Canon fax basic 2000 Manuale Di Servizio

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G3 FACSIMILE COMMUNICATIONS

“parameter K”. This is standardized as shown in the table below. By this

measure, if, for example, a transmission error prevents data from being

decoded correctly, decoding can be performed correctly from after the next

MH data. The line that was coded by the MH scheme to be referenced to at

this time is called the “reference line.”

Fig. 5-16   Transmission Error and Parameter K

Table 5-4   Parameter K

Vertical Scanning Line Density

Parameter K

Standard (3.85 lines/mm)

2

Fine (7.7 lines/mm)

4

Super-fine (15.4 lines/mm)

4

Ultra-fine (15.4 lines/mm)

4

In case of parameter K = 4

Without parameter

4 lines

Transmission error

Subsequent lines cannot
be correctly decoded.

4 lines

Transmission error

These two scanlines cannot
be correctly decoded.
Error can be recovered
at this line.

MH coding (reference line)

MR coding