Synonyms
Opaque
Related Concepts
Definition
Opacity describes the degree to which an object or material is not transmitting light. Sometimes the opposite is referred to as transmittance (mostly in physics). In computer graphics, the opposite of opacity is typically referred to as transparency.
Background
Most computer vision algorithms, whether designed for 3D reconstruction, object detection, object classification, etc., require the scene and the objects it consists of to be opaque. More precisely, objects are required to be diffusely opaque. Specularly reflective objects, e.g., are opaque by definition but most vision techniques cannot handle them.
A multitude of research has gone into lifting the restriction on scene opacity. When going beyond opaque objects, images are typically enhanced by an alpha channel – a fractional measure of opacity, or the amount by which an object obscures the background in an image.
In television and film...
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Gerald Millerson J Owens (2009) Television production. Focal Press, Amsterdam/Boston
Born M, Wolf E (1999) Principles of optics, 7th edn. Cambridge University Press, Cambridge, UK
Siegel R, Howell JR (1992) Thermal radiation heat transfer, 3rd edn. Taylor & Francis, New York, USA
Chuang YY, Agarwala A, Curless B, Salesin DH, Szeliski R (2002) Video matting of complex scenes. In: SIGGRAPH '02: proceedings of the 29th annual conference on computer graphics and interactive techniques, San Antonio. ACM, New York, pp 243–248
Matusik W, Pfister H, Ngan A, Beardsley P, Ziegler R, McMillan L (2002) Image-based 3D photography using opacity hulls. In: SIGGRAPH '02: proceedings of the 29th annual conference on computer graphics and interactive techniques, San Antonio. ACM, New York, pp 427–437
. Ihrke I, Magnor M (2004) Image-based tomographic reconstruction of flames. In: ACM SIGGRAPH/Eurographics symposium proceedings, symposium on computer animation, Grenoble, pp 367–375
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2014 Springer Science+Business Media New York
About this entry
Cite this entry
Ihrke, I. (2014). Opacity. In: Ikeuchi, K. (eds) Computer Vision. Springer, Boston, MA. https://doi.org/10.1007/978-0-387-31439-6_564
Download citation
DOI: https://doi.org/10.1007/978-0-387-31439-6_564
Published:
Publisher Name: Springer, Boston, MA
Print ISBN: 978-0-387-30771-8
Online ISBN: 978-0-387-31439-6
eBook Packages: Computer ScienceReference Module Computer Science and Engineering