Title :
Estimation of the radiometric response functions of a color camera from differently illuminated images
Author :
Shafique, Khurram ; Shah, Mubarak
Author_Institution :
Sch. of Electr. & Comput. Sci., Central Florida Univ., Orlando, FL, USA
Abstract :
The mapping that relates the image irradiance to the image brightness (intensity) is known as the Radiometric Response Function or Camera Response Function. This usually unknown mapping is nonlinear and varies from one color channel to another. In this paper, we present a method to estimate the radiometric response functions (of R, G and B channels) of a color camera directly from the images of an arbitrary scene taken under different illumination conditions (The illumination conditions are not assumed to be known). The response function of a channel is modeled as a gamma curve and is recovered by using a constrained nonlinear minimization approach by exploiting the fact that the material properties of the scene remain constant in all the images. The performance of the proposed method is demonstrated experimentally.
Keywords :
cameras; constraint theory; image colour analysis; minimisation; radiometry; color camera response function; color channel; constrained nonlinear minimization; gamma curve; illuminated image irradiance; nonlinear mapping; radiometric response function; Brightness; Cameras; Computer science; Influenza; Layout; Lighting; Optical imaging; Photometry; Radiometry; Shape measurement;
Conference_Titel :
Image Processing, 2004. ICIP '04. 2004 International Conference on
Print_ISBN :
0-7803-8554-3
DOI :
10.1109/ICIP.2004.1421569