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Input
Output
Context
Fig. 7.16.
Sketch of the digit classifier network. The network has access to the output of the
block classifier for the other digit as context to the normalized digit.
From the test set 4 (0.36%) of the left digit examples are substituted when none
are rejected. To achieve a substitution rate of 0.25% of the accepted left digits, the
acceptance rate must be lowered to 99.64%.
15 (1.36%) of the right test digits are substituted when all examples are accepted.
Lowering the acceptance rate to 98.52% reduces the substitution rate to 0.25%. The
right digit is obviously more difficult to recognize than the left one since there is a
greater variance in the distribution of right digit labels (see Table 7.1).
Figure 7.17 shows some example inputs and outputs of the right-digit classifier.
In Part (a) of the figure, some examples are shown that are not easy to recognize but
→
→
6
(.99)
0
(.02)
6=8
→
→
1
(.99)
6
(.71)
6=0
→
→
9
(.99)
0
(.03)
6=2
→
→
8
(.98)
8
(.33)
6=9
→
→
4
(.99)
1
(.06)
6=6
(a) (b)
Fig. 7.17.
Digit classification for problematic right digit examples. The output of the block
classifier for the left digit, the normalized right, and the digit classifier output are shown. The
index of the most active output and the confidence label the output vector. (a) successful digit
recognition; (b) recognition failure with desired class.
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