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Under controlled masking of overlay-free imagery, restoration recovers 98.4% of checkerboard corners to within 0.048 px of their ground truth positions, while corners falling within the restored region carry a mean localisation error of 3.34 px and are identified for exclusion. Applied to a consumer handheld thermal camera, the framework raises calibration feasibility from complete failure without preprocessing to successful calibration in every configuration tested, achieving mean reprojection errors of 0.155\u20130.238 pixels, with held-out errors of 0.328\u20130.538 pixels on images not used in estimation, with both falling within the range reported in the literature for professional-grade systems. Bootstrap resampling establishes the repeatability of the estimated intrinsics, and hold-out validation confirms that the fitted model generalises to unseen views. Robustness is assessed across two substrate materials, three target scales and both indoor and outdoor environments, comprising 387 images. The complete preprocessing pipeline runs below 50 ms per image. This work demonstrates that computational preprocessing can overcome a hardware-imposed constraint previously assumed to preclude calibration of this class of device.<\/jats:p>","DOI":"10.3390\/s26196118","type":"journal-article","created":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T15:57:57Z","timestamp":1790611077000},"page":"6118","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["A Novel Image Inpainting Approach for Geometric Calibration of Low-Cost Handheld Thermal Cameras"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-4791-2544","authenticated-orcid":false,"given":"Mahmod","family":"Sahal","sequence":"first","affiliation":[{"name":"Faculty of Computing, Engineering & Science, University of South Wales, Pontypridd CF37 1DL, UK"},{"name":"Higher Institute for Engineering  Technologies, Zliten, Libya"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Yusuf","family":"Abubakar","sequence":"additional","affiliation":[{"name":"Electrical Engineering Department, National College for Nuclear (NCfN) Southern Hub, Bridgwater TA5 2LS, UK"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2306-4037","authenticated-orcid":false,"given":"Kang","family":"Li","sequence":"additional","affiliation":[{"name":"Faculty of Computing, Engineering & Science, University of South Wales, Pontypridd CF37 1DL, UK"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"supervision","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5506-6141","authenticated-orcid":false,"given":"Nigel","family":"Copner","sequence":"additional","affiliation":[{"name":"Engineering Unit, Faculty of Business & Physical Sciences, Aberystwyth University, Penglais, Aberystwyth SY23 3FL, UK"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"supervision","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,27]]},"reference":[{"key":"ref_1","unstructured":"Zhang, S. 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