Video Signal Processing Device OOTF Conversion HDR SDR Compatibility

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Solution Overview

Problem

Current workflows struggle to achieve compatibility between High Dynamic Range (HDR) and Standard Dynamic Range (SDR) video signals, leading to differences in visibility on monitors due to distinct Opto-Optical Transfer Function (OOTF) characteristics.

Innovation Solution

A video signal processing system that includes HDR and SDR video generation units, utilizing OOTF conversion through exponentiation and linear functions to align the visibility of HDR and SDR videos, with adjustable change points to match the dynamic range of SDR videos, ensuring compatibility and consistent display.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If HDR video signal processing is implemented with standard OOTF characteristics, then HDR visibility and dynamic range are improved, but compatibility with SDR displays and consistent visibility across different display types deteriorate

Engineering Contradiction:
ImproveHDR visibilityVSAvoidcompatibility with SDR displays
Core Design Contradiction:
Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by making the OOTF characteristics adjustable rather than fixed. The system can dynamically switch between standard HDR OOTF characteristics and modified OOTF characteristics that are adjusted to match SDR display characteristics, allowing the same HDR video signal to be optimally displayed on both HDR and SDR displays.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameters of the OOTF function itself. By modifying the OOTF characteristics (such as the gamma value or transfer function curve) to match SDR display characteristics, the system enables HDR video signals to be compatible with SDR displays while maintaining proper visibility and dynamic range representation.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If separate workflows are maintained for HDR and SDR video processing, then display quality on respective monitors is optimized, but workflow complexity and processing efficiency deteriorate

Engineering Contradiction:
Improvedisplay qualityVSAvoidworkflow complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements universality by creating a single video signal processing system that can handle both HDR and SDR workflows. The video signal processing apparatus can process HDR video signals and adapt them for both HDR and SDR displays using the same processing pipeline, eliminating the need for completely separate workflows while maintaining optimized display quality for both types of displays.

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

Solution Approach 2:

The patent uses an intermediary approach by introducing adjustable OOTF characteristics as a mediation layer between the HDR video signal and the display. This intermediary mechanism allows the system to bridge the gap between HDR and SDR workflows, enabling a unified processing approach that can adapt to different display types without requiring separate dedicated workflows.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If OOTF characteristics are adjusted to match SDR display properties, then compatibility with SDR displays is improved, but HDR dynamic range expression capability deteriorates

Engineering Contradiction:
Improvecompatibility with SDR displaysVSAvoidHDR dynamic range expression
Core Design Contradiction:
Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The patent applies dynamics by making the OOTF characteristics可调 (adjustable) rather than fixed. The system can dynamically switch between standard HDR OOTF characteristics (which preserve full HDR dynamic range expression) and modified OOTF characteristics (which are adjusted to match SDR display properties). This allows the same HDR video signal to be optimally displayed on both HDR and SDR displays without compromising either compatibility or HDR capability.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3518517B1Video signal processing device, video signal processing method and video signal processing system
Publication Date: 2024.07.03 SONY GROUP CORP
  • EP3518517B1 patent drawingFigure 1
  • EP3518517B1 patent drawingFigure 2
  • EP3518517B1 patent drawingFigure 3

AI summary

[Object] To contribute to the achievement of a workflow in which an HDR video and an SDR video are compatible with each other. [Solving Means] This video signal processing apparatus includes an HDR video generation unit including a first converter unit that performs OOTF conversion on an HDR video by using an exponentiation function for calculating an exponentiation of 1.2, where 100% is 1, to an input signal level of the HDR video having a range from a point of 0%, where an expression range of an input signal level of an SDR video is 100%, to a change point optionally determined within a range of 100% to 500%, and by using a linear function for multiplying an input signal level of the HDR video having a range higher than the change point by a predetermined coefficient to maintain a change rate of a calculation result in a portion of the change point calculated by using the exponentiation function.