  The Hayabusa Spacecraft Asteroid Multiband Imaging Camera (AMICA) has
acquired more than 1400 multispectral and high-resolution images of its target
asteroid, 25143 Itokawa, since late August 2005. In this paper, we summarize
the design and performance of AMICA. In addition, we describe the calibration
methods, assumptions, and models, based on measurements. Major calibration
steps include corrections for linearity and modeling and subtraction of bias,
dark current, read-out smear, and pixel-to-pixel responsivity variations. AMICA
v-band data were calibrated to radiance using in-flight stellar observations.
The other band data were calibrated to reflectance by comparing them to
ground-based observations to avoid the uncertainty of the solar irradiation in
those bands. We found that the AMICA signal was linear with respect to the
input signal to an accuracy of << 1% when the signal level was < 3800 DN. We
verified that the absolute radiance calibration of the AMICA v-band (0.55
micron) was accurate to 4% or less, the accuracy of the disk-integrated spectra
with respect to the AMICA v-band was about 1%, and the pixel-to-pixel
responsivity (flatfield) variation was 3% or less. The uncertainty in
background zero-level was 5 DN. From wide-band observations of star clusters,
we found that the AMICA optics have an effective focal length of 120.80 \pm
0.03 mm, yielding a field-of-view (FOV) of 5.83 deg x 5.69 deg. The resulting
geometric distortion model was accurate to within a third of a pixel. We
demonstrated an image-restoration technique using the point-spread functions of
stars, and confirmed that the technique functions well in all loss-less images.
An artifact not corrected by this calibration is scattered light associated
with bright disks in the FOV.
