Specifications
COPYRIGHT
©
1999 CANON INC. CANON SUPER G3 FAX BOARD-F1 REV.0 MAY 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
2-49
CHAPTER 2 OPERATION AND TIMING
When correct predictions continue, coding will be as follows:
Here, the value of LSZ consisting of correct predictions will be assumed to be 100*
1
(decimal)
for all statuses.
The area A will be within 8000 to 10000*
2
(decimal), and uses the initial bit when it falls below
8000*
3
(decimal), generating a coded image data output.
At this time, adjustments are made (by adding 1000*
4
, decimal) so that the area A will be
8000*
3
(decimal) or higher. The area of correct predictions will be MPS, and the area of wrong
predictions will be LPS.
Figure 2-408 Correct Predictions Continue
In this case, the code of 1 bit is generated when the area A grows to be less than 8000 at the 21st
pixel.
This way, the length of a code output will be short, and the rate of compression will be high.
Position (binary)
1.0000
0.1111
0.1110
0.1101
0.1100
0.1011
0.1010
0.1001
0.1000
0.0111
0.0101
0.0100
0.0011
0.0010
0.0001
0
Area A1
LPS
MPS MPS MPS MPS MPS MPS
MPS
MPS MPS MPS
LPS
Area A2
Standardization
Number of pixel
selected for coding
Position of coding
Initial value of area
Standardization
New initial value
LSZ
Area A
Coding output
Output coding
1
Correct
2
Correct
3
Correct
4
Correct
5
Correct
6
Correct
19
Correct
20
Correct
21
Correct
23
Correct
0
10000
100
9900
No
0
9900
100
9800
No
0
9800
100
9700
No
0
9700
100
9600
No
0
9600
100
9500
No
0
9500
100
9400
No
0
8200
100
8100
No
0
8100
100
8000
No
0
8000
100
7900
Ye s
1bit0
7900
1000
8900
100
8900
0
8900
100
8800
No