BACKGROUND

[0001] Image forming apparatuses may be capable of performing functions such as printing documents, scanning documents, copying documents, and/or the like. An image forming apparatus may be a single function peripheral (SFP) or a multi-function peripheral (MFP). Such image forming apparatuses may include replaceable printer components that may be depleted with use. For example, laser printers may include toner cartridges (e.g., black and/or color) having a limited print capacity, inkjet printers may include ink cartridges (e.g., black and/or color) having a limited print capacity, and the like. Some example image forming apparatuses may subscribe to a print material provider service over a network. The print material provider service may enable an image forming apparatus to dispense or consume ink, toner, or other marking agent that is available at the image forming apparatus according to a subscription.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] Examples are described in the following detailed description and in reference to the drawings, in which:

[0003] FIG. 1 is a block diagram of an example image forming apparatus, including a credit data adjustment module to adjust subscription credit data based on a print material coverage;

[0004] FIG. 2 is a block diagram of an example system architecture, including a subscription management server to monitor a number of pages printed by an image forming apparatus;

[0005] FIG. 3 is a block diagram of an example computer including a non- transitory machine-readable storage medium storing instructions to adjust subscription credit data associated with an image forming apparatus; [0006] FIG. 4 is a flowchart illustrating an example printer-implemented method for adjusting subscription credit data based on a print material coverage for a page; and

[0007] FIG. 5 illustrates an example document including multiple pages with different print material coverages.

DETAILED DESCRIPTION

[0008] Some image forming apparatuses (e.g., printers) may subscribe to a print material provider service over a network. The print material provider service may enable an image forming apparatus to dispense or consume the print material (e.g., ink, toner, or other marking agent) that is available at the image forming apparatus according to a subscription. As part of the subscription, the print material provider service may monitor the usage of the print material and the number of pages printed, and send a replaceable component (e.g., an ink cartridge, a toner cartridge, or the like) when the print material runs low.

[0009] In such scenarios, the image forming apparatus may allow printing using replaceable components that are restricted according to the terms of the subscription. In some examples, the subscription is based on a number of pages to be printed, and not on a number of ink or toner cartridges to be used. Thus, the print material provider service may, according to the subscription, authorize the image forming apparatus to print a defined number of pages (i.e., subscription credits) over a time period (e.g., a month).

[0010] When a page gets printed by the image forming apparatus, the subscription credits (e.g., a page count associated with the subscription) of the image forming apparatus may be decremented. Furthermore, the image forming apparatus may block printing when the defined number of pages is exhausted. An example subscription to utilize the print material at the image forming apparatus may include: - Subscription=$X/month, 100 pages included per month, $1 per 20 additional pages per month, with payment due: 30 days after an end of month usage report.

[0011] in such subscription-based services, the ink consumed for printing a page may depend on the content of the page. In this example, printing a page with a first print material coverage may consume higher ink compared to printing a page with a second print material coverage (e.g., the first print material coverage is greater than the second print material coverage). Thus, an amount of toner or ink used to print a page may be directly proportional to the print material coverage. However, in known methods, a printed page counts the same irrespective of whether the page includes a higher print material coverage or a lower print material coverage. Known methods may not account for the print material coverage while deducting the page count from the subscription credits (i.e., a remaining page count associated with the subscription). Hence, the subscription credits may be decremented by 1 per printed page irrespective of the print material coverage for the page.

[0012] Examples described herein may estimate a print material coverage for a page to be printed and decrement a page count associated with a subscription based on the estimated print material coverage for the page. In an example, an image forming apparatus may store subscription credit data indicative of a number of pages attributed to an image forming apparatus as part of a subscription. The subscription may authorize the image forming apparatus to print the number of pages over a time period based on a threshold coverage for each page. Further, the image forming apparatus may receive a print request including a page to be printed. Furthermore, the image forming apparatus may estimate a print material coverage for the page. Upon executing the print request, the image forming apparatus may adjust the subscription credit data to decrement the number of pages (i.e., the page count) based on the estimated print material coverage and the threshold coverage. [0013] In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present techniques. However, the example apparatuses, devices, and systems, may be practiced without these specific details. Reference in the specification to “an example” or similar language means that a particular feature, structure, or characteristic described may be included in at least that one example but may not be in other examples.

