Methods, apparatuses, and machine-readable media

Abstract

A print mode determination method is disclosed. The method includes receiving image data defining parameters of pixels of an image to be printed using a printing device; identifying, based on the image data, a first fill region of the image that exceeds a defined threshold area, wherein the first fill region is to be printed in a first color; determining, based on the image data, a first proportion of print agent for each of a plurality of colors used to print the first color; and determining, based on the determined first proportions of print agent, a print mode to be used by the printing device to print the image. Apparatuses and machine-readable media are also disclosed.

Description

Technical Field

[0001] The present disclosure generally relates to print mode determination. Background Art

[0002] A printing device can be used to print an image based on image data, for example, by depositing a printing agent onto a printable medium in a specific manner based on the image data. In some cases, specific conditions associated with the printing device or the printing agent (e.g., ink) used to print the image can cause print defects to appear in the printed image. An example of a possible print defect is sometimes referred to as "banding," which appears as a stripe extending across the printed image. Summary of the Invention

[0003] According to one aspect of the present disclosure, a printing mode determination method includes: receiving image data using a processor, the image data defining parameters of pixels of an image to be printed using a printing device; identifying a first fill area in the image that exceeds a defined threshold area using the processor and based on the image data, wherein the first fill area is to be printed in a first color; determining a first ratio of printing agent for each of a plurality of colors to be used to print the first color using the processor and based on the image data; and determining a printing mode to be used by the printing device to print the image from a plurality of printing modes using the processor and based on the determined first ratio of printing agent for the plurality of colors, the printing mode indicating a number of passes to be used by the printing device to print the image, wherein the number of passes to be used by the printing device corresponds to a maximum number of passes with a minimum amount of perceptible banding.

[0004] According to another aspect of the present disclosure, a device for determining a printing mode includes: a processor for: receiving image data representing an image to be printed using a printing device; identifying, based on the image data, a color block of a first color in the image, the color block having an area exceeding a defined threshold area; determining, based on the image data, a proportion of printing agent for each of a plurality of colors used to print the first color; and determining, from a plurality of printing modes, a printing mode to be used by the printing device to print the image based on the determined proportions of printing agent for the plurality of colors, the printing mode indicating a number of passes to be used by the printing device to print the image, wherein the number of passes corresponds to a maximum number of passes with a minimum amount of perceptible banding.

[0005] According to another aspect of the disclosure, a machine-readable medium comprising instructions, which when executed by a processor, cause the processor to: identify, from data representing an image to be printed using a printing device, a first color fill region having an area that exceeds a defined threshold area, wherein the first color fill region is to be printed in a first color; determine, from the data, a proportion of print agent for each of a plurality of colors used to print the first color; and based on the determined proportions of print agent for the plurality of colors, determine, from a plurality of print modes, a print parameter to be applied to the printing device to print the image, the print parameter comprising an indication of a number of passes to print the image, wherein the number of passes to be used by the printing device corresponds to a maximum number of passes having a minimum amount of perceptible banding. BRIEF DESCRIPTION OF DRAWINGS

[0006] Examples will now be described, by way of non-limiting examples, and with reference to the accompanying drawings in which:

[0007] Figure 1 is a schematic diagram of an example of an apparatus for determining a print mode of a printing device;

[0008] Figure 2 is a table showing example print modes for different print agent combinations;

[0009] Figure 3 is a flowchart of an example of a print mode determination method; and

[0010] Figure 4 is a schematic diagram of an example of a processor in communication with a machine-readable medium. DETAILED DESCRIPTION

[0011] Examples disclosed herein provide mechanisms by which a suitable print mode of a printing device can be automatically determined based on an image to be printed without the need to print and analyze the image to identify any print defects. The print mode of a printing device can define configuration parameters or settings to be used by the printing device when performing a print operation. For example, a print mode can include a number of times a print agent dispenser (e.g., a print head) passes over a region of a printable medium when printing a swath. When a printing device performs a print operation using a print mode that involves a relatively low number of print passes (e.g., 6 passes), a relatively large amount of print agent can be deposited from the print head during each print pass, in contrast, when a printing device performs a print operation using a print mode that involves a relatively large number of print passes (e.g., 12 passes), a relatively small amount of print agent can be deposited from the print head during each print pass. Different print modes can have different effects on a print operation, such as the total time to perform the print operation, the quality of the printed image as a result of the print operation, the drying program used to drive the printed image, etc. By selecting a suitable print mode for a print operation, a printed image with an expected quality can be obtained and the likelihood of print defects (also referred to as image quality defects) in the printed image occurring during the print operation can be reduced, resulting in a printed image with fewer defects.

