How to find Negative of Image in Matlab

How to find Negative of Image in Matlab

A negative is an image in which the lightest areas of the photographed subject appear darkest and the darkest areas appear lightest. This reversed order occurs because the extremely light-sensitive chemicals a camera film must use to capture an image quickly enough for ordinary picture-taking are darkened.

Basically, In the Negative image, we subtract each value of the pixel from the maximum value in Image.

Follow these steps to make Program for conversion of Color Image to Gray Level Image without Matlab built-in function with GUI

  1. Run Matlab, First window you will get something like below
Matlab Main Window
Matlab Main Window

2. Type “guide” in command window, “GUIDE Quick Start” window will appear

3. Select “Blank GUI (Default)” and press Okay, see in below picture

GUI in matalb
GUI in Matlab

4. In GUI window select “Static Text”  from left sidebar then double click on “Static Text”

5. “Inspector window” will appear, Type your desired Text in String Field

6. Then drag a “Button” from sidebar and Rewrite desired text, GUI will look like below picture

GUI: Negative Image
GUI: Negative Image

7. Save GUI with “Ctrl + S” then write code for color to grayscale conversion after pushbutton1_Callback

function varargout = GUI(varargin)
% GUI MATLAB code for GUI.fig
% GUI, by itself, creates a new GUI or raises the existing
% singleton*.
%
% H = GUI returns the handle to a new GUI or the handle to
% the existing singleton*.
%
% GUI(‘CALLBACK’,hObject,eventData,handles,…) calls the local
% function named CALLBACK in GUI.M with the given input arguments.
%
% GUI(‘Property’,’Value’,…) creates a new GUI or raises the
% existing singleton*. Starting from the left, property value pairs are
% applied to the GUI before GUI_OpeningFcn gets called. An
% unrecognized property name or invalid value makes property application
% stop. All inputs are passed to GUI_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 GUI

% Last Modified by GUIDE v2.5 22-Apr-2017 21:46:45

% Begin initialization code – DO NOT EDIT
gui_Singleton = 1;
gui_State = struct(‘gui_Name’, mfilename, …
‘gui_Singleton’, gui_Singleton, …
‘gui_OpeningFcn’, @GUI_OpeningFcn, …
‘gui_OutputFcn’, @GUI_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 GUI is made visible.
function GUI_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 GUI (see VARARGIN)

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

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes GUI wait for user response (see UIRESUME)
% uiwait(handles.figure1);
% — Outputs from this function are returned to the command line.
function varargout = GUI_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)
[Filename, Path] = uigetfile({‘*.*’},’File Selector’);
FullFilePath = strcat(Path,Filename);
Matrix = imread(FullFilePath);
processedMatrix = Matrix;
[width, height, d] = size(Matrix);
[value, index] = max(Matrix,[],2);
MaxValue = max(max(value));

for col = 1 : 1 : width
for row = 1 :1 : height
processedMatrix(row,col) = MaxValue – Matrix(row,col);
end
end
figure,imshow(Matrix),title(‘Original Image’);
figure,imshow(processedMatrix),title(‘Processed Image’);

Input Image:

Gray Level Image
Gray Level Image

Processed Image:

 

NegativeImage.PNG
Negative Image

 

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