Project Number : A052
Class/Subclass : H04N 19/00
Date
: September 9, 2011
CA thanks the Rapporteur for the Revision Proposal of Annex 1. CA shares the
perspective of the Rapporteur that the classification of video coding technology is due for
a fresh approach. CA has performed a small-scale test of the proposed scheme on some
Canadian applications. CA would like to point out some instances where changes in the
subgroup titles might make the Classification Scheme easier to use. CA is also a bit
baffled by the hierarchy of Subgroup H04N 19/99.
H04N 19/99
Concerning H04N 19/99, what CA finds baffling is that this subgroup is indented under
one-dot Subgroup H04N 19/90 (“using special coding techniques not provided for in
groups H04N 19/10-H04N 19/895”). In view of the title of Subgroup H04N 19/99
(“Adaptive dynamic range coding”), this group would appear to belong to the hierarchy
of one-dot subgroup H04N 19/10 (“using adaptive coding”).
Subgroup titles
CA’s test with the scheme suggested that the upper levels of the hierarchy (the one-dot
and two-dot subgroups) are not straightforward to use: it can be challenging to tell the
difference in subject matter coverage between some one-dot or two-dot subgroups.
One-dot subgroups
In some instances, the coverage is clear, as is the case of the residual one-dot subgroup
H04N 19/90, and other one-dot subgroups have titles that are explicit enough that the
user can quickly home in on the proper hierarchy, examples being H04N 19/10 (“using
adaptive coding”) or H04N 19/40 (“using video transcoding”).
However, with one-dot subgroups H04N 19/20 (“using video object coding”), H04N
19/44 (“Decoders specifically adapted therefor”), H04N 19/50 (“using predictive
coding”) and H04N 19/60 (“using transform coding”), the coverage can overlap some of
the indented subgroups of the more explicit subgroups, and the user is only provided
guidance (in the form of a limiting reference) for H04N 19/50 (referring the subject
matter to H04N 19/61 when both predictive and transform coding are involved). It would
be helpful to the user if the Classification Scheme was more explicit on potential overlap.
For example, when predictive coding is found as part of a more specific system (for
example, within adaptive coding, as in H04N 19/1202 to H04N 19/1215), is that subject
matter also classified in H04N 19/50 (multi-aspect classification), or is the classification
limited to the hierarchy of H04N 19/10? Worded differently, does the Rapporteur intend
the more functional places like H04N 19/50 and H04N 19/60 to be comprehensive or to
cover patent documents that are not accommodated into the more application-oriented
subgroups?
Another example would be H04N 19/44 (“Decoders specifically adapted therefor”).
Based on its classification rules, CA would use that one-dot subgroup on every patent
document where a claim is directed to a video decoder.
Two-dot subgroups
At the two-dot subgroup level, CA found difficult to grasp precisely the distinction
between subgroups H04N 19/12 and H04N 19/14. One difficulty is that the word
“adaptivity” is not defined in any of the dictionaries (electronic or book form) that CA
consulted. (Obviously, this could be solved using the “Glossary” part of the Definition,
when that stage is reached.) Because there are indented subgroups with similar subject
matter indented under two-dot subgroups H04N 19/12 and H04N 19/14 (in particular,
H04N 19/1202 vs H04N 19/146; and H04N 19/1208 vs H04N 19/1463), it would be very
helpful to the IPC user if the titles of groups H04N 19/12 and H04N 19/14 pointed more
clearly to the distinction between the two hierarchies.
CA notes firstly that both two-dot subgroups use the singular form for the words
“element” and “parameter”, whereas the plural “criteria” is used in H04N 19/14. Is that
distinction intended? For example, if a patent document involved a plurality of
parameters or elements, should H04N 19/12 or H04N 19/14 be avoided?
Secondly, while testing the proposed scheme, CA found the title of Subgroup H04N
19/12 difficult to interpret on its own, and resorted to a two-step process of eliminating
Subgroup H04N 19/14 before considering Subgroup H04N 19/12 and its hierarchy. It
would be more efficient for the user if classification in the hierarchy of H04N 19/12
could be based on a positive determination, rather than an elimination process.
If CA understands correctly the intention of the Rapporteur, the hierarchy of subgroup
H04N 19/12 would cover patent documents where the inventive aspect is in transforming
(through adaptive coding) an element, or in changing a parameter of the coding process,
or in altering the coding process itself, whereas the hierarchy of Subgroup H04N 19/14
would cover patent documents where the inventive aspect pertains to the element,
parameter or process controlling the coding process. If that is so, some slight rewording
of the titles of these two-dot subgroups might make the distinction clearer. A (nonexhaustive) list of options is given below:
H04N 19/12
characterised by the transformation
occurring to an element, parameter or a
selection during the adaptive coding
characterised by an element, parameter or
selection altered during the adaptive coding
characterised by an element, parameter or
selection affected, i.e. controlled, by the
adaptive coding
characterised by the element, parameter or
selection acted upon during the adaptive
coding
H04N 19/14
characterised by an element, parameter or
criterion controlling the adaptive coding
characterised by a controlling element,
parameter or criterion
characterised by an element, parameter or
criterion affecting, i.e. controlling, the
adaptive coding
Also at the two-dot subgroup level, CA finds the subject matter of Subgroup H04N 19/16
difficult to circumscribe. The expression “the coding unit” covers many different pictorial
entities, as inferred from the titles of Subgroups H04N 19/161 to H04N 19/169, and
seems therefore to have a very broad meaning. Hence, CA wonders if the subject matter
of Subgroup H04N 19/164 could not always be accommodated under Subgroup H04N
19/1255. CA would have the same concern for the subject matter of Subgroup H04N
19/162, which would appear suitably covered in Subgroup H04N 19/1232. (The clause
“characterised by the structural or semantic portion of the video signal being the object or
the subject of the adaptive control during the coding” did not enlighten CA; in particular,
CA could not figure out what distinction was intended between “object” or “subject” with
respect to the adaptive control.)
CA would like to emphasise that it welcomes the proposal of the Rapporteur for a
revision of the video coding area. The problem that CA faces is in avoiding an overload
of classification places on patent documents pertaining to video coding.
Claude Plante
Senior Patent Classification Examiner
John Dowding
Senior Patent Classification Examiner