Projection Device Nonplanar Surface Keystone Correction
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Solution Overview
Problem
Conventional projection devices struggle to correct keystone distortion on nonplanar projection surfaces, leading to image deformation and reduced projection quality.
Innovation Solution
A projection device with an image processing circuit that performs directional scaling on image portions to generate a trapezoidal image block aligned with the target polygon formed by noncoplanar projection surface planes, thereby projecting a distortion-free image.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional keystone correction is used, then projection quality is improved on planar surfaces, but image distortion remains on nonplanar surfaces
Solution Approach 1:
The projection surface is divided into multiple coplanar regions, and each region is independently corrected using directional scaling parameters. The image is segmented into corresponding portions that map to each surface region, allowing precise local correction adapted to the specific geometric characteristics of each plane.
Solution Approach 2:
Different directional scaling parameters are applied to different regions of the projection surface based on their individual geometric characteristics. Each coplanar region receives customized correction parameters tailored to its specific orientation and position, rather than applying a uniform correction across the entire nonplanar surface.
2Manufacturing precision
If the optical axis is manually adjusted to be perpendicular to the projection surface, then keystone distortion is reduced, but the adjustment is time-consuming and may not achieve ideal correction on nonplanar surfaces
Solution Approach 1:
The system pre-calculates and stores directional scaling parameters for multiple coplanar regions of the projection surface before actual projection. When projection begins, the appropriate parameters are automatically selected and applied without requiring manual optical axis adjustment, eliminating the time-consuming trial-and-error process while achieving precise correction.
Solution Approach 2:
The projection device automatically performs keystone correction by selecting and applying appropriate directional scaling parameters based on the detected projection surface characteristics. The system self-adjusts the image parameters without requiring manual intervention to align the optical axis, making the correction process automatic and efficient.
3Device complexity
If directional scaling is performed on image portions, then computational complexity is reduced, but the correction must be divided into multiple processing steps
Solution Approach 1:
The image processing is segmented into directional scaling operations on separate image portions corresponding to different coplanar regions. Each region is processed independently with its own scaling parameters, which simplifies the computational complexity compared to processing the entire image as a single nonplanar surface, while maintaining overall correction effectiveness.
Data Source
AI summary
A projection device and a projection picture correction method thereof are provided. When the projection device performs projection toward a projection surface, a plurality of target coordinates of a plurality of target vertexes are obtained based on a plurality of planes of the projection surface. The plurality of planes are not coplanar with each other, and the plurality of target vertexes form a target polygon. A first direction scaling process is performed respectively on a plurality of first image portions of an original trapezoidal image and a trapezoidal image block is generated. A second direction scaling process is performed respectively on a plurality of second image portions of the trapezoidal image block and a target image block aligned with the target polygon is generated. An output image including the target image block is projected onto the projection surface.