev nozzle and Od nozzle) with respect to the arrangement positions shown in each of the first to fourth embodiments. As an example, Fig. 30A shows that the input image data is Fig.14A The dot arrangement of this embodiment in the case of a solid image shown in FIG. Note that the definitions of the first end and the second end in this example are the same as those in the description of the third embodiment. Fig. 30A As shown, except for the pixel indicated by B, the dots are arranged only on the downstream side of the edge pixel at the upper end, and the dots are arranged only on the upstream side of the edge pixel at the lower end. If it is preferred to arrange the dots on the non-end side of the pixel indicated by B, this can be achieved by changing the edge mode output in step S403. More specifically, in step S403, the image analysis unit 210 outputs "2" for the lower left pixel similarly to the edge pixel at the lower end, and outputs "1" for the upper right pixel similarly to the edge pixel at the upper end. Fig. 30B is a diagram showing the output result. Thus, for the lower left pixel and the upper right pixel, Fig.29A and Fig.29B The nozzle used for printing is changed between the Ev nozzle and the Od nozzle. Fig. 30C is a diagram showing dot arrangement.

[0176] Next, a processing example will be described when four dots are arranged in a pixel of 600 dpi×600 dpi in the case where printing is performed at a high resolution in the X direction also for the input image data similar to the seventh embodiment. For the process of edge processing, all steps S301 to S303 and S305 are the same as the second process of the seventh embodiment, and their description will be omitted. Fig.31A and Fig.31B An example of the internal processing procedure of the color separation / quantization processing performed in step S304 is shown. Fig.31A and Fig.31B as well as Fig.26A and Fig.26B The difference between the seventh embodiment is that steps S4403, S4406, S4410 to S4412 and S4418 to S4420 are different from steps S3603, S3606, S3610 to S3612 and S3618 to S3620. More specifically, for the detected end, the first end and the second end are interchanged, and the third end and the fourth end are interchanged. That is, by Fig.27FThe dot arrangement of edge pixels of this embodiment is obtained by interchanging the upstream nozzle and the downstream nozzle (Ev nozzle and Od nozzle) and the left and right sides. As an example, Fig.32A shows that the input image data is Fig.14A Note that the definitions of the first end to the fourth end in this example are the same as those in the description of the seventh embodiment. Fig.32A As shown, except for the pixel indicated by C, the dots are arranged only on the downstream side of the edge pixel at the upper end, the dots are arranged only on the upstream side of the edge pixel at the lower end, the dots are arranged only on the right side of the edge pixel at the left end, and the dots are arranged only on the left side of the edge pixel at the right end. If it is preferred not to arrange the dots on the end side of the pixel indicated by C, this can be achieved by changing the edge mode output in step S403 and the processing of steps S4403 and S4406. First, in step S403, similar to the description of avoiding the blank area A in the seventh embodiment, the image analysis unit 210 outputs Fig.28D Then, if in step S4403, in addition to the "1" indicating the edge pixel at the upper end, a "5" indicating the upper left edge pixel and a "7" indicating the upper right edge pixel are detected, then in step S4405, the color separation / quantization unit 211 sets the concentration value K1'=0. If in step S4406, in addition to the "2" indicating the edge pixel at the lower end, a "6" indicating the lower left edge pixel and an "8" indicating the lower right edge pixel are detected, then in step S4408, the color separation / quantization unit 211 sets the concentration value K2'=0. Fig.32B and Fig.32C 2 are diagrams showing subsequent quantized data K1" and K2", respectively. Fig.32D is a diagram showing the arrangement of dots by this process. With this process, the upper left edge pixel and the upper right edge pixel have quantization data K1"="0000", where dots are not arranged on the end side, and the lower left edge pixel and the lower right edge pixel have quantization data K2"="0000", where dots are not arranged on the end side. That is, in the pixel indicated by C, dots are not arranged on the end side.

[0177] As described above, in the present embodiment, in an apparatus configuration capable of printing dots at a high resolution compared to image data to be subjected to edge detection, it is detected and determined whether each edge pixel of an object is an upper end pixel, a lower end pixel, a left end pixel, or a right end pixel, and the dot arrangement is changed accordingly. This can realize a dot arrangement in which dots are formed only on the non-end side for all end pixels. That is, an arrangement preferably for reducing the image width of a printed image can be realized.

[0178] Note that this embodiment explains an example of a solid image as an input image, but the present invention is not limited thereto. Similar to the other embodiments, the operation of this embodiment can be applied to horizontal lines or vertical lines.

