CCD成像的英文资料

<p><a href="http://www.ri.cmu.edu/pubs/pub_3742.html">http://www.ri.cmu.edu/pubs...</a><br /><font face="Arial, Helvetica, 'Sans Serif'"><a href="http://www.ri.cmu.edu/pub_files/pub3/tsin_yanghai_2001_3/">http://www.ri.cmu.edu/pub_...</a><br />tsin_yanghai_2001_3.pdf</font><br /><font face="Arial, Helvetica, 'Sans Serif'"><font face="Arial, Helvetica, 'Sans Serif'"><b>Abstract<br /></b></font></font><font face="Arial, Helvetica, 'Sans Serif'">Charge-Coupled Device (CCD)<br />cameras are widely used imaging sensors in computer vision systems.<br />Many photometric algorithms, such as shape from shading, color<br />constancy, and photometric stereo, implicitly assume that the image<br />intensity is proportional to scene radiance. The actual image<br />measurements deviate significantly from this assumption since the<br />transformation from scene radiance to image intensity is non-linear and<br />is a function of various factors including: noise sources in the CCD<br />sensor, as well as various transformations occurring in the camera<br />including: white balancing, gamma correction and automatic gain<br />control. This paper illustrates how careful modelling of the error<br />sources and the various processing steps enable us to accurately<br />estimate the ``response function'', the inverse mapping from image<br />measurements to scene radiance for a given camera exposure setting. It<br />is shown that the estimation algorithm outperforms the calibration<br />procedures known to us in terms of reduced bias and variance. Further,<br />we demonstrate how the error modelling helps us to obtain uncertainty<br />estimates of the camera irradiance value. The power of this uncertainty<br />modeling is illustrated by a vision task involving High Dynamic Range<br />image generation followed by change detection. Change can be detected<br />reliably even in situation where the two images (the reference scene<br />image and the current image) are taken several hours apart.<br /></font><font face="Arial, Helvetica, 'Sans Serif'"><b>Copyright notice</b><br /></font><font face="Arial, Helvetica, 'Sans Serif'">This material is presented to<br />ensure timely dissemination of scholarly and technical work. Copyright and<br />all rights therein are retained by authors or by other copyright<br />holders. All persons copying this information are expected to adhere to the<br />terms and constraints invoked by each author's copyright. These works may<br />not be reposted without the explicit permission of the copyright holder.<br /></font></p>