Video Processor OSD Signal Scaling Without Vertical Filtering
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Solution Overview
Problem
Conventional video processing technologies deteriorate the frequency characteristic and gradation of video signals due to multiple stages of vertical filtering during OSD synthesis, which becomes noticeable with improved display device performance.
Innovation Solution
A video processor that converts OSD signals into YUV format, scales luminance and color difference signals separately, and synthesizes them with 4:2:0 format video signals without initial vertical filtering, using scaling factors adjusted based on sampling phase and inserting dummy data to maintain pixel equality, thereby minimizing signal deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If vertical filtering is performed during OSD synthesis to match sampling phases, then the video signal can be processed to achieve proper phase alignment, but the frequency characteristic and gradation of the signal deteriorate
Solution Approach 1:
The patent extracts and eliminates the vertical filtering step from the conventional OSD synthesis process. By removing this unnecessary processing stage, the invention preserves the frequency characteristic and gradation of the color difference signals while still achieving proper phase alignment through alternative means (direct synthesis without filtering).
Solution Approach 2:
The patent skips the vertical filtering operation that was traditionally performed before OSD synthesis. By rushing through this step and proceeding directly to synthesis, the invention avoids the deterioration of frequency characteristics and gradation that would otherwise occur during filtering operations.
2Manufacturing precision
If multiple stages of vertical filtering are applied during OSD synthesis, then the sampling phase can be matched between video and OSD signals, but the frequency characteristic and gradation are significantly deteriorated
Solution Approach 1:
The patent removes the vertical filtering stage from the multi-stage processing chain. By extracting this unnecessary step, the invention maintains gradation precision while still achieving sampling phase matching through the synthesis process itself, eliminating the need for separate filtering operations.
Solution Approach 2:
The patent skips the intermediate vertical filtering stages that would otherwise be performed. By rushing through these unnecessary processing steps and proceeding directly to synthesis, the invention preserves gradation precision and frequency characteristics that would otherwise be significantly deteriorated.
3Adaptability or versatility
If color difference signals are converted to 4:2:2 format through vertical filtering before synthesis, then the signals can be processed to match luminance signal sampling, but the frequency characteristic deteriorates
Solution Approach 1:
The patent extracts and eliminates the vertical filtering operation that converts 4:2:0 signals to 4:2:2 format. By removing this step, the invention maintains frequency characteristic precision while still achieving signal compatibility through direct synthesis of 4:2:0 formatted color difference signals with the luminance signal.
Solution Approach 2:
The patent skips the format conversion step via vertical filtering. By rushing through this unnecessary transformation and proceeding directly to synthesis, the invention preserves frequency characteristics while maintaining adaptability through the synthesis process that handles 4:2:0 format signals directly.
Data Source
AI summary
Color difference signals of demodulated video are vertically filtered to be converted into 4:2:2 signals before subjected to OSD synthesis, after which those signals are once again vertically filtered as a sort of scaling to obtain the output resolution. As filtering is carried out in two stages, the frequency characteristic deteriorates. A video processor superimposes an OSD video signal on a 4:2:0 format video signal, and includes: a converting section for converting the OSD video signal into YUV signals; an OSD luminance signal scaling section for performing scaling on an OSD luminance signal included in the YUV signals; a luminance signal synthesizing section for synthesizing the scaled OSD luminance signal and the luminance signal of the 4:2:0 format video signal; an OSD color difference signal scaling section for performing scaling on OSD color difference signals included in the YUV signals; and a color difference signal synthesizing section for synthesizing the scaled OSD color difference signals and the color difference components of the 4:2:0 format video signal.