[0014] Turning now to the figures, FIG. 1 is a block diagram of an example image forming apparatus 100, including a credit data adjustment module 106 to adjust subscription credit data based on a print material coverage. Example image forming apparatus 100 may be a laser beam printer (e.g., using an electrophotographic method for printing), an ink jet printer (e.g., using an ink jet method for printing), or the like. Further, image forming apparatus 100 may be registered to a subscription service. The subscription service may provide a replaceable component of image forming apparatus 100 and define a number of pages that can be printed over a time period as part of the subscription. For example, the subscription service can communicate with image forming apparatus 100 to check a status of print material of the replaceable component, and further to perform actions that replenish the print material on image forming apparatus 100. As part of the subscription, the subscription service may physically deliver (e.g., through a shipping service) a replacement for the replaceable component.

[0015] Image forming apparatus 100 may include a processor 102 and a memory 104 coupled to processor 102. Further, memory 104 may include credit data adjustment module 106. In an example, credit data adjustment module 106 may store the subscription credit data indicative of a number of pages attributed to image forming apparatus 100 as part of a subscription. The subscription may correspond to the replaceable component of image forming apparatus 100. An example replaceable component may include a toner cartridge, an ink cartridge, or the like. [0016] During operation, credit data adjustment module 106 may receive a print request 108 including a page to be printed. An example print request may be a print job or a copy job that includes a document (e.g., including a single page or multiple pages) to be printed. In an example, image forming apparatus 100 may receive print request 108 from a user device via a network. Further, the user device may include a printer driver (e.g., to support the printing application) that is either installed in or accessible to the user device to generate print request 108 and send print request 108 to image forming apparatus 100 for printing.

[0017] In another example, image forming apparatus 100 may include an email-based print function which allows a user to print the document by emailing the document to an email address associated with image forming apparatus 100. In yet another example, image forming apparatus 100 may include a read-slot (e.g., a universal serial bus (USB) interface) to receive a memory card (e.g., an SD™ card (Secure Digital card), a CompactFlash™, flash drives having a USB interface, or the like), in which electronic documents to-be-printed are stored. In this example, print request 108 associated with the electronic documents may be triggered through a user interface (e.g., a control panel) of image forming apparatus 100. Examples described herein may also include types of printing that outputs a printed copy of information on a print medium (e.g., a paper).

[0018] Upon receiving print request 108, credit data adjustment module 106 may estimate a print material coverage for the page. The print material coverage may indicate an amount of print material that can be consumed to print the page. In an example, the print material coverage may be a sum of color print material coverages when print request 108 is a color print job. In another example, the print material coverage may be a black print material coverage when print request 108 is a monochrome black print job. An example print material coverage may include a toner coverage or an ink coverage.

[0019] In an example, credit data adjustment module 106 may estimate the print material coverage for the page by determining a ratio of a number of pixels (e.g., black pixels) to be printed to a total number of printable pixels in the page. In this example, credit data adjustment module 106 may estimate the print material coverage as a percentage of the total number of printable pixels of the page. The total number of printable pixels may include the total number of pixels on a printable area of the page and may depend on a size of a selected page (e.g., an A4 size). The number of pixels to be printed for the page may be determined from a count of image pixels that are received from the user device. Particularly, each pixel value that is received by credit data adjustment module 106 may be indicative of a spot which may have ink/toner applied. Each such pixel value may be counted, and the count may be used to provide an indication of the amount of ink/toner used for the page.

[0020] In response to executing print request 108, credit data adjustment module 106 may adjust the subscription credit data to decrement the number of pages based on the estimated print material coverage for the page. In an example, credit data adjustment module 106 may:

- determine a ratio of the estimated print material coverage to a threshold coverage. The estimated print material coverage may represent a number of pixels to be printed in the page. The threshold coverage may specify a defined percentage of a total number of printable pixels in the page based on the subscription.

- adjust the subscription credit data to decrement the number of pages by the determined ratio.

[0021] FIG. 2 is a block diagram of an example system architecture 200, including a subscription management server 202 to monitor a number of pages printed by an image forming apparatus 216. Example subscription management server 202 may be a cloud-based server. As shown in FIG. 2, subscription management server 202 may be coupled to image forming apparatus 216 over a network 214. For example, network 214 may include a wired network or a wireless network such as a local area network (LAN), a wide area network (WAN), the Internet, and/or the like. [0022] in an example, subscription management server 202 may include a subscription service 204, a registration component 206, an authentication component 208, and a subscription manager 210. Registration component 206, authentication component 208, and subscription manager 210 may be implemented as engines or modules including any combination of hardware and programming to implement the functionalities of the modules or engines described herein. The functions of registration component 206, authentication component 208, and subscription manager 210 may also be implemented by a processor. In examples described herein, processor may include, for example, one processor or multiple processors included in a single device or distributed across multiple devices.

