Dynamic Range Converter Using Logarithmic Interpolation for HDR to SDR Conversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current video processing technologies face challenges in accurately converting High Dynamic Range (HDR) signals to Standard Dynamic Range (SDR) while maintaining artistic intent, as existing standards like SMPTE ST 2086 do not provide sufficient metadata for optimal color transformation, leading to suboptimal image reproduction on SDR displays.
Innovation Solution
A dynamic range converter with a generic and reconfigurable architecture that includes color space converters, linearizers, delinearizers, color volume transformers, and dithering limiters, capable of converting HDR to SDR signals using dynamic color transform metadata from standards like SMPTE ST 2094, allowing for content-dependent processing and hardware-specific optimizations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If existing standards like SMPTE ST 2086 are used for HDR to SDR conversion, then the conversion process is standardized, but the artistic intent and color accuracy are not preserved due to insufficient metadata
Solution Approach 1:
The patent applies preliminary action by embedding dynamic color transform metadata (such as scene-referred metadata, camera response curves, and creative intent information) into the HDR video signal before conversion. This allows the SDR conversion process to access and preserve artistic intent information that would otherwise be lost, enabling accurate color transformation while maintaining the creator's original vision.
2Adaptability or versatility
If a fixed architecture converter is used, then the device complexity is reduced, but the adaptability to different HDR standards and display devices is limited
Solution Approach 1:
The patent implements a dynamic and reconfigurable converter architecture that can adapt to different HDR standards (such as SMPTE ST 2084, PQ, HLG) and display device characteristics. The system dynamically adjusts conversion parameters, metadata processing, and color transformation algorithms based on the input signal type and target display capabilities, providing versatility without requiring multiple dedicated hardware devices.
Solution Approach 2:
The converter is designed with universal functionality to handle multiple HDR standards, SDR to HDR upconversion, color space transformations, and various metadata formats through a single integrated system. This multi-functional approach allows one device to replace multiple specialized converters, reducing overall system complexity while maintaining broad adaptability.
3Manufacturing precision
If complex color transformation algorithms are used, then the color accuracy is improved, but the processing latency increases
Solution Approach 1:
The patent segments the color transformation process into distinct stages: metadata extraction and analysis, tone mapping and color transformation, and output generation. Each stage is optimized independently, allowing complex algorithms to be applied only where necessary while maintaining low latency overall. This segmented approach enables parallel processing of different signal components and reduces bottlenecks in the conversion pipeline.
Data Source
AI summary
In various embodiments, a dynamic range converter includes at least one circuit including a logarithm base 2 (log 2) domain circuit that uses piecewise linear interpolation to perform as at least a portion of one of: a linearizer configured to convert nonlinear color space signals to linearized color space signals; a delinearizer configured to convert linear color space signals to nonlinearized color space signals; a chrominance tone mapper for scaling gamut shaped components in accordance with dynamic color transform metadata to generate chrominance mapped components; or a luminance tone mapper for scaling color remapped components in accordance with the dynamic color transform metadata to generate luminance mapped components. Other embodiments are disclosed.