【图像压缩】基于matlab GUI DCT图像无损压缩【含Matlab源码 726期】
一、简介
基于matlab GUI图像无损压缩，提高图像压缩比；
DCT又称离散余弦变换，是一种块变换方式，只使用余弦函数来表达信号，与傅里叶变换紧密相关。常用于图像数据的压缩，通过将图像分成大小相等（一般为8*8）的块，利用DCT对其进行变换，得到更加简洁的数据。因为图像像素间存在较大的空间相关性，DCT可以大大减小这些相关性，使图像能量集中在左上角区域，从而利于数据压缩。变换后得到的数据称为DCT系数。这一过程是无损的。
二维DCT变换
这里来看看二维DCT变换的公式：
二、源代码
function varargout = ImageCompression1(varargin)
% IMAGECOMPRESSION1 MATLAB code for ImageCompression1.fig
% IMAGECOMPRESSION1, by itself, creates a new IMAGECOMPRESSION1 or raises the existing
% singleton*.
%
% H = IMAGECOMPRESSION1 returns the handle to a new IMAGECOMPRESSION1 or the handle to
% the existing singleton*.
%
% IMAGECOMPRESSION1('CALLBACK',hObject,eventData,handles,...) calls the local
% function named CALLBACK in IMAGECOMPRESSION1.M with the given input arguments.
%
% IMAGECOMPRESSION1('Property','Value',...) creates a new IMAGECOMPRESSION1 or raises the
% existing singleton*. Starting from the left, property value pairs are
% applied to the GUI before ImageCompression1_OpeningFcn gets called. An
% unrecognized property name or invalid value makes property application
% stop. All inputs are passed to ImageCompression1_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 ImageCompression1
% Last Modified by GUIDE v2.5 15-Oct-2014 22:20:56
% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name', mfilename, ...
'gui_Singleton', gui_Singleton, ...
'gui_OpeningFcn', @ImageCompression1_OpeningFcn, ...
'gui_OutputFcn', @ImageCompression1_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 ImageCompression1 is made visible.
function ImageCompression1_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 ImageCompression1 (see VARARGIN)
% Choose default command line output for ImageCompression1
handles.output = hObject;
% Update handles structure
guidata(hObject, handles);
guidata(hObject, handles);
set(handles.axes1,'visible','off')
set(handles.axes2,'visible','off')
axis off
axis off
% UIWAIT makes ImageCompression1 wait for user response (see UIRESUME)
% uiwait(handles.figure1);
% --- Outputs from this function are returned to the command line.
function varargout = ImageCompression1_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)
global file_name;
%guidata(hObject,handles)
file_name=uigetfile({
'*.bmp;*.jpg;*.png;*.tiff;';'*.*'},'Select an Image File');
fileinfo = dir(file_name);
SIZE = fileinfo.bytes;
Size = SIZE/1024;
set(handles.text7,'string',Size);
imshow(file_name,'Parent', handles.axes1)
% --- 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)
% 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)
global file_name;
if(~ischar(file_name))
errordlg('Please select Images first');
else
I1 = imread(file_name);
% I1 = imread('chicken.jpg');
I = I1(:,:,1);
I = im2double(I);
T = dctmtx(8);
B = blkproc(I,[8 8],'P1*x*P2',T,T');
mask = [1 1 1 1 0 0 0 0
1 1 1 0 0 0 0 0
1 1 0 0 0 0 0 0
1 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0];
B2 = blkproc(B,[8 8],'P1.*x',mask);
I2 = blkproc(B2,[8 8],'P1*x*P2',T',T);
I = I1(:,:,2);
I = im2double(I);
T = dctmtx(8);
B = blkproc(I,[8 8],'P1*x*P2',T,T');
mask = [1 1 1 1 0 0 0 0
1 1 1 0 0 0 0 0
1 1 0 0 0 0 0 0
1 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0];
B2 = blkproc(B,[8 8],'P1.*x',mask);
I3 = blkproc(B2,[8 8],'P1*x*P2',T',T);
I = I1(:,:,3);
I = im2double(I);
T = dctmtx(8);
B = blkproc(I,[8 8],'P1*x*P2',T,T');
mask = [1 1 1 1 0 0 0 0
1 1 1 0 0 0 0 0
1 1 0 0 0 0 0 0
1 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0];
B2 = blkproc(B,[8 8],'P1.*x',mask);
I4 = blkproc(B2,[8 8],'P1*x*P2',T',T);
三、运行结果
四、备注
完整代码或者代写添加QQ 1564658423