[0023] Further, system architecture 200 may also include a subscription database 212 to store information pertaining to registered users and image forming apparatuses associated with subscription service 204. Registration component 206 may be operative to enroll users/image forming apparatuses to subscription service 204. Subscription service 204 may be provided by a service provider.

[0024] A user can register image forming apparatus 216 (e.g., a network- enabled printer) with the service provider so that image forming apparatus 216 can communicate with the service provider over network 214. The user can initiate a registration process for subscription service 204 using the user’s computing device, such as a smartphone, tablet device, a personal computer, laptop, or the like. For example, the service provider can provide a portal via a webpage (e.g., on a browser program) or a designated print application (e.g., downloaded and stored on the computing device) that the user can access using the computing device to initiate the registration process for subscription service 204. In some examples, the registration process can require the user to create an account or profile with the remote service provider and provide user information, such as the user's name, email address, and password for the account. [0025] In some examples, the registration process may enable the user to select a subscription plan from a plurality of different subscription plans. In this example, the subscription plan may include a defined number of pages (i.e., subscription credit data) that can be printed over a time period (e.g., a month) based on a threshold coverage for each page. As described above, the user can select from a variety of different plans based on the user’s printing habits and printing frequency. A first plan, for example, can be suitable for an occasional print user, which enables the user to print up to 50 pages for $2.99 per month based on a first threshold coverage for each page, while a second plan can be suitable for a frequent print user, which enables the user to print up to 300 pages for $9.99 per month based on a second threshold coverage for each page. The second threshold coverage may be different from the first threshold coverage.

[0026] As part of the registration process, the user can also provide other user information, such as user profile information, payment information, billing information, and/or shipping information. The payment and billing information can be used by the service provider to charge the user for subscription service 204 rendered on behalf of the user, while the shipping information can provide a designated location in which replaceable components can be physically mailed or shipped to the user. Depending on implementation, the user can provide the payment information, the billing information, and/or the shipping information by manually inputting the information via the portal or through any other user action.

[0027] Information provided by the users may be stored securely in subscription database 212. This information may include identification information, financial information (e.g., credit card or bank account information), printer hardware information, or the like. Registration component 206 may utilize the information for enrolling in subscription service 204. Enrollment may include providing the identification, financial, and/or printer hardware information for subscription service 204 to perform associated functions as well as setting up an account such as a user identifier (ID) and password. Once enrolled, the user may execute a subscription agreement (e.g., the number of pages to be printed within a time period based on the threshoid coverage for each page).

[0028] As part of the subscription, image forming apparatus 216 may receive a replaceable component, such as an ink cartridge or a toner cartridge, to enable image forming apparatus 216 to perform print operations. For example, the replaceable component can be provided by the service provider in connection with subscription service 204. When image forming apparatus 216 receives the replaceable component, image forming apparatus 216 can verify the replaceable component (e.g., authenticate/authorize the replaceable component) before enabling the print operations to be performed.

[0029] Furthermore, authentication component 208 may authenticate image forming apparatus 216, for instance, using a printer identifier prior to permitting printing at image forming apparatus 216. Further, subscription manager 210 may manage subscriptions associated with subscription service 204. Further, subscription manager 210 may monitor the usage of print material (e.g., ink, toner, or the like) and the number of pages printed corresponding to the subscription. An example replaceable component may include a print cartridge or a plurality of print cartridges corresponding to different ink colors. In such examples, subscription manager 210 may monitor a quantity of ink in each ink color remaining in the corresponding print cartridges.

[0030] As shown in FIG. 2, image forming apparatus 216 may include an image statistics controller 218, a print controller 220, and a subscription controller 222. Image statistics controller 218, print controller 220, and subscription controller 222 may be implemented as engines or modules including any combination of hardware and programming to implement the functionalities of the modules or engines described herein. The functions of image statistics controller 218, print controller 220, and subscription controller 222 may also be implemented by a processor. In examples described herein, processor may include, for example, one processor or multiple processors included in a single device or distributed across multiple devices.

