Optical Music Recognition: State of the Art and Major Challenges

Optical Music Recognition (OMR) is concerned with transcribing sheet music into a machine-readable format. The transcribed copy should allow musicians to compose, play and edit music by taking a picture of a music sheet. Complete transcription of sheet music would also enable more efficient archival. OMR facilitates examining sheet music statistically or searching for patterns of notations, thus helping use cases in digital musicology too. Recently, there has been a shift in OMR from using conventional computer vision techniques towards a deep learning approach. In this paper, we review relevant works in OMR, including fundamental methods and significant outcomes, and highlight different stages of the OMR pipeline. These stages often lack standard input and output representation and standardised evaluation. Therefore, comparing different approaches and evaluating the impact of different processing methods can become rather complex. This paper provides recommendations for future work, addressing some of the highlighted issues and represents a position in furthering this important field of research

Recognition of handwritten music scores

The recognition of handwritten music scores still remains an open problem. The existing approaches can only deal with very simple handwritten scores mainly because of the variability in the handwriting style and the variability in the composition of groups of music notes (i.e. compound music notes). In this work on the one hand I study the isolated symbols (i.e half-note, quarter-note, clefs, sharps) and on the other hand the compound music notes. Firstly, I will separate the isolated symbols (i.e half-notes, quarter-notes, clefs, sharps) to the compounds and I will study each one separately. The isolated symbols will be recognized with symbol recognition methods and compounds with a primitive hierarchy and syntactic rules. The method has been tested using several handwritten music scores of the CVC-MUSCIMA database and compared with a commercial Optical Music Recognition software. Given that my method is learning-free, the obtained results are promising.El reconeixement de partitures musicals manuscrites segueix sent un problema obert. Els enfocaments existents només poden reconéixer partitures manuscrites molt simples, principalment a causa de la variabilitat en l'estil d'escriptura i la variabilitat en la composició dels grups de notes musicals (p.e. els símbols musicals compostos). En aquest treball, per començar, se separaran els símbols simples (p.e blanques, negres, claus, sostinguts) dels compostos i els estudiaré per separat. Els símbols simples mitjançant mètodes de reconeixement de símbols i els compostos a partir d'una jerarquia de primitives i regles sintàctiques. El meu mètode ha estat provat utilitzant diferents partitures de música escrita a mà de la base de dades CVC-MUSCIMA i comparat amb un programari de reconeixement òptic musical comercial. Tenint en compte que el meu mètode és d'aprenentatge lliure, els resultats obtinguts són prometedors.El reconocimiento de partituras musicales manuscritas sigue siendo un problema abierto. Los enfoques existentes sólo pueden reconocer partituras manuscritas muy simples, principalmente debido a la variabilidad en el estilo de escritura y la variabilidad en la composición de los grupos de notas musicales (p.e. los símbolos musicales compuestos). En este trabajo, para empezar, se separarán los símbolos simples (p.e blancas, negras, llaves, sostenidos) de los compuestos y los estudiaré por separado. Los símbolos simples mediante métodos de reconocimiento de símbolos y los compuestos a partir de una jerarquía de primitivas y reglas sintácticas. Mi método ha sido probado utilizando diferentes partituras de música escrita a mano de la base de datos CVC-MUSCIMA y comparado con un software de reconocimiento óptico musical comercial. Teniendo en cuenta que mi método es de aprendizaje libre, los resultados obtenidos son prometedores

A holistic approach for image-to-graph: application to optical music recognition

A number of applications would benefit from neural approaches that are capable of generating graphs from images in an end-to-end fashion. One of these fields is optical music recognition (OMR), which focuses on the computational reading of music notation from document images. Given that music notation can be expressed as a graph, the aforementioned approach represents a promising solution for OMR. In this work, we propose a new neural architecture that retrieves a certain representation of a graph—identified by a specific order of its vertices—in an end-to-end manner. This architecture works by means of a double output: It sequentially predicts the possible categories of the vertices, along with the edges between each of their pairs. The experiments carried out prove the effectiveness of our proposal as regards retrieving graph structures from excerpts of handwritten musical notation. Our results also show that certain design decisions, such as the choice of graph representations, play a fundamental role in the performance of this approach.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Work produced with the support of a 2021 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation. The Foundation takes no responsibility for the opinions, statements and contents of this project, which are entirely the responsibility of its authors. The second author is supported by grant ACIF/2021/356 from the “Programa I+D+i de la Generalitat Valenciana”

Integration of Language Models in Sequence to Sequence Optical Music Recognition Systems

El present projecte és un estudi del potencial d'integrar per mitjà de diverses tècniques un model de llenguatge a un sistema de Reconeixement Òptic de Partitures (OMR) basat en una arquitectura Sequence to Sequence. L'objectiu és millorar el rendiment del model sobre partitures manuscrites antigues, que són especialment complexes d'interpretar a causa del seu elevat grau de variabilitat i les distorsions que solen incorporar.The following project is a study of the potential of integrating a language model into a Sequence to Sequence-based Optical Music Recognition (OMR) system through various techniques. The goal is to improve the performance of the model on handwritten old music scores, whose interpretation is particularly error-prone due to their high degree of variability and distortion.El presente proyecto es un estudio del potencial de integrar por medio de varias técnicas un modelo de lenguaje a un sistema de Reconocimiento Óptico de Partituras (OMR) basado en una arquitectura Sequence to Sequence. El objetivo es mejorar el rendimiento del modelo sobre partituras manuscritas antiguas, que son especialmente complicadas de interpretar a causa de su elevado grado de variabilidad y las distorsiones que suelen incorporar

Understanding Optical Music Recognition

For over 50 years, researchers have been trying to teach computers to read music notation, referred to as Optical Music Recognition (OMR). However, this field is still difficult to access for new researchers, especially those without a significant musical background: Few introductory materials are available, and, furthermore, the field has struggled with defining itself and building a shared terminology. In this work, we address these shortcomings by (1) providing a robust definition of OMR and its relationship to related fields, (2) analyzing how OMR inverts the music encoding process to recover the musical notation and the musical semantics from documents, and (3) proposing a taxonomy of OMR, with most notably a novel taxonomy of applications. Additionally, we discuss how deep learning affects modern OMR research, as opposed to the traditional pipeline. Based on this work, the reader should be able to attain a basic understanding of OMR: its objectives, its inherent structure, its relationship to other fields, the state of the art, and the research opportunities it affords