Delhi High Court Dismisses NEC's Patent Appeal, Holds Video Coding Invention Obvious In Light Of Prior Art

The Delhi High Court has dismissed an appeal filed by NEC Corporation challenging the rejection of its patent application relating to video coding and decoding technologies, holding that the claimed invention lacks an inventive step and is rendered obvious in light of prior art documents.

A Bench of Justice Tejas Karia held:

“the contentions advanced by the Appellant that D1 to D3 are confined merely to colour space conversion or switching, akin to transformation in the present invention, and do not disclose the concept of selecting a colour space from among a plurality of colour spaces, is found to be untenable and is, accordingly, rejected.”

NEC Corporation, a Japanese multinational IT and network technology company, had filed a patent application titled “VIDEO CODING DEVICE, VIDEO DECODING DEVICE, VIDEO CODING METHOD, VIDEO DECODING METHOD AND PROGRAM” in India on 28 March 2017 as part of its international patent filings.

The application related to video coding and decoding technologies and sought to improve image quality and compression efficiency by using an adaptive colour transform in the residual domain along with a chroma quantisation offset.

The Patent Office issued a First Examination Report and subsequently refused the application for lack of inventive step under Section 2(1)(ja) of the Patents Act, 1970, citing three prior art documents (D1, D2 and D3).

Before the Court, NEC argued that its invention improved compression efficiency and image quality by deriving adaptive chroma quantisation offsets for each of multiple colour spaces. It contended that the prior art documents did not disclose deriving chroma quantisation offsets across multiple colour spaces.

The company submitted that D1 lacked the concept of a plurality of colour spaces and did not suggest deriving a chroma quantisation value for a selected colour space. It further argued that D2 and D3 used preset values rather than adaptive derivation and did not teach the selection of a colour space in coded block units.

The Patent Office, however, argued that the invention lacked inventive step in light of D1 and D2 independently, as well as in view of D3. It submitted that D1 already disclosed adjustment of quantisation parameters (QPs) for chroma components using specific equations, while D2 taught the use of different QPs for different colour components. D3, it argued, disclosed separate syntax elements for QP offsets across different colour spaces.

The Court observed that D1 discloses adjustment of quantisation parameters using offset values (-5, -3, or 0) depending on the adaptive colour transform flag, thereby satisfying the claimed feature of chroma quantisation offset for each colour space. The Court also noted that D1 discloses the selection and switching of colour spaces through adaptive colour transform.

The Bench further observed that D2 discloses the use of delta QPs (-5, -3, -5) to adjust the normal QP when colour space transform is applied. It held that a person skilled in the art would understand that if the transform is not applied, the normal QP would remain unchanged, implying a QP offset of zero.

The Court further noted that D3 discloses separate syntax elements for QP offsets in different colour spaces, indicating that quantisation parameter adjustments operate across colour spaces.

On a combined reading of D1, D2 and D3, the Court rejected NEC's contention that the prior art does not disclose selection from among multiple colour spaces. It held that the claimed invention would be obvious to a person skilled in the art and therefore fails to meet the requirement of inventive step under the Act.

Accordingly, the Court dismissed the appeal.

For the Appellant: Mr. Vineet Rohilla, Mr. Rohit Rangi, Ms. Vaishali Joshi, and Ms. Gurneer Chawla, Advocates.

For the Respondent: Mr. Rohan Jaitley, CGSC, with Mr. Varun Pratap Singh, Mr. Dev Pratap, and Mr. Yogya Bhatia, Advocates.