[0179] Note that this embodiment illustrates an example of eliminating dots for the upper pixel, the lower pixel, the left pixel, and the right pixel, but the present invention depends on the characteristics required for the image and is not limited to this. For example, if it is necessary to output an image width of the printed image that is larger than the image width in this embodiment and smaller than the image width in the first to seventh embodiments, it is preferred to eliminate dots for the upper pixel or the lower pixel, and to eliminate dots for the right pixel or the left pixel. In this case, this can be achieved by setting the output of the upper pixel or the lower pixel to 0 and setting the output of the right pixel or the left pixel to 0 in the edge mode output in step S403.

[0180] Note that this embodiment describes processing in the case where an object in the input image has a brightness value of 0 for R, G, and B (i.e., a so-called black pixel). Of course, the present invention is not limited to black pixels. Similar to the description of the fourth and seventh embodiments, even for an intermediate density input image, if the density is converted into quantized data of "XX01" or "XX10" (XX is other than 00), the dot arrangement of the edge pixels is the same as that of the black pixels. That is, even for an intermediate density, an arrangement that is preferably used to reduce the image width of a printed image can be achieved.

[0181] Note that the present embodiment explains an example in which the image analysis process in step S303 is the same between the present embodiment and the third to seventh embodiments, and the end information detected in the color separation / quantization process in step S304 is changed. However, the present invention is not limited to this. For example, all "1", "2", "3", and "4" as the actual values ​​of the parameters of the end information detected in step S304 may be the same as in the third to seventh embodiments, and the edge judgment output of the image analysis process of step S303 may be changed. As an actual setting example, when two dots are arranged in a pixel of 600 dpi×600 dpi, in step S303, the image analysis unit 210 outputs "2" for the upper end pixel and the left end pixel, and outputs "1" for the lower end pixel and the right end pixel. Alternatively, when four dots are arranged in a pixel of 600 dpi×600 dpi, in step S303, the image analysis unit 210 outputs "2" for the upper end pixel, "1" for the lower end pixel, "4" for the left end pixel, and "3" for the right end pixel. In this setting as well, the same dot arrangement as in the present embodiment can be obtained.

[0182] [Ninth Embodiment]

[0183] <Effective use of subject resources>

[0184] The ninth embodiment will be described below with regard to the differences from the first to eighth embodiments. In the first embodiment, image analysis using pattern matching information is performed. A configuration is described in which the image analysis unit 210 performs image analysis and transmits the analysis result to the color separation / quantization unit 211.

[0185] For office documents in inkjet printers, productivity (printing speed) is an important indicator, and if the analysis process and the correction process based on the analysis process are performed at a speed lower than the required speed, the print head may stop to cause degradation of image quality. In order to prevent the analysis process and the correction process from being delayed relative to the required speed, it is effective to implement the process through a "dedicated circuit". If the circuit logic is dedicated to a limited purpose like an ASIC, control can be performed to prevent excessive calculation costs or memory accesses from occurring compared to a CPU, and a design can be made so that data processing can be performed on the circuit wiring with low latency. Therefore, compared to a CPU, the processing speed is usually increased by a dedicated circuit, and this is also used in the printing step and scanning step of an inkjet printer. On the other hand, the design time until the dedicated circuit is determined is long, and the function cannot be changed after the circuit is implemented. There is also a semi-dedicated circuit form with functional flexibility like a field programmable gate array (FPGA), but many wiring switches need to be provided in exchange for flexibility. By limiting the scale of the circuit that can be assembled in the image processing device, the function may be limited similarly to an ASIC. When the time required to assemble a new dedicated circuit is assumed, market responsiveness deteriorates.

[0186] To solve this, this embodiment will describe a configuration that implements dot thinning and placement control using a dedicated circuit assembled for a printing step or a scanning step in an inkjet printer. This can achieve market responsiveness and also reduce the circuit scale (production cost reduction) by not implementing special processing of a dedicated circuit.

[0187] Fig.33A An example of an assumed environment of the image processing apparatus according to the present embodiment is shown. Figure 2B Reference Fig.33A , there is no image analysis unit 210. The respective processing units of the image processing unit 208 are connected to a shared bus 215, and information is transmitted between the processing units only via the shared bus.

