| Re: Automatic Segmentation of a region [message #29578] |
Wed, 06 March 2002 19:54  |
idlfreak
Messages: 47
Registered: October 2001
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Member |
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hi,
sorry abt that question. I figured out the function of max_subscript
and there was some small problem in the logic and i fixed it. Sorry
abt this question.
cheers
Akhila
idlfreak@yahoo.com (Akhila) wrote in message news:<b1ad7b05.0203061408.5a5ae0ea@posting.google.com>...
> 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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