Mean Square Error (MSE), Root Mean Squared Error (RMSE), dan Peak Signal-to-Noise Ratio (PSNR) merupakan contoh parameter yang biasa digunakan sebagai indikator untuk mengukur kemiripan dua buah citra. Parameter tsb sering digunakan untuk membandingkan hasil pengolahan citra dengan citra awal atau citra asli. Persamaan yang digunakan untuk menghitung ketiga paramater tersebut adalah sebagai berikut:

MSE dan RMSE tidak memiliki satuan sedangkan satuan dari PSNR adalah desibel. Semakin mirip kedua citra maka nilai MSE dan RMSE nya semakin mendekati nilai nol. Sedangkan pada PSNR, dua buah citra dikatakan memiliki tingkat kemiripan yang rendah jika nilai PSNR di bawah 30 dB.

Berikut ini merupakan contoh pemrograman GUI matlab untuk menghitung nilai MSE, RMSE, dan PSNR. Ketiga nilai tersebut digunakan untuk menghitung tingkat kemiripan citra yang terkontaminasi derau/noise dengan citra asli dan citra hasil restorasi dengan citra asli. Derau aditif ditambahkan pada citra asli antara lain adalah derau impuls (salt & pepper), derau uniform, derau gaussian, dan derau rayleigh. Sedangkan filter yang digunakan untuk merestorasi citra antara lain adalah filter rata-rata dan filter median masing-masing menggunakan kernel berukuran 3 x 3 dan 5 x 5.

1. Tampilan Menu GUI

2. Buka Citra Grayscale Asli

3. Penambahan Derau Impuls dan filtering menggunakan filter rata-rata 3 x 3

4. Penambahan Derau Impuls dan filtering menggunakan filter median 5 x 5

5. Penambahan Derau Uniform dan filtering menggunakan filter rata-rata 5 x 5

6. Penambahan Derau Gaussian dan filtering menggunakan filter median 3 x 3

7. Penambahan Derau Rayleigh dan filtering menggunakan filter rata-rata 3 x 3

Tampilan source code nya adalah sebagai berikut:

function varargout = restorasi_citra_dengan_parameter(varargin)
% RESTORASI_CITRA_DENGAN_PARAMETER MATLAB code for restorasi_citra_dengan_parameter.fig
%      RESTORASI_CITRA_DENGAN_PARAMETER, by itself, creates a new RESTORASI_CITRA_DENGAN_PARAMETER or raises the existing
%      singleton*.
%
%      H = RESTORASI_CITRA_DENGAN_PARAMETER returns the handle to a new RESTORASI_CITRA_DENGAN_PARAMETER or the handle to
%      the existing singleton*.
%
%      RESTORASI_CITRA_DENGAN_PARAMETER('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in RESTORASI_CITRA_DENGAN_PARAMETER.M with the given input arguments.
%
%      RESTORASI_CITRA_DENGAN_PARAMETER('Property','Value',...) creates a new RESTORASI_CITRA_DENGAN_PARAMETER or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before restorasi_citra_dengan_parameter_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to restorasi_citra_dengan_parameter_OpeningFcn via varargin.
%
%      *See GUI Options on GUIDE's Tools menu.  Choose "GUI allows only one
%      instance to run (singleton)".
%
% See also: GUIDE, GUIDATA, GUIHANDLES

% Edit the above text to modify the response to help restorasi_citra_dengan_parameter

% Last Modified by GUIDE v2.5 02-Jun-2017 20:30:35

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
    'gui_Singleton',  gui_Singleton, ...
    'gui_OpeningFcn', @restorasi_citra_dengan_parameter_OpeningFcn, ...
    'gui_OutputFcn',  @restorasi_citra_dengan_parameter_OutputFcn, ...
    'gui_LayoutFcn',  [] , ...
    'gui_Callback',   []);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT

% --- Executes just before restorasi_citra_dengan_parameter is made visible.
function restorasi_citra_dengan_parameter_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to restorasi_citra_dengan_parameter (see VARARGIN)

% Choose default command line output for restorasi_citra_dengan_parameter
handles.output = hObject;

% Update handles structure
guidata(hObject, handles);
movegui(hObject,'center');

% UIWAIT makes restorasi_citra_dengan_parameter wait for user response (see UIRESUME)
% uiwait(handles.figure1);

% --- Outputs from this function are returned to the command line.
function varargout = restorasi_citra_dengan_parameter_OutputFcn(hObject, eventdata, handles)
% varargout  cell array for returning output args (see VARARGOUT);
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure
varargout{1} = handles.output;

% --- Executes on button press in pushbutton1.
function pushbutton1_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
try
    [filename,pathname] = uigetfile({'*.*'});

    if ~isequal(filename,0)
        axes(handles.axes1)
        cla reset
        set(gca,'XTick',[])
        set(gca,'YTick',[])

        axes(handles.axes2)
        cla reset
        set(gca,'XTick',[])
        set(gca,'YTick',[])

        axes(handles.axes3)
        cla reset
        set(gca,'XTick',[])
        set(gca,'YTick',[])

        set(handles.edit1,'String','')
        set(handles.edit2,'String','')
        set(handles.edit3,'String','')
        set(handles.edit4,'String','')
        set(handles.edit5,'String','')
        set(handles.edit6,'String','')