[0188] In the printing process in the case where the present embodiment is not performed, in the image processing unit 208, dedicated circuits are used in the order of the decoder unit 209, the color separation / quantization unit 211, and the nozzle separation processing unit 212. In the copy process, in the image processing unit 208, dedicated circuits are used in the order of the scan image correction unit 216, the color separation / quantization unit 211, and the nozzle separation processing unit 212. In the scan process, in the image processing unit 208, a dedicated circuit of the scan image correction unit 216 is used. Note that in the copy / scan process, the image may be compressed once for data transmission, and the decoder unit 209 may be used in this case as well.

[0189] This embodiment will describe a method of performing image analysis using the same dedicated circuit as that in the correction step of the scanned image actually performed by the scanned image correction unit 216.

[0190] Fig.33B5001 is a schematic diagram of a processing block of a dedicated circuit present in the scanned image correction unit 216. The scanned image correction unit 216 obtains data from the RAM 207 via the DMAC 5001. DMAC is an abbreviation for a direct memory access controller, and the scanned image correction unit 216 can perform memory access without any instruction from the CPU. Using the DMAC, data can be transferred at a speed higher than the CPU without considering the CPU processing load. The data received by the scanned image correction unit 216 includes image data obtained from the scanner 202 and processing data (e.g., lookup table data, etc.) to be stored in the SRAM in the processing unit from the DMAC 5001 to the LUT 3D 5005. The scanned image correction unit 216 includes four processing units. The LUT 3D 5002 is a lookup table for outputting RGB three-dimensional output features for RGB three-dimensional input features. The scanned image is color space information related to the scanner device when it is obtained from the scanner 202, and is thus converted into standard color space information by the LUT 3D 5002. LUT 1D5003 is a lookup table for outputting one-dimensional output features of R, G and B for one-dimensional input features of R, G and B, respectively. Based on the UI instruction from the user, the density of the acquired scanned image is adjusted. Next, FLT 5004 is a 5×5 filter for RGB three-dimensional input features. Although the data resolution of the scanned image acquired from the scanner 202 is determined based on the scanning resolution of the scanner and the arrangement resolution of the sensor, the reading accuracy of the sensor is inaccurate, so the scanned image is blurred. FLT 5004 improves the blur by applying a filter coefficient for clarifying the blurred image. LUT 3D 5005 is a lookup table for outputting RGB three-dimensional output features for RGB three-dimensional input features. A blackening / whitening process is performed to fill the darkest part of the pixel value acquired from the scanned image with black (0, 0, 0) and make the brightest part white (255, 255, 255).

[0191] Fig.33B The processing shown is obtained by extracting the minimum necessary functions in the scanned image correction unit 216, and may include processing other than that. For example, a separate circuit for color misregistration correction or shading correction of the scanner may be provided.

[0192] like Fig.33C As shown, reference Fig.33B The described single dedicated circuit of the scanned image correction unit 216 is used in the application in the present embodiment. The respective processes will be described in detail.

[0193] Fig.34Ais a flowchart of the analysis process according to this embodiment. This flowchart is used to describe the details of the image analysis process of the first embodiment by implementing other configurations. Figure 3B An example of a method of processing is shown.

[0194] In step S5201 , the bitmap image as a result of decoding is converted into a brightness value using the LUT 3D 5002 in the scanned image correction unit 216 . Fig.34B and Fig.34C Each shows an example of information of a lookup table in the SRAM of the LUT 3D. Fig.34B Table information when used for scan image correction is shown. Fig.34B An example of a conversion table from the device color space when acquired from the scanner 202 to the sRGB color space as the standard color space is shown. Fig.34C Table information in the case where brightness conversion is performed according to the present embodiment is shown. Fig.34C An example of a conversion table from input information RGB of a bitmap image as a decoding result to brightness Y is shown. To describe this embodiment, the same brightness value information is designed for the output three dimensions, but it can be freely designed within the design constraints of the lookup table (e.g., the number of grids and the internal interpolation method, etc.).

[0195] In step S5202, the information converted into brightness is binarized using the LUT 1D 5003 in the scanned image correction unit 216. In the first embodiment, binarization is performed by expression (1) using the threshold value Th acquired in advance. In the present embodiment, binarization is performed using a lookup table. Fig.35A and Fig.35B Each shows an example of information of a lookup table in the SRAM of the LUT 1D. Fig.35A Table information when used for scan image correction is shown. Fig.35A Table information for deriving a desired density correction from each RGB information of a standard color space is shown. Fig.35B An example of a conversion table in the case of performing binarization according to the present embodiment is shown. In the case of a circuit specification in which interpolation is performed between grids in a lookup table, it is necessary to design so that binary information in a design value does not become information of three or more values ​​by interpolation.