[0031] During operation, print controller 220 may receive a print job or copy job. in an example, the print job or the copy job may include a page of a document to be printed. Upon receiving the print job or the copy job, image statistics controller 218 may estimate a print material coverage of the page in the print job or the copy job. In an example copy job, image forming apparatus 216 may include a scanner to scan the page. Further, image forming apparatus 216 may store the scanned document (e.g., electronic raw data representing the document) in a storage device 224. The electronic raw data may be generated by image forming apparatus 216 based on maximum values of setting information. In an example, the electronic raw data may include minimally processed image data from an image sensor of the scanner. The purpose of the electronic raw data may be to save the image data obtained from the image sensor with minimum or no loss of information. In this example, image statistics controller 218 may estimate an amount of print material coverage for the page using the electronic raw data.

[0032] Further, print controller 220 may compare the estimated print material coverage against the threshold coverage. The threshold coverage may specify a defined percentage of a total number of printable pixels in the page according to the subscription. In an example, print controller 220 may determine a ratio of the estimated print material coverage to the threshold coverage. An example threshold coverage may be specified as a percentage of the total number of printable pixels in a page. In another example, the threshold coverage may be specified as a defined number of pixels of the total number of printable pixels.

[0033] Further, subscription controller 222 may use the comparison results to adjust the subscription credit data to decrement the number of pages. In an example, when the estimated print material coverage is less than the threshold coverage, then a value less than 1 may be decremented from the number of pages. For example, consider the threshold coverage as 50% of the total number of printable pixels, the estimated print material coverage of the page is 30% of the total number of printable pixels, and the number of pages (i.e., the subscription credit data) that can be printed according to the subscription is 100. In this example, the ratio of the estimated print material coverage to the threshold coverage is 30/50, i.e., 0.6. In this example, the number of pages may be decremented by 0.6 (i.e., 100-0.6 = 99.4).

[0034] In another example, when the estimated print material coverage is equal to the threshold coverage, then a value of 1 may be decremented from the number of pages. For example, consider the threshold coverage as 50% of the total number of printable pixels, the estimated print material coverage of the page is 50% of the total number of printable pixels, and the number of pages (i.e., the subscription credit data) that can be printed according to the subscription is 100. In this example, the ratio of the estimated print material coverage to the threshold coverage is 50/50, i.e., 1. In this example, the number of pages may be decremented by 1 (i.e., 100-1 = 99).

[0035] In yet another example, when the estimated print material coverage is greater than the threshold coverage, then a value greater than 1 may be decremented from the number of pages. For example, consider the threshold coverage as 50% of the total number of printable pixels, the estimated print material coverage of the page is 80% of the total number of printable pixels, and the number of pages (i.e., the subscription credit data) that can be printed according to the subscription is 100. In this example, the ratio of the estimated print material coverage to the threshold coverage is 80/50, i.e., 1.6 In this example, the number of pages may be decremented by 1.6 (i.e., 100-1.6 = 98.4).

[0036] Similarly, each page in the document of the print job or the copy job may be analysed and printed by image forming apparatus 216, and the remaining page count associated with the subscription credit data may be updated accordingly in storage device 224. Furthermore, image forming apparatus 216 may communicate available subscription credit data upon executing the print job or the copy job to subscription manager 210. Subscription manager 210 may monitor the number of pages printed on image forming apparatus 216 corresponding to subscription service 204 and store the monitored page count in a storage (e.g., subscription database 212).

[0037] in an example, subscription manager 210 may have the capability to block further printing on image forming apparatus 216 when the subscription credit data is used. As an example, when the subscription credit data (i.e. , an authorized number of pages that can be printed) is 50 per month based on the threshold coverage, then the user can print until the subscription credit data reaches zero within a single month based on the estimated print material coverage of each page as described above. After the subscription credit data reaches zero, image forming apparatus 216 may be blocked from printing any further pages or may permit printing with a fee corresponding to each additional page over 50 pages.

[0038] FIG. 3 is a block diagram of an example computer 300 including non- transitory machine-readable storage medium 304 storing instructions to adjust subscription credit data associated with an image forming apparatus. Example computer 300 may be a server that connects image forming apparatuses to user devices over a network. For example, the server may act as an intermediary between the user devices and the image forming apparatuses, accepting print requests from the user devices, and sending them on to an appropriate image forming apparatus. In some examples, the server may be an on-premises server or a cloud-based server (e.g., including a cloud printing service).

