@techreport{oai:ipsj.ixsq.nii.ac.jp:00069952,
 author = {石垣, 麻子 and 松原, 正樹 and 斎藤, 博昭 and Asako, Ishigaki and Masaki, Matsubara and Hiroaki, Saito},
 issue = {24},
 month = {Jul},
 note = {ピアノ演奏においては，複数の声部が重なり合うポリフォニー音楽に対し，各声部の役割を読み取り，声部ごとに表情付けを行いながら演奏することが求められる．しかし，初中級者には，複雑なポリフォニー音楽の楽譜から声部構造の読解と演奏を両立することが難しい．そこで本稿では，J.S. バッハのピアノ曲を対象に，MIDIファイルの入力から，音高，音長の情報を用いて声部分離を自動的に行う手法を提案し，声部ごとに色付けされた楽譜を生成した．提案手法では，まずChewらのコンティグマッピング手法に基づき，楽曲をコンティグという単位に分割し，コンティグ内で声部分離を行う．次に，休符の出現による声部数の変化に着目し，声部数の小さいコンティグ，声部数の大きいコンティグの順に隣り合う場合のみ，2つのコンティグのどの声部とどの声部が同一の声部であるか，対応を求め結合する処理を行う．この繰り返しにより，全てのコンティグを声部数が最大となるコンティグと対応付け，楽曲全体の声部分離を完成させた．実験では，J.S. バッハのInvention15曲，Sinfonia15曲，Fugue48曲を対象に，声部分離の正解率を求めた．その結果，従来手法では精度の低かった4声，5声の楽曲に関しても，提案手法では8割を超える正解率で声部分離が行えることを示した．, To play the polyphonic music on the piano requires expressive performance of each voice based on the interpretation of the each voice's role. For beginners and intermediate students of piano, however, it is a significant challenge to read complex polyphonic scores, comprehend the underlying multi-voice composition and play the music accordingly. This paper proposes the technique of automatic voice segregation of J.S. Bach's piano pieces based upon pitch and length of sound from MIDI file input and generated colored scores. In the technique proposed in this paper, following the “Contig Mapping Approach” by Chew, et al. a music piece is divided into the unit called “contig” first, and voices are segregated within the “contig”. Next, as the number of voices vary depending on rests, identical voices across two adjacent contigs were matched and the two contigs were combined, only when a contig with smaller number of voices and another contig with a larger number of voices were next to each other. The voice segregation of the entire music piece was completed by matching all the “contigs” to the “contigs” with the maximum number of voices. Voice segregation accuracy was verified by experiments with 15 Inventions, 15 Sinfonias, and 48 Fugues of J.S. Bach. The experimental results of the proposed technique indicated more than 80 percent of voice segregation accuracy even with 4-voice or 5-voice music pieces, with which conventional techniques had lower levels of accuracy.},
 title = {コンティグマッピング手法に基づくポリフォニー音楽の声部分離と色付け楽譜の生成},
 year = {2010}
}