Gradient-Based Image Filtering for HDR Motion Artefact Reduction
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Solution Overview
Problem
Existing methods for combining images to form High Dynamic Range (HDR) images struggle with handling motion, leading to noticeable artefacts such as ghosting effects, especially on mobile devices with limited processing power.
Innovation Solution
The method involves determining image gradient indications and filter costs for image regions, which are then used to apply filtering operations that depend on image gradients. This approach allows for denoising and blending of images while smoothing transitions and handling motion by treating motion regions as 'inconsistent' areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If complex motion tracking procedures are used to handle motion in HDR image processing, then motion artefacts are reduced, but processing time and computational complexity increase significantly
Solution Approach 1:
The patent extracts and utilizes image gradient information to identify motion regions without performing complex motion tracking. By separating the task into gradient computation (simple) and motion region identification (complex), the solution achieves effective motion handling while keeping processing complexity manageable for mobile devices
Solution Approach 2:
The patent employs a simplified gradient-based approach that computes lightweight gradient indications rather than expensive motion tracking algorithms. This disposable-like approach uses minimal computational resources to achieve the desired motion artifact reduction
2Shape
If gradient-based filtering is applied to smooth transitions, then transition sharpness is reduced, but processing time increases
Solution Approach 1:
The patent applies gradient-based filtering selectively only in regions where transitions are detected, rather than processing the entire image uniformly. This local quality approach reduces overall processing time while maintaining transition smoothness where needed
Solution Approach 2:
The patent uses a simplified gradient computation that performs partial filtering action focused on transition regions. By applying filtering only where gradients indicate transition zones rather than everywhere, the solution achieves sufficient smoothness with reduced processing time
Data Source
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AI summary
An image processing method comprising: determining image gradient indications (S312) for at least one image; determining filter costs (S314) for image regions based on the determined image gradient indications for the at least one image; processing data relating to the at least one image including applying a filtering operation (S316) using the determined filter costs for the image regions, so that the processing is performed for image regions in dependence upon image gradients of the at least one image, the processing comprising using the filtering operation to apply denoising to the at least one image such that the extent of the denoising applied to an image region is dependent upon the filter cost for the image region.