[0012] One example of a print defect that can occur in a printed image is referred to as banding or dark line zone banding. A printed image that includes banding can have a region (or regions) within which a stripe or band is visible on the image. Stripes and other print defects can be particularly noticeable or noticeable in regions of a printed image that include blocks or regions of a particular color. Such regions are sometimes referred to as area fills of color blocks. For example, an area fill can include a region in which a single color is to be printed in the image. Other factors that can affect the occurrence and severity of banding in a printed image include the order in which print agents are deposited onto the printable medium, the speed at which the print head moves over the printable medium as the print agents are deposited, and the print agent formulation, etc.

[0013] Examples disclosed herein can be used for any type of printing device and can be used for any type of print operation. One example of a type of printing device that can be used with the present disclosure is a printing device that prints using latex print agents. Such a printing device can be referred to as a latex printer. The present disclosure can be used for any color of print agent. In one example, examples of the present disclosure can be applied to a printing device that is capable of printing an image using four different colors of print agent (cyan (C), yellow (Y), magenta (M), and black (K)).

[0014] When a print operation is to be performed, the print mode to be used by the print apparatus can be selected manually by an operator of the print apparatus, or can be selected automatically by the print apparatus or a computing or processing apparatus capable of operating or controlling an aspect of the print apparatus. In some examples, the print apparatus or an associated computing or processing apparatus can establish a suitable print mode to be used, which is provided as a recommendation to the operator. The operator can select the recommended print mode or any other print mode.

[0015] In some examples, the computing or processing apparatus that determines a suitable print mode to be used by the print apparatus can be implemented in the apparatus or device. Figure 1 is a schematic diagram of an example of an apparatus 100. The apparatus 100, which can be referred to as a print mode determination apparatus, comprises a processor 102. Thus, in some examples, the apparatus 100 can comprise a computing apparatus, such as a desktop computer, a laptop computer, a tablet computer, a smart phone, a wearable apparatus or a print apparatus (e.g. a printer of the type discussed herein).

[0016] The processor 102 can comprise modules that perform various functions. In some examples, the processor 102 comprises a receiving module 103a, a fill area detection module 103b, a print agent proportion determination module 103c and a print mode determination module 103d. The processor 102 (e.g. the receiving module 103a of the processor) is configured to receive image data 104 representing an image to be printed using a print apparatus. The image data 104 can be received in the form of an image file or in some other format suitable for printing an image by a print apparatus. The image data 104 can define parameters of pixels of the image to be printed. The parameters of the pixels defined in the image data 104 can comprise, for example, data indicative of a colour of each pixel in the image. The colour of a pixel in the image can be defined in terms of amounts of red (R), green (G) and blue (B) (sometimes referred to as continuous tones or continuous tone values) used to create the intended colour of the pixel. When a colour of a particular pixel is to be printed according to a RGB colour set, the colour of the pixel can optionally be defined in terms of a combination of print agents to be delivered or deposited at a print addressable location corresponding to the pixel in order to obtain the intended colour. For example, in a printer that prints an image using cyan, magenta, yellow and black print agents (CMYK), the intended colour of each pixel in the image can be defined in terms of amounts of cyan, magenta, yellow and black print agents used in order to obtain the intended colour. In some examples, the image data 104 can define parameters of the image pixels to be printed in terms of CYMK values representing proportions of different colours of print agent to be printed at each print addressable location.

