[vtkusers] Curve growing

[Dominik Szczerba]

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Have a go at active contours, distance/curvature energy minimization
etc. Sethian/Osher, level sets and derivatives. (if I am not mistaken
ITK has most of these wonders)
- --ds

Anja Ende wrote:
> Hi everyone,
> 
> This is not a VTK question per se, but I am hoping some algorithm
> experts can help me here.
> 
> I am a curve defined by a set of floating point numbers. So each x, y
> pair descrives a curve and the curve is created by simple joining these
> point pairs.
> 
> Now, my probem is that the curve should snap to each pixel that it touches.
> 
> So, if we consider the x part of the coordinates... then the points
> lying on the "left side" of the curve should round off to the lower
> value...
> 
> So, if you have x value like 63.5 on the lft side, it should becomne 63.0.
> 
> and if you have points on the "right side" of the curve, it should round
> off to the upper value...
> 
> So, if you have value like 130.5 on the right side, it should become 131.0
> 
> Similar logic should follow for the y values.
> 
> My initial idea was to increment/decrement the values by 1.0 and see if
> that pixel lies in my region. If the pixel to the right lies in thr
> region, then I take the floow of the value, else I take the ceiling.
> 
> This worked for most of ther curves but every now and then I come across
> curves that act not int he way I want.
> 
> I was wondering if there is an algorithm for growing a curve so that it
> snaps to the touched pixel...
> 
> Thanks for any help you might give me here. I would really appreciate it.
> 
> 
> Cheers,
> 
> Anja
> 
> 
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