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<DIV>Tom -</DIV>
<DIV> </DIV>
<DIV>While the Resource object seems like a potentially useful discussion topic,
I'm not sure that I see the relationship between several of the proposed
sub-types and IPP. For example, how would a client use IPP to position an
image stored in a library on the device correctly in a printed document?
Aren't the PPML folks over at PODI working on a document schema based on XML to
solve the general class of variable data printing problems? I know I would
benefit from a more complete discussion of where you are headed with this, since
at first glance it seems contrary to the principle of separating job submission,
management, and monitoring protocol (IPP) from document content.</DIV>
<DIV> </DIV>
<DIV>I guess my real question is "Are you trying to define a general purpose
printer resource selection mechanism by extending IPP syntax?" If you are,
I'd suggest that you also consider additional resources typically associated
with color printers, such as ICC profiles, Color Rendering Dictionaries, and
other by-products of print engine characterization, including (but not limited
to) halftone screens (possibly implemented as threshold arrays) and grey balance
transforms (possibly implemented as 1-D lookup tables). Such resources can
be downloaded into a printer, selected from a pre-existing store in the printer,
or even uploaded from the printer for use by a host based RIP (there is existing
standard PDL syntax to accomplish the first two operations, but I don't know of
any standard method for accomplishing the latter).</DIV>
<DIV> </DIV>
<DIV>Eric Random<BR>Core Technology<BR>Peerless Systems<BR>(310)
297-3251<BR>(310) 727-5715 - Fax<BR><A
href="mailto:erandom@peerless.com">erandom@peerless.com</A><BR><BR>>>>
"Hastings, Tom N" <hastings@cp10.es.xerox.com> 05/09/00 11:16AM
>>><BR>We have discussed several times on the IPP telecons about adding
a new<BR>Resource object. This mail note is a sketch of the idea to see if
there is<BR>support for developing an IPP spec along these lines. The
reason to being<BR>this idea up now is because of the discussion of the Print
Driver Extension.<BR>The Resource object approach would allow a way to install
print drivers on<BR>the Printer and to Get Print Drivers from the Printer to
install on a<BR>client. It would allow a Printer to have more than one
print driver, say<BR>one for each of a number of different OS platforms and/or
PDLs.<BR><BR>Should the Resource object be an agenda topic for the New York City
IPP WG<BR>Meeting, 5/17-18?<BR><BR><BR>Here is the sketch of the Resource object
idea and its operations:<BR><BR>The Resource object is a generic container
object for a number of sub-typed<BR>objects. The Resource object would
have a number of operations defined.<BR>Each operation would include an
operation attribute that identifies the<BR>object sub-type in question.
Then implementers could define new sub-types<BR>easily without having to invent
new operations.<BR><BR>There are some attributes common to all sub-types, such
as the<BR>"resource-name", "resource-sub-type",
"resource-owner",<BR>"resource-creation-date-time", etc., and a lot that are
specific to a<BR>particular sub-type. Some sub-types will also have opaque
data associated<BR>with each object instance (such as fonts, forms, images, and
print drivers),<BR>and others will only have attributes (such as
media).<BR><BR>The initial list of sub-types include:<BR><BR>media - Just
attributes which define the media characteristics. So the<BR>client can
query the media library and the administrator can add new media<BR>and define
their characteristics<BR>fonts - attributes and the PDL data<BR>forms -
attributes and the PDL data<BR>logos - attributes and the PDL data<BR>images -
attributes and the PDL data. high resolution images can be put<BR>into a
shared image library and called out from a number of documents<BR>print drivers
- attributes and the opaque data is the executable code<BR><BR>The operations
would include:<BR><BR>Create-Resource - the client specifies the resource type
and a user-friendly<BR>name for it that is used in all subsequent operations,
including Job<BR>Submission operations (Print-Job, Create-Job,
Send-Document). A lease time<BR>is also requested (just like our
Subscription objects) and the Printer<BR>returns the lease time granted (which
may be infinite meaning no need to<BR>renew or finite, meaning that the client
must renew the lease, else the<BR>resource will be
deleted).<BR><BR>Delete-Resource - delete the named resource of the indicated
sub-type<BR><BR>Renew-Resource - renews the lease, in case it wasn't
infinite<BR><BR>Get-Resource-Attributes - returns the requested (or all)
attributes of a<BR>specified resource type and instance.<BR><BR>Get-Resources -
returns the requested (or all) attributes of a specified<BR>resource type that
matches the supplied filter criteria consisting of any of<BR>the resource
attributes. Here the filtering is more complex than we have<BR>for
Get-Jobs or Get-Subscriptions operations, since the client could filter<BR>on
any of the resource attribute values. For example, a client
could<BR>request all of the media that has a "media-size" equal to particular
pair of<BR>x and y dimensions and get back the other resource attributes of any
matched<BR>media instances. <BR><BR>Get-Resource-Data - returns the opaque
data for those resources for which<BR>the data is not copyrighted,
etc.<BR><BR>These operations are very similar to the Subscription object
operations that<BR>the IPP WG has nearly approved for notification. The
only differences are:<BR>Subscription Ids are assigned by the Printer as
numbers, while resource<BR>object instances have user friendly names assigned by
the creator. Both<BR>have leases, but Subscription leases are expected to
be much shorter<BR>(minutes, hours) and handled by the software, not the user,
while Resource<BR>objects leases are much longer (days, weeks, months), though
both can be<BR>infinite depending on SA policy, and the user or administrator
explicitly<BR>creates the Resources. Also Resources are known to users and
administrators<BR>and are managed by them. Also Subscriptions don't have any
complex filtering<BR>in the query requests.<BR><BR>[We don't want to merge
Subscriptions into Resources, just illustrate their<BR>similarities]<BR><BR>It
will also allow the administrator to set up policy on who can create<BR>which
kinds of resources and for how
long.<BR><BR>Comments?<BR><BR>Thanks,<BR>Tom<BR><BR></DIV></BODY></HTML>