| 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, pd?3_yU 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, EC<g7_0F 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? m}54yo 那些系数是通过对29525*10阶的矩阵每列的值算出来的嘛? Fo|6 PoSo ^i&sQQ({ :aS8%m MDZ,a0?4t UA>UW!I function z = zernfun(n,m,r,theta,nflag) s5F,*< %ZERNFUN Zernike functions of order N and frequency M on the unit circle. sOhQu>gN % Z = ZERNFUN(N,M,R,THETA) returns the Zernike functions of order N s"7wG!yf % and angular frequency M, evaluated at positions (R,THETA) on the :G=N|3 % unit circle. N is a vector of positive integers (including 0), and u0(H! % M is a vector with the same number of elements as N. Each element oKLL~X>!U % k of M must be a positive integer, with possible values M(k) = -N(k) ]vo&NE % to +N(k) in steps of 2. R is a vector of numbers between 0 and 1, 52
?TLID % and THETA is a vector of angles. R and THETA must have the same ~Gx"gK0 % length. The output Z is a matrix with one column for every (N,M) ..`J-k % pair, and one row for every (R,THETA) pair. !B5 }`*1D % _Q_"_*e % Z = ZERNFUN(N,M,R,THETA,'norm') returns the normalized Zernike P~HzNC % functions. The normalization factor sqrt((2-delta(m,0))*(n+1)/pi), ,_
} % with delta(m,0) the Kronecker delta, is chosen so that the integral F)Oe;z6 % of (r * [Znm(r,theta)]^2) over the unit circle (from r=0 to r=1, d:cs8f4> % and theta=0 to theta=2*pi) is unity. For the non-normalized "#anL8 % polynomials, max(Znm(r=1,theta))=1 for all [n,m]. }F=scbpXj % dtD)VNkBZ % The Zernike functions are an orthogonal basis on the unit circle. 9|R]Lz3PA % They are used in disciplines such as astronomy, optics, and 9.:r;H G % optometry to describe functions on a circular domain. q$6fb)2I]e % ^Tgu]t % The following table lists the first 15 Zernike functions. s
~c_9,JK % 3 (Bd`=9 % n m Zernike function Normalization Q}zAC2@L % -------------------------------------------------- MHar9)$} % 0 0 1 1 BV_rk^}Ur % 1 1 r * cos(theta) 2 I-<U u2 % 1 -1 r * sin(theta) 2 <mN.6@*{ % 2 -2 r^2 * cos(2*theta) sqrt(6) |+K3\b % 2 0 (2*r^2 - 1) sqrt(3) /R\]tl#2j % 2 2 r^2 * sin(2*theta) sqrt(6) =8:m:Y&|`G % 3 -3 r^3 * cos(3*theta) sqrt(8) EX zA(igS % 3 -1 (3*r^3 - 2*r) * cos(theta) sqrt(8) mhU ?N % 3 1 (3*r^3 - 2*r) * sin(theta) sqrt(8) *Y'nDv6_P % 3 3 r^3 * sin(3*theta) sqrt(8) "O@L
IR7 % 4 -4 r^4 * cos(4*theta) sqrt(10) TN!8J=sx. % 4 -2 (4*r^4 - 3*r^2) * cos(2*theta) sqrt(10) .;nU"
a3' % 4 0 6*r^4 - 6*r^2 + 1 sqrt(5) qYjR % 4 2 (4*r^4 - 3*r^2) * cos(2*theta) sqrt(10) X <QSi
% 4 4 r^4 * sin(4*theta) sqrt(10) BSU%.tmI % -------------------------------------------------- .H;[s % $3.hZx> % Example 1: [HNWM/ff7+ % R{={7.As+ % % Display the Zernike function Z(n=5,m=1) 0*7N= % x = -1:0.01:1; `P/7Mf % [X,Y] = meshgrid(x,x); P|c[EUT % [theta,r] = cart2pol(X,Y); B q/<kEgM % idx = r<=1; ,c }R*\ % z = nan(size(X)); =SMI,p& % z(idx) = zernfun(5,1,r(idx),theta(idx)); $hv o^$ % figure 7tbM~+<0 % pcolor(x,x,z), shading interp v',% % axis square, colorbar 'VVEd[ % title('Zernike function Z_5^1(r,\theta)') "`WcE/( % -36pkC
6
\ % Example 2: _OR@S%$ % pHO,][VZ % % Display the first 10 Zernike functions &USKudXmb % x = -1:0.01:1; 8['8ctX % [X,Y] = meshgrid(x,x); W:5,zFW % [theta,r] = cart2pol(X,Y); r5#8Vzr % idx = r<=1; ^xz*%2@ % z = nan(size(X)); S:b-+w|* % n = [0 1 1 2 2 2 3 3 3 3]; uUy~$>V % m = [0 -1 1 -2 0 2 -3 -1 1 3]; Ky:y1\K1^K % Nplot = [4 10 12 16 18 20 22 24 26 28]; ~%.<rc0 % y = zernfun(n,m,r(idx),theta(idx)); @ ={Hx$zL % figure('Units','normalized') xcf`i:\ % for k = 1:10 _o,Mji| % z(idx) = y(:,k); kF,_o/Jc % subplot(4,7,Nplot(k)) LHJ}I5zv % pcolor(x,x,z), shading interp ^)wTCkH&y % set(gca,'XTick',[],'YTick',[]) s1"dd7&g' % axis square =H8
LBM % title(['Z_{' num2str(n(k)) '}^{' num2str(m(k)) '}']) >s*ZT%TF % end yv),>4_6 % 2^3N[pM; % See also ZERNPOL, ZERNFUN2. )7`2FLG 0 rge]w.X "~:AsZ"7 % Paul Fricker 11/13/2006 ],.1=iY aFfd!a"n 4xYW?s( gjbSB6[ Y:;]qoF % Check and prepare the inputs: = ^NTHc^* % ----------------------------- 8l< | |