Join dots in binary image.

Download the attached image (sc.png), which is the binary image you posted on your question, and move it to the folder your working on, save this first chunk of code as removeBlob.m

   function removeBlob
   I=imread('sc.png');  
   I = im2bw(I);
   I = bwlabel(imfill(I>0,'holes'));
%  I = bwlabel(imfill(imread('sc.png')>100,'holes'));
  h = imshow(label2rgb(I,jet(numel(unique(I(:)))),[0 0 0]));
  set(h,'buttondownfcn',{@removeIt,I})
    end
function removeIt(src,~,I)
cp = round(get(get(src,'parent'),'currentpoint'));
val = I(cp(3),cp(1));
I(I==val) = 0;
set(src,'cdata',bsxfun(@times,uint8(logical(I)),get(src,'cdata')));
figure
imshow(I)
save new_I.mat I 
end

finally execute the last chunk of code

removeBlob()
new_I=load('new_I.mat');
new_I=new_I.I;
imshow(new_I)

You should select the blob you want to delete and get this output:

About joining the steam blobs I am not quite sure, as I have tried bwmorph and imclose functions but not getting the desired result as I got this result...

SE = strel('rectangle',[100 40])
closeBW = imclose(new_I,SE);
imshow(closeBW)

Maybe you could try with Image Analyst demo tu burn lines in the image in order to fill the blank spaces, see answer of this post:

https://es.mathworks.com/matlabcentral/answers/292308-binary-image-morphological-operation-for-complete-broken-lines

Guillaume 2018-5-3

编辑：Guillaume 2018-5-3

在 MATLAB Online 中打开

getting this error!

And the error message explains clearly what the problem is:

Expected input number 2 to match one of these values:
'holes'
The input, 'holes ' did not match any of the valid values
Error in removeBlob
I = bwlabel(imfill(I>0, 'holes '));