Image Processing Circuit Dynamic SAD Selection for Motion Compensation
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Solution Overview
Problem
Existing image processing systems face challenges in accurately locating blocks for motion compensation, particularly when local regions in images flash or are motion objects, leading to incorrect block matching and deformation in interpolated images due to reliance on direct current (DC) sum of absolute difference (SAD) calculations.
Innovation Solution
An image processing circuit and method that calculates both alternating current (AC) and direct current (DC) sums of absolute difference (SAD) and uses an arbiter to selectively output either based on scene characteristics, enabling correct motion compensation by choosing between AC SAD and DC SAD for accurate block matching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If DC SAD is used for block matching, then the calculation is simple and fast, but the matching accuracy deteriorates when local regions flash or are motion objects
Solution Approach 1:
The patent dynamically switches between DC SAD and AC SAD calculation modes based on scene characteristics detected by an arbiter. When flashing or motion objects are detected, the system transitions to AC SAD mode to maintain matching accuracy, while normally operating in DC SAD mode for computational efficiency. This dynamic adaptation resolves the contradiction between calculation speed and matching accuracy.
Solution Approach 2:
The patent changes the calculation parameter from DC SAD to AC SAD based on scene conditions. The arbiter analyzes scene characteristics and triggers a parameter switch when flashing or motion objects are detected. This parameter change allows the system to maintain high matching accuracy in challenging scenarios while preserving the simplicity and speed of DC SAD in normal conditions.
2Device complexity
If DC SAD is used for block matching, then the implementation is simple, but the reliability deteriorates when local regions flash
Solution Approach 1:
The patent introduces an arbiter as an intermediary component that analyzes scene characteristics and determines whether to use DC SAD or AC SAD. This intermediary layer adds minimal complexity but significantly improves reliability by detecting flashing or motion objects and switching to the appropriate calculation mode, thereby ensuring reliable block matching in challenging scenarios.
Solution Approach 2:
The system dynamically adjusts its implementation complexity by switching between DC SAD and AC SAD based on scene conditions. The arbiter detects when reliability issues may arise (flashing or motion objects) and triggers a dynamic change in the matching algorithm, maintaining reliability while keeping the system simple in normal operating conditions.
3Measurement precision
If AC SAD is always used for block matching, then the matching accuracy is maintained, but the calculation complexity increases
Solution Approach 1:
Instead of always using AC SAD, the patent applies AC SAD only partially - specifically when and where it is needed (i.e., when flashing or motion objects are detected by the arbiter). This partial application maintains matching accuracy in critical scenarios while avoiding the unnecessary calculation complexity of AC SAD in normal conditions, thus resolving the contradiction between accuracy and complexity.
Solution Approach 2:
The patent changes the calculation parameter from AC SAD to DC SAD based on scene characteristics. The arbiter detects when high accuracy is needed and triggers a parameter switch to AC SAD, while normally operating with the simpler DC SAD parameter. This conditional parameter change maintains accuracy when necessary while minimizing calculation complexity.
Data Source
AI summary
An image processing circuit and an image processing method are disclosed. The image processing circuit comprises a block matching unit, a multiplexer, an arbiter, and a motion compensation circuit. The block matching unit calculates an alternating current (AC) sum of absolute difference (SAD) and a direct current (DC) sum of absolute difference (SAD) according to a current block in a current image and a reference block in a reference image. The arbiter controls the multiplexer selectively to output the AC SAD or the DC SAD according to an arbitration rule related to a scene characteristic of the current image. The motion compensation circuit executes motion compensation according to the AC SAD or the DC SAD outputted by the multiplexer.