[Insight-users] GradientImageFilter vs GradientRecursiveGaussianImageFilter
Pieter Vos
pieterv@radiology.azn.nl
Thu, 25 Apr 2002 11:54:35 +0200 (CEST)
Hello,
I compaired the outputs of the filter GradientImageFilter and the
GradientRecursiveGaussianImageFilter.
Both filters had the same 3D image: a black image with a white spot in the
middle. The vectoroutputs however, where not the same:
The vectors of the GradientImageFilter where pointing away form the spot.
------------------
|
| ^
| |
| <- ->
| <- ->
| |
|
|
------------------
And the vectors of the GradientRecursiveGaussian where pointing to the
white spot:
------------------
|
|
| |
| -> <-
| -> <-
| ^
| |
|
------------------
The second picture is as how it should be.
So, am I forgetting some basic theory (and should I study again)
or should the outcome of the GradientImageFilter not be the opposite?
Please help.
Greetings,
--
Pieter Vos
UMC Radboud Nijmegen
The Netherlands
mailto:pieterv@radiology.azn.nl