Tone Mapping Curves With Configurable HDR Diffuse White

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Solution Overview

Problem

The fixed constraint of HDR diffuse white at 203 nits restricts artistic freedom and maximizes speculars over details in HDR content production, leading to dull and unappealing SDR conversions.

Innovation Solution

A system allowing configurable and dynamic HDR Diffuse White levels for tone mapping, enabling flexible HDR to SDR conversions by considering HDR and SDR diffuse white values in tone mapping curve construction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If HDR diffuse white is constrained to a fixed value of 203 nits, then SDR to HDR and HDR to SDR conversions can use fixed 3D-LUTs, but artistic freedom and camera capabilities are restricted

Engineering Contradiction:
Improveease of conversion implementationVSAvoidartistic freedom
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent makes the HDR diffuse white level dynamic and configurable rather than fixed. The tone mapping curve construction now accepts configurable HDR and SDR diffuse white levels as parameters, allowing the system to adapt to different artistic intents and camera capabilities while maintaining the conversion functionality.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the parameter of HDR diffuse white level from a fixed value (203 nits) to a configurable parameter. This allows users to adjust the HDR diffuse white level according to artistic intent and camera capabilities, resolving the contradiction between ease of implementation and artistic freedom.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If HDR diffuse white is set to 203 nits, then fixed 3D-LUTs can be used for tone mapping, but luminance range allocation optimizes for speculars over details

Engineering Contradiction:
Improveease of tone mapping implementationVSAvoidluminance range allocation quality
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent allows configuration of HDR and SDR diffuse white levels as parameters in the tone mapping curve construction. This enables optimization of luminance range allocation for different content types and display conditions, improving the quality of detail preservation while maintaining ease of implementation through the configurable parameter approach.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If fixed HDR diffuse white constraint is applied, then safe and controlled HDR production is achieved, but HDR camera capabilities are not fully exploited

Engineering Contradiction:
ImproveHDR production safetyVSAvoidcamera capability utilization
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic configurability of HDR diffuse white levels, allowing the system to adapt to different camera capabilities and production requirements. This maintains the controlled and safe approach while enabling full exploitation of HDR camera capabilities through configurable parameters.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

By making the HDR diffuse white level a configurable parameter rather than a fixed constraint, the system can be adapted to match different camera capabilities and production scenarios, thereby fully exploiting camera capabilities while maintaining production safety through controlled parameter selection.

Inventive Principle:
Principle #35Parameter changes

4Device complexity

If fixed 3D-LUTs are used for HDR to SDR conversion, then conversion process is simplified, but SDR video quality and appeal are reduced

Engineering Contradiction:
Improveconversion process complexityVSAvoidSDR video quality
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent enhances the tone mapping curve construction with configurable HDR and SDR diffuse white levels, allowing optimization of SDR video quality while maintaining a relatively simple conversion process. The configurable parameters enable quality improvement without significantly increasing process complexity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4430557B1Tone mapping with configurable HDR and SDR diffuse white levels
Publication Date: 2025.12.03 INTERDIGITAL CE PATENT HOLDINGS SAS
  • EP4430557B1 patent drawingFigure 1A~1B
  • EP4430557B1 patent drawingFigure 2~3A
  • EP4430557B1 patent drawingFigure 3B~3C

AI summary

A method comprising: obtaining (401) high dynamic range data; computing (402, 403) a first tone mapping curve from the high dynamic range data corresponding to low high dynamic range values of a combined tone mapping curve, the first tone mapping curve ending by a point, called first point, with an abscissa representative of a high dynamic range diffuse white and an ordinate representative of a standard dynamic range diffuse white, the combined tone mapping curve allowing obtaining standard dynamic range data from the high dynamic range data; and completing (404) the combined tone mapping curve with a second tone mapping curve for high standard dynamic range starting from the first point.