[0017] The processor 102 (e.g. the fill area detection module 103b of the processor) is configured to identify, based on the image data 104, a colour patch of a first colour in the image having an area exceeding a defined threshold area. The colour patch can be referred to as a first fill area. Thus, the processor 102 can identify a first fill area in the image exceeding a defined threshold area, where the first fill area is to be printed in a first colour. As previously mentioned, some print defects, such as banding, are particularly noticeable in fill areas of an image where print agent of a particular colour is deposited in a single continuous block or zone. Banding appears as one or more streaks extending across the printed image in a direction parallel to the scan direction of the print head of the printing device that printed the image. The scan direction is the direction in which the print head traverses the printable medium as print agent is deposited during a print operation. Due to the nature of banding, such print defects can be unnoticeable in fill areas of the image having a size (e.g. height) that is smaller than a corresponding size (e.g. width or thickness) of the banding, which can be approximately equal to the swath height of the print head. Thus, according to some examples, fill areas that are sufficiently small so as to be unlikely to be noticeable in the printed image can be ignored. In other words, in some examples, fill areas in the image exceeding a defined threshold area are identified as potentially prone to banding and are thus considered, whereas fill areas not exceeding the defined threshold area are ignored.

[0018] The threshold area can be defined based on various factors, including for example the type of printing device, the parameters of the print head (e.g. the number of nozzles in the print head), and the swath size of the print head.

[0019] The colour to be printed in the first fill area (i.e. the first colour) can be any colour, although obviously, in order to be identified as a fill area, the first fill area will only include one colour. In some examples, a fill area can be defined as an area in which all pixels have substantially the same colour. Thus, in some examples, the size of a fill area and / or the threshold area can be measured in terms of the number of pixels included within a particular area. In other examples, the size of a fill area and / or the threshold area can be measured in some other way, for example in square millimetres, square centimetres, or the like.

[0020] Once the first fill region in the image is identified, the processor 102 (e.g. the print agent ratio determination module 103c of the processor) is to determine, based on the image data, a ratio of print agent for each of a plurality of colours used to print the first colour. In other words, the processor 102 can determine a first ratio of print agent for each of a plurality of colours used to print the first colour. In an example, if the processor 102 identifies a first fill region having a colour of a particular blue colour, the combination of print agents to be deposited in the first fill region is determined to create that colour. If the printing device uses cyan, magenta, yellow and black print agents, then blue can be achieved by depositing a relatively large ratio of cyan print agent and a relatively small ratio of magenta print agent. The processor 102 and / or the printing device can use existing mechanisms (e.g. algorithms or look-up tables) to determine the ratio of print agent colours to achieve the intended colour in the fill region, and more generally, to achieve the intended colour at each pixel of the image.

[0021] In one example, the ratio of each different print agent colour to be deposited at a particular print addressable location can be defined in terms of a ratio of a total amount of print agent of a particular colour print agent that can be deposited at the print addressable location. This ratio can be defined in percentage terms. For example, the combination of print agents to be deposited at a particular print addressable location can be 100% cyan (i.e. C: 100), 0% magenta (i.e. M: 0), 0% yellow (i.e. Y: 0) and 0% black (i.e. K: 0). This combination of print agents would result in a darker cyan, whereas a combination of C: 20, M: 0, Y: 0, K: 0 would result in a lighter cyan.

[0022] The processor 102 (e.g. the print mode determination module 103d) is then to determine, based on the determined first ratio of print agent, a print mode 106 to be used by the printing device to print the image. In some examples, once the combination of print agent colours is determined, the print mode to be used by the device can be determined by checking or interrogating a look-up table or database. Thus, the processor 102 can determine the print mode based on a check of a look-up table or database comprising an indication of a respective print mode for each of a plurality of combinations of print agent ratios. The print agent ratios can represent the relative proportions of different coloured print agents to be used to print a colour in the identified first fill region. For example, such a look-up table or database can comprise, for each possible combination of print agent colours, a print mode (e.g. a suitable or optimal print mode) that is most likely to print an image with little or no banding. In other words, the processor 102 is to determine a print mode that aims to produce the least image quality defects when printing the image. In some examples, the image quality defects can comprise banding defects as discussed herein.

