用opencv做的水平集程序 要求每次水平集移动前的图像全部保留需要什么命令啊

如果不想修改现有图片，可以采用

cvCopyImage、memcpy等函数将现在的图像复制一个，采用复制的图像进行处理即可啊。

如果是存在处理当前图像，还希望保存前一个图像，则可以定义一个图像变量，本次结束前将图像复制到指定的图像变量内，也可以采用cvSaveImage函数将图像保存到硬盘，等下次需要再出来。

u=EVOLUTION(u, g ,lambda, mu, alf, epsilon, timestep, 1)

必须要有函数支持，或者调用动态链接库（dll）。

核心代码在这个函数或dll文件中。

在这里：

function u = EVOLUTION(u0, g, lambda, mu, alf, epsilon, delt, numIter)

% EVOLUTION(u0, g, lambda, mu, alf, epsilon, delt, numIter) updates the level set function

% according to the level set evolution equation in Chunming Li et al's paper:

% "Level Set Evolution Without Reinitialization: A New Variational Formulation"

% in Proceedings CVPR'2005,

% Usage:

% u0: level set function to be updated

% g: edge indicator function

% lambda: coefficient of the weighted length term L(\phi)

% mu: coefficient of the internal (penalizing) energy term P(\phi)

% alf: coefficient of the weighted area term A(\phi), choose smaller alf

% epsilon: the papramater in the definition of smooth Dirac function, default value 1.5

% delt: time step of iteration, see the paper for the selection of time step and mu

% numIter: number of iterations.

%

u=u0

[vx,vy]=gradient(g)

for k=1:numIter

u=NeumannBoundCond(u)

[ux,uy]=gradient(u)

normDu=sqrt(ux.^2 + uy.^2 + 1e-10)

Nx=ux./normDu

Ny=uy./normDu

diracU=Dirac(u,epsilon)

K=curvature_central(Nx,Ny)

weightedLengthTerm=lambda*diracU.*(vx.*Nx + vy.*Ny + g.*K)

penalizingTerm=mu*(4*del2(u)-K)

weightedAreaTerm=alf.*diracU.*g

u=u+delt*(weightedLengthTerm + weightedAreaTerm + penalizingTerm) % update the level set function

end

% the following functions are called by the main function EVOLUTION

function f = Dirac(x, sigma) %水平集狄拉克计算

f=(1/2/sigma)*(1+cos(pi*x/sigma))

b = (x<=sigma) &(x>=-sigma)

f = f.*b

function K = curvature_central(nx,ny) %曲率中心

[nxx,junk]=gradient(nx)

[junk,nyy]=gradient(ny)

K=nxx+nyy

function g = NeumannBoundCond(f)

% Make a function satisfy Neumann boundary condition

[nrow,ncol] = size(f)

g = f

g([1 nrow],[1 ncol]) = g([3 nrow-2],[3 ncol-2])

g([1 nrow],2:end-1) = g([3 nrow-2],2:end-1)

g(2:end-1,[1 ncol]) = g(2:end-1,[3 ncol-2])

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