JP6425424B2 - Image processing apparatus and image processing method - Google Patents

Description

  The present invention relates to an image processing apparatus and an image processing method, and more specifically, when there is an ejection failure such as a non-ejection in a nozzle for ejecting ink, recording is performed by a nozzle having an ejection failure by an adjacent nozzle. It relates to a complementary process that substitutes and records data to be stored.

  For example, in an inkjet recording apparatus, when one of a plurality of arranged nozzles has a discharge failure such as non-ejection, the recording data to be recorded by discharging ink from the nozzle is adjacent nozzles in the above array It is known to perform so-called non-ejection complementation by recording with substitution, etc. Patent Document 1 describes, as an example of non-ejection complement, selection of a nozzle for performing complementary recording from two nozzles adjacent to each other on both sides of the non-ejection nozzle. More specifically, when recording is performed by moving a recording head in which a plurality of nozzles are arranged in a direction intersecting with the arrangement of the nozzles, the recording data to be recorded by each nozzle is the data arranged in the above-mentioned crossing direction It is prescribed. Then, when there is a discharge failure in a certain nozzle, the data to be recorded by that nozzle is added to the adjacent data array on the one side or the data array one ahead thereof on one side, and the adjacent nozzle or one nozzle ahead It will be recorded.

JP, 2005-096232, A Unexamined-Japanese-Patent No. 2007-176158 JP 2012-024970 A

  However, in the case of performing the complementing process on the nozzle in which the ejection failure has occurred, the image based on the print data after the edge processing is largely processed by the complementing process in relation to the so-called edge processing performed earlier than that. It may be damaged.

  Edge processing performs processing of detecting an edge of an image to be recorded. Then, as described in, for example, Patent Literature 2 and Patent Literature 3, processing corresponding to the detected edge portion and non-edge portion is performed. By the way, in such edge processing, the size of the processing unit may be limited by the memory capacity of the processing device or the like. On the other hand, when performing complementary processing after edge processing, it is desirable to perform processing in a so-called pipeline manner from the viewpoint of restriction of memory capacity and suppression of reduction in processing speed as in edge processing. That is, edge processing is not performed after all of the processing units are executed, but complementary processing is performed after performing edge processing on a part of the processing units, instead of performing complementary processing. I do.

  On the other hand, edge detection in edge processing also requires information around the area of the processing unit described above. In edge detection, for example, as described also in Patent Document 3, the outermost (edge) of an image to be recorded is detected. In this case, in the processing for each processing unit, it is determined whether the edge is the outermost end of the region of the processing unit, and for this purpose, information on the outside (surrounding) of the processing unit is also required. And when performing complementation processing about the processing unit to which edge processing was performed in this way, the edge processing is not applied to the outside (periphery) of the processing unit, so that the recording is performed by complementation processing near the boundary of the unit area. Images based on data may be compromised. For example, when there is a failure in the nozzles that print the area adjacent to the boundary of the processing unit, the printing data of the nozzle is made to be data of a normal nozzle for printing the area in the processing unit by the complementing process. Then, depending on the image to be recorded, the image recorded after the edge processing may be largely different depending on the recording dot by the data added in the complementing processing in the image recorded based on the data to which the complementing is performed.

  An object of the present invention is to provide an image processing apparatus and an image processing method capable of preventing a large loss of a recorded image even if non-ejection complementing processing of the same processing unit is performed after edge processing.

Therefore, in the present invention, the non-ejection complementing processing according to the position of the ejection failure nozzle in the recording head is added to the recording data after the edge processing has been performed on the recording data for each processing unit consisting of a predetermined number of pixels. The image processing apparatus performs the processing in units of processing, and the recording head can record a plurality of types of ink , and the edge processing records the edge portion of the image of the first ink with the first ink. A process of dividing print data of the first ink so as to print non-edge portions in the image of the first ink with the plurality of types of ink including the first ink; the edge processing results for the recorded data of the first ink to be obtained, non-ejection complement to permit distribution of the record data to pixels corresponding to the other nozzle beyond the boundary of the area of the processing unit of And performing.

  According to the above configuration, in the image processing apparatus, even if the non-ejection complementing process of the same processing unit is performed after the edge processing, it is possible to prevent the recorded image from being largely damaged.

