區分正常和不規則形狀的斑點

Question

我有一組連接的斑點，我想區分更規則的（a,c和d）與更不規則的區域，如b。

我嘗試過使用卷積區域（在blob_area/convolved_blob_area上設置閾值），shape factor and roundness，但沒有一個可以很好地區分d和香蕉形狀。你會建議使用哪些參數？謝謝！那我腦子裏浮現

Answer 1

一個想法是，你可以使用number of corners每size of blob確定regularity/irregularity。測試結果似乎也符合我們的假設。下面的代碼 -

im = imread(input_image_path); 
bw= im2bw(im); 

%// Parameter for cutting into four slices into the third dimsensions 
%// corresponding to the four objects 
common_width = 270; 

%// Threshold to decide between regular and irregular ones 
factor1_th = 0.01; 

bw1 = bw(:,1:common_width*floor(size(bw,2)/common_width)); %// Cropped image 
objs =reshape(bw1,size(bw1,1),common_width,[]);%//Objects stored as dim3 slices 
for objc=1:size(objs,3) %// Object counter 
    disp(['-------------- Processing Obj #' num2str(objc)]); 
    obj = objs(:,:,objc); 
    corners = corner(obj); 
    factor1 = size(corners,1)/nnz(obj) 
    if factor1 > factor1_th 
     disp('This is an irregular one.'); %//' 
    else 
     disp('This is a regular one.'); %//' 
    end 
end 

輸出 -

-------------- Processing Obj #1 
factor1 = 
    0.0050 
This is a regular one. 
-------------- Processing Obj #2 
factor1 = 
    0.0109 
This is an irregular one. 
-------------- Processing Obj #3 
factor1 = 
    0.0052 
This is a regular one. 
-------------- Processing Obj #4 
factor1 = 
    0.0078 
This is a regular one. 

如果有人有興趣運行的代碼，這裏有A，B，C，D去除的符號輸入圖像 -

鏈接 - http://i.stack.imgur.com/uPpUU.jpg