Page 32 - Predicting the Risk of Attaining Breast Cancer

Cartesian Gradient


g (P )
For an image function

I(P) where P is a pixel,  )
(P

the Cartesian gradient P

at P is:  P) 
I(
  I  ( ) P
x
g( P) =   P)   y
I(
   I  ( )
P
 y  I  ( ) tan =  y
P
P
 x I  ( )
Orientation:  x

  PI( )  Magnitude:
  2

(  P) = arctan  y   PI(  ) 2  PI(  )
I
(
  P)  m( P) =   +  
   x   y 
 x 