FIG. 1 is a perspective view showing a schematic configuration of an ink jet recording apparatus according to an embodiment of the present invention. It is a block diagram which shows the control structure of the inkjet recording device shown in FIG. It is a block diagram which shows the structure of the image processing in the image processing system comprised by the inkjet recording device and host PC which were shown in FIG. (A)-(e) is a figure for demonstrating the problem by edge processing and subsequent non-ejection complementation processing when not applying this invention. (A)-(g) is a figure explaining the difference in the image quality after complementation by the difference in the method of non-ejection complementation. (A)-(t) is a figure explaining edge processing concerning one embodiment of the present invention. (A)-(l) is a figure explaining the non-discharge complementation process which concerns on one Embodiment of this invention. (A) And (b) is a flow chart which shows edge detection processing concerning the above-mentioned embodiment, and edge processing based on it. (A)-(w) is a figure which illustrates edge processing concerning the above-mentioned embodiment more concretely focusing attention on a processing unit. (A)-(w) is a figure which illustrates the non-ejection complement process mentioned above similarly more concretely paying attention to a processing unit. (A)-(c) is a figure explaining the reason for performing the complementation process which exceeded the boundary of a process unit area | region about K ink regarding the said embodiment. It is a flowchart which shows the process which determines whether it carries out non-ejection complementation within a process unit area | region or carries out non-ejection complementation over a process unit area | region based on the kind of ink based on this embodiment. (A)-(y) is a figure which shows the edge process which concerns on the 2nd Embodiment of this invention. (A)-(t) is a figure which shows the non-discharge complementation process which concerns on the said 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First Embodiment
FIG. 1 is a perspective view showing a schematic configuration of an ink jet recording apparatus according to an embodiment of the present invention. Recording heads 201 to 204 that eject four color inks of black (K), cyan (C), magenta (M), and yellow (Y) are mounted on the carriage 106. The ink tanks 205 to 208 are configured to store the ink ejected by the four recording heads and to be able to supply the corresponding ink to the recording heads. The ink tanks 205 to 208 are detachably mounted on the carriage 106.

  The carriage 106 mounts the ink tanks 205 to 208 and the recording heads 201 to 204, and is configured to be reciprocally movable in the direction of arrow X in the drawing and the opposite direction. By the movement of the carriage, the recording head scans relative to the recording medium, and during this scanning, ink can be ejected from the recording head to record an image on the recording medium. At the time of non-recording operation such as at the time of recovery operation of the recording heads 201 to 204, the carriage 106 is controlled to stand by at a home position position h indicated by a broken line in the figure. The conveyance roller 103 rotates while holding the recording medium (recording sheet) 107 together with the auxiliary roller 104 to convey the recording medium 107, and also plays a role of holding the recording medium 107.

  In the recording apparatus of this embodiment, the recording heads 201 to 204 waiting at the home position h shown in FIG. 1 move in the X direction in the figure by the movement of the carriage 106 when the recording start instruction is input. Thus, the print head is scanned to eject ink to print an image on the print medium 107. Printing is performed on an area having a width corresponding to the arrangement range of the ejection openings (nozzles) of the printing head 201 by one scan of the printing head. When the recording accompanying one scan of the carriage 106 in the main scanning direction (X direction) is completed, the carriage 106 returns to the home position h and scans the ink from the recording heads 201 to 204 while scanning again in the X direction in the drawing. Discharge and record. During the scanning and the next scanning, the conveyance roller 103 rotates, and the recording medium is conveyed by an amount corresponding to the width corresponding to the arrangement range in the sub scanning direction (Y direction) intersecting the main scanning direction. Be done. By repeating the scanning of the recording head and the conveyance of the recording medium as described above, the recording of the image on the recording medium 107 is completed. The above recording operation is performed based on control by control means described later.

  In the above example, an example in which the recording operation is performed only when the recording head scans in the forward direction, that is, so-called unidirectional recording is described. However, the present invention is also applicable to those in which so-called bidirectional recording is performed in which recording is performed both when the recording head scans in the forward direction and in the backward direction. In the above example, the ink tanks 205 to 208 and the recording heads 201 to 204 are detachably mounted on the carriage 106. However, a configuration may be adopted in which a cartridge in which the ink tanks 205 to 208 and the recording heads 201 to 204 are integrated is mounted on a carriage. Furthermore, a multicolor integrated head capable of ejecting multiple colors of ink from one recording head may be mounted on the carriage.

  FIG. 2 is a block diagram showing a control configuration of the ink jet printing apparatus shown in FIG. The inkjet recording apparatus 600 is connected to a data supply apparatus such as a host computer (hereinafter, host PC) 1200 via an interface 400. Various data transmitted from the data supply apparatus, control signals related to printing, and the like are input to the printing control unit 500 of the inkjet printing apparatus 600. The recording control unit 500 includes a memory for storing a mask for generating recording data for multi-pass recording and a CPU for performing calculations. The recording control unit 500 may include an ASIC. The motor drivers 403 to 404 and the head driver 405 are controlled according to a control signal input via the interface 400. In addition, the recording control unit 500 performs processing to be described later with reference to FIG. 3 and the like, and processing of a signal input from the head type signal generation circuit 405 on input image data. The conveyance motor 401 is a conveyance motor for rotating the conveyance roller 103 for conveying the recording medium 107. The carriage motor 402 is a carriage motor for reciprocating the carriage 106 on which the recording heads 201 to 204 are mounted. Motor drivers 403 and 404 drive the conveyance motor 401 and the carriage motor 402, respectively. The head type signal generation circuit 405 is a head driver for driving the recording heads 201 to 204, and a plurality of head type signal generation circuits 405 are provided corresponding to the number of recording heads. The head type signal generation circuit 406 also supplies a signal indicating the type and number of the recording heads 201 to 204 mounted on the carriage 106 to the recording control unit 500.

