%提取圖像中的圓形特征
%%?Identifying?Round?objects
%?Your?goal?is?to?classify?objects?based?on?their?roundness?using
%?|bwboundaries|?a?boundary?tracing?routine.
%
%?Copyright?1993-2005?The?MathWorks?Inc.?
%?$Revision:?1.1.6.3?$??$Date:?2005/12/12?23:21:52?$
%

%%?Step?1:?Read?Image
%?Read?in?|pills_etc.png|.

RGB?=?imread（‘test.bmp‘）;
imshow（RGB）;
hold?on

%%?Step?2:?Threshold?the?Image
%?Convert?the?image?to?black?and?white?in?order?to?prepare?for
%?boundary?tracing?using?|bwboundaries|.

I?=?rgb2gray（RGB）;
threshold?=?graythresh（I）;
bw?=?im2bw（Ithreshold）;
figure;
imshow（bw）

%%?Step?3:?Remove?the?Noise
%?Using?morphology?functions?remove?pixels?which?do?not?belong?to?the
%?objects?of?interest.

%?remove?all?object?containing?fewer?than?30?pixels
bw?=?bwareaopen（bw10）;

%?fill?a?gap?in?the?pen‘s?cap
se?=?strel（‘disk‘2）;
figure;

bw?=?imclose（bwse）;

%?fill?any?holes?so?that?regionprops?can?be?used?to?estimate
%?the?area?enclosed?by?each?of?the?boundaries
bw?=?imfill（bw‘holes‘）;
imshow（bw）


%%?Step?4:?Find?the?Boundaries
%?Concentrate?only?on?the?exterior?boundaries.??Option?‘noholes‘?will
%?accelerate?the?processing?by?preventing?|bwboundaries|?from?searching?
%?for?inner?contours.

[BL]?=?bwboundaries（bw‘noholes‘）;

%?Display?the?label?matrix?and?draw?each?boundary
figure;
imshow（label2rgb（L?@jet?[.5?.5?.5]））
hold?on
figure;
for?k?=?1:length（B）
??boundary?=?B{k};
??plot（boundary（:2）?boundary（:1）?‘w‘?‘LineWidth‘?2）
end

%%?Step?5:?Determine?which?objects?are?Round
%?Estimate?each?