Multi-Projector Image Alignment via Feature-Point Calibration

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Solution Overview

Problem

Current projection technologies face challenges in projecting high-quality images using multiple monochromatic projectors due to alignment and distortion issues, leading to inaccuracies and reduced image quality.

Innovation Solution

An image processing apparatus and method that generates projection images with a content image region and a feature-point image region, using correction parameters to align and correct the images projected by multiple monochromatic projectors, allowing for accurate overlap and high-quality color image projection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple monochromatic projectors are used to project color images, then image quality and color accuracy are improved, but alignment accuracy and image distortion deteriorate due to positioning errors and lens distortions

Engineering Contradiction:
Improveimage qualityVSAvoidalignment accuracy
Core Design Contradiction:
Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The system performs preliminary calibration by projecting a calibration image containing feature points before normal operation. The correction parameters are calculated in advance based on the detected feature point positions, allowing the system to pre-compensate for alignment errors and lens distortions. This preliminary action ensures that when color images are projected using multiple monochromatic projectors, the pre-calculated correction parameters are applied to maintain accurate alignment and positioning.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements a feedback mechanism where the actual positions of feature points in the projected calibration image are detected and compared with their expected positions. Based on this feedback, correction parameters are dynamically calculated and applied to adjust the projection images from each monochromatic projector. This closed-loop feedback ensures continuous alignment accuracy and compensates for positioning errors and lens distortions in real-time.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If correction parameters are applied to align projection images from multiple monochromatic projectors, then alignment accuracy is improved, but device complexity increases due to calibration and parameter management

Engineering Contradiction:
Improvealignment accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system performs self-calibration by automatically detecting feature points in the projected calibration image and calculating correction parameters without requiring manual intervention. The apparatus autonomously manages the entire calibration process, from projecting the calibration pattern to detecting feature points and generating correction parameters. This self-service approach reduces operational complexity while maintaining high alignment accuracy through automated parameter management.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If feature-point images are projected in the second pixel region for calibration, then alignment precision is improved, but loss of useful projection area increases

Engineering Contradiction:
Improvealignment precisionVSAvoidprojection area
Core Design Contradiction:
Measurement precisionVSLoss of substance

Solution Approach 1:

The projection image is segmented into two distinct regions: the first pixel region for normal content image projection and the second pixel region for calibration feature-point projection. This segmentation allows the system to dedicate specific areas for their respective functions without interfering with each other. The feature-point images are projected only in the second pixel region, enabling accurate alignment calibration while preserving the first pixel region for useful content projection, thus minimizing the loss of projection area.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS12088956B2Image processing apparatus, image processing method, and program
Publication Date: 2024.09.10 SONY GROUP CORP
  • US12088956B2 patent drawing
  • US12088956B2 patent drawing
  • US12088956B2 patent drawing

AI summary

An image processing apparatus according to an embodiment of the present technology includes a first generator and a second generator. The first generator generates projection images correspondingly to respective monochromatic projectors of a plurality of monochromatic projectors using respective correction parameters, each projection image including a first pixel region that includes a content image, and a second pixel region that is a region other than the first pixel region, the second pixel region including a feature-point image in at least a portion of the second pixel region. The second generator detects the feature-point image in a captured image obtained by capturing the projection image projected by each of the plurality of monochromatic projectors, and generates the correction parameter on the basis of a result of the detection of the feature-point image.