1 | % 'ima_noise_rms': gives the variance of relative noise by difference to the
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2 | % filered image in ppm (part per million) (for grey scale image)
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3 | %------------------------------------------------------------------------
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4 | %%%% Use the general syntax for transform fields with a single input and parameters %%%%
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5 | % OUTPUT:
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6 | % DataOut: output field structure
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7 | %
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8 | %INPUT:
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9 | % DataIn: input field structure
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10 | % Param: matlab structure whose field Param.TransformInput contains the filter parameters
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11 |
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12 | %=======================================================================
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13 | % Copyright 2008-2017, LEGI UMR 5519 / CNRS UGA G-INP, Grenoble, France
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14 | % http://www.legi.grenoble-inp.fr
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15 | % Joel.Sommeria - Joel.Sommeria (A) legi.cnrs.fr
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16 | %
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17 | % This file is part of the toolbox UVMAT.
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18 | %
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19 | % UVMAT is free software; you can redistribute it and/or modify
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20 | % it under the terms of the GNU General Public License as published
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21 | % by the Free Software Foundation; either version 2 of the license,
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22 | % or (at your option) any later version.
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23 | %
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24 | % UVMAT is distributed in the hope that it will be useful,
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25 | % but WITHOUT ANY WARRANTY; without even the implied warranty of
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26 | % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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27 | % GNU General Public License (see LICENSE.txt) for more details.
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28 | %=======================================================================
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29 |
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30 | function DataOut=ima_noise_rms(DataIn,Param)
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31 |
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32 | %% request input parameters
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33 | if isfield(DataIn,'Action') && isfield(DataIn.Action,'RUN') && isequal(DataIn.Action.RUN,0)
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34 | prompt = {'npx';'npy'};
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35 | dlg_title = 'get the filter size in x and y';
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36 | num_lines= 2;
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37 | def = { '20';'20'};
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38 | if isfield(Param,'TransformInput')&&isfield(Param.TransformInput,'FilterBoxSize_x')&&...
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39 | isfield(Param.TransformInput,'FilterBoxSize_y')
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40 | def={num2str(Param.TransformInput.FilterBoxSize_x);num2str(Param.TransformInput.FilterBoxSize_y)};
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41 | end
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42 | answer = inputdlg(prompt,dlg_title,num_lines,def);
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43 | DataOut.TransformInput.FilterBoxSize_x=str2num(answer{1}); %size of the filtering window
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44 | DataOut.TransformInput.FilterBoxSize_y=str2num(answer{2}); %size of the filtering window
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45 | return
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46 | end
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47 |
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48 | DataOut=DataIn; %default
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49 |
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50 | %definition of the cos shape matrix filter
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51 | ix=[1/2-Param.TransformInput.FilterBoxSize_x/2:-1/2+Param.TransformInput.FilterBoxSize_x/2];%
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52 | iy=[1/2-Param.TransformInput.FilterBoxSize_y/2:-1/2+Param.TransformInput.FilterBoxSize_y/2];%
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53 | %del=np/3;
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54 | %fct=exp(-(ix/del).^2);
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55 | fct2_x=cos(ix/((Param.TransformInput.FilterBoxSize_x-1)/2)*pi/2);
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56 | fct2_y=cos(iy/((Param.TransformInput.FilterBoxSize_y-1)/2)*pi/2);
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57 | %Mfiltre=(ones(5,5)/5^2);
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58 | Mfiltre=fct2_y'*fct2_x;
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59 | Mfiltre=Mfiltre/(sum(sum(Mfiltre)));%normalize filter
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60 |
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61 | Atype=class(DataIn.A);% detect integer 8 or 16 bits
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62 | B=filter2(Mfiltre,DataIn.A);
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63 | B(B==0)=1; %set to 1 the zero values
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64 | C=(double(DataIn.A)-B)./B;
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65 | C=filter2(Mfiltre,C.*C);% take variance integrated in the filtering area
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66 | C=1000000*sqrt(C); % take the root and *10^6 to get an image with integer values (parts per million)
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67 | DataOut.A=feval(Atype,C);%transform to the initial image format
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68 |
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69 |
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70 |
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