Camera Distance and Tilt Calculation Using Fiducial Lines

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Solution Overview

Problem

Existing image processing systems for reading marks, such as two-dimensional codes and barcodes, require additional sensors or light projection devices to improve recognition accuracy, particularly for extending the readable range or distance, and require detailed positional relationship calculations between the mark and the reader.

Innovation Solution

An image processing system that includes a camera with a movable assistance apparatus, using fiducial lines and points to calculate the distance and tilt angle of the camera with respect to the mark, and a movement control unit to adjust the camera's position based on this information for improved recognition accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a sensor device or light projection device is added to measure distance, then recognition accuracy of the mark is improved, but device complexity increases

Engineering Contradiction:
Improverecognition accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The mark itself serves as the measurement reference by incorporating fiducial lines with known regulation lengths and angles. The camera captures the apparent lengths and angles of these fiducial lines in the image data, and the system calculates distance and tilt angle by comparing the known regulation values with the captured apparent values. This eliminates the need for separate sensor devices or light projection devices, as the mark provides its own measurement functionality through its fiducial line structure.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If the readable range or distance is extended, then recognition accuracy is improved, but device complexity increases

Engineering Contradiction:
Improverecognition accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The mark structure with fiducial lines of known regulation lengths and angles serves as an self-contained reference system that works across extended distances. The camera captures the apparent lengths and angles of these fiducial lines regardless of distance, and the system calculates the actual distance and tilt angle by comparing the captured apparent values with the known regulation values stored in the mark itself. This allows extended readable range without adding complex measurement devices.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If detailed positional relationship calculations are performed, then recognition accuracy is improved, but loss of time increases

Engineering Contradiction:
Improverecognition accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The regulation lengths and regulation angles of the fiducial lines are predetermined and stored in the mark structure before the actual reading operation. This preliminary preparation of reference values allows the system to perform rapid calculations during operation by simply comparing the captured apparent lengths and angles with the pre-stored regulation values, eliminating the need for complex real-time measurements and reducing processing time while maintaining high recognition accuracy.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2953054B1Image processing system and aid system
Publication Date: 2019.10.23 FUJI CORP
  • EP2953054B1 patent drawingFigure 1
  • EP2953054B1 patent drawingFigure 2
  • EP2953054B1 patent drawingFigure 3~4

AI summary

An objective is to provide an image processing system in which information presented by a mark can be acquired through image processing and information related to a position of a camera with respect to the mark can be acquired, and an assistance system. An image processing system includes a mark in which an information display portion presenting predetermined information is included in a region formed by a pair of fiducial lines; a camera that is provided to be relatively movable with respect to the mark; an information acquisition unit that acquires the information presented in the information display portion of the mark, out of the image data; a distance calculation unit that calculates a distance from the camera to the mark in an optical axis direction; and an angle calculation unit that calculates a tilt angle of the camera with respect to the mark.