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Thread Subject:
image vision

Subject: image vision

From: imagevision

Date: 2 Aug, 2011 09:07:09

Message: 1 of 4


Hi everybody,
I am trying to detect objects in the following image
http://imageshack.us/f/26/example2q.png/
As a beginner i started as followings:
a=imread('example2q.png');
% a is image now
imshow(a,[])
% it is clear to see dark objects
 bw = im2bw(a);
imshow(bw)
% gives me something which is not required
%%%%%%%%%%%%%%%%%%%%%
% even following is not helpful
bw = im2bw(a, graythresh(a));
imshow(bw)
%
Please guide
1) how to get bw-image ?
2) i actually want to detect small (dark) objects in the image-a
Thanks in advance
A beginner in image process:
Image Visionary.

Subject: image vision

From: Image Analyst

Date: 2 Aug, 2011 11:19:09

Message: 2 of 4

You can't use a global threshold for this image because the background varies too much. Try using CLAHE first by calling adapthisteq().

Subject: image vision

From: imagevision

Date: 2 Aug, 2011 12:14:08

Message: 3 of 4

"Image Analyst" wrote in message <j18mfd$le7$1@newscl01ah.mathworks.com>...
> You can't use a global threshold for this image because the background varies too much. Try using CLAHE first by calling adapthisteq().


HI,
Thanks Image Analyst,

i tried this example
%I = imread('tire.tif');
%A = adapthisteq(I,'clipLimit',0.02,'Distribution','rayleigh');

A = adapthisteq(a,'clipLimit',0.02,'Distribution','rayleigh');

however
imshow(A) or imshow(im2bw(A))
is still problem. May be i need some other 'function' or other settings?
Please guide.
regards,
Image Visionary

Subject: image vision

From: imagevision

Date: 4 Aug, 2011 20:36:11

Message: 4 of 4


Hi,
I am still sure, there will be one solution to my problem. Could any one please suggest some hint or solution?
thanks
regards,
Image vision

"imagevision" wrote in message <j18ent$1br$1@newscl01ah.mathworks.com>...
>

Hi everybody,
I am trying to detect objects in the following image
http://imageshack.us/f/26/example2q.png/
As a beginner i started as followings:
a=imread('example2q.png');
 a is image now
 imshow(a,[])
> % it is clear to see dark objects
> bw = im2bw(a);
> imshow(bw)
> % gives me something which is not required
> %%%%%%%%%%%%%%%%%%%%%
> % even following is not helpful
> bw = im2bw(a, graythresh(a));
> imshow(bw)
> %
> Please guide
> 1) how to get bw-image ?
> 2) i actually want to detect small (dark) objects in the image-a
> Thanks in advance
> A beginner in image process:
> Image Visionary.

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