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fderiv

$ \bigcirc$Name


fderiv 1st and 2nd order derivatives of an image (3x3 stencil)




$ \bigcirc$Command Synopsis


fderiv [-k curv] [-a anti] [-c canny] [-l laplacian] [-x gradx] [-y grady] [-n gradn] [-p gradp] [-m MinGrad] [-s nsize] in



-k curv : curvature: D2u ( Du+ , Du+ ) / |  Du |   $ \hat{{}}$  3

-a anti : anticurvature: D2u ( Du , Du+ ) / |  Du |   $ \hat{{}}$  3

-c canny : Canny operator: D2u ( Du , Du ) / |  Du |   $ \hat{{}}$  3

-l laplacian : Laplacian: Trace ( D2u )

-x gradx : gradient (x coordinate)

-y grady : gradient (y coordinate)

-n gradn : gradient norm |  Du |  

-p gradp : gradient phase (degrees) in [-180,180] U {mw_not_an_argument (=1.0e9)}

-m MinGrad : minimum of |  Du |   to compute 2nd order derivatives (default 0.0)

-s nsize : neighborhood size used for the gradient: 8 (default), 4, 3 or 2

in : input Fimage




$ \bigcirc$Function Summary


void fderiv (in , curv , anti , canny , laplacian , gradx , grady , gradn , gradp , MinGrad , nsize )

Fimage in , curv , anti , canny , laplacian , gradx , grady , gradn , gradp ;

float *MinGrad ;

int *nsize ;




$ \bigcirc$Description


This module allows to compute first and second derivatives of an image.




$ \bigcirc$See Also


fnorm, harris, ll_boundaries2, ll_boundaries, ll_edges, mac_snakes.


$ \bigcirc$Version 1.3


Last Modification date : Thu Nov 29 20:23:56 2001


$ \bigcirc$Author


Lionel Moisan






next up previous contents index
Next: fdiff Up: Reference Previous: fconst   Contents   Index
mw 2004-05-05