Canon FAX-L350, Руководство по обслуживанию

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FAX-L350 Chapter 2: Technical Reference
This table shows probability of accuracy/inaccuracy in the form of a range, according to
the accurate/inaccurate results of a given status prediction value.
The plan of the probability estimation table is such that if the prediction is accurate, the
range of the next status number will be smaller than would be the case in an inaccurate
prediction.
The status number with this smaller range will be selected to be the next status number.
e) After the predicted value is found to be accurate/inaccurate by the actual pixel, the model template, and
the study table, that accuracy/inaccuracy is encoded in the arithmetic encoding section, and the encoded
image data is output.
f) In the encoding (mathematical encoding) done in the arithmetic encoding section, there is no conversion
table for encoding as is the case in encoding with conventional MH and MR. Using the LSZ (probability
estimation value of an inaccurate prediction: the form of a range) of the probability estimation table and
the accuracy/inaccuracy of the predicted value as a base, encoding is done by showing the position of the
progress of the prediction on an integer line (between 0~1.0). Encoding shown as a position on this
integer line, take a position under MPS in the case of accurate predictions, and under LPS in the case of
inaccurate predictions, as shown in the figure below.
Furthermore, there is a concept of range (A) in this arithmetic encoding. This range (A)
*2
is shown as an
MPS range in the case of accurate predictions and as an LPS range in the case of inaccurate predictions
for each pixel. When these ranges (A) are below a certain range
*3
, the leading edge bit (which excludes
the encoding
“0”
. shown by the position on the integer line) shifts one position to the left as encoded
image data, and is output. At this time, the limit of this range (A) which was below the certain range is
narrow and it is difficult to show a position more detailed than this, so the range (A) is magnified
*4
to
show it in more detail. This operation is called “Renormalization” , and this range (A) is reset to a
value above a certain range
*3
.
NOTE