A survey of computer uses in music

This thesis covers research into the mathematical basis inherent in music including review of projects related to optical character recognition (OCR) of musical symbols. Research was done about fractals creating new pieces by assigning pitches to numbers. Existing musical pieces can be taken apart and reassembled creating new ideas for composers. Musical notation understanding is covered and its requirement for the recognition of a music sheet by the computer for editing and reproduction purposes is explained. The first phase of a musical OCR was created in this thesis with the recognition of staff lines on a good quality image. Modifications will need to be made to take care of noise and tilted images that may result from scanning

Document recognition of printed scores and transformation into MIDI

The processing of printed music pieces on paper images is an interesting application to analyze printed information by a computer. The music notation presented on paper should be recognized and reproduced. Numerous methods of image processing and knowledge-based procedures are necessary. The DOREMIDI System allows the processing of simple piano music pieces for two hands characterized by the following steps: - Scanning paper images - Processing of binary image data into basic components - Knowledge-based analysis and symbolic representation of a musical score - Visual and acoustic reproduction of the results. DOREMIDI has been realized on a Macintosh II, using Common-Lisp (Clos) programming language. The user interface is equivalent to the common Macintosh-interface, which enables in an uncomplicated way to use windows and menus. A keyboard presents the results of the acoustical reproduction

Avoiding staff removal stage in optical music recognition: application to scores written in white mensural notation

Staff detection and removal is one of the most important issues in optical music recognition (OMR) tasks since common approaches for symbol detection and classification are based on this process. Due to its complexity, staff detection and removal is often inaccurate, leading to a great number of errors in posterior stages. For this reason, a new approach that avoids this stage is proposed in this paper, which is expected to overcome these drawbacks. Our approach is put into practice in a case of study focused on scores written in white mensural notation. Symbol detection is performed by using the vertical projection of the staves. The cross-correlation operator for template matching is used at the classification stage. The goodness of our proposal is shown in an experiment in which our proposal attains an extraction rate of 96 % and a classification rate of 92 %, on average. The results found have reinforced the idea of pursuing a new research line in OMR systems without the need of the removal of staff lines.This work has been funded by the Ministerio de Educación, Cultura y Deporte of the Spanish Government under a FPU Fellowship No. AP20120939, by the Ministerio de Economía y Competitividad of the Spanish Government under Project No. TIN2013-48152-C2-1-R and Project No. TIN2013-47276-C6-2-R, by the Consejería de Educación de la Comunidad Valenciana under Project No. PROMETEO/2012/017 and by the Junta de Andalucía under Project No. P11-TIC-7154

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

Staffline detection and removal in the grayscale domain

Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores. Faculdade de Engenharia. Universidade do Porto. 201

Sheet Music Unbound: A fluid approach to sheet music display and annotation on a multi-touch screen

In this thesis we present the design and prototype implementation of a Digital Music Stand that focuses on fluid music layout management and free-form digital ink annotation. An analysis of user constraints and available technology lead us to select a 21.5” multi-touch monitor as the preferred input and display device. This comfortably displays two A4 pages of music side by side with space for a control panel. The analysis also identified single handed input as a viable choice for musicians. Finger input was chosen to avoid the need for any additional input equipment. To support layout reflow and zooming we develop a vector based music representation, based around the bar structure. This representation supports animation of transitions, in such a way as to give responsive dynamic interaction with multi-touch gesture input. In developing the prototype, particular attention was paid to the problem of drawing small, intricate annotation accurately located on the music using a fingertip. The zoomable nature of the music structure was leveraged to accomplish this, and an evaluation carried out to establish the best level of magnification. The thesis demonstrates, in the context of music, that annotation and layout management (typically treated as two distinct tasks) can be integrated into a single task yielding fluid and natural interaction

Optical Music Recognition

Nowadays records, radio, television and the internet spread music more widely than ever before, and an overwhelming number of musical works are available to us. During the last decades, a great interest in converting music scores into a computer-readable format has arisen, and with this the field of Optical Music Recognition. Optical Music Recognition (OMR) is the name of systems for music score recognition, and is similar to Optical Character Recognition (OCR) except that it is used to recognize musical symbols instead of letters. OMR systems try to automatically recognize the main musical objects of a scanned music score and convert them into a suitable electronic format, such as a MIDI file, an audio waveform or ABC Notation. The advantage of such a digital format, compared to retaining the whole image of a music score, is that only the semantics of music are stored, that is notes, pitches and durations, contextual information and other relevant information. This way much computer space is saved, and at the same time scores can be printed over and over again, without loss of quality, and they can be edited and played on a computer \citep{Vieira01}. OMR may also be used for educational reasons - to convert scores into Braille code for blind people, to generate customized version of music exercises etc. In addition, this technology can be used to index and collect scores in databases. Today, there are a number of on-line databases containing digital sheet music, making music easily available for everyone, free of charge. The earliest attempts at OMR were made in the early 1970's. During the last decades, OMR has been especially active, and there are currently a number of commercially available packages. The first commercial products came in the early 90's. However, in most cases these systems operate properly only with well-scanned documents of high quality. When it comes to precision and reliability, none of the commercial OMR systems solve the problem in a satisfactory way. The aim of this thesis is to study various existing OMR approaches and suggest novel methods, or modifications/improvements of current algorithms. The first stages of the process is prioritized, and we limit to concentrate on identifying the main musical symbols, essential for playing the melody, while text, slurs, staff numbering etc. are ignored by our program. The last part of an OMR program usually consists of correcting classification errors by introducing musical rules. In this thesis, this is only applied to correct wrongly classified pitched for accidentals

An Expert System for Guitar Sheet Music to Guitar Tablature

This project applies analysis, design and implementation of the Optical Music Recognition (OMR) to an expert system for transforming guitar sheet music to guitar tablature. The first part includes image processing and music semantic interpretation to interpret and transform sheet music or printed scores into editable and playable electronic form. Then after importing the electronic form of music into internal data structures, our application uses effective pruning to explore the entire search space to find the best guitar tablature. Also considered are alternate guitar tunings and transposition of the music to improve the resulting tablature