Valenti and Gevers  used the curvature of isophotes
to design a voting system for eye and pupil localization.
Using CCDs to map the isophotes
of these galaxies has revealed some interesting structures.
To date, the numerous approaches [3-8] have been proposed for image inpainting since the seminal work of BSCB [3,4]: for example, the classical Total Variation (TV)  and Curvature-Driven Diffusion (CDD)  models, which are based on solving Partial Differential Equation (PDE) to preserve the directions of the isophotes
in the missing region.
Morse and Schwartzwald  considered smoothing the isophotes
of the HR ima ge to reduce the undesirable artifacts.
The inpainting smoothly propagates the image information along the level lines directions (isophotes
) from outside to inside the hole.
Using IRAF's STSDAS package, we first extracted luminosity profiles and isophotes
from the panchromatic image obtained by combining all slices from the spectral cube (see Figure 12(a)).
An image can be thought of as a collection of curves with equal value, the isophotes
. At extrema an isophote
reduces to a point, at saddle points the isophote
, or contours of equal brightness, are approximately circular around the center and the variation of brightness outward is close to that of an inverse square law.