People Watching: Human Actions as a Cue for Single View Geometry

International audienceWe present an approach which exploits the coupling between human actions and scene geometry to use human pose as a cue for single-view 3D scene understanding. Our method builds upon recent advances in still-image pose estimation to extract functional and geometric constraints on the scene. These constraints are then used to improve single-view 3D scene understanding approaches. The proposed method is validated on monocular time-lapse sequences from YouTube and still images of indoor scenes gathered from the Internet. We demonstrate that observing people performing different actions can significantly improve estimates of 3D scene geometry

Forecasting Human-Object Interaction: Joint Prediction of Motor Attention and Actions in First Person Video

We address the challenging task of anticipating human-object interaction in first person videos. Most existing methods ignore how the camera wearer interacts with the objects, or simply consider body motion as a separate modality. In contrast, we observe that the international hand movement reveals critical information about the future activity. Motivated by this, we adopt intentional hand movement as a future representation and propose a novel deep network that jointly models and predicts the egocentric hand motion, interaction hotspots and future action. Specifically, we consider the future hand motion as the motor attention, and model this attention using latent variables in our deep model. The predicted motor attention is further used to characterise the discriminative spatial-temporal visual features for predicting actions and interaction hotspots. We present extensive experiments demonstrating the benefit of the proposed joint model. Importantly, our model produces new state-of-the-art results for action anticipation on both EGTEA Gaze+ and the EPIC-Kitchens datasets. Our project page is available at https://aptx4869lm.github.io/ForecastingHOI

Predicting Actions from Static Scenes

International audienceHuman actions naturally co-occur with scenes. In this work we aim to discover action-scene correlation for a large number of scene categories and to use such correlation for action prediction. Towards this goal, we collect a new SUN Action dataset with manual annotations of typical human actions for 397 scenes. We next discover action-scene associations and demonstrate that scene categories can be well identified from their associated actions. Using discovered associations, we address a new task of predicting human actions for images of static scenes. We evaluate prediction of 23 and 38 action classes for images of indoor and outdoor scenes respectively and show promising results. We also propose a new application of geo-localized action prediction and demonstrate ability of our method to automatically answer queries such as "Where is a good place for a picnic?" or "Can I cycle along this path?"

Laparoscopic versus open splenectomy for nontraumatic diseases

BACKGROUND: Laparoscopic splenectomy (LS) is the standard procedure for normal size or moderately enlarged spleens; open splenectomy (OS) is preferred in cases of splenomegaly. In this study, indications for and complications of open and laparoscopic splenectomy were analyzed, with the aim to identify patients who will benefit from either technique. METHOD: A consecutive series of 52 patients undergoing elective open or laparoscopic splenectomy between January 2001 and December 2006 was analyzed. Spleen volume was calculated as length x width x depth from the pathologist's measurements. RESULTS: LS was performed in 25 patients with a median age of 41 years (range = 24-65). OS was performed in 27 patients with a median age of 60 years (range = 24-86) (p < 0.001). Conversion to OS was necessary in two patients (8%). Operation time was significantly shorter in LS (p < 0.05). Spleen volume was significantly greater in patients who underwent open (median = 2520 ml, range = 150-16,800 ml) versus laparoscopic (median = 648 ml, range = 150-4860 ml) splenectomy (p = 0.001). In 36% of all laparoscopic procedures, spleen volume exceeded 1000 ml. The underlying disease was mainly immunothrombocytopenia in LS patients and lymphoma and osteomyelofibrosis in OS patients. Five patients died after OS. Significantly more patients were hospitalized longer than 7 days following OS than following LS (p < 0.05). Overall complication rate was higher after OS (LS, 8; OS, 13 patients; p < 0.05). CONCLUSIONS: LS was preferred in younger patients with moderate splenomegaly, while massive splenomegaly mostly led to OS. In view of the absence of technique-related differences, LS can primarily be attempted in all patients