  FIG. 3 is a block diagram showing the configuration of image processing in the image processing system configured by the ink jet printing apparatus and the host PC shown in FIG. The recording control unit 500 processes data transferred from the host PC 1200 in which the printer driver is installed via the interface shown in FIG.

  The host PC 1200 receives input image data 1000 from the application. First, the received input image data 1000 is subjected to rendering processing 1001 at a resolution of 1200 dpi. As a result, multi-value RGB data for recording 1002 is generated. In the present embodiment, the multi-value RGB data for recording 1002 is data of 256 values. The generated multi-value RGB data for recording 1002 is transferred to the recording control unit 500.

  The recording control unit 500 performs color conversion processing 1007 to convert the recording multi-value RGB data 1002 into multi-value (256 values) CMYK data 1008. Next, quantization processing 1009 (for example, error diffusion) is performed to quantize (binarize) multi-level (256-value) CMYK data 1008. As a result, binary CMYK data 1010 with a resolution of 1200 dpi is generated.

  Next, as described later with reference to FIG. 6 and the like, edge processing is performed as processing of print data based on the binary CMYK data 1010 to generate edge processed data 1011. Then, the non-ejection complementing process is performed on the data after the edge processing in accordance with the ejection failure nozzle detected by the non-ejection detection unit (not shown), and the non-ejection complemented data 1012 is generated.

  Although FIG. 3 describes that the processing shown in the next block is performed after the processing shown in one block is completed, in the present embodiment, each processing is performed in a pipeline manner. That is, when the number of images necessary for processing is input, the processing is performed and the post-processing data is passed to the subsequent process. For example, when image data of 1200 ppi × 1200 ppi is input to a recording apparatus having a processing resolution of 1200 ppi × 1200 ppi, processing may be performed in units of one pixel to generate data of blocks 1000 to 1008 in FIG. Therefore, if the process of generating the data of blocks 1000 to 1008 is performed in units of one pixel and the process is repeated, the required memory can be minimized. Although quantization processing is performed at 1009, if the processing system is, for example, a dither method, processing can be similarly performed in units of one pixel. In the error diffusion method, processing can be performed in units of one raster (pixel group for one row) or two rasters. Even in this case, if the data of the block 1008 is one raster or two rasters, the data of the blocks 1000 to 1007 can be one pixel. Note that the unit of blocks 1000 to 1007 may be matched with the unit of block 1008 in order to make the processing of block 1008 a raster unit in terms of the design of the recording apparatus. The processing of blocks 1010 to 1012 is also the same, and the processing of each of blocks 1001 to 1012 can be an optimized unit instead of having memory for all image areas.

  The recording is performed based on the non-ejection complemented data 1012. That is, the non-ejection complemented data 1012 in the printing range is read from the memory by scanning the printing head, the logical product with the multi-pass printing mask stored in the memory is taken, and the printing data is generated in each scan Do.

  In the following, the non-ejection complementing process to the edge processing and the print data subjected to the edge processing according to the present embodiment will be described, but before that, the edge processing and the subsequent non-ejection complementation when the present invention is not applied Explain the problems caused by the process.

  FIGS. 4 (a) to 4 (e) are diagrams for explaining the above-mentioned problems that may occur due to edge processing and subsequent non-ejection complement processing when the present invention is not applied.

  FIG. 4A shows an example of edge processing described in Patent Document 3, and shows an example where edge processing is performed for each type of ink (recording head). That is, edge processing generates a plurality of data (planes) that differ depending on the ink color. In FIG. 4A, in step S101, print data for an area (hereinafter, unit area) which is a processing unit of edge processing consisting of a predetermined number of pixels is cut out from print data, and edge processing is performed in step S102. An area 201 indicated by a broken line around the unit area 202 is ambient information (recording data of the surroundings) necessary for edge processing. When there is no surrounding information, all the boundaries of the unit area become edges. However, by referring to the surrounding information, it is possible to appropriately determine the edge / non-edge even at the boundaries of the unit area. In the edge processing of step S102, a first plane is generated by the edge processing of step S102a, and a second plane is generated by the edge processing of step S102b. Then, in steps S103a and S103b, the non-ejection complementing process is performed. Thereafter, in steps S104a and S104b, print data for one scan of the print head is stored, and printing is performed based thereon. In step S200, the same processing as the processing of step S100 described above is repeated, and recording is performed to the next recording position. Thus, an image is recorded by sequential processing of recording while processing image data.

  In the above processing, in the non-ejection complementing processing performed in step S103a, the input information is referred to the information (recording data) 203a in the processing unit area and the edge processing in addition to the position information of the pixel corresponding to the nozzle to be complemented. Information (recording data of surrounding pixels) 201 around the processing unit area is input information. That is, of the input information in the non-ejection complementing process, the data subjected to the edge process is only the information of the process unit area. Therefore, when the above-mentioned surrounding information is required when performing non-ejection complementation to a pixel near the boundary between the processing unit area and the surrounding, this information is not subjected to edge processing. For this reason, non-ejection complementation across the boundary of the processing unit area is performed based on the data 201 which has not been subjected to the edge processing, thereby recording data in which the data is largely different before and after the edge processing. In this case, the data that is originally intended to be recorded is relatively different.