[0196] In step S5203, edge element detection is performed on the binary information using FLT 5004 in the scanned image correction unit 216. Fig.35C and Fig.35D Each shows an example of information of filter coefficients in the SRAM of FLT. Fig.35CThe filter coefficient information when used for scanned image correction is shown. The coefficient value becomes larger at a position closer to the center, and the filter end can be designed to have a negative intensity. In addition, a shift process or an offset process can be performed on the filter design result to obtain the desired filtering result. Also included is a process of limiting the result less than 0 in the processing result to 0. In scanned image correction, the same filter coefficient is applied to each RGB channel. Since if a filtering process is applied to an isolated point, the point may disappear or diffuse, an isolated point detection process may be performed in advance. On the other hand, in Fig.35D In the embodiment, the filter coefficients are designed in the case where edge element detection is performed according to the present embodiment. As an example, the embodiment assumes Fig.35D The filter coefficients on the left are applied to a given channel and Fig.35D The filter coefficients on the right are applied to another channel. The result obtained after the filtering process is offset by +48. Fig.35D The various filter application results shown correspond to the extraction of "edge elements".

[0197] FIG. 37A to FIG. 37D An example of the application of the filter is shown. Fig.35D shows an example in which a 3×3 region of filter coefficients is effective, so reference will be made to FIG. 37A to FIG. 37D The application example is described by focusing on a 3×3 area of ​​binary data. FIG. 37A to FIG. 37D Each shows a filter application result in a case where the characteristics of a 3×3 region of binary data are different for two fixed filters. Fig.37A An example is shown in which the target pixel is an edge pixel at the upper end. Fig.35D The two filters shown are applied with the results being "48" and "32". Fig.37B An example is shown in which the target pixel is the upper right edge pixel. Fig.35D The two filters shown in FIG. 1 and FIG. 2 are applied, and the results are "16" and "32". In this way, it is found that Fig.35D The edge pixel at the upper end and the upper right edge pixel are determined by the difference between the filtering results in . Fig.37C An example is shown in which the target pixel is an edge pixel at the right end. Fig.35D The two filters shown in the figure have the following results: 16 and 48. Fig.35D The edge pixel at the right end and the upper right edge pixel are determined by the difference between the filtering results in . Fig.37D An example is shown in which the target pixel is an edge pixel of a 1-point line. Fig.35D The two filters shown in FIG. 1 and FIG. 2 are applied, and the results are "16" and "16". In this way, it is found that Fig.35DThe edge pixel at the right end and the edge pixel of the 1-point line are judged by the difference between the filtering results in . It is difficult to judge the edge shape of the target pixel only by the application results of two filters, but the application results can be element information that can be used in combination to judge the edge shape of the target pixel. Instead of verifying the pattern matching information to be acquired by a separate pattern as in the first embodiment, elements can be extracted without deviating from the functional specifications of FLT 5004 in the scanned image correction. Note that since it is assumed that the scanned image correction unit 216 processes RGB information, three filter coefficients can be used to detect edge elements on brightness information. Two filters are used in this example, but three filter coefficients can be used within the range of not changing the existing circuit configuration. In this case, the filter can be designed to be able to estimate a more detailed edge shape. It is assumed here that the filter coefficient of FLT 5004 has a 5×5 form. The amount of coefficients can be adjusted within the range of not changing the existing circuit configuration. Also in this embodiment, it is designed to use only 3×3 areas in the 5×5 form, but a more detailed judgment can be made using the 5×5 form. If a 7×7 form design can be made for FLT 5004, filtering processing can be performed in an area wider than the area for edge element detection.

[0198] In step S5204, using the LUT 3D 5005 in the scanned image correction unit 216, edge pattern matching is performed on the information obtained after the filter is applied. FIG. 36A to FIG. 36C Each shows an example of information of a lookup table in the SRAM of the LUT 3D. Fig.36A Table information when used for scan image correction is shown. For blackening / whitening, a design is made so that a tone value close to an input value of 0 becomes closer to 0 and a tone value close to an input value of 255 becomes closer to 255. Fig.36B An example of a table in the case of performing edge pattern matching according to the present embodiment is shown. As an example, the table is designed to set non-detection=0, upper detection=1, lower detection=2, right detection=3, left detection=4, and adjacent to edge=5.

[0199] Reference Fig.36C Describe the considerations in the design of the lookup table. Binary data is converted into edge elements by FLT 5004. If Fig.35D The filter coefficient on the left is applied to the information of the edge pixel at the right end, and the result is "16", and if Fig.35DThe filter coefficient on the right is applied to this information, and the result "48" is obtained. In LUT 3D 5005, the output signal of the portion corresponding to the grid of Rch=16 and Gch=48 is set to "3", and then the pixel value after the lookup table processing is output as 3. If the result of FLT 5004 does not match the grid interval of LUT 3D 5005, this situation can be dealt with by designing to output the same value for all adjacent grids in a manner that sandwiches the result of FLT 5004. In the present embodiment, all results of edge pattern matching are collected to the R channel. However, any channel can be set as the output destination, and the results can be distributed to the RGB channels.

[0200] In the present embodiment, three filters and a lookup table with three input dimensions are used as an example. However, the number of filters and the number of dimensions of the lookup table are not limited thereto. Even if the number of filters is one and Fig.35D The setting value on the left can also be based on Fig.37A , Fig.37B and Fig.37C The application result is used to distinguish whether the target pixel is an edge pixel at the upper end, an upper right edge pixel, or an edge pixel at the right end. As described above, pattern matching can be performed as long as the number of dimensions equal to or greater than the number of filters can be input into the lookup table.

[0201] If you can use one filter and a one-dimensional lookup table to determine X types of edges, you can use two filters and a two-dimensional lookup table to determine X×X types of edges. Using M filters and an N-dimensional lookup table, you can determine X Min (M,N) If only filters are used to determine the number of edge types equal to the number determined by two filters and two lookup tables, four filters are required. If only filters are used to determine the number of edge types equal to the number determined by three filters and three lookup tables, eight filters are required.

[0202] As in this embodiment, by combining multiple filters and multidimensional lookup tables, multiple types of edges can be efficiently judged using a smaller circuit scale. Compared with the case of using only filters, the larger the X (the number of edge types to be judged) in the above example, the greater the effect.

[0203] When the number of filters or the dimension of the lookup table increases, more kinds of patterns can be detected. Typically, one to three filters are maintained as circuit resources to be used for scanned image correction.

[0204] As described above, by using the dedicated circuit provided in the scanned image correction unit 216, the same detection result as in the first embodiment can be generated. In order to transmit the multi-valued data as the generated edge pattern matching result to the color separation / quantization unit 211 via the RAM 207, only the R channel can be transmitted. As a result, compared with transmitting all RGB channels via the shared bus 215, bandwidth is saved. Since three RGB channels are transmitted to be input to / output from the scanned image correction unit 216 when the copy process is performed in the image processing device 100, the necessary transmission bandwidth in the present embodiment can be reduced compared with the copy process. Therefore, from the viewpoint of bandwidth, the required performance can be met without improving the circuit performance of the printer. In addition, when the print process is performed via the host computer 201, if there is an existing mechanism for transmitting the attribute information of one channel in addition to the RGB channels, the new design operation for the data flow can be reduced by transmitting only the configuration of the R channel.

[0205] Since according to the first embodiment, a dedicated circuit for analysis is required to realize the configuration of image analysis by satisfying the required speed, cost and time are required to develop / produce a new circuit. In this embodiment, dot spacing elimination and layout control can be realized by using the configuration of an existing image processing device. Therefore, the production cost of a new circuit can be reduced. Since the image quality on the market can be immediately improved, user satisfaction is improved, feedback from users can be quickly received, and the need for element development can be discovered early.

[0206] The scanned image correction according to the present embodiment is used not only for the use case of the copy process but also for the use case of the scan process. The image acquired by the scanner 202 is corrected by the scanned image correction unit 216 and then transmitted to a memory card or the like connected to the host computer 201 or the image processing device 100. The present embodiment describes a configuration in which an existing circuit used in the scan process and the copy process is used for image analysis. On the other hand, since it is assumed that the existing circuit will be used for the scanned image correction, when the scan process or the copy process and the print process are performed simultaneously, the same circuit may be used at the same timing, that is, "circuit competition" may occur. Therefore, the product specifications are set to obtain an exclusive relationship between the use cases, or the circuit is used in a time-division manner. In the latter case, an exclusive relationship between the use cases is not obtained, but circuit resources are shared in fine time units, and thus a long processing time tends to be required.

[0207] This embodiment describes the processing overview of scanned image correction, but this is only an example. If there is another function that has been implemented by a dedicated circuit as scanned image correction, this can be used for image analysis processing. Other existing circuits present in the image processing device 100 can also be used. As described above, if an existing circuit used within a use case is used, special control is also performed to use the existing circuit in a time-division manner for image analysis and other processing. Note that the implementation circuits and setting values ​​described in this embodiment are only examples, and the present invention is not limited to this.

