Uncalibrated flatfielding and illumination vector estimationfor photometric stereo face reconstruction
| Autor: | Maria E. Angelopoulou, Maria Petrou |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Computer science
business.industry ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION Context (language use) Session (web analytics) Computer Science Applications Set (abstract data type) Photometric stereo Pixel brightness Hardware and Architecture Face (geometry) Pattern recognition (psychology) Calibration Computer vision Computer Vision and Pattern Recognition Artificial intelligence business Software ComputingMethodologies_COMPUTERGRAPHICS |
| Zdroj: | Machine Vision and Applications. 25:1317-1332 |
| ISSN: | 1432-1769 0932-8092 |
| Popis: | Within the context of photometric stereo reconstruction, flatfielding may be used to compensate for the effect of the inverse-square law of light propagation on the pixel brightness. This would require capturing a set of reference images at an off-line imaging session, which employs a calibrating device that should be captured under the exact conditions as the main session. Similarly, the illumination vectors, on which photometric stereo relies, are typically precomputed based on another dedicated calibration session. In practice, implementing such off-line sessions is inconvenient and often infeasible. This work aims at enabling accurate photometric stereo reconstruction for the case of non-interactive on-line capturing of human faces. We propose unsupervised methodologies, which extract all information that is required for accurate face reconstruction from the images of interest themselves. Specifically, we propose an uncalibrated flatfielding and an uncalibrated illumination vector estimation methodology, and we assess their effect on photometric stereo face reconstruction. Results demonstrate that incorporating our methodologies into the photometric stereo framework halves the reconstruction error, while eliminating the need of off-line calibration. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|