error using ricernd matlab function

hi, all

when i run the following code:

clear, close('all'), clc data = load('mri'); % MRI dataset (magnitude image) distributed with MATLAB im = double(data.D(:,:,1,16)); % (particular slice through the brain) s=5; % noise level (NB actual Rician stdev depends on signal, see ricestat) im_g = im + 5 * randn(size(im)); % Add Gaussian noise im_r = ricernd(im, s); % "Add" Rician noise (make Rician distributed) % Compute ranges min_o = round(min(im(:))); max_o = round(max(im(:))); min_g = round(min(im_g(:))); max_g = round(max(im_g(:))); min_r = round(min(im_r(:))); max_r = round(max(im_r(:))); % Show each image with the same color scaling limits clim = [min_g max(max_g, max_r)]; figure('Position', [30 500 800 300]); colormap(data.map); subplot(1,3,1); imagesc(im, clim); axis image; title('Original'); xlabel(['Range: (' num2str(min_o) ', ' num2str(max_o) ')']) subplot(1,3,2); imagesc(im_g, clim); axis image; title('Gaussian noise'); xlabel(['Range: (' num2str(min_g) ', ' num2str(max_g) ')']) subplot(1,3,3); imagesc(im_r, clim); axis image; title('Rician noise') xlabel(['Range: (' num2str(min_r) ', ' num2str(max_r) ')'])

i have the following error:

Undefined function 'ricernd' for input arguments of type 'double'. how i can add Rician noise to image?

thank in advance

Answer 1

[Walter Roberson]

https://www.mathworks.com/matlabcentral/fileexchange/14237-rice-rician-distribution