*Proceeding Paper* **COVID-19 Lung Radiography Segmentation by Means of Multiphase Transfer Learning †**

**Plácido L. Vidal 1,2,\*, Joaquim de Moura 1,2, Jorge Novo 1,2 and Marcos Ortega 1,2**


**Abstract:** COVID-19 is characterized by its impact on the respiratory system and, during the global outbreak of 2020, specific protocols had to be designed to contain its spread within hospitals. This required the use of portable X-ray devices that allow for a greater flexibility in terms of their arrangement in rooms not specifically designed for such purpose. However, their poor image quality, together with the subjectivity of the expert, can hinder the diagnosis process. Therefore, the use of automatic methodologies is advised. Even so, their development is challenging due to the scarcity of available samples. For this reason, we present a COVID-19-specific methodology able to segment these portable chest radiographs with a reduced number of samples via multiple transfer learning phases. This allows us to extract knowledge from two related fields and obtain a robust methodology with limited data from the target domain. Our proposal aims to help both experts and other computer-aided diagnosis systems to focus their attention on the region of interest, ignoring unrelated information.

**Keywords:** CAD system; radiography; X-ray; lung segmentation; COVID-19; transfer learning