[0039] Computer 300 may include a processor 302 and machine-readable storage medium 304 communicatively coupled through a system bus. Processor 302 may be any type of central processing unit (CPU), microprocessor, or processing logic that interprets and executes machine-readable instructions stored in machine-readable storage medium 304. Machine-readable storage medium 304 may be a random-access memory (RAM) or another type of dynamic storage device that may store information and machine-readable instructions that may be executed by processor 302. For example, machine-readable storage medium 304 may be synchronous DRAM (SDRAM), double data rate (DDR), rambus DRAM (RDRAM), rambus RAM, etc., or storage memory media such as a floppy disk, a hard disk, a CD-ROM, a DVD, a pen drive, and the like. In an example, machine- readable storage medium 304 may be non-transitory machine-readable medium. Machine-readable storage medium 304 may be remote but accessible to computer 300.

[0040] As shown in FIG. 3, machine-readable storage medium 304 may store instructions 306-316. In an example, instructions 306-316 may be executed by processor 302 to adjust subscription credit data associated with an image forming apparatus based on a print material coverage. Instructions 306 may be executed by processor 302 to store subscription credit data indicative of a number of pages attributed to the image forming apparatus as part of a subscription. For example, the subscription may correspond to a replaceable component of the image forming apparatus. The replaceable component may include a print cartridge that is being provided by a subscription service in connection with the subscription. In an example, the subscription may authorize the image forming apparatus to print the number of pages over a time period based on a threshold coverage for each page.

[0041] Instructions 308 may be executed by processor 302 to receive a print request including a page to be printed. Instructions 310 may be executed by processor 302 to estimate a print material coverage for the page, in an example, the print material coverage may represent a number of pixels to be printed in the page. In an example, instructions to estimate the print material coverage for the page may include instructions to:

- detect a number of objects in a page,

- determine a type of the detected objects within the page,

- determine an amount of dot area coverage in a region of the detected objects, and

- estimate the amount of print material coverage for the page based on the number of objects within the page, the type of the objects, and the amount of dot area coverage for the objects. The print material coverage may be the total number of pixels of the objects in a page and/or the area of the objects in the page.

[0042] instructions 312 may be executed by processor 302 to compare the estimated print material coverage for the page to be printed with the threshold coverage. Instructions 314 may be executed by processor 302 to adjust the subscription credit data to decrement the number of pages based on the comparison. In an example, instructions to adjust the subscription credit data to decrement the number of pages may include instructions to:

- determine a ratio of the estimated print material coverage to the threshold coverage, and

- adjust the subscription credit data to decrement the number of pages by the determined ratio.

[0043] For example, instructions to adjust the subscription credit data may include instructions to:

- decrement the quantity of pages by a value less than 1 (i.e. , the determined ratio is less than 1) when the estimated print material coverage is less than the threshold coverage,

- decrement the quantity of pages by a value greater than 1 (i.e., the determined ratio is greater than 1) when the estimated print material coverage is greater than the threshold coverage, and

- decrement the quantity of pages by a value equal to 1 (i.e., the determined ratio is equal to 1) when the estimated print material coverage is equal to the threshold coverage.

[0044] Upon adjusting the subscription credit data, instructions 316 may be executed by processor 302 to send the print request to the image forming apparatus for printing. Further, machine-readable storage medium 304 may store instructions to send a notification indicative of a remaining quantity of pages associated with the subscription credit data to a subscription service via a network. The subscription service may keep track of the number of printed pages to prevent the user from exceeding an allowed allotment of pages corresponding to the subscription.

[0045] FIG. 4 is a flowchart illustrating an example printer-implemented method 400 for adjusting subscription credit data based on a print material coverage for a page. Method 400 depicted in FIG. 4 represents generalized illustrations, and other processes may be added, or existing processes may be removed, modified, or rearranged without departing from the scope of the present application. In addition, the processes may represent instructions stored on a computer-readable storage medium that, when executed, may cause a processor to respond, to perform actions, to change states, and/or to make decisions. The processes of method 400 may represent functions and/or actions performed by functionally equivalent circuits like analog circuits, digital signal processing circuits, application specific integrated circuits (ASICs), or other hardware components associated with a system. Furthermore, example method 400 may not be intended to limit the implementation of the present application, but rather example method 400 illustrates functional information to design/fabricate circuits, generate machine- readable instructions, or use a combination of hardware and machine-readable instructions to perform the illustrated processes.

