Database Reference
In-Depth Information
Table 3.3
A comparison of average precision rate (AVR) (%) between pseudo-RF
method and user-controlled RF method, using DB1, and MHI descriptor, where
ʔ
denotes AVR differences between the two methods
Number of user
RF (iteration)
Method
Initial
Iter. 1
Iter. 4
ARBFN
a
: Pseudo-RF
63.42
71.66
76.51
-
b
: User-controlled RF
63.42
77.64
80.17
4
ʔ
=
a
−
b
-
+5.98
+3.66
Single-RBF
a
: Pseudo-RF
63.42
70.31
73.06
-
b
: User-controlled RF
63.42
73.65
77.43
4
ʔ
=
a
−
b
-
+3.34
+4.37
QAM
a
: Pseudo-RF
60.35
67.89
72.79
-
b
: User-controlled RF
60.35
74.68
77.53
4
ʔ
=
a
−
b
-
+6.79
+4.74
Table 3.4
A comparison of average precision rate (AVR) (%) between
semiautomatic and user-controlled RF methods, after one round of user
interaction, using DB1
Method
Initial
User-controlled RF
Semiautomatic RF
Retrieval based on WM descriptor
ARBFN
58.78
77.53
83.41
Sigle-RBF
58.78
75.59
78.34
QAM
53.88
61.75
63.25
Retrieval based on MHI descriptor
ARBFN
63.42
77.64
81.14
Sigle-RBF
63.42
73.65
77.03
QAM
60.35
74.68
76.39
Figure
3.8
a-c shows the results for each method when convergence is reached.
The improvement resulting from the adoption of the semiautomatic approach is
indicated by a correspondingly small amount of user feedback for convergence. In
particular, the semiautomatic methods can reach or surpass the best performance of
user controlled RF within only one to two interactions of user feedback.
3.3.3.3
Result of Retrieval in DCT Compressed Domains
The ARBFN method utilizing pseudo-RF learning was applied for retrieval of
images in DB2, JPEG photograph database [
93
]. The energy histograms of the
lower frequency DCT coefficients [
76
] were used to characterize each image in the
database. This constituted the feature space
1
for retrieval. The four coefficients
bounded within the upper left corner of the DCT block are used to obtain the
energy histograms. Separate energy histograms are constructed for the DC and AC
coefficients of each of the color channels, and 30 bins are used for each histogram.
F
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