Aim:
     Improves the signal-to-noise ratio of images without degrading seriously
 edge contrast and resolution.
  
     
Method:
     Anisotropic diffusion is now a well-established technique 
(see Perona & Malik, 1990), based on the resolution of partial differential 
equations which make the diffusion faster within objects or regions, and slower
across edges.
     
 User interface:
      
 
     Number of iterations: chosen by the user
 Diffusion parameter: depends on the amount of noise in the image.
 Directions: 4 ==> 8-connexity (default value)  2 ==> 4-connexity
 Shows the gradients: unclicked: No (default value); clicked: yes
 Show only the result of last iteration : unclicked (default value): yes; 
clicked: a stack of images is produced, one for 
each iteration (see the illustration below)
 
 
     Illustration: