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ISO/IEC 10918-1 : 1993(E)
In the hierarchical mode of operation each component is encoded or decoded in a non-differential frame followed by a
sequence of differential frames. A non-differential frame shall use the procedures defined in Annexes F, G, and H.
Differential frame procedures are defined in this annex.
J.1
Hierarchical encoding
J.1.1
Hierarchical control procedure for encoding an image
The control structure for encoding of an image using the hierarchical mode is given in Figure J.1.
TISO1700-93/d108
Encode_image
Encode_frame
Append EOI marker
Done
Yes
No
Yes
No
[Generate down-sampled images]
Append SOI marker
[Append tables/miscellaneous]
Append DHP marker segment
Reconstruct components
using matching
decoder process
[Upsample reference components and
append EXP marker segment]
Generate differential components
Encode_differential_frame
Reconstruct differential components
Reconstruct components
Differential frame
?
More frames
?
Figure J.1 Hierarchical control procedure for encoding an image
Figure J.1 [D108] = 18 cm = 704 %
In Figure J.1 procedures in brackets shall be performed whenever the particular hierarchical encoding sequence being
followed requires them.
138
CCITT Rec. T.81 (1992 E)
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