[0208] (Other embodiments)

[0209] Each of the above embodiments describes a tandem image processing device, but the present invention is not limited thereto as long as the characteristics and configuration are the same. A line type print head may be used, or a tandem device may be arranged vertically. In addition, each of the above embodiments describes an inkjet printer, but the present invention is not limited thereto as long as the characteristics and configuration are the same. For example, a laser printer or a copier using toner may be used.

[0210] The above embodiments each illustrate the bitmap data area or the like as an area in the RAM, but the present invention is not limited thereto, and any rewritable storage device may be used. For example, a HDD or an embedded multimedia card (eMMC) separated from the RAM may be provided, and the entire data area or a portion of the entire data area may be arranged in the storage area of ​​the HDD or the eMMC.

[0211] In addition, the above-mentioned embodiments each illustrate an example of conversion to three-value data in the quantization of density value data, but the present invention is not limited to this, as long as the characteristics and configuration are the same. The density value data can be converted into binary data or data with four or more values. The above-mentioned embodiments each assume that the print head includes an Ev nozzle and an Od nozzle, but the present invention is not limited to this, as long as the characteristics and configuration are the same. In the above-mentioned embodiments, when printing is performed at a high resolution in the Y direction compared to the image data to be subjected to edge detection, if the nozzles are arranged at a high resolution compared to the image data to be subjected to edge detection, then each embodiment is applicable.

[0212] The above embodiments each explain that image processing including edge processing is performed in the image forming device 10, but the present invention is not limited thereto as long as the characteristics and configurations are the same. More specifically, part or all of the image processing including edge processing may be performed by a device outside the image forming device 10, and then subsequent processing may be performed in the image forming device 10 based on the processing result.

[0213] The above embodiments each assume that the width of the edge pixel is one pixel, but the present invention is not limited thereto, as long as the characteristics and configurations are the same. The end pixel and one or more adjacent pixels on the non-end side (inner side) can be collectively defined as an end pixel group, and in step S303, the image analysis unit 210 can detect each of the upper end pixel group, the lower end pixel group, the left end pixel group, and the right end pixel group, and then perform point spacing elimination in subsequent processing. Fig.38A and Fig.38B 3801 or 3811 represents a left pixel group, an end pixel group 3802 or 3812 represents an upper pixel group, an end pixel group 3803 or 3813 represents a lower pixel group, and an end pixel group 3804 or 3814 represents a right pixel group. By applying the operations of the various embodiments to the end pixel groups, line coarsening can be effectively reduced.

[0214] Other embodiments

[0215] The embodiments of the present invention may also be implemented by providing software (program) for performing the functions of the above-described embodiments to a system or device via a network or various storage media, and a computer or a central processing unit (CPU) or a microprocessing unit (MPU) of the system or device reads and executes the program.

[0216] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. An image processing device, comprising: a printing unit configured to print dots at a resolution higher than a resolution of the image data; a quantization unit configured to perform quantization processing based on image data including the object; as well as a dot arrangement unit configured to perform a process of arranging dots in a pixel using a dot arrangement pattern corresponding to the quantization value that has been subjected to the quantization process, wherein the printing unit comprises a first printing unit configured to print dots in a first area of ​​each pixel of the object, and a second printing unit configured to print dots in a second area of ​​each pixel of the object, and As a result of processing by the point arrangement unit, in a first edge pixel in a first edge portion of the object, a ratio of points arranged in the second zone is lower than a ratio of points arranged in the first zone, and in a second edge pixel in a second edge portion of the object different from the first edge portion, a ratio of points arranged in the first zone is lower than a ratio of points arranged in the second zone.

2. The image processing apparatus according to claim 1, wherein: The quantization unit performs quantization processing on each of the image data corresponding to the first printing unit and the image data corresponding to the second printing unit, so that the quantization value is different between the first edge pixel in the first edge portion of the object and the second edge pixel in the second edge portion different from the first edge portion.

3. The image processing apparatus according to claim 2, wherein: The quantization unit causes a quantization value applied to the first edge pixel for image data corresponding to the first printing unit to be different from a quantization value applied to the first edge pixel for image data corresponding to the second printing unit, and The quantization unit causes a quantization value applied to the second edge pixel for image data corresponding to the first printing unit to be different from a quantization value applied to the second edge pixel for image data corresponding to the second printing unit.

