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, :iEIo7B 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, E7`Q=4@e 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? &x.n>O 那些系数是通过对29525*10阶的矩阵每列的值算出来的嘛? xf|vz|J?y 2~B9 (| Of gmJ(% #E;a;$p Rm&4Pku function z = zernfun(n,m,r,theta,nflag) :ceT8-PBRx %ZERNFUN Zernike functions of order N and frequency M on the unit circle. cOoF +hz0O % Z = ZERNFUN(N,M,R,THETA) returns the Zernike functions of order N -qs
R,H % and angular frequency M, evaluated at positions (R,THETA) on the pPH"6
% unit circle. N is a vector of positive integers (including 0), and 0
zn }l6OS % M is a vector with the same number of elements as N. Each element Lk`,mjhk % k of M must be a positive integer, with possible values M(k) = -N(k) ^3O`8o % to +N(k) in steps of 2. R is a vector of numbers between 0 and 1, 4?',E ddo % and THETA is a vector of angles. R and THETA must have the same _t-e.2a
v % length. The output Z is a matrix with one column for every (N,M) d`sIgll&n % pair, and one row for every (R,THETA) pair. c2~oPUj % `gE_u % Z = ZERNFUN(N,M,R,THETA,'norm') returns the normalized Zernike H$)__V5I,q % functions. The normalization factor sqrt((2-delta(m,0))*(n+1)/pi), 2]'cj % with delta(m,0) the Kronecker delta, is chosen so that the integral 4S\S t< % of (r * [Znm(r,theta)]^2) over the unit circle (from r=0 to r=1, a0)] W%F % and theta=0 to theta=2*pi) is unity. For the non-normalized Y+Cqc.JBQ % polynomials, max(Znm(r=1,theta))=1 for all [n,m]. /
0ra]}[( % @3_."-d % The Zernike functions are an orthogonal basis on the unit circle. t2_pwd*B % They are used in disciplines such as astronomy, optics, and ,8&ND864v % optometry to describe functions on a circular domain. bFB.hkTP % L
IN$Y % The following table lists the first 15 Zernike functions. X$(YCb % fl+dL#] % n m Zernike function Normalization KYM%U"j D % -------------------------------------------------- *}RV)0mif % 0 0 1 1 Sej(jJX1 % 1 1 r * cos(theta) 2 B#, TdP]/ % 1 -1 r * sin(theta) 2 $TY1'#1U; % 2 -2 r^2 * cos(2*theta) sqrt(6) JWVn@)s % 2 0 (2*r^2 - 1) sqrt(3) I*EHZctH % 2 2 r^2 * sin(2*theta) sqrt(6) hwi$:[ % 3 -3 r^3 * cos(3*theta) sqrt(8) cNG`-+U' % 3 -1 (3*r^3 - 2*r) * cos(theta) sqrt(8) <o: O<p@6 % 3 1 (3*r^3 - 2*r) * sin(theta) sqrt(8) +z O.|`+ % 3 3 r^3 * sin(3*theta) sqrt(8) kn= fW1 % 4 -4 r^4 * cos(4*theta) sqrt(10) 0NMmN_Lr % 4 -2 (4*r^4 - 3*r^2) * cos(2*theta) sqrt(10) 4YyVh.x % 4 0 6*r^4 - 6*r^2 + 1 sqrt(5) )~C+nb '6/ % 4 2 (4*r^4 - 3*r^2) * cos(2*theta) sqrt(10) ={B?hjo<- % 4 4 r^4 * sin(4*theta) sqrt(10) 19*D*dkBR % -------------------------------------------------- Jl@YBzDfF % KvNw'3Ua % Example 1: .q5WK#^ % +?ilTU % % Display the Zernike function Z(n=5,m=1) 'M=V{.8U % x = -1:0.01:1; Rd,5&X$ % [X,Y] = meshgrid(x,x); R=<uf:ca % [theta,r] = cart2pol(X,Y); tE]Y=x[Ux % idx = r<=1; n}3fItSJ % z = nan(size(X)); LDYk\[81 % z(idx) = zernfun(5,1,r(idx),theta(idx)); GEJy?$9 % figure IP+.L]S % pcolor(x,x,z), shading interp VskdC?yIp % axis square, colorbar 8Uoqj=5F % title('Zernike function Z_5^1(r,\theta)') g;\_MbfP % Ybp';8V % Example 2: 0/fA>%& % li % % Display the first 10 Zernike functions n1)~/
> % x = -1:0.01:1; 2T3b6 % [X,Y] = meshgrid(x,x); Fh~
pB>t % [theta,r] = cart2pol(X,Y); C~c|};&% % idx = r<=1; kA{eT % z = nan(size(X)); VY j
pl % n = [0 1 1 2 2 2 3 3 3 3]; p{w:^l( % m = [0 -1 1 -2 0 2 -3 -1 1 3]; nrJW.F]S8[ % Nplot = [4 10 12 16 18 20 22 24 26 28]; s/0~!0 % y = zernfun(n,m,r(idx),theta(idx)); !d{Ijs'T % figure('Units','normalized') 4N_iHe5U % for k = 1:10 de,4Ms!% % z(idx) = y(:,k); [=& tN)_ % subplot(4,7,Nplot(k)) [f#7~ % pcolor(x,x,z), shading interp hs?cV)hDS % set(gca,'XTick',[],'YTick',[]) Tw@:sWC % axis square /5j]laYK) % title(['Z_{' num2str(n(k)) '}^{' num2str(m(k)) '}']) `+ 5,=S % end b&I{?'"% 8 % Ht&%`\9s % See also ZERNPOL, ZERNFUN2. (T1d!v"~" llRQxk 9 $Ud\ % Paul Fricker 11/13/2006 (laVmU?I7 ySNXjH
Q= k*!f@ M Hi#f
Qji <gjA(xT5 % Check and prepare the inputs: 5v5K}hx % ----------------------------- LNI]IITx/ if ( ~any(size(n)==1) ) || ( ~any(size(m)==1) ) 7cV
GB error('zernfun:NMvectors','N and M must be vectors.') /}R*'y end C~8;2/F7 OG{vap) 6w*q~{"( if length(n)~=length(m) );1UbqVPD error('zernfun:NMlength','N and M must be the same length.') S*S@a4lV7 end m
4V0e~] TUM7(-,9 ER)to<k n = n(:); 9q>rUoK^ m = m(:); f~v@;/HL if any(mod(n-m,2)) k8O%gO error('zernfun:NMmultiplesof2', ... ]_y0wLq 'All N and M must differ by multiples of 2 (including 0).') :WAFBK/x end 0/,Dy2h faPgp 8mv}-; if any(m>n) Bb@m-+f error('zernfun:MlessthanN', ... b";D*\=x 'Each M must be less than or equal to its corresponding N.') V8+8?5'l end v)-:0f wSIfqf+y G ,?l
o=m if any( r>1 | r<0 ) 7f#r&~= error('zernfun:Rlessthan1','All R must be between 0 and 1.') |QxT"`rT
end \Zmn!Gg 3p#BEH<re 0qhSV B5 if ( ~any(size(r)==1) ) || ( ~any(size(theta)==1) ) W
B7gY\Y&M error('zernfun:RTHvector','R and THETA must be vectors.')
Mt
end @;g|styh^ oz#;7
?9 ;SVAar4r r = r(:); 9t o2V theta = theta(:); )&wJ | |