| jssylttc |
2012-04-23 19:23 |
如何从zernike矩中提取出zernike系数啊
下面这个函数大家都不会陌生,计算zernike函数值的,并根据此可以还原出图像来, J( 我输入10阶的n、m,r,theta为38025*1向量,最后得到的z是29525*10阶的矩阵, U '#Xwax 这个,跟我们用zygo干涉仪直接拟合出的36项zernike系数,有何关系呢? B3lP#ckh 那些系数是通过对29525*10阶的矩阵每列的值算出来的嘛? nYcj6? 7( &\)qf=n 9"=1 O 6 Ch
[!=p{ :q.g#:1s function z = zernfun(n,m,r,theta,nflag) Wy[Ua#Dd %ZERNFUN Zernike functions of order N and frequency M on the unit circle. (W~')A"hC' % Z = ZERNFUN(N,M,R,THETA) returns the Zernike functions of order N @nuMl5C-` % and angular frequency M, evaluated at positions (R,THETA) on the =q%Q^ % unit circle. N is a vector of positive integers (including 0), and }'y=JV>l % M is a vector with the same number of elements as N. Each element JFyw,p&xB % k of M must be a positive integer, with possible values M(k) = -N(k) Eu4-=2!4 % to +N(k) in steps of 2. R is a vector of numbers between 0 and 1, Lad8C % and THETA is a vector of angles. R and THETA must have the same &.zG?e. % length. The output Z is a matrix with one column for every (N,M) J\kGD % pair, and one row for every (R,THETA) pair. (^:0g.~c % Y -Zw' % Z = ZERNFUN(N,M,R,THETA,'norm') returns the normalized Zernike 6z6\-45 % functions. The normalization factor sqrt((2-delta(m,0))*(n+1)/pi), 5@Y rtZI % with delta(m,0) the Kronecker delta, is chosen so that the integral `Dck$ % of (r * [Znm(r,theta)]^2) over the unit circle (from r=0 to r=1, =V- ^ % and theta=0 to theta=2*pi) is unity. For the non-normalized 6%hr]>L % polynomials, max(Znm(r=1,theta))=1 for all [n,m]. m0I)_R#X[ % X7cqAi % The Zernike functions are an orthogonal basis on the unit circle. mzh8<w?ns % They are used in disciplines such as astronomy, optics, and )Oxsasn)M % optometry to describe functions on a circular domain. K/Q%tr1W0 % VO (KQx % The following table lists the first 15 Zernike functions. y_>l'{w3^ % V__|NVoOm % n m Zernike function Normalization Y
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