Specifications
COPYRIGHT
©
1999 CANON INC. CANON SUPER G3 FAX BOARD-F1 REV.0 MAY 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
2-43
CHAPTER 2 OPERATION AND TIMING
c. The learning table, as shown below, consists of all 10-bit pixel patterns from the model template
and the prediction levels and status numbers corresponding to these image patterns.
The prediction level and the status number of the pixel in question are compared against the
actual pixel by the arithmetic coding block each time the model template moves to the next pixel.
The result of comparison (whether the prediction is correct or wrong) is checked against the rate
of probability table based on the status number, thereby correcting (learning) the prediction level
and the status number to be used for the same pattern for the future.
As learning advances, the rate of making correct predictions by the learning table will increase,
while the need of coding will decrease.
Figure 2-404 Position of a Pixel within a Model Template
3-line model template
123
123456
789
10
?
45678
910?
2-line model template
Table 2-401 Learning Table (initial settings)
Pixel pattern within model template
Hexadecimal
Prediction
level of pixel
in question
000h
001h
002h
003h
004h
005h
Decimal
0
1
2
3
4
5
0
1
0
0
0
0
0
0
2
0
0
0
0
0
0
3
0
0
0
0
0
0
4
0
0
0
0
0
0
5
0
0
0
0
0
0
6
0
0
0
0
0
0
7
0
0
0
0
0
0
8
0
0
0
1
1
0
9
0
1
1
0
0
0
10
1
0
1
0
1
0
(white)
0
0
(white)
0
0
(white)
0
0
(white)
0
0
(white)
0
0
(white)
0
3FBh
3FCh
3FDh
3FEh
3FFh
1019
1020
1021
1022
1023
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
1
1
1
1
1
0
0
1
1
1
0
1
0
1
0
(white)
0
0
(white)
0
0
(white)
0
0
(white)
0
0
(white)
0
Status
number (ST)