circle detection using hough transform
作者：D J Kcrbywn and T J Atherton，
University of Warwick, U.K.霍夫檢測(cè)圓的IEEE,1995的文章，對(duì)指導(dǎo)霍夫變換圓檢測(cè)的原理有一定的指導(dǎo)。
ITU-T G.729 Annex C+ - Reference C code for floating point
implementation of G.729 at 6.4/8/11.8 kbit/s with DTX functionality
(integration of Annexes B, D and E)