[0023] In some examples, a print mode can define the number of passes that a print agent dispenser (e.g., a print head) makes over a printable medium on which an image is to be printed by the printing device during a print operation. For example, a first print mode can include a print agent dispenser depositing print agent at particular print addressable locations during 6 passes of printing, a second print mode can include a print agent dispenser depositing print agent at particular print addressable locations during 8 passes of printing, and a third print mode can include a print agent dispenser depositing print agent at particular print addressable locations during 12 passes of printing. In other examples, other print modes involving different numbers of printing passes can be used. In some examples, a print mode can define other parameters to be considered during a print operation, such as the speed at which a print head is to move over a printable medium, the amount of print agent to be deposited during each pass of printing, etc. In some examples, the processor 102 will further determine a print mode based on the printable medium on which the printing device is to print an image. When particular combinations of print agent colors are printed onto some types of printable media, print defects such as streaks can be more easily perceived or noticeable to an observer. Thus, by considering the type of printable medium on which an image is to be printed, a print mode can be selected that is both suitable for the combination of print agent colors to be printed in the fill region and the printable medium on which they are to be deposited.

[0024] A lookup table or database for determining print modes can be populated as a result of a testing or information gathering phase. During this phase, images including fill regions of particular colors are printed using each available print mode of the printing device (e.g., using a 6 pass print mode, an 8 pass print mode, and a 12 pass print mode), and it is determined, either automatically by image analysis software or manually by an observer, which print mode produces the highest quality printed image (i.e., the printed image with the least amount of streaks). The print mode that produces the highest quality image can be associated with the particular print agent type (e.g., composition) and stored in the lookup table or database. In some examples, the amount of streaks produced by each print mode can be associated with the particular print agent type and stored in the lookup table or database. The type, composition, color, and / or other elements of the print agent can affect the amount of streaks produced, including, for example, the properties and amounts of any pre-treatment or overcoat print agents applied, and the interactions of the print agents with each other and / or with the printable medium on which they are printed.

[0025] Figure 2is table 200, which shows an example of various associations between print patterns and print agent color combinations that can be stored in a lookup table or database. Columns 202, 204, 206, and 208 indicate the proportion of cyan, magenta, yellow, and black print agents, respectively, for each combination of print agents that would be deposited to achieve the intended color. For example, the color represented in the first row of table 200 is achieved by depositing a maximum of 20% of cyan print agent only, which can be deposited at a particular print addressable location. The color represented in the bottom row of table 200 is achieved by depositing the following combination of print agents: C: 75, M: 31, Y: 63, K: 45. To the right of columns 202-208, columns 210, 212, and 214 indicate the amount of banding that results from each color combination in table 200 when using a 12-pass print pattern (column 210), when using an 8-pass print pattern (column 212), and when using a 6-pass print pattern (column 214), respectively. The amount of banding that occurs when using a particular print pattern is indicated on a scale of 0 to 4, where 0 indicates no perceptible banding, 1 indicates slight banding, 2 indicates more severe banding, and 3 indicates the most severe banding.

[0026] In some examples, the proportions of each print agent color can be included in the lookup table or database as ranges. For example, the proportions of print agent colors in a particular combination can be given as 10 + / - 5, or a range of 0 to 5, 5 to 10, etc. In this way, the lookup table or database can include fewer entries than all possible combinations of print agent proportions. In other examples, if a particular combination of print agent proportions is not included in the lookup table or database, the print pattern can be determined based on the closest available combination of proportions (e.g., the closest color), such as a numerical calculation from the proportions.

[0027] When a print operation is performed, the operator of the printing device can have their own preference on the particular print mode to use. For example, printing an image using a 6-pass print mode can be much faster and, in some examples, can consume less print agent than using a 12-pass print mode. However, in most cases, a print mode that makes more passes will produce a higher quality image. Thus, for some printing device operators, a small amount of banding is acceptable. According to this example, table 200 includes an indication of which of the available print modes will be the print mode determined by processor 102 for the printing device to use. For example, for an image having a fill area generated in a color by a combination of print agents appearing at the top of table 200 (labeled 216), processor 102 will determine that a 6-pass print mode is appropriate; for an image having a fill area generated in a color by a combination of print agents appearing in the middle of the table (labeled 218), the processor will determine that an 8-pass print mode is appropriate; and, for an image having a fill area generated in a color by a combination of print agents appearing at the bottom of the table (labeled 220), the processor will determine that a 12-pass print mode is appropriate. As is clear from the table, the print mode determined by processor 102 is the print mode that results in the least severe banding.

