Digital Music Score Recognition Through Stave and Stem Detection

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Solution Overview

Problem

Existing musical scores in hard copy or low-quality scanned formats are inconvenient to navigate, annotate, and search through, and current optical character recognition techniques struggle to accurately convert sheet music into digitized formats due to the superimposition of musical characters on staves.

Innovation Solution

A method involving image processing techniques to convert digital images of musical scores into matrices, identify staves and musical characters, remove debris, adjust orientation, and re-engrave the scores to enhance their digital representation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional optical character recognition is used to convert sheet music into digital formats, then text conversion capability is provided, but accuracy deteriorates due to superimposition of musical characters on staves

Engineering Contradiction:
Improverecognition accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the image processing into distinct stages: stave detection and removal, musical character identification, and separate processing of each element. This segmentation allows the system to handle the superimposition problem by treating staves and musical characters as separate entities that can be processed independently, thereby improving recognition accuracy without requiring overly complex integrated processing

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary representation system using matrix data structures that separate stave information from musical character information. By creating intermediate processing stages where staves are identified and removed before character recognition, the system mediates the conflict between maintaining structural integrity and achieving accurate character identification

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If hard copy musical scores are used, then visual quality is maintained, but ease of operation deteriorates due to difficulty in navigation, annotation and search

Engineering Contradiction:
Improvenavigation convenienceVSAvoidmetadata loss
Core Design Contradiction:
Ease of operationVSLoss of information

Solution Approach 1:

The patent creates digital copies of musical scores that preserve the visual appearance of the original hard copy scores while enabling enhanced digital operations. The re-engraved scores maintain the look and feel of traditional scores but provide searchable, annotatable, and navigable digital formats, effectively copying the visual qualities while adding digital functionality

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent performs preliminary processing of the score data during the digitization stage, extracting and storing metadata, structural information, and musical elements in organized formats. This preliminary action enables efficient navigation, search, and annotation capabilities in the final digital product without requiring complex processing during user interaction

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If low quality scanned copies are used, then digital format is achieved, but visual appearance deteriorates and manufacturing precision is lost

Engineering Contradiction:
Improvedigital conversion efficiencyVSAvoidvisual quality
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent replaces simple scanning mechanics with advanced image processing and computational methods. Instead of relying solely on physical scanning quality, the system uses digital algorithms to detect staves, remove artifacts, identify musical characters, and re-engrave scores, substituting mechanical precision requirements with computational processing capabilities

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transforms the quality parameters of digital scores by adjusting processing parameters during conversion. By controlling threshold values, matrix resolution, and re-engraving parameters, the system can produce high-quality digital scores from various input qualities, effectively changing the quality parameters of the output regardless of input quality

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3776334B1Musical notation system
Publication Date: 2026.01.28 NKODA LTD
  • EP3776334B1 patent drawingFigure 1
  • EP3776334B1 patent drawingFigure 2
  • EP3776334B1 patent drawingFigure 3

AI summary

Disclosed herein is a method of identifying a line of a stave or a stem of a note in a digital image of a musical score comprising: converting the digital image into a matrix in which at least one cell of the matrix corresponds to a pixel of the digital image; setting the at least one cell of the matrix to a first value if the corresponding pixel of the digital image has a pixel intensity above a threshold intensity; identifying adjacent cells having the first value as linked cells, the adjacent cells corresponding to pixels being adjacent in one of a horizontal direction or a vertical direction of the digital image; identifying linked cells having a number of cells exceeding a threshold as a chain of cells; grouping adjacent chains of cells into a group of chains; determining a dimension of the group of chains; and comparing the dimension with a dimension threshold; wherein, if the dimension is above the dimension threshold, determining that pixels corresponding to linked cells of the group of chains correspond to a line of a stave if the adjacent cells corresponding to pixels being adjacent in a horizontal direction of the digital image or a stem of a note if the adjacent cells correspond to pixels being adjacent in a vertical direction of the digital image.