  FIG. 4B shows data in the non-ejection complementing process in step S103a, and shows non-ejection complementation of a method (FIG. 4C) of alternately distributing data to upper and lower pixels. As described above, the data 203a subjected to the edge processing is only the recording data in the processing unit, and the surrounding recording data 201 is not processed. Then, when there is a non-ejection in the nozzles corresponding to the surrounding pixels (arrow in the upper part of the figure), in the case of non-ejection complementation where data is distributed to upper and lower pixels alternately, the print data of the pixels corresponding to non-ejection nozzles A part is used as recording data of pixels in the processing unit area as indicated by the downward arrow. On the other hand, when there is a non-discharge nozzle inside the processing unit area (arrow in the lower part of the figure), since the non-discharge complementation is completed within the processing unit area, the above-mentioned problem does not occur.

  In addition, as a method of non-discharge complementation, as described in Patent Document 1, there is also a method of performing non-discharge complementation close to one side (FIGS. 4D and 4E). If this method is adopted at the boundary of edge processing, as shown in FIG. 4B, even if there is a failure in the nozzles corresponding to the surrounding pixels (arrows in the upper part of the figure), the print data By distributing to the upper pixel of the pixel, there is no influence on the recording data which has already been subjected to the edge processing in the processing unit area. However, by distributing to only one pixel, the frequency of use of the nozzle corresponding to the allocated pixel becomes high. In addition, when the non-ejection nozzles are adjacent to each other, the image quality may be greatly degraded.

  FIGS. 5 (a) to 5 (g) are diagrams for explaining the difference in image quality after complementation according to such a method of non-ejection complementation. FIG. 5A shows print data to be processed in the complementing process. FIGS. 5 (b) and 5 (c) show the two methods of the above-described complementing process, and FIG. 5 (b) shows a method of alternately distributing to the upper and lower pixels, and FIG. 5 (c) , Shows a method of distributing to pixels on one side (the example shown in the upper is the upper side).

  FIGS. 5 (d) and 5 (e) and FIGS. 5 (f) and 5 (g) show data after non-ejection complementation by the above two methods, and FIGS. 5 (d) and 5 (e) show data. 5 (f) and 5 (g) show the results of non-ejection complementation according to the method shown in FIG. 5 (b) according to the method shown in FIG. 5 (c). In (d) to (g) of FIG. 5, it is shown that the corresponding nozzle of the pixel indicated by the symbol “x” is not discharging.

  As shown in FIGS. 5 (d) and 5 (f), when the number of non-discharge nozzles generated is one, a large difference does not occur in the image after processing. However, as shown in FIGS. 5 (e) and 5 (g), when two non-ejection nozzles are generated, in the method of distributing to the pixels on one side (FIG. 5 (g)) There is a portion where dots are not recorded in the pixels, which greatly impairs the recorded image.

  As described above, in the non-ejection complementing process, it is preferable to distribute the print data to pixel arrays in both directions with respect to the pixel array corresponding to the nozzle causing the non-ejection. However, since pixels around the processing unit area of edge processing are print data before edge processing, there is a problem that non-ejection complementation of this portion can not be appropriately performed.

  On the other hand, in the embodiment of the present invention, since the edge portion of the image is subjected to the edge processing, the recording data of the ink color (black (K)) for recording the edge portion does not change so much by the edge processing. It is considered as data, and non-ejection complementing processing is performed which exceeds the boundary of the processing unit area of edge processing. That is, when the print data is data that does not change so much by edge processing, the print data around the processing unit area also does not change so much before and after the edge processing, so non-ejection complementing processing across the boundaries of the processing unit area is performed. Even if this is done, the recorded data will not be greatly damaged. On the other hand, the non-ejection complementing process is performed in the unit area of the edge process for the recording data of the ink color for recording the area other than the edge area (non-edge area) of the image. That is, since the print data of the non-edge portion changes relatively largely due to the edge processing, the print data before and after the processing is processed by the non-ejection complementing processing with the print data not subjected to the edge processing around the unit area. Because the change is relatively large, processing is performed only within the processing unit.

  6 (a) to 6 (t) illustrate edge processing according to the present embodiment, and FIGS. 7 (a) to 7 (l) illustrate non-ejection complement processing according to the present embodiment. FIG. In these figures, "area A" is one of processing unit areas of edge processing. As described above, the size of this processing unit (processing unit area) in edge processing is determined to some extent by the constraints such as the memory capacity, but in consideration of this constraint and the influence of this processing unit on the image quality of the recorded image, It can be determined. For example, the size of the pixel array corresponding to the direction of the nozzle array in the processing unit area is equal to or less than the number of pixels corresponding to the length of the nozzle array of the recording head, and the size in the direction orthogonal to the nozzle array direction is also the same. It can be In the example shown, this size is represented as a size of 8 pixels × 8 pixels for the sake of simplification of illustration and explanation.