[0028] Once processor 102 has determined a print mode, the processor can operate the printing device to print the image using the determined print mode. For example, the printing device operator can accept the print mode determined by processor 102, and thus the printing device can print the image using the print mode determined by the processor. In other examples, processor 102 can provide the determined print mode of the printing device to the operator of the printing device as a recommendation. For example, processor 102 can provide the determined print mode for presentation on a user interface (e.g., a user interface of the printing device), thereby indicating to the operator that the determined print mode is recommended for the image to be printed. In this way, the operator can choose to accept the recommended print mode, or to select a different print mode to use. In such examples, processor 102 can receive a selection of a print mode of the printing device to use to print the image from the operator. Processor 102 can then operate the printing device to print the image using the selected print mode. As described above, the selected print mode can or can not include the recommended print mode as determined by processor 102. In some examples, the printing device can print the image using a latex print agent (e.g., a latex ink).

[0029] In the examples discussed above, it was assumed that a single fill region was identified in the image to be printed, and the print mode to be used was determined based on the color of the fill region. However, the image can include multiple fill regions, each of which exceeds the defined threshold area, and each of which has a different color. In such a case, the processor 102 can determine a print mode for each identified fill region or for each different color to be printed, resulting in multiple print modes. In some examples, each determined print mode can be provided to an operator for selection of the print mode to be used. In other examples, the processor 102 can select a print mode from the multiple print modes that involves the largest number of print passes and is most likely to result in a printed image having the least amount of perceptible banding.

[0030] In other examples in which multiple fill regions are identified in the image to be printed, the determination of the print mode to be used can be based on the size of the identified fill regions. For example, if one fill region in the image is identified that is significantly larger than any other fill region, the largest fill region can include the most perceptible banding. Thus, the print mode determined by the processor 102 can be the mode that results in the least banding in the largest identified fill region. Accordingly, in some examples, the processor 102 can identify, based on the image data, a second fill region in the image that exceeds the defined threshold area, where the second fill region is to be printed in a second color. For example, the second color can be different than the first color. The processor 102 can determine, based on the image data, a second proportion of print agent for each of a plurality of colors used to print the second color. This can be done in the same manner as the processor determines a first proportion of print agent for each of a plurality of colors used to print the first color. For example, an algorithm or lookup table can be used to determine which combination of print agent colors will be used to produce the intended second color. In other examples, a conversion technique can be used to convert the first and / or second color from a first color space (e.g., RGB) to a second color space (e.g., CYMK).

[0031] The processor 102 can then determine which of the first fill region and the second fill region is the largest. As discussed above, the area of a fill region can be measured in pixels or some metric, such as square millimeters, square centimeters, etc. Once the largest fill region is identified, the processor 102 can determine a print mode to be used by the printing device to print the image based on the determined proportions of print agent for the largest fill region. Thus, the print mode used to print the image can be selected based on the color of the largest fill region, based on the assumption that banding occurring in the largest fill region is more likely to be observed by an observer than banding occurring in the smaller fill regions in the image.

