Canon FAX L1000 Service Manual page 240

FAX-L1000 Chapter 3: Technical Reference
Example:
A brief explanation of how the study table works is given below.
It is assumed that each of the model template pixels 1~10 in the image below are white.
1. In this case, the model template pixel pattern is 000h.
2. The predicted value of pixel pattern 000h for pixel "X" is "white", but it is actually black.
Thus the prediction is "inaccurate".
3. The status ST is "0", so the probability estimation table is consulted, and the next status
is moved to "1". At the same time, by the reversal of the predicted value, the next
prediction is for "black".
Original image
1 2 3
4 5 6
9 10 X
X is actualy black
4. Next, the model template is moved to the adjoining pixel in order to perform the next
prediction. At this time, pixels 1~9 of the model template are white, and pixel 10 is
black.
5. In this case, the model template pixel pattern is 001h.
6. The predicted value of pixel pattern 001h for pixel "X" is "white", and it is actually
white. Thus the prediction is "accurate".
7. The status ST is "0", so the probability estimation table is consulted, and the next status
is moved to "1". The prediction for the next pixel remains "white".
Move to next pixel
1 2 3
4 5
9 10
X is actualy white
The study table is constantly updated in this way, increasing the probability of accurate
predictions.
Study table for current pixel
Pixel Actual
Predicted
pattern value
value
0 0 0 h 0 (white) 1 (black)
0 0 1 h
0 (white)
0 0 2 h
0 (white)
Probability estimation table
ST LSZ NLPS
0 5A1Dh 1
1 2586h 14
7 8
2 1114h 16
3 080Bh 18
Figure 3-45 Study Table Study Example 1
Study table for current pixel
Pixel Predicted Actual
pattern value
value
6 7 8
0 0 0 h 1 (black)
X
0 0 1 h 0 (white) 0 (white)
0 0 2 h
0 (white)
Probability estimation table
ST LSZ NLPS
0 5A1Dh 1
1 2586h 14
2 1114h 16
3 080Bh 18
Figure 3-46 Study Table Study Example 2
Study table for next pixel
Status
Accurate/ Pixel Predicted
ST
Inaccurate pattern
value
0 0 0 0 h 1 (black)
Inaccurate
0 0 0 1 h 0 (white)
0 0 0 2 h
0 (white)
NMPS SWITCH
1 1
2 0
3 0
4 0
Study table for next pixel
Status
Accurate/ Pixel Predicted
ST
Inaccurate pattern
value
1 0 0 0 h 1 (black)
0
Accurate 0 0 1 h 0 (white)
0 0 0 2 h
0 (white)
NMPS SWITCH
1 1
2 0
3 0
4 0
3-96
Actual Status
Accurate/
value ST
Inaccurate
1
0
0
Actual Status
Accurate/
value ST
Inaccurate
1
1
0