Chord information extraction device, chord information extraction method and non-transitory computer readable medium storing chord information extraction program

A chord information extraction method comprising:

• extracting a character group corresponding to chord information from score image data representing a music score, the extracted character group including a plurality of characters;
• determining whether the extracted character group follows a chord notation rule by determining whether one or more of the plurality of characters included in the extracted character group match one or more of a known plurality of characters corresponding to known chord information;
• and
• correcting, in a case where it is determined that the extracted character group does not follow the chord notation rule based on a determination that the one or more of the plurality of characters included in the extracted character group do not match the one or more of the known plurality of characters corresponding to the known chord information, the extracted character group such that the one or more of the plurality of characters included in the corrected extracted character group follow the chord notation rule by matching the one or more of the known plurality of characters corresponding to the known chord information.

A chord information extraction device comprising:

• a character group extractor configured to extract a character group corresponding to chord information from score image data representing a music score;
• a determiner configured to determine whether the extracted character group follows a chord notation rule;
• and
• a corrector configured to, in a case where the determiner determines that the extracted character group does not follow the chord notation rule, correct the extracted character group to a character group that follows the chord notation rule, wherein
• the chord notation rule defines (i) a chord root rule in regard to a chord root and (ii) a chord type rule in regard to a chord type,
• the chord root rule defines a plurality of chord root character groups that represent a plurality of chord roots, and the chord type rule defines a plurality of chord type character groups that represent a plurality of chord types, and
• the determiner is configured to determine that the extracted character group follows the chord notation rule when the extracted character group includes (iii) any one of the plurality of chord root character groups defined by the chord root rule and (iv) any one of the plurality of chord type character groups defined by the chord type rule.

A chord information extraction device comprising:

• a character group extractor configured to extract a character group corresponding to chord information from score image data representing a music score;
• a determiner configured to determine whether the extracted character group follows a chord notation rule;
• a corrector configured to, in a case where the determiner determines that the extracted character group does not follow the chord notation rule, correct the extracted character group to a character group that follows the chord notation rule;
• a position information acquirer configured to acquire position information representing a position of the extracted character group in the music score;
• and
• a time position specifier configured to specify a time position in a music piece represented by the music score based on the acquired position information, wherein
• the chord notation rule defines (i) a chord root rule in regard to a chord root and (ii) a chord type rule in regard to a chord type, and
• the chord root rule defines a plurality of chord root character groups that represent a plurality of chord roots, and the chord type rule defines a plurality of chord type character groups that represent a plurality of chord types.