Camera Offset Imaging for Moiré-Free Display Quality Evaluation
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Solution Overview
Problem
Existing methods for reducing Moiré interference in images captured by cameras from pixel-based display devices often result in reduced spatial resolution or fail to effectively eliminate very low aliasing spatial frequencies, particularly when the pixel pitches of the camera and display device are not optimally aligned.
Innovation Solution
The method involves moving the camera relative to the display device along a specific offset path during image capture, with the offset path being in the order of the display pixel pitch, allowing for Moiré interference reduction without significantly reducing effective spatial resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If optical defocusing is used to reduce Moiré interference, then Moiré interference is reduced, but spatial resolution is reduced
Solution Approach 1:
The patent applies dynamics by moving the camera relative to the display device during image capture. Instead of using static optical defocusing, the system dynamically shifts the camera position to disrupt Moiré patterns while maintaining focus, thereby reducing harmful interference without sacrificing spatial resolution.
Solution Approach 2:
The patent implements periodic action by capturing multiple images at different camera positions and combining them. The camera is moved to at least one additional position during capture, and the resulting images are processed to eliminate Moiré interference while preserving the spatial resolution information from the focused images.
2Object-affected harmful factors
If the camera is moved relative to the display device during image capture, then Moiré interference is reduced, but image capture complexity increases
Solution Approach 1:
The patent applies preliminary action by determining the camera movement offset before the actual image capture. The offset is calculated based on the display pixel pitch and camera sensor pitch, allowing the camera to be positioned and moved in a controlled manner during capture, which simplifies the overall process despite the added complexity of movement.
Solution Approach 2:
The patent uses copying by capturing multiple images at different positions and then combining them to create a final result. Instead of requiring a single complex capture operation, the system creates copies of the display image at different camera positions and processes these copies to eliminate Moiré interference, distributing the complexity across multiple simpler operations.
3Object-affected harmful factors
If multiple camera images are captured at different positions, then Moiré interference is reduced, but measurement time increases
Solution Approach 1:
The patent applies partial action by capturing images at a limited number of specific positions rather than continuously or excessively. The camera is moved to at least one additional position (total of 2+ positions) which is sufficient to reduce Moiré interference without requiring excessive time. The offset is calculated to achieve effective Moiré reduction with minimal additional capture operations.
Data Source
AI summary
The invention relates to a method for reducing aliasing errors in a moire-corrected final image formed by at least one camera image, wherein the at least one camera image is captured, by a camera (1) having imaging optics (1.1) and a sensor surface (1.2) with sensor pixels (1.3), as the depiction of a display image of a display device (2) with display pixels (2.1) arranged in a matrix-like manner and spaced apart in a display pixel pitch (D A) on the sensor surface (1.2), wherein, during the capture, the camera (1) is shifted relative to the display device (2) along at least one offset path (VP) in relation to a starting position (S). The invention also relates to a method for evaluating the presentation quality of a pixel-based display device (2), and a device for carrying out methods of this type.