[0046] At 402, subscription credit data according to a subscription may be received from a server (e.g., subscription management server 202 as shown in FIG. 2). In an example, the subscription credit data may indicate a quantity of pages that a printer is authorized to print over a time period based on a threshold coverage range for each page. In an example, the threshold coverage range may specify a defined percentage range of a total number of printable pixels in the page according to the subscription.

[0047] At 404, a print request including a page to be printed may be received. At 406, an amount of a print material coverage for the page may be estimated. At 408, the amount of the print material coverage may be compared with the threshold coverage range. At 410, in response to executing the print request, the subscription credit data may be adjusted to decrement the quantity of pages by a value based on the comparison.

[0048] in an example, adjusting the subscription credit data to decrement the quantity of pages by the value may include:

- decrementing the quantity of pages by a first defined value when the amount of the print material coverage is less than the threshold coverage range. In this example, the first defined value is less than 1.

- decrementing the quantity of pages by a second defined value when the amount of the print material coverage is greater than the threshold coverage range. In this example, the second defined value is greater than 1.

- decrementing the quantity of pages by a third defined value when the amount of the print material coverage is within the threshold coverage range. In this example, the third defined value is equal to 1.

[0049] The first defined value, the second defined value, and the third defined value may be specified by a subscription service according to the subscription. An example document with multiple pages to be printed is depicted in FIG. 5.

[0050] FIG. 5 illustrates an example document 500 including multiple pages 502, 504, and 506 with different print material coverages. As shown in FIG. 5, pages 502, 504, and 506 may include different print material coverages. Consider that the threshold coverage range is 40% to 60% of the total number of printable pixels in the page. Further, consider that the amount of a print material coverage for page 502 may be estimated as 20%, for page 504 may be estimated as 45%, and for page 506 may be estimated as 65%. Further, consider that the first defined value, the second defined value, and the third defined value as may be specified based on the print material coverage as follows:

- when the amount of the print material coverage is less than the threshold coverage range: the first defined value is 0.5, - 1 / -

- when the amount of the print material coverage is greater than the threshold coverage range: the second defined value is 1.5, and

- when the amount of the print material coverage is equal to the threshold coverage range: the third defined value is 1 .

[0051] In the above example, page 502 includes print material coverage (e.g., 20%) that is less than the threshold coverage range (e.g., 40% to 60%). When page 502 is printed, the quantity of pages (e.g., 100) may be decremented by 0.5 (i.e., 100-0.5 = 99.5). Further, page 504 includes print material coverage (e.g., 45%) that is within the threshold coverage range (e.g., 40% to 60%). When page 504 is printed, the quantity of pages (e.g., 100) may be decremented by 1 (i.e., 100-1 = 99). Similarly, page 506 includes print material coverage (e.g., 65%) that is greater than the threshold coverage range (e.g., 40% to 60%). When page 506 is printed, the quantity of pages (e.g., 100) may be decremented by 1.5 (i.e., 100- 1.5 = 98.5). When pages 502, 504, and 506 are printed, the quantity of pages (e.g., 100) may be decremented by 3 (i.e., 100-0.5-1-1.5 = 97).

[0052] Referring to FIG. 4, upon adjusting the subscription credit data, a notification indicative of a remaining quantity of pages associated with the subscription credit data may be sent to a subscription service via a network.

[0053] The above-described examples are for the purpose of illustration. Although the above examples have been described in conjunction with example implementations thereof, numerous modifications may be possible without materially departing from the teachings of the subject matter described herein. Other substitutions, modifications, and changes may be made without departing from the spirit of the subject matter. Also, the features disclosed in this specification (including any accompanying claims, abstract, and drawings), and/or any method or process so disclosed, may be combined in any combination, except combinations where some of such features are mutually exclusive. [0054] The terms “include,” “have,” and variations thereof, as used herein, have the same meaning as the term "comprise” or appropriate variation thereof. Furthermore, the term “based on”, as used herein, means “based at least in part on.” Thus, a feature that is described as based on some stimulus can be based on the stimulus or a combination of stimuli including the stimulus. In addition, the terms “first” and “second” are used to identify individual elements and may not meant to designate an order or number of those elements.

[0055] The present description has been shown and described with reference to the foregoing examples. It is understood, however, that other forms, details, and examples can be made without departing from the spirit and scope of the present subject matter that is defined in the following claims.