[0032] As mentioned above, the processor 102 identifies a first fill region (or multiple fill regions) that exceeds a defined threshold area. However, in some examples, the processor 102 can also determine whether the fill region satisfies particular shape criteria. For example, an elongated streak appearing in the image can have an area that exceeds a defined threshold area, and thus would be identified by the processor 102 as a fill region. However, such an elongated streak can be too narrow to display a band in a manner that is perceptible to an observer. Thus, the processor 102 can consider the shape of the fill region or the geometric distribution of pixels within the fill region, and if the shape of the fill region (or the geometric distribution of pixels within the fill region) satisfies a particular defined criterion, a print mode can be determined for the fill region. In one example, if the width / height of the fill region is greater than a defined width / height, which is the minimum width / height at which a band can be perceived, a print mode can be determined based on the fill region. The width / height of the fill region at which a band becomes perceptible can be related to, for example, the number of contiguous nozzles present in a print head (i.e. a print agent applicator). In other examples, if the fill region is not a particular shape, such as a thin line, a print mode can be determined based on the fill region. More generally, in some examples, the processor 102 can determine, based on the image data, a geometric distribution of pixels within the first fill region. The processor 102 can further determine a print mode based on the determined geometric distribution of pixels within the first fill region. For example, if it is determined that the geometric distribution of pixels within the first fill region satisfies a defined criterion (e.g. has a width, thickness, or height that is greater than a defined threshold), it can be determined that the first fill region is likely to include some degree of banding, and thus a print mode that minimizes banding appearing in the first fill region can be selected. Similarly, if it is determined that the geometric distribution of pixels within the first fill region does not satisfy a defined criterion (e.g. has a width, thickness, or height that is less than a defined threshold), it can be determined that the first fill region is unlikely to include any banding, and thus a print mode can be selected based on the color of a different fill region (e.g. a second fill region).

[0033] Thus, in some examples, the processor 102 determines, based on the image data, a geometric distribution of pixels within the first fill region. When a criterion regarding the shape of the first fill region is to be satisfied in order to select a print mode based on the color of the first fill region, the processor 102 can check whether the criterion has been satisfied prior to determining the print mode. Thus, in response to determining that the geometric distribution of pixels within the first fill region satisfies a defined criterion, the processor 102 can determine a print mode based further on the determined geometric distribution of pixels within the first fill region.

[0034] Examples of the present disclosure also relate to methods. Figure 3is a flowchart of an example of the method 300, such as a print mode determination method. In some examples, the method 300 can comprise a computer-implemented method. As such, the method 300 can use one or more processors, such as processors of a computing device or a printing device. The method 300 comprises, at block 302, receiving, using a processor (such as the processor 102), data representing an image to be printed using a printing device. The data can comprise image data as described above, such as data defining parameters of pixels of the image to be printed. At block 304, the method 300 comprises identifying, using the processor and based on the image data, a patch of a first color in the image having an area that exceeds a defined threshold area. The patch can comprise a fill area as described above or be similar to a fill area. As such, block 304 can involve identifying a first fill area in the image that exceeds a defined threshold area, where the first fill area is to be printed in a first color. Such a patch or fill area can be of any shape. A patch can be considered to be a patch if the pixels within a region of the image are contiguous and have the same color, and the total size (i.e. area) of the region exceeds a defined threshold area.

[0035] The method 300 comprises, at block 306, determining, using the processor and based on the image data, a first proportion of print agent of each of a plurality of colors used to print the first color. In other words, block 306 can comprise determining a proportion of each of a plurality of colors of print agent used to print the first color. For example, in a printing device that uses C, M, Y and K print agents to print the image, block 306 then involves determining proportions of C, M, Y and K print agents used to print the first color. As described above, the determination can comprise using a lookup table or algorithm, or a conversion from one color space to another, such as a conversion from a color space used in the data received at block 302 to a color space of the printing device. At block 308, the method 300 comprises determining, using the processor and based on the determined print agent proportions, a print mode to be used by the printing device to print the image. As described above, one way in which the determination of block 308 can be made is to use a lookup table or database comprising indications of suitable print modes to be used for each possible combination of print agent colors.

[0036] In some examples, the method 300 can comprise other blocks corresponding to functionality performed using the processor 102, as described herein.

[0037] Examples of the present disclosure also relate to machine readable media. Figure 4is a schematic diagram of an example of a processor 402 in communication with a machine-readable medium 404. According to some examples, the machine-readable medium 404 includes instructions (e.g., image recognition instructions 406) that, when executed by the processor 402, cause the processor to recognize, from data representing an image to be printed using a printing device, a first color fill region having an area that exceeds a defined threshold area, wherein the first color fill region is to be printed in a first color. In some examples, the machine-readable medium can include instructions that can cause the processor to receive or acquire the data representing the image to be printed prior to recognizing the first color fill region. The machine-readable medium 404 further includes instructions (e.g., print agent proportion determination instructions 408) that, when executed by the processor 402, cause the processor to determine, from the data, a proportion of print agent for each of a plurality of colors used to print the first color. The machine-readable medium 404 further includes instructions (e.g., print parameter determination instructions 410) that, when executed by the processor 402, cause the processor to determine, based on the determined print agent proportions, print parameters to be applied to the printing device to print the image. The print parameters can include, form, or be referred to as a print mode. In some examples, the print parameters can include an indication of a number of print passes to be made by a print head (i.e., a print agent dispenser) of the printing device when depositing print agent at a print addressable location of a printable medium (e.g., a number of print passes to be made when printing a swath).

