Colour quality of facial prostheses in additive manufacturing
- 218 Downloads
Recent progress in additive manufacturing technology has improved the realistic colour reproduction of 3D facial prostheses with computational optimisation of skin colour profiles. The colour appearance of the prosthetic surface depends on both the spectral characteristics of the surfaces and the scene illumination. Considering everyday environments, the colours of prosthetic surfaces should appear constant under various illuminations, although such evaluations on facial prostheses have had limited success to date. In this study, colour quality was assessed throughout the additive manufacturing process, namely, from the colour profile optimisation to the colour reproduction on the 3D facial prostheses. Colour profiles optimised for typical skin colour samples were applied to manufacture facial prostheses with two skin types, Caucasian and Chinese. The colour quality was assessed by the colour difference metric CIEDE2000 and spectral similarity against corresponding real skin data. The constant colour appearance of the prosthetic surfaces under different illuminations was estimated by introducing a reproduction colour-constancy index. The CIEDE2000 between the prosthetic and real skins was approximately 7.2 on average over all skin types and facial areas, which is slightly larger than the acceptable perceptual error. The level was relatively constant under different illuminations selected from the CIE standard daylight and fluorescent lights. The reproduction colour-constancy index ranged from 0.34 to 0.89, which is remarkably similar to the level observed in traditional colour constancy data in vision sciences. Spectral errors were close to those obtained by computational spectral reconstruction from digital RGB colours. These results suggest that the proposed colour management for facial prostheses may satisfy the requirement of colour quality in everyday environments with various illuminations. The causes and further improvement of the remaining errors in the manufacturing process are also discussed.
KeywordsHuman facial prostheses 3D colour printing Skin colour, colour management Perceptual error JND DeltaE
Some of the results were reported at the 17th Vision Sciences Society Annual Meeting, 19–24 May 2017, St. Pete Beach, FL., USA.
This work was supported by the Engineering and Physical Sciences Research Council, UK (Grants EP/L001012/1 and EP/K040057).
Compliance with ethical standards
All experiments were conducted following approval by the University of Liverpool Research Ethics Committee, which operates in accordance with the Declaration of Helsinki. Signed consent was obtained from each subject who took part in the measurements.
Conflict of interest
The authors declare that they have no conflict of interest.
- 2.Ramirez GA, Fuentes O, Crites SL, Jimenez M, Ordonez J (2014) Color analysis of facial skin: detection of emotional state. In: 2014 I.E. Conference on Computer Vision and Pattern Recognition Workshops, 23–28 June 2014. pp 474–479. doi: https://doi.org/10.1109/CVPRW.2014.76
- 4.Da Pos, Green-Armytage P (2007) Facial expressions, colours and basic emotions. J Int Colour Assoc 1(2):1–20Google Scholar
- 10.Xiao K, Wuerger S, Mostafa F, Sohaib A, Yates JM (2016) Colour image reproduction for 3D printing facial prostheses. New trends in 3D printing. InTech. https://doi.org/10.5772/63339
- 15.Curodeau A, Sachs E, Caldarise S (2000) Design and fabrication of cast orthopedic implants with freeform surface textures from 3-D printed ceramic shell. J Biomed Mater Res 53(5):525–535. https://doi.org/10.1002/1097-4636(200009)53:5<525::AID-JBM12>3.0.CO;2-1 CrossRefGoogle Scholar
- 19.Zardawi FM, Xiao K, van Noort R, Yates JM (2015) Mechanical properties of 3D printed facial prostheses compared to handmade silicone polymer prostheses. Eur Sci J 11(12):1–11Google Scholar
- 20.Pantone LLC (2012) PANTONE SkinTone™ Guide. Carlstadt, NJ, USAGoogle Scholar
- 26.CIE, Technical Committee 1–48 (2004) Colorimetry, 3rd edn. Commission Internationale de l'Eclairage, Vienna, AustriaGoogle Scholar
- 28.Sweet J, Granahan J, M. Sharp (2000) An objective standard for hyperspectral image quality. In: Proceedings of AVIRIS workshop, jet propulsion laboratory, Pasadena, California. Jet Propulsion Laboratory, California Institute of TechnologyGoogle Scholar
- 29.Shrestha R, Pillay R, George S, Hardeberg JY (2014) Quality evaluation in spectral imaging—quality factors and metrics. J Int Colour Assoc 12:22–35Google Scholar
- 33.Hong G, Luo MR, Rhodes PA (2001) A study of digital camera colorimetric characterization based on polynomial modeling. Color Res Appl 26(1):76–84. https://doi.org/10.1002/1520-6378(200102)26:1<76::AID-COL8>3.0.CO;2-3 CrossRefGoogle Scholar
- 38.CIE (2008) CIE Standard llluminants for Colorimetry. S 014-2/E:2006/ISO 11664-2:2007(E). Commission Internationale de L'Eclairage, Vienna, AustriaGoogle Scholar
- 40.Amano K, Sohaib A, Xiao K, Yates JM, Whitford C, Wuerger SM (2017) Color quality assessments of 3D facial prostheses in varying illuminations. Paper presented at the Vision Sciences Society Annual Meeting, St Pete Beach, 19-24 May 2017Google Scholar
- 41.Wang M, Xiao K, Luo R, Zhu Y, Wuerger S Investigation of uncertainty of skin colour measurements. In: Proceedings of the 28th Session of the CIE, 28 June - 4 July 2015, Manchester, UK, 07/01/2015Google Scholar
- 43.Xiao K, Wang M, Luo R, Li C, Wuerger S (2016) Characterisation of skin spectra in a Caucasian and Oriental sample. Electron Imaging 2016(20):1–4. https://doi.org/10.2352/ISSN.2470-1173.2016.20.COLOR-338 Google Scholar
- 44.Sinthanayothin C, Bholsithi W (2005) Image warping based on 3D thin plate spline. Paper presented at the International Conference on Information Technology in Asia 2005, Sarawak, Malaysia., December 12-15, 2005Google Scholar
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.