  In this embodiment, a pigment ink is used as the black (K) ink, and a dye ink is used as the cyan (C), magenta (M), and yellow (Y) inks. Among these, the K ink is an ink which hardly penetrates into the plain paper. In the black recording data K, the edge portion is recorded with the pigment K ink, and the non-edge portion is recorded with the pigment K ink and the dye C, M, Y inks. That is, in the edge processing of the present embodiment, the edge portion and the non-edge portion are detected in the image of the K ink, and the edge portion is recording data to be printed with the K ink, and the non-edge portion is C, M together with the K ink. , Y ink is used as recording data to be recorded.

  6A to 6D show print data 1010 of binary C, M, Y, and K inks, respectively. In this example, it is shown that only printing data of K ink is present (FIG. 6 (d)). When the image of the printing data of the K ink shown in FIG. 6D is divided into an edge portion and a non-edge portion, the images are as shown in FIGS. 6E and 6F.

  6G to 6K show mask data for print data of C, M, Y and K inks in the non-edge portion and mask data for print data of K ink in the edge portion. By taking the logical product of the print data of the non-edge portion and the edge portion of the K ink shown in FIGS. 6 (e) and 6 (f) and the corresponding mask data shown in FIGS. 6 (g) to 6 (k). 6 (l) to 6 (p) are obtained as recording data after edge processing. Note that although the masks shown in FIGS. 6G to 6K are relatively small masks of 3 pixels × 3 pixels, they are repeatedly arranged and used in a tile shape. And, with regard to the recording data C, M, Y obtained on the basis of the recording data of the K ink in this manner, the logical OR with the original recording data C, M, Y (FIGS. 6A to 6C). Take Further, with regard to the recording data K, the edge portion and the non-edge portion are logically ORed to obtain final edge-processed data shown in (q) to (t) of FIG. In this example, since the original print data C, M and Y are not present (no dot print data is present), the data shown in FIGS. 6 (l) to 6 (n) and 6 (q) to 6 (s) are the same. It is.

  FIGS. 8A and 8B are flowcharts showing edge detection processing according to the present embodiment and edge processing based thereon. First, in the edge detection process, as shown in FIG. 8B, for the black recording data K, a matrix of 3 pixels × 3 pixels centered on the pixel of interest is considered, and the recording data of the pixel of interest is “On”. It is determined whether (dot recording) and the number of "On" pixels in the 3 pixel × 3 pixel matrix is 9 (S821). If the determination is affirmative, the pixel is determined to be a non-edge portion pixel (S823). When the determination in step S821 is negative, it is determined whether the target pixel is "On" (dot recording) (S822). If the determination is affirmative, the pixel is determined to be the pixel of the edge portion (S824). In the case of a negative determination in step S822, no determination is made (S825). The above process is repeated until there is no pixel to be detected (S826), and when it is determined that the process for all the target pixels is completed (S827), this process ends.

  In the edge processing shown in FIG. 8A, first, in step S801, edge detection processing is performed as described above with reference to FIG. Then, based on the result of this detection processing, for the print data K of black, the print data of the edge portion and the print data of the non-edge portion are determined for each processing unit area (S802). Then, as described above with reference to FIG. 6, the print data of the edge portion is ANDed with the edge mask (S 803). Further, regarding the print data of the non-edge portion, the logical product with the edge mask corresponding to each of the print data K, C, M, and Y is taken (S804, S805, S806, S807). Further, the logical sum of the data obtained in steps S 803 and S 804 is calculated for the black recording data K (S 808). Further, with regard to data of cyan, magenta and yellow, the logical sum of the data obtained by the edge processing and the original recording data C, M and Y is calculated (S809, S810 and S811). Finally, each piece of data is set as edge-processed data (edge-processed data 1011 shown in FIG. 3) (S812, S813, S814, and S815).

  In the non-ejection complementing process according to an embodiment of the present invention, data is distributed inside the processing unit area for edge processed data of C, M, Y ink at the boundary of the processing unit area, and the K ink is processed. With regard to edge processed data of (1), distribution of print data beyond the processing unit area is permitted.

  FIGS. 7A to 7D show data after edge processing of C, M, Y, and K. More specifically, of the data shown in FIGS. 6G to 6T, Data of area A which is one processing unit area is shown. Since edge processing is performed for each processing unit area, only the image inside area A can be obtained as an image after edge processing when processing area A. Data around the area A is used for edge detection but has not been subjected to edge processing yet. On the other hand, in the nozzle row of C, M, Y, and K inks, it is assumed that a non-ejection occurs in the nozzle corresponding to the pixel at the position indicated by “x →” in FIGS. In this case, in the present embodiment, the complementing process is performed as shown in FIGS.

  Here, in the edge processing on the image of black K as in the present embodiment, the recording data of the ink K does not change so much before and after the edge processing. Therefore, the surrounding information after the edge processing of the recording data of the ink K is also similar to the surrounding information (recording data) before the edge processing. From this point, according to the present embodiment, the non-ejection complementation is performed for the print data of the ink K beyond the processing unit area. That is, in the case of the recording data of the ink K, even if the non-ejection complementing is performed using the data outside the processing unit area which is not edge-processed, the non-ejection complementing to the edge-processed data and Almost similar results are obtained. On the other hand, the print data of C, M and Y inks change relatively largely before and after the edge processing. For example, as shown in the examples shown in FIGS. 6A to 6C, although there is no recording data of the original C, M, Y inks, the edge processing on the recording data of the K ink makes FIG. Data is generated as shown in (n). As described above, although the data is present by the edge processing, the surrounding information of the area A to be referred to in the non-ejection complementing processing is data of all “0” in which the edge processing has not been performed yet. It is. Therefore, in the present embodiment, the non-ejection complementation of the recording data of C, M, and Y inks is performed so as to be completed within the processing unit area.

