Video Scan Converter for Interlaced Progressive Conversion
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Solution Overview
Problem
Conventional scan conversion methods for interlaced 60 fields per second video, which has been subjected to 3-2 pull down conversion, result in inferior image quality due to the lack of correlation between odd- and even-numbered fields, leading to reduced coding efficiency and deteriorated video quality in five out of ten frames.
Innovation Solution
A video scan converter that decodes and processes video streams by selectively combining fields from the same frame to minimize the use of fields encoded differently, thereby reducing image quality deterioration, using a decoder and scan converter to output frames based on data from associated fields without relying on redundant or poorly encoded fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional scan conversion methods are used to convert interlaced 60 fields per second video to progressive video, then the video format conversion is achieved, but the image quality deteriorates due to lack of correlation between odd- and even-numbered fields
Solution Approach 1:
The patent segments the video processing into distinct detection and conversion stages. It divides the interlaced video fields into odd-numbered and even-numbered groups, then selectively processes them based on detection results. This segmentation allows the system to identify frames that underwent 3-2 pull-down conversion and handle them differently from regular interlaced frames, thereby improving image quality while managing complexity through structured processing.
Solution Approach 2:
The patent performs preliminary detection of 3-2 pull-down converted frames before executing the scan conversion. By detecting the presence of redundant fields in advance (through analyzing field differences and temporal correlations), the system can prepare appropriate conversion strategies beforehand. This preliminary action prevents image quality deterioration by avoiding inappropriate field combinations before they occur.
2Adaptability or versatility
If 3-2 pull down conversion is applied to progressive 24 frames per second video, then the video is converted to interlaced 60 fields per second format, but redundant fields are created reducing coding efficiency
Solution Approach 1:
The patent extracts and identifies redundant fields created by 3-2 pull-down conversion through detection mechanisms. By analyzing temporal correlations and field differences, it isolates the redundant even-numbered fields that were artificially created during conversion. This extraction allows the system to recognize and subsequently eliminate or properly handle these redundant fields, reducing overall data redundancy while maintaining format compatibility.
Solution Approach 2:
The patent discards redundant fields identified through detection processes. When 3-2 pull-down converted frames are detected, the system selectively discards the redundant even-numbered fields that duplicate information from odd-numbered fields. This discarding reduces the total data volume and improves coding efficiency while preserving the essential video content. The process recovers from the redundancy by keeping only the necessary fields for high-quality progressive conversion.
3Productivity
If odd- and even-numbered fields are combined for scan conversion, then progressive video frames are generated, but image quality deteriorates when fields come from different frames
Solution Approach 1:
The patent implements feedback mechanisms through detection processes that analyze the relationship between odd- and even-numbered fields. By continuously monitoring field differences and temporal correlations, the system receives feedback about whether fields originate from the same source frame or different frames. This feedback enables dynamic adjustment of the conversion process, ensuring that only fields with proper correlation are combined, thereby maintaining high video quality while sustaining productive frame generation.
Solution Approach 2:
The patent introduces dynamic processing where the scan conversion approach changes based on detected conditions. Rather than applying a fixed conversion method, the system dynamically adjusts its behavior: when 3-2 pull-down converted frames are detected, it applies specialized handling; when regular interlaced frames are present, it uses standard conversion. This dynamic adaptation ensures optimal image quality across varying input conditions while maintaining efficient frame generation rates.
Data Source
AI summary
A video scan converter processes a video stream including a first coding unit, which has been obtained by encoding a pair of fields N1 and N2 that has come from a first frame of film video, and a second coding unit, which has been obtained by encoding a pair of a field N3 that has also come from the first frame and a field M1 that has come from a second frame, not the first frame. The video scan converter includes: a decoder, which receives the video stream, decodes the first and second coding units, and sequentially outputs the data of the respective fields N1, N2, N3 and M1; and a scan converter, which generates a frame based on associated two of those fields that have been supplied from the decoder. In outputting a frame associated with the field N3, the scan converter generates the frame based on the fields N1 and N2 without using the data of the field N3.