| Re: Automatic Segmentation of a region [message #29579 is a reply to message #29578] |
Wed, 06 March 2002 14:08   |
idlfreak
Messages: 47
Registered: October 2001
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Member |
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HI,
Thanx for the help Martin Downing. But i'm not able to understand
the function of max_subscript. When i'm plotting a histogram for the
image i have, the max region is the outer black. But i don't want that
and i want the second highest region.
So i tried this command:
Histo = Histogram(image, min = 0, binsize = 1)
max_area = max(Histo(Where(Histo lt 150000)), max_label)
imagefin = image eq max_label
tv, imagefin
There's no image. I ahve no idea why. But the max region i get now is
the one that i want. Please help me with this and tell me what
max_subscript does.
Thank you in advance for ur help and time.
Cheers,
Akhila.
hradilv.nospam@yahoo.com (Vince) wrote in message news:<3c84d7c2.602066575@news>...
> On Mon, 4 Mar 2002 13:59:39 -0000, "Martin Downing"
> <martin.downing@ntlworld.com> wrote:
>
>>
>> "Akhila" <idlfreak@yahoo.com> wrote in message
>> news:b1ad7b05.0203031342.226685ea@posting.google.com...
>>> Hi,
>>> I have a small problem in segmentation. I first threshold a image and
>>> then i perform morphological operations on the binary image. Using
>>> label_regions i've identified all the blobs. I used the where function
>>> to get the regions in each blob. I have one huge blob and the rest are
>>> small. I want to make all the pixels in the small blob as 0.
>>> I tried the following:
>>>
>>> Method1:
>>>
>>> im = Origimage and morphimage
>>> tv,image
>>>
>>
>> I havent a clue how this would be what you want, try adding a comment to say
>> what it should be doing
>>
>>> Method 2:
>>>
>>> for j = 1, noofblobs do begin
>>> region = Where (morphimage eq j)
>>> Area = n_elements(region)
>>> if (Area le 80000) then begin
>>> morphimage[region] = 0B
>>> endif
>>> endfor
>>>
> refering also to:
>>> ... I have one huge blob and the rest are
>>> small. I want to make all the pixels in the small blob as 0.
>>
>> or to put it another way, you want everything but the large blob to be 0,
>> and the large blob set to 1?
>> this method is taken from working code
>> ==============================
>> ; threshold_image could be from an segmentation routine
>> ;e.g.: threshold_image = image LT 100b
>>
>> label_im = label_region1(threshold_image)
>>
>> ; use histogram to count area of each labeled region (blob)
>> area = histogram(label_im, min=0, binsize = 1))
>>
>> ; if you want just the blob of maximum area:
>> max_area = max(area,max_label)
>>
>> ; now create a binary mask of the biggest blob
>> big_blob = label_im eq max_label
>>
>> ; and display it
>> tvscl, big_blob
>
> I suspect that using tvscl (instead of tv) is the crux of the
> problem?
>
>> ======================
>>
>> hope this help you,
>>
>> cheers
>>
>> Martin
>>
>>
>> ----------------------------------------
>> Martin Downing,
>> Clinical Research Physicist,
>> Grampian Orthopaedic RSA Research Centre,
>> Woodend Hospital, Aberdeen, AB15 6LS.
>>
>>
>>
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