They are initialized to the sample_depth value from the IHDR chunk that appears when the object is first created but can be changed by the appearance of the IHDR chunk in a Delta-PNG datastream that has a nonzero delta_type .
(They; are initialized; to the sample_depth value from the IHDR chunk) (the IHDR chunk; appears; T:when the object is first created but can be changed by the appearance of the IHDR chunk in a Delta-PNG datastream) (the object; is created; T:first) (the object; can be changed; by the appearance of the IHDR chunk in a Delta-PNG datastream) (a Delta-PNG datastream; has; a nonzero delta_type)
They the IHDR chunk the object the object a Delta-PNG datastream
are initialized appears is created can be changed has
to the sample_depth value from the IHDR chunk
T:when the object is first created but can be changed by the appearance of the IHDR chunk in a Delta-PNG datastream
T:first
by the appearance of the IHDR chunk in a Delta-PNG datastream
a nonzero delta_type