4. The image processing apparatus according to claim 3, wherein: The quantization unit applies a first quantization value to the first edge pixel and a second quantization value to the second edge pixel for the image data corresponding to the first printing unit, and The quantization unit applies the second quantization value to the first edge pixel and applies the first quantization value to the second edge pixel for the image data corresponding to the second printing unit.

5. The image processing apparatus according to claim 1, wherein: In the first edge portion, dots are evenly arranged in the first region.

6. The image processing apparatus according to claim 5, wherein: In the first edge portion, no dots are arranged in the second region.

7. The image processing apparatus according to claim 5, wherein: In the second edge portion, dots are evenly arranged in the second region.

8. The image processing apparatus according to claim 7, wherein: In the second edge portion, no dots are arranged in the first region. 9 . The image processing apparatus according to claim 1 , further comprising a changing unit configured to change a tone value of each of the first edge pixel and the second edge pixel.

10. The image processing apparatus according to claim 9, wherein: In a case where the changing unit changes the tone value, in the first edge portion, dots are not arranged in some of the first regions.

11. The image processing apparatus according to claim 9, wherein: In a case where the changing unit changes the tone value, in the first edge portion, dots are arranged in some of the second regions.

12. The image processing apparatus according to claim 9, wherein: In a case where the changing unit changes the tone value, in the second edge portion, dots are not arranged in some of the second regions.

13. The image processing apparatus according to claim 9, wherein: In a case where the changing unit changes the tone value, in the second edge portion, dots are arranged in some of the first regions.

14. The image processing apparatus according to claim 1, wherein: The dot arrangement pattern is determined such that, in the first edge portion, dots are not arranged in some of the first regions.

15. The image processing apparatus according to claim 1, wherein: The dot arrangement pattern is determined such that, in the first edge portion, dots are arranged in some of the second regions.

16. The image processing apparatus according to claim 1, wherein: The dot arrangement pattern is determined such that, in the second edge portion, dots are not arranged in some of the second regions.

17. The image processing apparatus according to claim 1, wherein: The dot arrangement pattern is determined so that, in the second edge portion, dots are arranged in some of the first regions.

18. The image processing apparatus according to claim 1, wherein: The first edge portion and the second edge portion are one side of the object and another side different from the one side.

19. The image processing apparatus according to claim 1, wherein: The object is an object having a predetermined pixel width.

20. The image processing apparatus according to claim 19, wherein: The object is a line.

21. The image processing apparatus according to claim 19, wherein: The object is solid.

22. The image processing apparatus according to claim 19, wherein: In a case where the object is an object not having a predetermined pixel width, the quantization unit sets a quantization value of at least one of the first edge pixel and the second edge pixel to a quantization value of a pixel in a portion other than an edge portion of the object. 23 . The image processing apparatus according to claim 1 , further comprising a detection unit configured to detect the first edge pixel and the second edge pixel from the image data.

24. The image processing apparatus according to claim 23, wherein: The detection unit detects the first edge pixel and the second edge pixel using pattern matching.

25. The image processing apparatus according to claim 24, wherein: The detection unit performs detection by an arrangement for correcting a scanned image.

26. The image processing apparatus according to claim 1, further comprising a color separation unit configured to perform color separation processing based on the image data, in, For a predetermined color that has been subjected to the color separation process, the quantization process by the quantization unit and the process by the dot arrangement unit are performed.

27. The image processing apparatus according to claim 26, wherein: The predetermined color is black.

28. The image processing apparatus according to claim 1, wherein: The object is an intermediate concentration object.

29. The image processing apparatus according to claim 1, wherein: The first nozzle array provided in the first printing unit is arranged by shifting by half a pitch in the nozzle array direction relative to the second nozzle array provided in the second printing unit, the first area corresponds to the first nozzle array, and the second area corresponds to the second nozzle array.

30. The image processing apparatus according to claim 29, wherein: The first area and the second area are arranged in an array direction of a first nozzle array provided in the first printing unit and a second nozzle array provided in the second printing unit.

31. The image processing apparatus according to claim 29, wherein: The first area and the second area are arranged in a direction orthogonal to an array direction of a first nozzle array provided in the first printing unit and a second nozzle array provided in the second printing unit.

