numpy-discussion

[Numpy-discussion] numarray.nd_image.label() help

[Andrew W. <a_w...@mi...>]

Hello,
    I'm having some trouble with the numarray.nd_image.label() function 
as it is not connecting two objects (that are adjacent) on some images.  
I have tried using the struct:
                   [[1,1,1]
struct  =      [1,1,1]
                     [1,1,1]]

this does change how it is connecting various objects in my image (as 
compared to the default struct) but it still splits the objects 
eventhough they are touching.  Any hints or clues?  I could send the 
pictures, just don't want to post them to the entire list.

    Thanks for your help
       Andrew

Re: [Numpy-discussion] numarray.nd_image.label() help

[Russell E O. <rowen@u.washington.edu>]

At 2:49 PM +0200 2004-06-02, Andrew Wilson wrote:
>Hello,
>    I'm having some trouble with the numarray.nd_image.label() 
>function as it is not connecting two objects (that are adjacent) on 
>some images.  I have tried using the struct:
>                   [[1,1,1]
>struct  =      [1,1,1]
>                     [1,1,1]]
>
>this does change how it is connecting various objects in my image 
>(as compared to the default struct) but it still splits the objects 
>eventhough they are touching.  Any hints or clues?  I could send the 
>pictures, just don't want to post them to the entire list.

I use it and have not (yet) noticed this, so I hope it's something 
you're doing and not a bug.

You could try generating a boolean version of your image, examine 
that to make sure the objects are still adjacent on that and use 
label on it. Here's my code:

   import numarray as num
   # smoothed data is a median-filtered version of my image
   # dataCut is a value above which pixels are considered data
   shapeArry = num.ones((3,3))
   labels, numElts = num.nd_image.label(smoothedData>dataCut, shapeArry)

If this doesn't do it (and nobody has anything better to offer), 
please put the image up somewhere that we can access it and show us 
your code.

-- Russell

Re: [Numpy-discussion] numarray.nd_image.label() help

[Peter V. <ve...@em...>]

Hi Andrew,

If you use the latest release or an older version you may have run into 
a bug that displayed that behaviour. I fixed that in the CVS version, 
so please try to use that if you are not already doing that. If you are 
using the CVS version and still get the problem, please show me the 
smallest possible array that displays the problem, and I will fix it.

Cheers, Peter

On Jun 2, 2004, at 2:49 PM, Andrew Wilson wrote:

> Hello,
>    I'm having some trouble with the numarray.nd_image.label() function 
> as it is not connecting two objects (that are adjacent) on some 
> images.  I have tried using the struct:
>                   [[1,1,1]
> struct  =      [1,1,1]
>                     [1,1,1]]
>
> this does change how it is connecting various objects in my image (as 
> compared to the default struct) but it still splits the objects 
> eventhough they are touching.  Any hints or clues?  I could send the 
> pictures, just don't want to post them to the entire list.

Re: [Numpy-discussion] numarray.nd_image.label() help

[Andrew W. <a_w...@mi...>]

Hi Peter,
    The latest CVS did fix the problem. 
    Thank you very much!
       Andrew

p.s. -- BOOLEAN_BITWISE_NOT  was not defined in 
Src/_ufunc_Boolmodule.c,  so I just commented it out, recompiled and CVS 
worked





Peter Verveer wrote:

> Hi Andrew,
>
> If you use the latest release or an older version you may have run 
> into a bug that displayed that behaviour. I fixed that in the CVS 
> version, so please try to use that if you are not already doing that. 
> If you are using the CVS version and still get the problem, please 
> show me the smallest possible array that displays the problem, and I 
> will fix it.
>
> Cheers, Peter
>
> On Jun 2, 2004, at 2:49 PM, Andrew Wilson wrote:
>
>> Hello,
>>    I'm having some trouble with the numarray.nd_image.label() 
>> function as it is not connecting two objects (that are adjacent) on 
>> some images.  I have tried using the struct:
>>                   [[1,1,1]
>> struct  =      [1,1,1]
>>                     [1,1,1]]
>>
>> this does change how it is connecting various objects in my image (as 
>> compared to the default struct) but it still splits the objects 
>> eventhough they are touching.  Any hints or clues?  I could send the 
>> pictures, just don't want to post them to the entire list.
>
>

Re: [Numpy-discussion] numarray.nd_image.label() help

[Todd M. <jm...@st...>]

On Thu, 2004-06-03 at 04:34, Andrew Wilson wrote:

> p.s. -- BOOLEAN_BITWISE_NOT  was not defined in 
> Src/_ufunc_Boolmodule.c,  so I just commented it out, recompiled and CVS 
> worked

Thanks for the info.  This is fixed now.

Todd