Publication
SpectroFX: real-time audio effects via graphical spectrogram manipulation
| datacite.subject.fos | Engenharia e Tecnologia::Engenharia Eletrotécnica, Eletrónica e Informática | |
| dc.contributor.author | Rocha, Manuel | |
| dc.contributor.author | Pestana, Pedro Duarte | |
| dc.date.accessioned | 2026-01-08T17:15:42Z | |
| dc.date.available | 2026-01-08T17:15:42Z | |
| dc.date.issued | 2025 | |
| dc.description.abstract | SpectroFX turns the short-time Fourier transform (STFT) spectrogram into a band- limited canvas for real-time audio effects inside VCV Rack. The digital signal processing (DSP) pipeline is deterministic: STFT/inverse short-time Fourier transform (ISTFT) with a periodic √Hann window and 50 % overlap (𝐹𝐹𝑇 𝑠𝑖𝑧𝑒 𝑁 = 1024, hop 𝐻 = N/2), explicit 1/N IFFT scaling, and overlap-add (OLA). Magnitude operators use the Open-Source Computer Vision (OpenCV) library over a 1 × 𝐾 vector per frame—Gaussian blur, unsharp-mask sharpening, Sobel edge emphasis, emboss, mirror, gating and frequency stretch—and act only within a full-width horizontal band set in the widget. Phase is reconstructed by a dedicated engine with three non-iterative modes: RAW, phase vocoder (PV) and identity phase-locking (PV-Lock). Output conditioning applies a first-order high-pass direct current (DC) blocker and a soft limiter. The design privileges predictable cost and glitch-free operation. | eng |
| dc.identifier.citation | Rocha, M. & Pestana, P.D. (2025). SpectroFX: Real-Time Audio Effects via Graphical Spectrogram Manipulation, Revista de Ciências da Computação, 2025, no19, pp.85-100. | |
| dc.identifier.issn | 2182-1801 | |
| dc.identifier.uri | http://hdl.handle.net/10400.2/20719 | |
| dc.language.iso | eng | |
| dc.peerreviewed | yes | |
| dc.publisher | Universidade Aberta | |
| dc.rights.uri | http://creativecommons.org/licenses/by/4.0/ | |
| dc.subject | Spectral processing | |
| dc.subject | Phase vocoder | |
| dc.subject | Phase locking | |
| dc.subject | VCV Rack | |
| dc.subject | Real-time audio | |
| dc.subject | Processamento espectral | |
| dc.subject | Vocoder de fase | |
| dc.subject | Bloqueio de fase | |
| dc.subject | Audio em tempo real | |
| dc.title | SpectroFX: real-time audio effects via graphical spectrogram manipulation | eng |
| dc.title.alternative | SpectroFX: efeitos sonoros em tempo real por manipulação gráfica | por |
| dc.type | journal article | |
| dspace.entity.type | Publication | |
| oaire.citation.endPage | 100 | |
| oaire.citation.issue | 19 | |
| oaire.citation.startPage | 85 | |
| oaire.citation.title | Revista de Ciências da Computação | |
| oaire.citation.volume | 2025 | |
| oaire.version | http://purl.org/coar/version/c_970fb48d4fbd8a85 | |
| person.affiliation.name | Universidade Aberta | |
| person.familyName | Pestana | |
| person.givenName | Pedro Duarte | |
| person.identifier.ciencia-id | 2714-8A7B-5CCA | |
| person.identifier.orcid | 0000-0002-3406-1077 | |
| person.identifier.rid | E-7273-2016 | |
| person.identifier.scopus-author-id | 56074016300 | |
| relation.isAuthorOfPublication | 755592cd-7905-4c94-9eba-1bb83ce10355 | |
| relation.isAuthorOfPublication.latestForDiscovery | 755592cd-7905-4c94-9eba-1bb83ce10355 |