32. The image processing apparatus according to claim 29, wherein: The printing unit is capable of printing dots in the third area and the fourth area of ​​each pixel of the object, The third area and the fourth area are arranged in the array direction, the third area is arranged beside the first area in a direction orthogonal to the array direction, and the fourth area is arranged beside the second area in a direction orthogonal to the array direction. As a result of the processing of the dot arranging unit, in a first edge pixel in the first edge portion, a ratio of dots arranged in the second area and the fourth area is lower than a ratio of dots arranged in the first area and the third area, and in a second edge pixel in the second edge portion, a ratio of dots arranged in the first area and the third area is lower than a ratio of dots arranged in the second area and the fourth area, and As a result of processing by the point arrangement unit, in a third edge pixel in a third edge portion different from the first edge portion and the second edge portion, a ratio of points arranged in the third zone and the fourth zone is lower than a ratio of points arranged in the first zone and the second zone, and in a fourth edge pixel in a fourth edge portion different from the first edge portion, the second edge portion and the third edge portion, a ratio of points arranged in the first zone and the second zone is lower than a ratio of points arranged in the third zone and the fourth zone.

33. The image processing apparatus according to claim 1, wherein: As a result of the processing of the dot arranging unit, in each of the first edge portion and the second edge portion, a ratio of arranging dots inside the object is lower than a ratio of arranging dots on the end side of the object.

34. The image processing apparatus according to claim 1, wherein: As a result of the processing of the dot arranging unit, in each of the first edge portion and the second edge portion, a ratio of arranging dots on the end side of the object is lower than a ratio of arranging dots on the inner side of the object.

35. A method performed by an image processing device, the method comprising: performing a quantitative process based on image data including the object; as well as performing a process of arranging dots in a pixel using a dot arrangement pattern corresponding to the quantization value that has been subjected to the quantization process, wherein the printing unit provided in the image processing device and configured to print dots at a resolution higher than the resolution of the image data comprises a first printing unit and a second printing unit, the first printing unit being configured to print dots in a first area of ​​each pixel of the object, the second printing unit being configured to print dots in a second area of ​​each pixel of the object, and As a result of the processing in the point arrangement, in a first edge pixel in a first edge portion of the object, a ratio of points arranged in the second zone is lower than a ratio of points arranged in the first zone, and in a second edge pixel in a second edge portion of the object different from the first edge portion, a ratio of points arranged in the first zone is lower than a ratio of points arranged in the second zone.

36. A non-transitory computer-readable storage medium storing a program for causing a computer to: performing a quantitative process based on image data including the object; and performing a process of arranging dots in a pixel using a dot arrangement pattern corresponding to the quantization value that has been subjected to the quantization process, in, a printing unit configured to print dots at a resolution higher than a resolution of the image data, comprising a first printing unit configured to print dots in a first region of each pixel of the object, and a second printing unit configured to print dots in a second region of each pixel of the object, and As a result of the processing in the point arrangement, in a first edge pixel in a first edge portion of the object, a ratio of points arranged in the second zone is lower than a ratio of points arranged in the first zone, and in a second edge pixel in a second edge portion of the object different from the first edge portion, a ratio of points arranged in the first zone is lower than a ratio of points arranged in the second zone.

37. A program product storing a program for causing a computer to: performing a quantitative process based on image data including the object; and performing a process of arranging dots in a pixel using a dot arrangement pattern corresponding to the quantization value that has been subjected to the quantization process, in, a printing unit configured to print dots at a resolution higher than a resolution of the image data, comprising a first printing unit configured to print dots in a first region of each pixel of the object, and a second printing unit configured to print dots in a second region of each pixel of the object, and As a result of the processing in the point arrangement, in a first edge pixel in a first edge portion of the object, a ratio of points arranged in the second zone is lower than a ratio of points arranged in the first zone, and in a second edge pixel in a second edge portion of the object different from the first edge portion, a ratio of points arranged in the first zone is lower than a ratio of points arranged in the second zone.

38. An image processing device comprising: an acquisition unit configured to acquire image data including an object; a detection unit configured to detect, from the image data acquired by the acquisition unit, first edge pixels in a first edge portion of the object and second edge pixels in a second edge portion different from the first edge portion; as well as a printing unit configured to be capable of printing dots at a resolution higher than a resolution of the image data acquired by the acquisition unit, wherein the printing unit comprises a first printing unit configured to print dots in a first area of ​​each pixel of the object, and a second printing unit configured to print dots in a second area of ​​each pixel of the object, The detecting unit detects the first edge pixel and the second edge pixel through pattern matching by using a filter and a lookup table, and Each of the first edge pixel and the second edge pixel is detected in at least one of a nozzle array direction of the printing unit and a scanning direction of the printing unit different from the nozzle array direction.

Images