[Insight-users] offset of a curve using level sets

[Juan Cardelino]

Hey Kishore,

No, I intended to take that into account.
Actually, the 10 pixels was an example, I originally intended to move
the curve outwards a fixed amount of euclidean distance. But if I
could live with that aproximation too.
I'm segmenting a sequence and I want to use the segmentation of the
previous frame as initial condition for the next, so actually I don't
care doing a rough approximation
Thanks

On Thu, Feb 3, 2011 at 4:27 PM, Kishore Mosaliganti
<kishoreraom at gmail.com> wrote:
> Hi Juan,
>
> For moving exactly 10 pixels, are you thinking of ignoring different
> pixel widths in diagonal neighbors and face neighbors at a given pixel
> ?
>
> Kishore
>
>
> On Thu, Feb 3, 2011 at 12:05 PM, Juan Cardelino
> <juan.cardelino at gmail.com> wrote:
>> I want to perform a very simple task: I have a curve represented as
>> the level set of an implicit function (coming from a level set
>> segmentation algorithm) and I want to inflate (or deflate) it a
>> certain amoun. Lets say 10 pixels from the original location. As I'm
>> used to work with full level sets, I usually substract 10 pixels from
>> the implicit function. For that you need the full implicit function.
>> As in ITK we use only a band near the level set, that won't work for
>> sure.
>> All the alternatives I'm thinking seem to be somehow complicated:
>>
>> 1) compute the zero contour and use fastmarching (signed) on the it,
>> then cut  this distance function at the desired level.
>> 2) evolve the level set function with a constant curvature dependent
>> speed, until it advances the desired amount of pixels
>>
>> I'm just wondering if there is anything already built in ITK.
>> Thanks in advance.
>> Regards,
>>       Juan
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>