Color Space Reduction for Subpicture Transcoding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge lies in efficiently transcoding subpicture elements between different audio/video standards, particularly due to variations in maximum color bit depth and fixed color palettes, which restrict the approximation of original colors, especially when converting from standards like DVB to DVD-VR, where the destination colors cannot be chosen from a complete color space.
Innovation Solution
A method and apparatus that collect color statistics during decoding, sort colors based on these statistics, and generate a mapping function to match the color space of the target standard, allowing for scalable and standard-independent color space reduction, applicable to DVB and Teletext subtitles, and enabling the creation of color map tables.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If color statistics are collected during decoding and colors are sorted based on these statistics, then color space reduction efficiency is improved, but device complexity increases due to the need for additional circuits for statistics collection and color sorting
Solution Approach 1:
The patent applies preliminary action by collecting color statistics and sorting colors during the decoding phase, before the actual transcoding operation. This allows the color mapping strategy to be pre-determined based on actual color distribution, making the subsequent transcoding process faster and more efficient without requiring complex real-time calculations during transcoding.
Solution Approach 2:
The patent introduces an intermediary color statistics collection mechanism that acts as a bridge between the source and target color spaces. By collecting statistics on color usage frequency and importance, the system creates an intermediate representation that guides the color mapping process, simplifying the complexity of direct color space transformation.
2Device complexity
If a fixed color palette is used as in DVD-VR standard, then device complexity is reduced, but manufacturing precision deteriorates because destination colors cannot be chosen from a complete color space
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the color mapping strategy based on collected statistics. Instead of using a fixed palette assignment, the system modifies which destination colors are selected and how source colors are mapped to them, based on the actual color distribution and importance in the source content. This allows optimization of color approximation accuracy while working within the constraints of the fixed DVD-VR palette.
Solution Approach 2:
The patent applies local quality by treating different color regions and importance levels differently in the mapping process. Colors that are more important or frequently used in the source content receive more careful mapping consideration, while less important colors may be mapped more simply. This localized optimization approach improves overall color approximation accuracy without requiring a complete overhaul of the fixed palette system.
3Device complexity
If color mapping is performed without collecting color statistics, then device complexity is reduced, but loss of information increases because the most significant colors cannot be identified
Solution Approach 1:
The patent applies self-service by having the transcoding system automatically analyze its own input content and generate color statistics during the decoding process. This self-analysis capability allows the system to identify important colors and optimize the mapping strategy without requiring external intervention or pre-processing, making the information preservation automatic and integrated into the normal transcoding workflow.
Data Source
AI summary
An apparatus including a first circuit, a second circuit and a third circuit. The first circuit may be configured to collect color statistics. The second circuit may be configured to sort colors based upon the color statistics collected by the first circuit. The third circuit may be configured to generate a mapping function between the sorted colors and a color space of a receiving standard.