  FIGS. 9 (a) to 9 (w) illustrate the above-described edge processing in more detail focusing on the processing unit, and FIGS. 10 (a) to 10 (w) are the same as the non-ejection shown above. It is a figure which illustrates complementation processing more concretely paying attention to processing unit.

  FIGS. 9A to 9D show print data 1010 of binary C, M, Y, and K inks. In order to perform edge processing on the print data, as shown in FIGS. 9E to 9H, print data of an area A which is a processing unit area and its periphery (for two pixels) is cut out. The edge processing of this embodiment does not perform processing other than replacing the data of ink K with the data of C, M, Y, and K ink with respect to the surrounding information (recording data). , Y ink ambient information is not referenced. However, as described later with reference to FIG. 13, when performing edge processing in consideration of the adjacent relationship between C, M, and Y inks and K ink, ambient information on C, M, and Y inks is required. There is a case.

  As shown in FIG. 8B, edge detection is performed on the recording data cut out for the area A shown in FIGS. 9E to 9H using the recording data of the area A and its surroundings, The data of the non-edge portion and the data of the edge portion shown in FIGS. 9 (i) to 9 (m) are obtained. Then, the logical product of each data and the mask shown in FIG. 9 (n) to (r) is taken to obtain data after edge processing shown in FIG. 9 (s) to (w). Further, the data of C, M and Y inks are logically ORed with the data of C, M and Y inks originally shown in FIGS. 9 (e) to (g). Further, with regard to the K ink data, the edge portion data and the non-edge portion data shown in FIGS. 9 (v) and (w) are logically ORed. Thereby, the edge-processed data 1011 shown in FIGS. 10A to 10D of the region A are finally obtained.

  FIGS. 10E to 10H show data used in the non-ejection complementing process of C, M, Y, and K inks. That is, although these data are the edge-processed data shown in FIGS. 10A to 10D inside area A which is the processing unit, the area around them is shown in FIGS. The data before the edge processing shown in h). Here, since the data of C, M and Y inks are data before edge processing, the surrounding information of C, M and Y inks is all “0” (dot non-recording).

  FIGS. 10 (i) to 10 (l) show the non-ejection complementing process for such data shown in FIGS. 10 (e) to 10 (h). For example, in the complementing process for data of C ink shown in FIG. 10I, non-ejection complementing is performed inside the processing unit area. Specifically, the print data 101 of the pixel corresponding to the non-ejecting nozzle, which is indicated by “x →”, is distributed to the pixels of the pixel row one below the inside of the region A. As described above, in the case where the nozzles corresponding to the pixel row adjacent to the boundary of the region A have non-protrusion, they are distributed to the next pixel row in one direction toward the inside of the region. As shown in FIG. 10 (j), when there is a failure in the nozzle corresponding to the pixel row not adjacent to the boundary inside the region A, the distribution is alternately distributed to the pixels in the vertical direction instead of one direction. .

  On the other hand, the complementing process on the data of the K ink shown in FIG. 10 (l) allows the complementing process beyond the boundary of the area A. For example, when there is a failure in the nozzles corresponding to the adjacent pixel row outside the boundary of the area A, the print data 102 is distributed to the pixels in the area A adjacent in the lower direction. As described above, since the data related to the complement processing of the K ink is similar to the peripheral information of the area A as well as the data after the edge processing, the edge processing is temporarily performed even if the print data is distributed beyond the processing unit area. The result is almost similar to the case of non-discharge complementation for already completed data.

  The reason for performing the complementing process beyond the boundary of the processing unit area for the K ink is as follows. One is to suppress the use frequency of the nozzle, which is increased by the non-ejection complementing process, as much as possible. In the first place, the non-ejection complementing process is a technique used when the number of times of scanning of the recording head is small, and is frequently used in the recording mode used on plain paper or the like. It is assumed that the recorded content output on plain paper has many black characters, for example. Therefore, when the ejection frequency of the K ink nozzle is increased by the non-ejection complementing process, the probability of connecting to the failure of the nozzle used for the non-ejection complementing process may increase. In order to suppress this, it is desirable to distribute the distribution of print data of the non-ejection complementing process up and down especially for the nozzles of the K ink. The second is an image quality reason. FIGS. 11A to 11C are diagrams for explaining the reason. FIG. 11A shows data before the non-ejection complementation. On the other hand, it is assumed that the non-ejection occurs in the pixel row adjacent below the boundary of the region A and the two continuous nozzles corresponding to the pixel row adjacent in the same direction. In this case, as shown in FIG. 11B, when the non-ejection complementation is performed only in the processing unit area, only two of the recording data 111 of the corresponding pixels are distributed to the adjacent pixels, and the image is continuous It loses sex. On the other hand, as shown in FIG. 11C, when the non-ejection complementation is performed beyond the processing unit area, four of the recording data 111 of the corresponding pixels are distributed to the adjacent pixels in the upward or downward navigation, respectively. , The continuity of the image is not so impaired. In the case of this example, it is understood that non-ejection complementation not restricted by the processing unit area is preferable.

