HDR Image Reconstruction via Dynamic Metadata Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing single-layer HDR distribution solutions face challenges in ensuring the availability and integrity of dynamic metadata, which are critical for reconstructing HDR images from SDR signals, particularly in real-world production and distribution environments where metadata can be lost or corrupted due to various factors such as overlay, logo management, and lack of standardization.
Innovation Solution
A method for reconstructing HDR images from SDR images by determining if required parameters are available in a bitstream, recovering lost or corrupted parameters from additional data, and using pre-determined parameter values or metadata indicators to ensure accurate reconstruction, including the use of weighted combinations of parameters from previous HDR images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If dynamic metadata is transmitted in distribution environments, then HDR reconstruction quality is improved, but metadata can be lost or corrupted due to overlay, logo management, and lack of standardization
Solution Approach 1:
The patent applies preliminary action by pre-defining multiple sets of parameter values (first set, second set, third set) before transmission. These pre-defined parameter sets are prepared in advance based on different scenarios (e.g., with/without logo overlay), so that when metadata is lost or corrupted during transmission, the receiving device can immediately switch to using a suitable pre-defined set without requiring retransmission or complex error correction, thus ensuring continuous HDR reconstruction quality.
Solution Approach 2:
The patent implements parameter changes by providing multiple alternative parameter sets with different characteristics. The receiving device dynamically selects and switches between different parameter sets (first set for normal conditions, second or third set for conditions with logo overlay or other distortions) based on the actual transmission environment and metadata integrity, thereby adapting to varying reliability conditions while maintaining HDR reconstruction quality.
2Reliability
If multiple parameter sets are provided for recovering lost metadata, then reliability of HDR reconstruction is improved, but device complexity increases
Solution Approach 1:
The patent reduces device complexity by applying preliminary action - all multiple parameter sets are pre-defined and prepared in advance at the encoding stage. The receiving device does not need to perform complex real-time analysis or generate parameter sets dynamically; it only needs to store these pre-defined sets and select among them based on simple criteria (such as metadata integrity detection), significantly simplifying the device complexity while maintaining high reliability.
Solution Approach 2:
The patent uses a strategy similar to cheap short-living objects by providing multiple lightweight parameter sets that can be quickly switched between. Rather than implementing a complex, expensive error correction system, the patent uses multiple simple parameter sets that can be rapidly selected and discarded, reducing the computational burden and device complexity while ensuring reliable HDR reconstruction under various conditions.
Data Source
Figure 1
Figure 2a~2b
Figure 2c
AI summary
The present principles relates to a method and device for reconstructing an HDR image by applying a reconstruction process on a SDR image whose the content is similar to the content of the HDR image but the dynamic range of the luminance values of said SDR image is lower than the dynamic range of the luminance values of said HDR image, said reconstruction process requiring parameters obtained from a bitstream. The method is characterized in that the method further comprises determining whether all the required parameters are available from the bitstream and recovering the lost or corrupted parameters from additional data, said reconstruction process further taking into account said recovered parameters.