A fully-annotated imagery dataset of sublittoral benthic species in Svalbard, Arctic

We present visual data of bottom macrofauna filmed in sublittoral of European Arctic – Svalbard. Some of the areas (Burgerbukta, Borebukta, Dahlbrebukta, St. Johnsfjorden, Trygghamna) are in the vicinity of melting glaciers, others are in ice-free areas (Adriabukta, Eidembukta, Gipsvika). The dataset consists of three types of data: video samples, 2D mosaics and annotations of objects found. In total, 22 min 51 s of video footage was collected and split into 10-30 s segments, resulting in 47 video samples. he labels of samples indicate site, transect, a part of raw video from which video sample was cropped and duration of video sample. E.g., file named B1_0332_30s.bmp, where B stands for Borebukta bay (AD – Adriabukta, B – Borebukta, D - Dahlbrebukta, E - Eidembukta, G - Gipsvika, HB - Burgerbukta, SJ - St. Johnsfjorden, T - Trygghamna), 1 – transect number, 0332 – 3 min 32 s start time from a raw video, 30s – length of video sample from which this mosaic file was made. All video samples were converted into still images (video mosaics), that were manually analysed by marine biologists - specialists in Arctic biota, who identified visible biological objects at the lowest possible taxonomic level. Twelve taxons were targeted for annotation: brown alga – kelp Laminaria, spider crab Hyas sp., brittlestars Ophiuroidea, burrowing anemone Halcampa sp., sea squirts Tunicata, tube anemone Ceriantharia sp., sea star Urasterias lincki, tube dwelling Polychaeta, snailfishes Liparidae, flatfishes Pleuronectiformes, Shrimps, and benthic trachymedusa Ptychogastria polaris. Annotation process, where 4 experts performed manual pixel-wise segmentation (with Labelbox tool) and mask refinement survey (on SurveyJS platform), resulted in 2242 annotated objects with the most popular category – Ophiuroidea. Dataset consists of three directories: video samples (3-5 fps, .AVI format), video mosaics (.JPG format) and annotated categories with/without background (.PNG format). 47 video samples and 47 resulting 2D mosaics with corresponding annotations (masks and mask overlays) for 2242 objects in 12 categories. Geographic information. The following bays of Svalbard archipelago: Adriabukta (77.000100, 16.192216), Burgerbukta (77.057108, 16.007882), Borebukta (78.38859, 14.28120), Dahlbrebukta (78.566666, 12.368533), Eidembukta (78.360133, 12.779950), Gipsvika (78.42591, 16.52873), St. Johnsfjord (78.506766, 12.931066), Trygghamna (78.254050, 13.761500)

Media 1: In situ study of two interacting femtosecond filaments in sapphire

Originally published in Optics Letters on 15 May 2015 (ol-40-10-2285

Ultrafast nonlinear dynamics in thin GaN films studied by femtosecond digital holography

We studied the nonlinear propagation dynamics of intense 300 fs infrared pulses in thin GaN films by use of pulsed digital holography technique with 25 fs temporal resolution