        Img = imread(fullfile(pathname,filename));
        axes(handles.axes1)
        imshow(Img)
        title('Citra Grayscale Asli')
        handles.Img = Img;
        guidata(hObject, handles)
    else
        return
    end
catch
end

% --- Executes on selection change in popupmenu1.
function popupmenu1_Callback(hObject, eventdata, handles)
% hObject    handle to popupmenu1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: contents = cellstr(get(hObject,'String')) returns popupmenu1 contents as cell array
%        contents{get(hObject,'Value')} returns selected item from popupmenu1

% --- Executes during object creation, after setting all properties.
function popupmenu1_CreateFcn(hObject, eventdata, handles)
% hObject    handle to popupmenu1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: popupmenu controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end

% --- Executes on selection change in popupmenu2.
function popupmenu2_Callback(hObject, eventdata, handles)
% hObject    handle to popupmenu2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: contents = cellstr(get(hObject,'String')) returns popupmenu2 contents as cell array
%        contents{get(hObject,'Value')} returns selected item from popupmenu2

% --- Executes during object creation, after setting all properties.
function popupmenu2_CreateFcn(hObject, eventdata, handles)
% hObject    handle to popupmenu2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: popupmenu controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end

% --- Executes on button press in pushbutton2.
function pushbutton2_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
try
    Img = handles.Img;
    [row,col,~] = size(Img);

    val1 = get(handles.popupmenu1,'Value');

    switch val1
        case 1
            Img_noise = imnoise(Img,'salt & pepper',0.2);
        case 2
            Img_noise = Img+60*rand(row,col);
        case 3
            Img_noise = Img+10*randn(row,col);
        case 4
            Img_noise = Img+raylrnd(20,row,col);
    end

    axes(handles.axes2)
    imshow(Img_noise)
    title('Citra Terkontaminasi Noise')

    MSE = sum((Img-Img_noise)^2)/(row*col);
    RMSE = sqrt(MSE);
    PSNR = 10*log(256*256/MSE);

    set(handles.edit1,'String',MSE)
    set(handles.edit2,'String',RMSE)
    set(handles.edit3,'String',PSNR)

    val2 = get(handles.popupmenu2,'Value');

    switch val2
        case 1
            Img_filter = imfilter(Img_noise,ones(3)/9);
        case 2
            Img_filter = imfilter(Img_noise,ones(5)/25);
        case 3
            Img_filter = medfilt(Img_noise,[3 3]);
        case 4
            Img_filter = medfilt(Img_noise,[5 5]);
    end

    axes(handles.axes3)
    imshow(Img_filter)
    title('Citra Hasil Restorasi')

    MSE = sum((Img-Img_filter)^2)/(row*col);
    RMSE = sqrt(MSE);
    PSNR = 10*log(256*256/MSE);

    set(handles.edit4,'String',MSE)
    set(handles.edit5,'String',RMSE)
    set(handles.edit6,'String',PSNR)
catch
end
function edit4_Callback(hObject, eventdata, handles)
% hObject    handle to edit4 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of edit4 as text
%        str2double(get(hObject,'String')) returns contents of edit4 as a double

% --- Executes during object creation, after setting all properties.
function edit4_CreateFcn(hObject, eventdata, handles)
% hObject    handle to edit4 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end

function edit5_Callback(hObject, eventdata, handles)
% hObject    handle to edit5 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of edit5 as text
%        str2double(get(hObject,'String')) returns contents of edit5 as a double

% --- Executes during object creation, after setting all properties.
function edit5_CreateFcn(hObject, eventdata, handles)
% hObject    handle to edit5 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end

function edit6_Callback(hObject, eventdata, handles)
% hObject    handle to edit6 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of edit6 as text
%        str2double(get(hObject,'String')) returns contents of edit6 as a double

% --- Executes during object creation, after setting all properties.
function edit6_CreateFcn(hObject, eventdata, handles)
% hObject    handle to edit6 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end

function edit1_Callback(hObject, eventdata, handles)
% hObject    handle to edit1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of edit1 as text
%        str2double(get(hObject,'String')) returns contents of edit1 as a double

% --- Executes during object creation, after setting all properties.
function edit1_CreateFcn(hObject, eventdata, handles)
% hObject    handle to edit1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end

function edit2_Callback(hObject, eventdata, handles)
% hObject    handle to edit2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of edit2 as text
%        str2double(get(hObject,'String')) returns contents of edit2 as a double

% --- Executes during object creation, after setting all properties.
function edit2_CreateFcn(hObject, eventdata, handles)
% hObject    handle to edit2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end

function edit3_Callback(hObject, eventdata, handles)
% hObject    handle to edit3 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of edit3 as text
%        str2double(get(hObject,'String')) returns contents of edit3 as a double

% --- Executes during object creation, after setting all properties.
function edit3_CreateFcn(hObject, eventdata, handles)
% hObject    handle to edit3 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end

File source code lengkap beserta citra pada pemrograman di atas dapat diperoleh melalui halaman berikut ini: Source Code

Tutorial mengenai pembuatan App Designer MATLAB untuk restorasi citra digital dapat dilihat pada video berikut ini: