anisotropic function convert to C code using matlab coder

2 visualizzazioni (ultimi 30 giorni)
Hi everyone,
is there anyone know how to change this function to be applicable to convert in C code using Matlab coder ??
function diff_sig = anisodiff1D(sig, num_iter, delta_t, kappa, option)%#codegen
% ARGUMENT DESCRIPTION:
% SIG - input column vector (Nx1).
% NUM_ITER - number of iterations.
% DELTA_T - integration constant (0 <= delta_t <= 1/3).
% Usually, due to numerical stability this
% parameter is set to its maximum value.
% KAPPA - gradient modulus threshold that controls the conduction.
% OPTION - conduction coefficient functions proposed by Perona & Malik:
% 1 - c(x,t) = exp(-(nablaI/kappa).^2),
% privileges high-contrast edges over low-contrast ones.
% 2 - c(x,t) = 1./(1 + (nablaI/kappa).^2),
% privileges wide regions over smaller ones.
%
% OUTPUT DESCRIPTION:
% DIFF_SIG - (diffused) signal with the largest scale-space parameter.
%
% Example
% -------------
% s = exp(-(-10:0.1:10).^2/2.5)' + rand(length(-10:0.1:10),1);
% num_iter = 15;
% delta_t = 1/3;
% kappa = 30;
% option = 2;
% ad = anisodiff1D(s,num_iter,delta_t,kappa,option);
% figure, subplot 121, plot(s), axis([0 200 0 2]), subplot 122, plot(ad), axis([0 200 0 2])
%
% See also anisodiff2D, anisodiff3D.
% References:
% P. Perona and J. Malik.
% Scale-Space and Edge Detection Using Anisotropic Diffusion.
% IEEE Transactions on Pattern Analysis and Machine Intelligence,
% 12(7):629-639, July 1990.
%
% G. Grieg, O. Kubler, R. Kikinis, and F. A. Jolesz.
% Nonlinear Anisotropic Filtering of MRI Data.
% IEEE Transactions on Medical Imaging,
% 11(2):221-232, June 1992.
%
% MATLAB implementation based on Peter Kovesi's anisodiff(.):
% P. D. Kovesi. MATLAB and Octave Functions for Computer Vision and Image Processing.
% School of Computer Science & Software Engineering,
% The University of Western Australia. Available from:
% <http://www.csse.uwa.edu.au/~pk/research/matlabfns/>.
%
% Credits:
% Daniel Simoes Lopes
% ICIST
% Instituto Superior Tecnico - Universidade Tecnica de Lisboa
% danlopes (at) civil ist utl pt
% http://www.civil.ist.utl.pt/~danlopes
%
% May 2007 original version.
% Convert input signal to double
sig = double(sig);
% PDE (partial differential equation) initial condition
diff_sig = sig;
% Center point distance
dx = 1;
% 1D convolution masks - finite differences
hW = [1 -1 0]';
hE = [0 -1 1]';
% Anisotropic diffusion
for t = 1:num_iter
% Finite differences
nablaW = imfilter(diff_sig,hW,'conv');
nablaE = imfilter(diff_sig,hE,'conv');
% Diffusion function
if option == 1
cW = exp(-(nablaW/kappa).^2);
cE = exp(-(nablaE/kappa).^2);
elseif option == 2
cW = 1./(1+(nablaW/kappa).^2);
cE = 1./(1+(nablaE/kappa).^2);
end
% Discrete PDE solution
diff_sig = diff_sig + ...
delta_t*(...
(1/(dx^2))*cW.*nablaW + (1/(dx^2))*cE.*nablaE);
% Iteration warning
fprintf('\rIteration %d\n',t);
end

Risposte (1)

Walter Roberson
Walter Roberson il 25 Feb 2012
imfilter() is not supported for Coder code generation; see http://www.mathworks.com/help/toolbox/eml/ug/bq1h2z7-11.html
Perhaps you could rewrite it in terms of conv() ?

Prodotti

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