[Insight-users] Erroneous Results calculating the gradient of an image with ITK

[Antonio Gómez Barquero]

Yes you were right, the problem is only in the border, but as Bradley
Lowekamp  has said in the last e-mail, is necessary to use
SetUseImageSpacingOff(); // for derivation in isotropic pixel space

Thanks so much both!! 

Antonio

-----Mensaje original-----
De: David Doria [mailto:daviddoria at gmail.com] 
Enviado el: miércoles, 28 de septiembre de 2011 14:43
Para: Antonio Gómez Barquero
CC: insight-users at itk.org
Asunto: Re: [Insight-users] Erroneous Results calculating the gradient of an
image with ITK

2011/9/28 Antonio Gómez Barquero <agb1 at alu.upct.es>:
>
> Sure, as an example, the first 6 results for the first line in each
channel:
>
> For MATLAB:
>
> Channel 1 :     -3              -4              -1      0               
> -1
> -3
> Channel 2 :     1       0,500000000000000       0       -1
> -0,500000000000000      2
>
> For ITK:
>
> Channel 1:       1.41           1.41            0          -2.83
> -1.417          5.67
> Channel 2:      -4.25           -5.7            -1.42   0
> -1.42           -4.25

Have you looked at the results as an image? My guess is that it is only
different on the border, due to different boundary conditions being used.

David