Looks like all the images I have inserted in galleries, by using Simple Image Pro, are no indexed into the Sitemap and (obviuosly) into Google Images.
Is there a solution?
Thank you.

Make sure that Joomla!'s robots.txt is not blocking access to the /media folder

Thank you Krikor.
I've already tried with that. This is my robots.txt

# If the Joomla site is installed within a folder such as at
# e.g. www.example.com/joomla/ the robots.txt file MUST be
# moved to the site root at e.g. www.example.com/robots.txt
# AND the joomla folder name MUST be prefixed to the disallowed
# path, e.g. the Disallow rule for the /administrator/ folder
# MUST be changed to read Disallow: /joomla/administrator/
#
# For more information about the robots.txt standard, see:
# www.robotstxt.org/orig.html
#
# For syntax checking, see:
# www.sxw.org.uk/computing/robots/check.html

User-agent: *
Disallow: /administrator/
Disallow: /cli/
Disallow: /installation/
Disallow: /language/
Disallow: /libraries/
Disallow: /logs/
Disallow: /templates/
Sitemap: www.hokutodestiny.com/xml/1-hokutodestiny.html?view=xml

Any other suggestion?