1 The Representation, Indexing and Retrieval of Music Data at NTHU Arbee L.P. Chen National Tsing Hua University Taiwan, R.O.C. http://www.cs.nthu.edu.tw/ ~alpchen
Transcript
Slide 1
1 The Representation, Indexing and Retrieval of Music Data at
NTHU Arbee L.P. Chen National Tsing Hua University Taiwan, R.O.C.
http://www.cs.nthu.edu.tw/~alpchen
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2 Outline Content-based media data retrieval Music data
retrieval Features of music data Feature indexing and matching
Prototypes Reference
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3 Content-based Media Data Retrieval Representation of media
contents features Feature extraction from media data Feature
indexing Query interface
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4 Content-based Media Data Retrieval Matching query features
against the feature index approximate/partial matching similarity
measure precision: how many of the answers are in fact correct
recall: how many of the correct answers are in fact retrieved
relevance feedback
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5 Music Data Retrieval: System Architecture
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6 Features of Music Data
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7 Static music information The intrinsic music characteristics
of music objects Key, beat, and tempo E.g., the Beethoven Symphony
No. 5, Op. 67, C minor, 4/4, Allegro con brio Acoustical features
Loudness, pitch, duration, bandwidth and brightness Can be computed
and represented as numerical values
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8 Features of Music Data Thematic features Themes, melodies,
rhythms, and chords Can be derived from the staff information of a
music object Melody The melody of a song is the sequence of the
pitches of all notes in the songs E.g., the melody of the theme of
the Beethoven s Symphony No.5 is sol sol sol mi fa fa fa - re
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9 Features of Music Data Rhythm The rhythm of a song is the
sequence of the durations of all notes in the songs E.g., the
rhythm of the theme of the Beethoven s Symphony No.5 is
1/2-1/2-1/2-2-1/2-1/2-1/2-4 Chord A chord consists of three (root,
third, and fifth) or more notes which sound together in
harmony
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10 Features of Music Data Coding scheme: a music object a
sequence of music segments music segment = (segment type, segment
duration, segment pitch) four segment types: (type A), (type B),
(type C), and (type D)
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11 Features of Music Data For example, the sequence of music
segments: (B,3,-3) (A,1,+1) (D,3,-3) (B,1,-2) (C,1,+2) (C,1,+2)
(C,1,+1)
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12 music segment = (type, duration, pitch)
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13 Features of Music Data Repeating Pattern A sequence of notes
appearing more than once in the music object Efficient
content-based retrieval Semantics-rich representation Extracting
repeating patterns Tree-based approach Matrix-based approach
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14 Features of Music Data Experiment 1
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15 Features of Music Data Dissimilarity of melody strings
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16 Features of Music Data Dissimilarity of repeating
patterns
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17 Features of Music Data Experiment 2
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18 Features of Music Data Validity of classes
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19 Finding Repeating Patterns: Tree-based Approach Construct an
RP-tree for RP s with lengths 2 n, n 0, 1,... S =
ABCDEFGHABCDEFGHIJABC
24 Finding Repeating Patterns: Tree-based Approach Prune
trivial patterns of length 2 n, n = 0, 1, Let X be an RP of S, Y a
substring of X, and Z a substring of Y If freq(X) = freq(Z), Y is
trivial