  Direct imaging of circumstellar disks at high angular resolution is mandatory
to provide morphological information that bring constraints on their
properties, in particular the spatial distribution of dust. New techniques
combining observing strategy and data processing now allow very high contrast
imaging with 8-m class ground-based telescopes (10^-4 to 10^-5 at ~1") and
complement space telescopes while improving angular resolution at near infrared
wavelengths. We carried out a program at the VLT with NACO to image known
debris disks with higher angular resolution in the near IR than ever before in
order to study morphological properties and ultimately to detect signpost of
planets. The observing method makes use of advanced techniques: Adaptive
Optics, Coronagraphy and Differential Imaging, a combination designed to
directly image exoplanets with the upcoming generation of "planet finders" like
GPI (Gemini Planet Imager) and SPHERE (Spectro-Polarimetric High contrast
Exoplanet REsearch). Applied to extended objects like circumstellar disks, the
method is still successful but produces significant biases in terms of
photometry and morphology. We developed a new model-matching procedure to
correct for these biases and hence to bring constraints on the morphology of
debris disks. From our program, we present new images of the disk around the
star HD 32297 obtained in the H (1.6mic) and Ks (2.2mic) bands with an
unprecedented angular resolution (~65 mas). The images show an inclined thin
disk detected at separations larger than 0.5-0.6". The modeling stage confirms
a very high inclination (i=88{\deg}) and the presence of an inner cavity inside
r_0~110AU. We also found that the spine (line of maximum intensity along the
midplane) of the disk is curved and we attributed this feature to a large
anisotropic scattering factor (g~0.5, valid for an non-edge on disk). Abridged
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