Projector Perspective Distortion Correction via Angle Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image projection technologies often distort the spatial configuration and perspective of images when projected onto surfaces at angles, leading to keystone effects, which affect the readability and legibility of two-dimensional data patterns like QR codes.
Innovation Solution
A system comprising a projector, scanner, sensor, and processor that renders a test pattern on a projection surface, detects the angle of projection, computes a transformation to correct perspective distortions, and adjusts the image projection accordingly, ensuring the projected image maintains its original spatial configuration and perspective.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the projector projects images onto a projection surface at an angle, then the projection can reach more areas and be more versatile, but the spatial configuration and perspective of the image become distorted
Solution Approach 1:
The system performs preliminary detection of the projection surface angle using a sensor before projecting the image. Based on the detected angle, the processor pre-calculates and applies a transformation to the image data to compensate for the expected distortion. This preliminary correction ensures that when the image is projected at an angle, its spatial configuration remains accurate and undistorted.
Solution Approach 2:
The system changes the parameters of the projected image based on the detected projection angle. The processor modifies the image data by applying geometric transformations (such as affine transformations) that adjust the spatial coordinates of the image pixels. This parameter change compensates for the distortion caused by angled projection, maintaining the integrity of the spatial configuration.
2Manufacturing precision
If the projector uses a fixed projection geometry, then the spatial configuration accuracy is maintained, but the ease of operation and adaptability to different surfaces are reduced
Solution Approach 1:
The system transitions from a fixed projection geometry to a dynamic, adaptive projection system. A sensor detects the actual projection angle in real-time, and the processor dynamically adjusts the image parameters based on the detected angle. This dynamic adaptation allows the system to maintain spatial configuration accuracy across various projection scenarios without requiring manual reconfiguration, thereby improving ease of operation.
Solution Approach 2:
The system implements a feedback mechanism where a sensor continuously monitors the projection angle and provides this information to the processor. The processor uses this feedback to automatically adjust the image transformation parameters, ensuring that the projected image maintains correct spatial configuration regardless of the projection angle. This closed-loop feedback system eliminates the need for manual setup while preserving accuracy.
3Device complexity
If no perspective correction is applied, then the device complexity is reduced, but the readability and legibility of two-dimensional data patterns are affected
Solution Approach 1:
The system applies perspective correction in advance by detecting the projection angle and pre-transforming the image data before projection. This preliminary correction ensures that when the image is projected onto the surface, the two-dimensional data patterns (such as QR codes) maintain their correct geometric configuration and remain readable, eliminating the need for post-projection correction or complex hardware adjustments.
Data Source
AI summary
Projecting an image is described. A test pattern is rendered over each of two dimensions of a projection surface. Upon the rendered test pattern conforming to a perspective related specification for a spatial configuration of data disposed over the two dimensions the data are decoded. An angle of a projection in each of the two dimensions corresponding to the rendering of the test pattern is detected, relative to a line orthogonal to a plane corresponding to a portion of the projection surface. Upon a nonconformity of the rendered test pattern to the specification, a transformation is computed to a spatial configuration of the rendered test pattern. The computed transformation relates to a perspective related characteristic of the spatial configuration corresponding to the angle of the projection. The projector is controlled based on the computed transformation.