The 2nd Workshop on Maritime Computer Vision (MaCVi) 2024

The 2nd Workshop on Maritime Computer Vision (MaCVi) 2024 addresses maritime computer vision for Unmanned Aerial Vehicles (UAV) and Unmanned Surface Vehicles (USV). Three challenges categories are considered: (i) UAV-based Maritime Object Tracking with Re-identification, (ii) USV-based Maritime Obstacle Segmentation and Detection, (iii) USV-based Maritime Boat Tracking. The USV-based Maritime Obstacle Segmentation and Detection features three sub-challenges, including a new embedded challenge addressing efficicent inference on real-world embedded devices. This report offers a comprehensive overview of the findings from the challenges. We provide both statistical and qualitative analyses, evaluating trends from over 195 submissions. All datasets, evaluation code, and the leaderboard are available to the public at https://macvi.org/workshop/macvi24.Comment: Part of 2nd Workshop on Maritime Computer Vision (MaCVi) 2024 IEEE Xplore submission as part of WACV 202

Visual servoing of an ROV relative to the fish cage net

Ovaj rad se bavi automatiziranjem inspekcije kaveza za ugoj ribe. Bitan podzadatak automatizirane inspekcije je održavanje optimalne udaljenosti od kaveza do ronilice. Koristeći se OpenCV Python bibliotekom kreirano je programsko rješene koje detektira ključne dijelove na strukturi kaveza. Nadalje, kreiran je i ROS čvor koji koristi poznate parametre poput širine sekcija mreže, u kombinaciji sa širinom sekcije u pikselima dobivenoj od Python skripte za procesuiranje slike kako bismo estimirali udaljenost do kaveza. Konačno, još jedan ROS čvor je kreiran koji se povezuje nazad sa Blueye ROVijem i šalje mu Twist poruke koje se koriste za kontrolu kretanja ROVa. Te poruke se temelje na estimiranoj i optimalnoj udaljenosti.A Blueye PRO Remotely Operated Vehicle (ROV) is being adapted to perform automated inspection of marine fish farm cages as a part of the HEKTOR project. An important subtask of automated inspection is keeping an optimal distance from the ROV to the fish cage. Using OpenCV Python library for image processing a script was created that detects key points on the structure of the fish cages. Furthermore, a ROS node was created which uses known length parameters such as width of a subsection of the cage netting, in combination with found width in pixels from the image processing script, to estimate distance to the cage. Finally, a second ROS node was created which links back to the Blueye and sends Twist messages to control its movement based on the estimated and optimal distances

Unifying stability and plasmonic properties in hybrid nanoislands: Au–Ag synergistic effects and application in SERS

In plasmon-based devices, the choice of metal for the nanostructures often leads to an undesirable tradeoff between either the superb performance of Ag or the stability of Au. There is a great interest in combining Au and Ag in a way that preserves both their favourable properties, while also exploiting synergistic effects to boost surface-enhanced Raman scattering (SERS) performance beyond the capabilities of a single metal. To address this issue, a large-area nanofabrication procedure based on galvanic replacement was used to create hybrid Au–Ag nanoislands with a diverse morphology and highly tunable (through visible to NIR) plasmon resonance. Their stability was comprehensively studied and shown to be complex to achieve. However, in the right conditions, Au–Ag nanoislands with silver-like plasmonic properties were fabricated, and shown to be stable over a period of at least 5 months. Moreover, their SERS efficiency considerably outperformed even that of Ag nanoislands. Computational investigation helped explain the advantageous properties and provided insights for future sensor design. Detection of the model molecules was achieved in the nanomolar range and in mild conditions (low laser power), indicating great potential for biomedicine sensing. Beyond that, nanoislands with simultaneous stability and good plasmonic properties can find application in a wide variety of photonic devices.The authors thank the financial support of the Croatian Science Foundation through the grant number IP-2019-04-5424. ICN2 acknowledges funding from Generalitat de Catalunya 2017 SGR 327, Spain. This study was supported by MCIN with funding from European Union NextGenerationEU (PRTR-C17.I1) and Generalitat de Catalunya. The authors thank support from “ERDF A way of making Europe”, by the “European Union”. ICN2 is supported by the Severo Ochoa program from Spanish MINECO (Grant No. SEV-2017-0706) and is funded by the CERCA Programme/Generalitat de Catalunya, Spain. MCS has received funding from the post doctoral fellowship Juan de la Cierva Incorporation, Spain from MICINN (JCI-2019) and the Severo Ochoa programme .Peer reviewe