Parameterized OETF EOTF Transfer Functions for HDR Video

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Solution Overview

Problem

Existing high dynamic range (HDR) imaging technologies lack adaptive solutions for modifying Opto-Electrical Transfer Functions (OETF) and Electro-Optical Transfer Functions (EOTF) curves, leading to interoperability issues, market fragmentation, and inefficiencies in bit-stream overhead, as different standards and devices require distinct mappings that are not optimally addressed by fixed proposals.

Innovation Solution

A parameterized OETF and EOTF pair that can dynamically adapt to various market needs and standards by adjusting parameters such as s, t, c, n, and m, allowing for optimization against modulation transfer functions and look-up tables, enabling forward compatibility and optimal encoding for different use cases, and signaling these parameters as metadata for decoding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If fixed OETF/EOTF mappings are used for different standards, then each standard can be optimized for its specific goals, but interoperability issues and market fragmentation occur

Engineering Contradiction:
Improveoptimization precision for specific standardVSAvoidinteroperability across standards
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent introduces a universal parameterized OETF/EOTF framework that can represent multiple standard-specific mappings through a common mathematical structure with adjustable parameters. This allows a single unified system to serve multiple standards (Rec. 709, Rec. 2020, SMPTE ST 2084, BBC NHK) without requiring separate fixed mappings for each, thereby achieving both optimization for specific standards and interoperability across them.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent transforms fixed OETF/EOTF mappings into parameterized functions where specific standards are achieved by setting particular parameter values. For example, Rec. 709 corresponds to specific gamma values, while Rec. 2020 and SMPTE ST 2084 correspond to other parameter settings. This allows dynamic adaptation between standards by changing parameters rather than using completely different fixed mappings.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If multiple distinct OETF/EOTF proposals are adopted for different market segments, then each segment can be optimized, but device complexity and implementation overhead increase

Engineering Contradiction:
Improveoptimization for market segmentVSAvoidimplementation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a universal parameterized framework that replaces the need for multiple distinct OETF/EOTF implementations. A single device can support all market segments (theatrical release, broadcast, packaged media) by adjusting parameters within the unified framework, rather than implementing separate fixed mappings for each segment, thereby reducing device complexity while maintaining segment-specific optimization.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent transforms static fixed mappings into dynamic parameterized functions that can adapt to different market segments through parameter adjustment. This allows devices to dynamically switch between different standard requirements without requiring separate hard-coded implementations for each segment, reducing implementation complexity.

Inventive Principle:
Principle #15Dynamics

3Productivity

If standard-specific OETF/EOTF mappings are used, then encoding can be optimized for each standard, but bit-stream overhead increases due to signaling requirements

Engineering Contradiction:
Improveencoding efficiencyVSAvoidbit-stream overhead
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent represents different standard-specific OETF/EOTF mappings as variations of a base parameterized function. Instead of signaling complete separate mappings for each standard, the system only needs to signal deviations from the base parameters or select from a limited set of predefined parameter combinations, significantly reducing bit-stream overhead while maintaining encoding efficiency for each standard.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a base parameterized OETF/EOTF function as a template that is copied and adapted for different standards by modifying parameters. This approach avoids transmitting complete separate mappings for each standard and instead references the common template with minimal additional signaling, reducing bit-stream overhead.

Inventive Principle:
Principle #26Copying

Data Source

PatentEP3251366B1Methods and apparatus for electro-optical and opto-electrical conversion of images and video
Publication Date: 2024.01.10 INTERDIGITAL MADISON PATENT HLDG
  • EP3251366B1 patent drawingFigure 1
  • EP3251366B1 patent drawingFigure 2
  • EP3251366B1 patent drawingFigure 3

AI summary

The present principles are directed to a parameterized OETF/EOTF for processing images and video. The present principles provide a method for encoding a picture, comprising: applying a parameterized transfer function to a luminance (L) signal of the picture to determine a resulting V(L) transformed signal; encoding the resulting V(L); wherein the parameterized transfer function is adjusted based on a plurality of parameters to model one of a plurality of transfer functions. The present principles also provide for a method for decoding a digital picture, the method comprising: receiving the digital picture; applying a parameterized transfer function to the digital picture to determine a luminance (L) signal of the digital picture, the parameterized transfer function being based on a plurality of parameters; wherein the parameterized transfer function is adjusted based on a plurality of parameters to model one of a plurality of transfer functions.