【图像检测】教室人数统计系统matlab源码

 

一.最基本两个形态学运算----膨胀与腐蚀

 

啥叫形态学操作

形态学操作其实就是改变物体的形状，比如腐蚀就是”变瘦”，膨胀就是”变胖”，看下图就明白了：

（http://ex2tron.wang/opencv-python-erode-and-dilate/）

 

经验之谈：形态学操作一般作用于二值化图，来连接相邻的元素或分离成独立的元素。腐蚀和膨胀是针对图片中的白色（即前景）部分！

开/闭运算

先腐蚀后膨胀叫开运算（因为先腐蚀会分开物体，这样容易记住），其作用是：分离物体，消除小区域。

经验之谈：很多人对开闭运算的作用不是很清楚，但看上图↑，不用怕：如果我们的目标物体外面有很多无关的小区域，就用开运算去除掉；如果物体内部有很多小黑洞，就用闭运算填充掉。

为什么有了膨胀腐蚀还要开运算闭运算呢？其实开闭运算最重要的一点就是，可以保持物体原有大小。然后一个是消除物体内部孔洞的另一个是增强物体之间连接点的。

其他形态学操作

• 形态学梯度：膨胀图减去腐蚀图，dilation - erosion，这样会得到物体的轮廓：

 

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膨胀与腐蚀能够实现以下作用：

   1.消除噪声

   2.分割出独立的图像元素，在图像中连接相邻的元素

   3.寻找图像中的明显的极大值区域或者极小值区域

   4.求出图像的梯度

需要注意之处： 腐蚀和膨胀都是对图像的白色部分(高亮部分)而言。膨胀是图像中的高亮部分进行膨胀，类似于领域扩张，效果图拥有比原图更大的高亮区域；腐蚀是原图的高亮部分被腐蚀，类似于领域被蚕食，效果图拥有比原图更小的高亮区域。

从数学的角度来说，膨胀和腐蚀操作就是将图像与核进行卷积，核可以是任意形状和大小的。

膨胀到底是怎么实现的呢？求局部最大值。

原图与核进行卷积，将最大值赋予指定像素，从而使亮者更亮，效果就是亮的区域膨胀了。

再讲腐蚀（Erosion）：

操作与膨胀相反，求局部最小值。

可以理解为，移动结构B（核），如果结构B与结构A的交集完全属于结构A的区域内，则保存该位置点，所有满足条件的点构成结构A被结构B腐蚀的结果。

A被腐蚀后的结果貌似不对，好像应该是这样的：

 

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se_diamond =strel('diamond',4)创建一个菱形的结构元素，4是从结构化元素原点到其点的距离，必须为非负整数。

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

% Last Modified by GUIDE v2.5 13-A-2021 12:23:11

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @face_collection_OpeningFcn, ...
                   'gui_OutputFcn',  @face_collection_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 face_collection is made visible.
function face_collection_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 face_collection (see VARARGIN)

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

% Update handles structure
guidata(hObject, handles);

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


% --- Outputs from this function are returned to the command line.
function varargout = face_collection_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;


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

% --- 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)
global I
[x,y,c]=ginput(2);
if c==1
    BB=imcrop(I,[min(x(1),x(2)),min(y(1),y(2)),abs(x(2)-x(1)),abs(y(2)-y(1))]);
    BB=imresize(BB,[252 202]);
    axes(handles.axes2); % 处理后的图像放在axes2中
    imshow(BB)
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


% --- 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)
[filename, pathname] = uigetfile( ...
{'*.jpg;*.png;*.jpeg', 'Image Files (*.bmp;*.jpg;*.png;*.jpeg)'; ...
'*.*', 'All Files (*.*)'}, ...
'Pick an image');
if isequal(filename,0) || isequal(pathname,0),
return;
end
fpath=[pathname filename];      %将文件名和目录名组合成一个完整的路径
img=imread(fpath);
axes(handles.axes1)
imshow(img)
title('教室照片')