[0038] In other examples, the machine-readable medium 404 can further include instructions that, when executed by the processor 402, cause the processor to perform the blocks of the methods disclosed herein and / or to perform the functions performed by the processor 102 described above.

[0039] The examples described herein provide a mechanism by which, prior to commencing a print operation, a suitable print mode for a printing device can be determined based on an analysis of an image to be printed. In this way, an operator of the printing device is able to print an image using the most suitable print mode (e.g., a print code that is likely to generate the least banding) without having to perform a test (e.g., a print test). As a result, the preparation time taken prior to printing an image can be reduced, which can lead to a corresponding reduction in the costs associated with the print operation. Furthermore, the image can be printed with less perceptible banding, and thus generally has a higher quality. Once a look-up table or database has been compiled for a particular set of print agent colors, it can be used for any image printed using those print agent colors.

[0040] Examples in this disclosure can be provided as methods, systems, or machine-readable instructions, such as any combination of software, hardware, firmware, etc. Such machine-readable instructions can include a computer-readable storage medium (including, but not limited to, disk storage, CD-ROMs, optical storage, etc.) having computer-readable program code embodied therein or thereon.

[0041] This disclosure is described with reference to flowcharts and / or block diagrams of methods, apparatuses, and systems according to examples of this disclosure. Although the flowcharts illustrate a particular order of execution, the order of execution can be different from that which is described. Blocks described with reference to one flowchart can be combined with blocks of another flowchart. It will be understood that each block of the flowcharts and / or block diagrams, and combinations of blocks in the flowcharts and / or block diagrams, can be implemented by machine-readable instructions.

[0042] The machine-readable instructions may, for example, be executed by a general purpose computer, a special purpose computer, an embedded processor, or a processor of other programmable data processing apparatus to implement the functions described in this specification and diagrams. Specifically, a processor or processing apparatus can execute machine-readable instructions. Therefore, the functional modules of the apparatus and device can be implemented by a processor executing machine-readable instructions stored in a memory or a processor operating according to instructions embedded in a logic circuit. The term "processor" will be interpreted broadly to encompass CPUs, processing units, ASICs, logic units, programmable gate arrays, and the like. The methods and functional modules can be executed by a single processor or divided among several processors.

[0043] Such machine-readable instructions can also be stored in a computer-readable storage that can direct the computer or other programmable data processing apparatus to operate in a specific mode.

[0044] Such machine-readable instructions can also be loaded onto a computer or other programmable data processing apparatus to cause the computer or other programmable data processing apparatus to execute a series of operations to generate a computer-implemented process, so that the instructions executed on the computer or other programmable apparatus implement the functions specified by the flowcharts and / or blocks in the block diagrams.

[0045] Furthermore, the teachings herein can be implemented in the form of a computer software product, which is stored in a storage medium that can be accessed by a computer device, and includes a plurality of instructions for causing the computer device to implement the methods described in the examples of this disclosure.

[0046] While the method, apparatus and related aspects have been described with reference to particular examples, various modifications, changes, omissions, and substitutions can be made without departing from the spirit of the disclosure. Therefore, the method, apparatus and related aspects are not to be restricted by the specific examples described. It is noted that the examples described above are illustrative only and not limiting on the disclosure, and that those skilled in the art will be able to devise other arrangements without departing from the scope of the appended claims. Features described in relation to one example can be combined with features of another example.

[0047] The word "comprising" does not exclude the presence of elements other than those listed in a claim, "a" or "an" does not exclude plural referents, and a single processor or other unit can fulfill the functions of several units recited in the claims.

[0048] The features of any dependent claims can be combined with features of any independent claim or other dependent claim.

Claims

1. A print mode determination method comprising: receiving, using a processor, image data defining parameters of pixels of an image to be printed using a printing device; identifying, using the processor and based on the image data, a first fill region in the image that exceeds a defined threshold area, wherein the first fill region is to be printed in a first color; determining, using the processor and based on the image data, a first proportion of print agent for each of a plurality of colors used to print the first color; and determining, using the processor and based on the determined first proportion of print agent for the plurality of colors, a print mode to be used by the printing device to print the image from a plurality of print modes, the print mode indicating a number of passes to be used by the printing device to print the image, wherein the number of passes to be used by the printing device corresponds to a maximum number of passes having a minimum amount of perceptible banding.

2. The method of claim 1, further comprising: operating the printing device to print the image using the determined print mode.

3. The method of claim 1, further comprising: providing the determined print mode of the printing device as a recommendation to an operator of the printing device.

4. The method of claim 3, further comprising: receiving a selection of a print mode of the printing device to be used to print the image from an operator; and operating the printing device to print the image using the selected print mode. determining the print mode is based on an examination of a lookup table or database comprising indications of respective print modes for each of a plurality of combinations of print agent proportions.

5. The method of claim 1, wherein, 6. The method of claim 1, further comprising: determining, based on the image data, a geometric distribution of pixels within the first fill region; and determining the print mode further based on the determined geometric distribution of pixels within the first fill region.

7. The method of claim 1, further comprising: determining, based on the image data, a geometric distribution of pixels within the first fill region; and determining the print mode further based on the determined geometric distribution of pixels within the first fill region in response to determining that the geometric distribution of pixels within the first fill region satisfies a defined criterion.

8. The method of claim 1, further comprising: identifying, based on the image data, a second fill region in the image that exceeds a defined threshold area, wherein the second fill region is to be printed in a second color; determining, based on the image data, a second proportion of print agent for each of a plurality of colors used to print the second color; determining which of the first fill region and the second fill region is a maximum fill region; and determining a print mode to be used by the printing device to print the image based on the determined proportion of print agent for the maximum fill region.

9. The method of claim 8, further comprising: ​ ​ ​ determine, based on the image data, a geometric distribution of pixels within the first fill region and a geometric distribution of pixels within the second fill region; and determine the print pattern further based on the determined geometric distribution of pixels within the first fill region and based on the determined geometric distribution of pixels within the second fill region.

10. The method of claim 1, wherein, determining the print pattern is further based on a printable medium on which the print apparatus is to print the image.

11. The method of claim 1, wherein, the print pattern includes a number of passes by a print agent dispenser over the printable medium on which the print apparatus is to print the image during a print operation.

12. The method of claim 1, further comprising: determining the print pattern that is expected to result in the least image quality defects when printing the image.

13. An apparatus for determining a print pattern, comprising: a processor to: receive image data representing an image to be printed using a print apparatus; identify, based on the image data, a color patch of a first color in the image, the color patch having an area that exceeds a defined threshold area; determine, based on the image data, a proportion of print agent for printing each of a plurality of colors of the first color; and and determine, based on the determined proportions of print agent for the plurality of colors, a print pattern from a plurality of print patterns to be used by the print apparatus for printing the image, the print pattern indicating a number of passes to be used by the print apparatus for printing the image, wherein the number of passes corresponds to a maximum number of passes with a minimum amount of perceptible banding.

14. The apparatus of claim 13, wherein, the print apparatus prints the image using latex print agent.

15. A machine-readable medium comprising instructions which, when executed by a processor, cause the processor to: A first color fill area is identified from data representing an image to be printed using a printing device, the first color fill area having an area that exceeds a defined threshold area, wherein the first color fill region is to be printed in a first color; determine, from the data, a proportion of print agent for printing each of a plurality of colors of the first color; and determine, based on the determined proportions of print agent for the plurality of colors, a print parameter from a plurality of print parameters to be applied to the print apparatus for printing the image, the print parameter including an indication of a number of passes to print the image, wherein the number of passes to be used by the print apparatus corresponds to a maximum number of passes with a minimum amount of perceptible banding.

Images