  In the present embodiment, whether the non-ejection complementation in the processing unit area or the non-ejection complementation over the processing unit area is performed is based on how much the original image is changed by the edge processing. That is, it changes with the parameter of edge processing.

  FIG. 12 is a flowchart showing a process of determining whether to perform non-ejection complementation in the processing unit area or non-ejection complementation over the processing unit area according to the type of ink according to the present embodiment. First, the edge processing is performed by performing the non-ejection complementation that the first ink (K ink in the present embodiment) similar to that before the edge processing is small or the processing unit applied is small. It is determined whether the second ink (C, M, or Y ink in the present embodiment) is largely different from that before the edge processing (S121). In the case of the first ink, as shown in FIG. 10 (l), the complementation process beyond the processing unit area is performed (S122 to S124). On the other hand, in the case of the second ink, as shown in FIGS. 10 (i) to 10 (k), the complementing process is performed inside the processing unit area (S125, S126).

  As another example, attribute information of an image may be input and edge processing may be performed by determining whether it is a character. In that case, if it is not a character, it is all determined as non-edge, and only the edge of the image data that can be determined as a character may be determined as an edge. As a result, it is possible to mix K ink such as a photo image other than characters with C, M, Y ink, and to record, and more smooth recording can be obtained.

  That is, in the present embodiment, among the plurality of types of ink (C, M, Y, K) ejected by the recording head, the recording data of the ink (K) having the least change before and after the edge processing is obtained. The non-ejection complementing is performed to allow distribution of print data to pixels (pixels outside or inside the boundary) corresponding to other nozzles beyond the boundary of the processing unit area.

Second Embodiment
The second embodiment of the present invention relates to a recording apparatus capable of recording two types of K ink having different densities. One of the K inks is an ink having a black hue (hereinafter referred to as a PBk ink), and the other is an ink having a density different from that of the PBk ink but having the same black hue (hereinafter referred to as an MBk ink) Is called). The PBk ink is apt to bleed but has good scratch resistance, and the MBk ink is a ink which is hard to bleed but has low scratch resistance. Considering the characteristics of this ink, in order to emphasize the sharpness, the edge is printed with the MBk ink which is difficult to bleed, and in the pixels where the other C, M and Y ink areas are adjacent, the PBk ink is used as a countermeasure against bleeding. Record with

  13 (a) to 13 (y) are diagrams showing edge processing according to the present embodiment, and FIGS. 14 (a) to 14 (t) are diagrams showing non-ejection complement processing according to the present embodiment.

  FIGS. 13A to 13D show data 1010 of binary C, M, Y, and K inks, respectively. From this recording data, data of the processing unit area (area A) of each ink and the surrounding area shown in FIGS. 13 (e) to 13 (h) are obtained. Then, the data shown in FIG. 13 (l) and (m) is obtained by dividing the K ink data shown in FIG. 13 (h) into an edge portion and a non-edge. That is, data for MBk ink (FIG. 13 (l)) and data for PB k ink (FIG. 13 (m)) are obtained. Next, it is determined whether the other C, M, Y ink data and the pixel are adjacent. In the example shown in the figure, since there is no C, M, Y ink data adjacent to the K ink data divided into the edge portion and the non-edge portion, there is no pixel for which PBk ink is newly generated. The data shown in FIG. 13 (m) is maintained as it is. As a result, the data for MBk ink is as shown in FIGS. 13 (n) and (o), and the data for PBk ink is as shown in FIG. 13 (m). When there is data of C, M, Y ink adjacent to the data for K ink, in the data shown in FIG. 13 (m), the data of PBk-in is placed in the pixel of K ink related to the adjacent one. Become.

  Next, the logical product of the data determined above and the mask shown in FIG. 13 (p) to (s) is taken to obtain edge processed data shown in FIG. 13 (t) to (w). By taking the logical sum, data for MBk and data for PBk shown in FIG. 13 (x) and (y) are obtained.

  FIGS. 14 (a) to 14 (e) show data obtained by combining these edge-processed data with ambient information that has not been edge-processed. And FIG.14 (f)-(j) has shown the data which performed the non-discharge complementation process with respect to these data.

  As in the first embodiment, whether the non-ejection complementation is performed within the processing unit area or the non-ejection complementation is performed beyond the processing unit area based on whether the data are similar before and after the edge processing Decide.

