Depending on what the rest of the blobs look like, this may be one way.
% fix the image and return it to what I assume the original size was
[A,map,~] = imread('https://www.mathworks.com/matlabcentral/answers/uploaded_files/974265/image.png');
A = rgb2gray(ind2rgb(A,map))>0.5;
A = imresize(A,[30 30],'nearest');
imshow(A)
% remove foreground pixels which have at least two
% unconnected BG pixels in their 8-neighborhood
B = ~bwmorph(~A,'bridge');
imshow(B)
