Direct YCbCr Tone Mapping for HDR Video Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing tone-mapping methods for high dynamic range (HDR) images to low dynamic range (LDR) displays involve complex intermediate processing steps, leading to increased computational cost and potential information loss, especially when converting between RGB and YCbCr color spaces.
Innovation Solution
A system comprising a tone mapping module for luminance and a color mapping module for chroma signals that directly maps HDR input data to LDR output data without transforming between color spaces, bypassing intermediate processing steps like up-sampling, gamma decoding, and color space transformations, using closed-form mapping formulas to derive tone-mapped chroma signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If intermediate processing steps (color space transformation, up-sampling, gamma decoding) are used in tone-mapping, then compatibility with standard processing pipelines is improved, but computational complexity increases and information loss occurs
Solution Approach 1:
The patent extracts and eliminates unnecessary intermediate processing steps (color space transformation, up-sampling, gamma decoding) from the tone-mapping pipeline. By directly mapping HDR YCbCr to LDR YCbCr without these intermediate steps, the invention removes computational overhead while preserving essential functionality.
Solution Approach 2:
Instead of following the conventional approach of transforming through multiple intermediate steps, the patent inverts the process by applying tone-mapping directly in the YCbCr color space. This reverse approach maintains compatibility outcomes while avoiding the computational burden of traditional pipelines.
2Adaptability or versatility
If intermediate processing steps are used in tone-mapping, then standard processing pipelines can be followed, but information loss and round-off errors increase
Solution Approach 1:
The patent removes intermediate processing steps that cause information loss, particularly color space transformations and repeated sampling operations. By operating directly in YCbCr space, the invention preserves chroma information and avoids cumulative round-off errors that occur in multi-step pipelines.
3Device complexity
If direct mapping without color space transformation is used, then computational complexity is reduced, but compatibility with existing pipelines may be affected
Solution Approach 1:
The patent creates a universal tone-mapping approach that works directly with YCbCr formatted video data. By designing the mapping to operate in the same color space as standard pipelines expect as input and output, the invention achieves compatibility without requiring transformation to or from other color spaces.
Data Source
AI summary
Several embodiments of an efficient tone mapping of high bit depth video to low bit depth displays are disclosed. In one embodiment, a system maps an input image data of a high dynamic range (HDR) onto output image data of a lower dynamic range (LDR) and where the mapping does not transform the input image data from one color space to another color space. One embodiment comprises a tone mapping module which outputs a tone-mapped luminance signal for output image data and a color mapping module which outputs chroma signals for the output image data. Intermediate image processing steps may be avoided and hence may increase the efficiency of the mapping.