Dynamic Range Converter for HDR to SDR Video Signal Conversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current video encoding methods, such as the H.264 standard, face challenges in accurately transmitting and storing high dynamic range (HDR) video signals, particularly when converting HDR to Standard Dynamic Range (SDR) for display on devices with limited dynamic range, as they lack sufficient metadata to ensure artistic intent is maintained during the conversion process.
Innovation Solution
A dynamic range converter system that includes color space converters, linearizers, delinearizers, color volume transformers, and metadata processors, capable of configurable operations based on various color spaces and standards, applies dynamic color transform metadata to convert HDR signals to SDR while maintaining artistic intent, using techniques like piecewise linear interpolation and logarithmic domain processing to optimize the conversion process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If H.264 encoding standard is used for video compression, then bandwidth reduction and memory efficiency are improved, but accuracy and quality of HDR video transmission deteriorate
Solution Approach 1:
The patent introduces tone mapping as an intermediary process between HDR encoding and SDR display. The tone mapping module processes HDR video signals to adapt them for SDR displays while preserving visual quality, acting as a mediator that resolves the conflict between compression efficiency and quality preservation.
Solution Approach 2:
The patent dynamically adjusts encoding parameters based on scene characteristics and target display capabilities. By changing parameters such as quantization levels, bit allocation, and tone mapping curves, the system optimizes both compression efficiency and visual quality for different HDR to SDR conversion scenarios.
2Adaptability or versatility
If HDR to SDR conversion is performed without dynamic metadata, then device compatibility is improved, but artistic intent preservation deteriorates
Solution Approach 1:
The patent applies tone mapping and color transformation operations in advance during the encoding process, embedding the artistic intent decisions into the encoded video stream. This preliminary action ensures that when the video is played back on SDR displays, the artistic intent is already preserved without requiring real-time metadata processing.
Solution Approach 2:
The patent creates transformed copies of the HDR video signal optimized for SDR displays. Multiple versions or representations of the video content are generated with different tone mapping characteristics, allowing selective use based on display capabilities while preserving the original artistic intent in each copy.
3Manufacturing precision
If complex color space transformation is applied to maintain artistic intent, then video quality is improved, but processing time and complexity increase
Solution Approach 1:
The patent divides the color space transformation process into separate modular stages: tone mapping, color transformation, and gamma correction. Each module handles a specific aspect of the conversion, allowing for optimized processing of each stage independently and reducing overall processing time while maintaining quality.
Solution Approach 2:
The patent employs efficient algorithms that pre-compute transformation matrices and lookup tables periodically, reducing real-time processing requirements. By preparing transformation data in advance and updating only when necessary, the system maintains high video quality without excessive processing time during playback.
Data Source
AI summary
In various embodiments, a dynamic range converter includes a first color space converter to convert a source color space of a source video having a source dynamic range to nonlinear color space signals. A linearizer configured converts the nonlinear color space signals to linearized color space signals having a mastering dynamic range via a piecewise linear interpolation of a transfer function. A color volume transformer applies dynamic color transform metadata associated with the source video to generate master adjusted color space signals from the linearized color space signals. A delinearizer converts the master adjusted color space signals to nonlinearized color space signals via a piecewise linear interpolation of an inverse transfer function in accordance with a display dynamic range. A second color space converter converts the nonlinearized color space signals to display domain signals. Other embodiments are disclosed.