  In the present embodiment, C, M, Y inks and MBk inks are subjected to non-ejection complementation beyond the processing unit, and PBk ink is postulated as non-ejection complementation within the processing unit. As for the C, M, and Y inks, unlike the first embodiment, since the data of the C, M, and Y inks are not purified by the edge processing of the data of the K ink, the data before and after the edge processing does not change so much. For this reason, suppression of the nozzle load rise by making it into non-ejection complementation over a process unit area | region is selected. Although data before edge processing does not exist for MBk ink and PBk ink, data before edge processing is data of K ink because it is data from which the data is generated. In this case, the data of the MBk ink has a high degree of similarity between the data after edge processing and the K data before processing. Therefore, as in the case of C, M, and Y, suppression of the nozzle load increase due to non-ejection complementation is selected. On the other hand, PBk ink selects non-ejection complementation in the processing unit area because K data before edge processing and data after processing are largely different.

(Other embodiments)
Although the embodiment described above describes the case where the recording data for edge detection in the edge processing is black (K) data, it goes without saying that the application of the present invention is not limited to this form. For example, edge detection may be performed on data of an ink other than black, which has a relatively high optical density, or data of a plurality of inks represented by mixed colors.

  Further, in the embodiment described above, an example in which the edge processing and the subsequent non-ejection complementing processing are performed in the recording apparatus has been described, but the present invention is not limited to this form. These processes may be executed by a host device such as a personal computer, or a part may be performed by the host device, and another part may be performed by the recording device. In this regard, a system including an apparatus or a plurality of apparatuses for performing edge processing and subsequent non-ejection complementing processing according to the present invention is referred to as an image processing apparatus in this specification.

201 to 204 recording head 500 recording control unit

Claims (6)

The recording data after the edge processing is performed for each processing unit comprising a predetermined number of pixels for recording data, an image to be non-ejection complementary processing in accordance with the position of the ejection failure nozzles in the print head for each of said processing units A processing device,
The recording head can record multiple types of ink ,
The edge processing records the edge portion in the first ink image with the first ink, and records the non-edge portion in the first ink image with the plurality of types of ink including the first ink. To divide the print data of the first ink,
For the recording data of the first ink obtained as a result of the edge processing, non-ejection complementation is performed that allows distribution of the recording data to pixels corresponding to the other nozzles beyond the boundary of the area of the processing unit. An image processing apparatus characterized by In the case of print data of ink other than the first ink obtained as a result of the edge processing, non-ejection allowing distribution of print data to pixels corresponding to other nozzles inside the boundary of the processing unit area The image processing apparatus according to claim 1, wherein the interpolation is performed . An image in which non-ejection complementing processing according to the position of the ejection failure nozzle in the recording head is performed for each processing unit on the recording data after edge processing has been performed on the recording data for each processing unit consisting of a predetermined number of pixels. A processing device,
The recording head can record a plurality of types of ink of the same hue ,
In the edge processing, the recording data of the color of the first ink, the recording data of the third ink having the same hue as the color of the first ink, and the third ink having the same hue as the third ink And recording data of the fourth ink different from
Among the third ink and the fourth ink, the number of pixels to be recorded in the print data of the processing unit of the color of the first ink before the edge processing, and the result of the edge processing for recording data of the ink towards the difference between the number of pixels to be recorded in the recording data of the processing unit is not small, the recording data in the pixels corresponding to the other nozzle beyond the boundary of the area of the processing unit An image processing apparatus characterized by performing non-ejection complementation that allows distribution of the image. Among the print data of the third ink and the fourth print data, the number of pixels to be printed in the print data of the processing unit of the color of the first ink before the edge processing, and the edge processing For the print data of the ink having a larger difference from the number of pixels to be printed in the print data of the processing unit obtained as a result of the above, pixels corresponding to other nozzles inside the boundary of the area of the processing unit the image processing apparatus according to claim 3, characterized in that the non-ejection complement you permit distribution of recorded data. In order to perform non-ejection complementing processing according to the position of the ejection failure nozzle in the recording head on the recording data after edge processing has been performed on the recording data for each processing unit consisting of a predetermined number of pixels for each processing unit Image processing method of
The recording head can record multiple types of ink ,
The edge processing records the edge portion in the first ink image with the first ink, and records the non-edge portion in the first ink image with the plurality of types of ink including the first ink. To divide the print data of the first ink,
For the recording data of the first ink obtained as a result of the edge processing, non-ejection complementation is performed that allows distribution of the recording data to pixels corresponding to the other nozzles beyond the boundary of the area of the processing unit. An image processing method characterized in that. In order to perform non-ejection complementing processing according to the position of the ejection failure nozzle in the recording head on the recording data after edge processing has been performed on the recording data for each processing unit consisting of a predetermined number of pixels for each processing unit Image processing method of
The recording head can record a plurality of types of ink of the same hue,
In the edge processing, the recording data of the color of the first ink, the recording data of the third ink having the same hue as the color of the first ink, and the third ink having the same hue as the third ink And recording data of the fourth ink different from
Among the third ink and the fourth ink, the number of pixels to be recorded in the print data of the processing unit of the color of the first ink before the edge processing, and the result of the edge processing For print data of ink having a small difference from the number of pixels to be printed in the print data of the processing unit, the print data is distributed to pixels corresponding to other nozzles beyond the boundary of the area of the processing unit. image processing method, characterized in that intends row ejection failure complement you acceptable <br/>.