JEITA CP-3451
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F. Scan header (SOS: Start of Scan)
SOS is a marker code giving various scan-related parameters (see Figure 23).
Address Offset
Code
Meaning
(Hex)
(Hex)
+00
FF
Marker Prefix
+00
DA
SOS
+02
00
Length of field
0C
2+1+3*2+3 = 12 (Bytes)
+04
03
Components in scan
+05
01
Component selector Y : 01
+06
00
Huffman table selector Y : 00
+07
02
Component selector Cb : 02
+08
11
Huffman table selector C : 11
+09
03
Component selector Cr : 03
+0A
11
Huffman table selector C : 11
+0B
00
Scan start position in block
+0C
3F
Scan end position in block
+0D
00
Successive approximation
Bit position
Figure 23 SOS Structure
G. Compressed data
Compressed data is byte data block Interoperability at the required ratio of Y:Cb:Cr and Huffman encoded. An EOB
(End of Block) is inserted in each block when the last value of its DCT coefficient is 0. If restart marker insertion is
defined in DRI, restart markers are inserted at 4 MCU Interoperability.
H. End of compressed data (EOI : End of Image)
EOI is a marker code indicating the end of Interoperability coded data, and is paired with SOI (see Figure 24). No
specification is made regarding data arrays that come after EOI.
Address Offset
Code
Meaning
(Hex)
(Hex)
+00
FF
Marker Prefix
+01
D9
EOI
Figure 24 EOI Structure