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CALIBRATING A LENS WITH A “LOCAL” DISTORTION MODEL

2020· article· en· W3048879332 on OpenAlexaff
Ivan Detchev, Derek D. Lichti

Bibliographic record

Venue˜The œinternational archives of the photogrammetry, remote sensing and spatial information sciences/International archives of the photogrammetry, remote sensing and spatial information sciences · 2020
Typearticle
Languageen
FieldComputer Science
TopicOptical measurement and interference techniques
Canadian institutionsUniversity of Calgary
Fundersnot available
KeywordsDistortion (music)Lens (geology)PhotogrammetryCamera resectioningCalibrationFocal lengthCamera lensMean squared errorMathematicsRange (aeronautics)Computer visionPixelObservational errorArtificial intelligenceOpticsComputer sciencePhysicsStatisticsEngineering

Abstract

fetched live from OpenAlex

Abstract. This paper is about camera calibration where an abnormal systematic effect was discovered. The effect was first encountered in a multi-camera system used for close range 3D photogrammetric reconstruction. The objectives for this research were two-fold. The first objective is to identify the source of the systematic error, and the second objective is to model the error as rigorously as possible. The first objective was met after acquiring several calibration data sets where the camera bodies, the lenses, and the image formats were varied. It was concluded that the source of error is the lens system. The second objective was also met. The so called “local” lens distortion was modelled using second order polynomials as the plots of the residuals vs. the image coordinates resembled parabolic shapes. Overall, the final room mean square error for the residuals after applying radial and “local” lens distortion was reduced from 1/2 to 1/6 of a pixel or a 200% relative estimated error improvement.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.001
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Other design · Consensus signal: none
GenreCandidate signal: Methods · Consensus signal: none
Teacher disagreement score0.986
Threshold uncertainty score0.984

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.001
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.001
Science and technology studies0.0010.003
Scholarly communication0.0010.001
Open science0.0020.001
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.031
GPT teacher head0.249
Teacher spread0.218 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designOther design
Domainnot available
GenreMethods

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations3
Published2020
Admission routes1
Has abstractyes

Explore more

Same venue˜The œinternational archives of the photogrammetry, remote sensing and spatial information sciences/International archives of the photogrammetry, remote sensing and spatial information sciencesSame topicOptical measurement and interference techniquesFrench-language works237,207