zoom.m

matlab实现双线性插值算法,在界面上实现读取存放缩放图片

%This function is used to room or shrinking an image.
%Function name is imzs.

% -------------------------------------------------------------------
%creat GUI by promgramming,including pushbuttons for zooming/shrinking 
%and getting img-path ,edit text for getting the value of v and h of the
%new img.
function imzs
fh = figure('Position',[100 100 512 512]);
start = uicontrol(fh,'Style','pushbutton','String','START',...
                'Position',[120 15 80 45],...
                'Callback',@zoom_callback);
eth = uicontrol(fh,'Style','edit',...
               'String','enter h value',...
               'Position',[30 40 80 20],...
               'Callback',@edittext_callback);
eth1 = uicontrol(fh,'Style','edit',...
               'String','enter v value',...
               'Position',[30 15 80 20],...
               'Callback',@edit1text_callback);
impath = uicontrol(fh,'Style','pushbutton','String','GET IMG',...
                'Position',[220 15 80 45],...
                'Callback',@get_img_callback);
 
        
% ----------------------------------------------------
% Reseize the img and show it
   function zoom_callback(hObject,eventdata)
       global h v imgpath; 
       sprintf('You moved the slider %d units.',h);
       f = imread(imgpath);
       %fnew = imresize(f,[v h],'bilinear'); 
       [nrows,ncols] = size(f);
        
       %resize the img.
       width = v;                  
       height = h;
       fnew = uint8(zeros(width,height));
       widthScale = nrows/width;
       heightScale = ncols/height;
       for x = 5:width - 5          
            for y = 5:height - 5
                xx = x * widthScale;     
                yy = y * heightScale;
                if (xx/double(uint16(xx)) == 1.0) & (yy/double(uint16(yy)) == 1.0)       
                    fnew(x,y) = f(int16(xx),int16(yy));
                else                         
                    a = double(uint16(xx));        
                    b = double(uint16(yy));
                    x11 = double(I(a,b));                % x11 <- I(a,b)
                    x12 = double(I(a,b+1));              % x12 <- I(a,b+1)
                    x21 = double(I(a+1,b));              % x21 <- I(a+1,b)
                    x22 = double(I(a+1,b+1));            % x22 <- I(a+1,b+1)          
                    fnew(x,y) = uint8( (b+1-yy) * ((xx-a)*x21 + (a+1-xx)*x11) + (yy-b) * ((xx-a)*x22 +(a+1-xx) * x12) );
                end
            end
        end

       figure, imshow(fnew),
       imwrite(fnew,'new.jpg');
   end
% ----------------------------------------------------
% Get the path of the img.
   function get_img_callback(hObject,eventdata)
     global imgpath   
     [FileName,PathName] = uigetfile(' ','Select the image');
     imgpath = strcat(PathName,'\');
     imgpath = strcat(imgpath , FileName);
       
     imshow(imgpath)
   end
% ----------------------------------------------------
% Set the value of the edit text component String 
   function edittext_callback(hObject,eventdata)
      global v;
      v = str2double(get(hObject,'String'));
     
   end
% ----------------------------------------------------
% Set the value of the edit1 text component String
   function edit1text_callback(hObject,eventdata)
      global h;
      h=str2double(get(hObject,'String'));
   end
end