HDR Tone Conversion Apparatus for Luminance Chrominance Signal Separation
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Solution Overview
Problem
Existing image processing technologies for HDR monitors often result in amplitude level differences between luminance and chrominance signals, leading to false signals and deteriorated image quality due to steep tone conversion characteristics in HDR standards like ST2084.
Innovation Solution
An image processing apparatus and method that separates high-frequency and low-frequency components from input signals, generates common color signal components for both luminance and chrominance, and performs specific tone conversion processes to match frequency bands and adjust amplitude levels, using first and second tone conversion units to optimize tone conversion characteristics for HDR monitors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If tone conversion processing optimized for both luminance and colors is performed using separate signal processing for chrominance and luminance, then output of colors and luminance is optimized, but amplitude level difference between luminance components increases leading to false signals and deteriorated image quality
Solution Approach 1:
The input image signal is separated into high-frequency components and low-frequency components. The low-frequency components are further processed to generate color signal components for luminance and chrominance signals separately, while high-frequency components are processed differently to avoid amplifying amplitude level differences.
Solution Approach 2:
Different tone conversion processing is applied to different frequency components. Specifically, the low-frequency components undergo tone conversion to optimize color and luminance output, while high-frequency components undergo separate tone conversion to prevent false signal generation. This local differentiation resolves the contradiction by optimizing each frequency band according to its specific requirements.
2Adaptability or versatility
If HDR tone conversion with steep rise in dark portion is applied, then dynamic range is expanded for HDR monitor, but difference in amplitude level of luminance components is emphasized causing false signals
Solution Approach 1:
The image signal is segmented by frequency components, with low-frequency components processed through HDR tone conversion and high-frequency components processed through separate tone conversion. This segmentation prevents the steep rise in dark portion from affecting high-frequency components, thereby avoiding false signal generation while maintaining HDR adaptability.
Solution Approach 2:
Different tone conversion characteristics are applied locally to different frequency components. The low-frequency components receive HDR-optimized tone conversion with steep rise in dark portion, while high-frequency components receive tone conversion designed to suppress false signals. This local quality differentiation resolves the contradiction between HDR adaptability and false signal prevention.
Data Source
AI summary
An image processing apparatus includes a separation unit that separates a high-frequency component and a low-frequency component, a first generation unit that generates a color signal component from the low-frequency component, a second generation unit that generates a color signal component from the low-frequency component, a third generation unit that generates a color signal component used in common for a luminance signal and a chrominance signal, a first tone conversion unit that performs first tone conversion processing on an output of the third generation unit, a color-and-luminance separation unit that generates a luminance signal and a chrominance signal, a second tone conversion unit that performs a second tone conversion on the high-frequency component, and a combining unit that combines outputs of the color-and-luminance separation unit and the second tone conversion unit.