Canon MultiPASS C530, Service Manual

Page: 141 / 243

2-62
MultiPASS C530/C560 Chapter 2: Technical Reference
8.2.7 Explanation of bi-level image data (BID) section
BID is as shown in the construction figure below, and consists only of the number of stripes.
BID is constructed by the connection of the floating marker code and the section which includes the
actual image data encoded with JBIG image compression encoding, called SDE (Stripe Data Entity).
Figure 2-42 BID Construction Diagram
8.2.8 Explanation and parameters for each symbol used in BID
a) Floating marker code section
The floating marker code is set at the head of the stripe data entity (SDE).
In order to distinguish the encoding and the floating marker code, it is imperative that ESC (escape
code: 0xFF) be set at the head.
The following marker code and parameters are in the floating marker code.
The 0x of each marker code shows that the following integers are hexadecimal.
ABORT (Abort: 0x05)
Encoding interruption. Only the abort code can be made to appear anywhere.
ESC 0x05
ATMOVE (AT move: 0x06)
Designates from which line the movement of the AT pixel starts, and where it wil move to.
ESC 0x06 yAT:Movement-starting line Tx:Movement Position(X) Ty:Movement Position (Y)
Floating marker code SDE (Stripe Data Entity)
Marker code Parameter
1byte 1byte
RESERVE
ABORT
NEWLEN
1byte
4bytes
YD
ATMOVE
4bytes
yAT
COMMENT
4bytes
Lc
Ty
1byte 1byte
Tx
Floating marker code SDE
1byte
SDNORM/SDRST PSCD ESC
1byte
Variable
ESC
1byte
ESC
1byte Variable
Image data STUFF
BID (Bi-level Image Data) BID (Bi-level Image Data) ---------
Stripe Stripe