An image coding method and an image decoding method is provided by which
an image can be restored correctly even if part of memory management
information is lost by a transmission channel error, a candidate of a
reference image that can be referred to is selected more appropriately,
and coding efficiency is improved. The image coding method includes a
step for executing coding of an image, a step for judging whether a
picture in the memory which is never used as reference exists, a step for
coding memory management information for releasing the picture in the
memory which is never used as reference when a picture in the memory
which is never used as reference exists, a step for releasing the picture
in the memory which is never used as reference, a step for judging
whether the memory management information that releases the picture in
the memory which is never used as reference is coded by coding of an
image immediately before, and a step for coding again the memory
management information that releases the picture in the memory which is
never used as reference when the memory management information is coded.