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And that has made all the difference "-Robert Frost

Darker Edges


Captured Image

Last week my friend was in need of her signature in digital format. Fortunately, it was not for any official purpose. So we captured the signature using the camera and used it.

The image that we acquired using the camera was not that much good. So we processed the image and then included in the document.

After this thing happened, I thought of trying the image with MATLAB.
First I adjusted the image intensity using the imadjust function . 
The syntax for the imadjust for rgb image is
imadjust(RGB,[Low_R Low_G Low_B; High_R High G High B],[]);
The Low values should always be lower than High values.
The range of these values between 0 to 1.
After Imadjust

Then I detected the edge of the image. Then to enlarge the image parts I dilated it. Use an appropriate structure element. Here I used 'disk'.
After that, using labeling method, I labeled all the connected components. Based on the size of the components the components where finally used and components whose size are less are ignored.
Edge detected Image

MATLAB CODE:



function my_edge
global filename A I ;
scz=get(0,'ScreenSize');
figure('Position',[round(scz(1,3)/4) round(scz(1,4)/8) 700 500],'MenuBar','None','NumberTitle','off','Name','Pencil sketch Application','Resize','off');
axes('Position',[0 0 .7 1],'xtick',[],'ytick',[]);
Low=uicontrol('Style','slider','Position',[500,280 200 20],'Max',0.99 ,'Min',0,'Value',0.0,'SliderStep',[0.05,0.1],'Callback',@draw);
High=uicontrol('Style','slider','Position',[500,370 200 20],'Max',1,'Min',0.1,'Value',.5,'SliderStep',[0.05,0.1],'Callback',@draw);
uicontrol('Style','pushbutton','String','Done','Position',[500 200 40 20],'Callback',@pushme);
directory=dir('*.jpg');
files={directory.name}';
uicontrol('style','text','Position',[500,310 100 20]','String','Low:');
uicontrol('style','text','Position',[500,395 100 20]','String','High :');
uicontrol('style','text','Position',[500,455 100 20]','String','Filename:');
uicontrol('Style','popupmenu','position',[500 420 160 30],'Value',1,'String',files,'Callback',@displayfile);
    function displayfile(obj,eve)
        ptr=get(obj,'value');
        filename=char(files(ptr));
        A=imread(filename);
        A=imresize(A,0.4);
        subplot('Position',[0.05 0.1 .6 .9]);imshow(A);
    end
    function draw(obj,eve)
        H=get(High,'Value');
        L=get(Low,'Value');
      uicontrol('Style','edit','position',[500 250 50 20],'String',L);
      uicontrol('Style','edit','position',[500 340 50 20],'String',H);
        if( L < H )
            %The intensity values for each R,G,B planes are adjusted.
            I=imadjust(A,[L L L; H H H],[]);
        end
           subplot('Position',[0.05 0.1 .6 .9]);imshow(I);
       end
                                                                                                         
                                                                                        
                                                                                         
                                                                                   
                                                                                    
    function pushme(obj,eve)
        myedges(I);
    end
    function myedges(A)
      
A1=rgb2gray(A);
B=(edge(A(:,:,1))|edge(A(:,:,2))|edge(A(:,:,3)));

Edge detected




SE=strel('disk',3);
C=~(imdilate(B,SE));
target=(ones([size(A1,1) size(A1,2)] ));
[BW,label]=bwlabel(~C,8);
for l=1:max(max(label))
[row, col] = find(BW==l);
if(size(row,1)>30)
for i=1:size(row,1)
    x=row(i,1);
    y=col(i,1);
    target(x,y)=C(x,y);
end
end
end


subplot('Position',[0 0.5 .8 .45]);imshow(A);title('Original Image');
subplot('Position',[0 0   .8 .45]);imshow(target);title('Final Image');
    end
end


Another example:

After Imadjust and edge detection (structuring element:disk Radius=1)


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1 comments:

Shadow said... Reply to comment

Sir please post sobel operator in Java

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