@InProceedings{GermanoGast:2021:ReFrAd,
               author = "Germano, Rafael L. and Gastal, Eduardo S. L.",
          affiliation = "{Instituto de Inform{\'a}tica -- UFRGS} and {Instituto de 
                         Inform{\'a}tica -- UFRGS}",
                title = "Real-Time Frequency Adjustment of Images and Videos",
            booktitle = "Proceedings...",
                 year = "2021",
               editor = "Paiva, Afonso and Menotti, David and Baranoski, Gladimir V. G. and 
                         Proen{\c{c}}a, Hugo Pedro and Junior, Antonio Lopes Apolinario 
                         and Papa, Jo{\~a}o Paulo and Pagliosa, Paulo and dos Santos, 
                         Thiago Oliveira and e S{\'a}, Asla Medeiros and da Silveira, 
                         Thiago Lopes Trugillo and Brazil, Emilio Vital and Ponti, Moacir 
                         A. and Fernandes, Leandro A. F. and Avila, Sandra",
         organization = "Conference on Graphics, Patterns and Images, 34. (SIBGRAPI)",
            publisher = "Sociedade Brasileira de Computa{\c{c}}{\~a}o",
              address = "Porto Alegre",
             keywords = "frequency adjustment, frequency analysis.",
             abstract = "We present a technique for real-time adjustment of spatial 
                         frequencies in images and videos. Our method allows for both 
                         decreasing and increasing of frequencies, and is orthogonal to 
                         image resizing. Thus, it can be used to automatically adjust 
                         spatial frequencies to preserve the appearance of structured 
                         patterns during image downscaling and upscaling. By pre-computing 
                         the image's space-frequency decomposition and its unwrapped 
                         phases, these operations can be performed in real time, thanks to 
                         our novel mathematical perspective on frequency manipulation of 
                         digital images: interpreting the problem through the theory of 
                         instantaneous frequencies and phase unwrapping. To make this 
                         possible, we introduce an algorithm for the simultaneous phase 
                         unwrapping of several unordered frequency components, which also 
                         deals with the frequency-sign ambiguity of real signals. As such, 
                         our method provides theoretical and practical improvements to the 
                         concept of spectral remapping, enabling real-time performance and 
                         improved color handling. We demonstrate its effectiveness on video 
                         and a large number of images subject to frequency adjustment. By 
                         providing real-time control over the spatial frequencies 
                         associated with structured patterns, our technique expands the 
                         range of creative and technical possibilities for image and video 
                         processing.",
  conference-location = "Gramado, RS, Brazil (virtual)",
      conference-year = "18-22 Oct. 2021",
             language = "en",
                  ibi = "8JMKD3MGPEW34M/45DJJT5",
                  url = "http://urlib.net/ibi/8JMKD3MGPEW34M/45DJJT5",
           targetfile = "Germano_Gastal_SIBGRAPI2021_WTD_Frequency_Adjustment.pdf",
        urlaccessdate = "2024, Apr. 28"
}