Unsupervised Multi-object Segmentation Using Attention and Soft-argmax

We introduce a new architecture for unsupervised object-centric representation learning and multi-object detection and segmentation, which uses an attention mechanism to associate a feature vector to each object present in the scene and to predict the coordinates of these objects using soft-argmax. A transformer encoder handles occlusions and redundant detections, and a separate pre-trained background model is in charge of background reconstruction. We show that this architecture significantly outperforms the state of the art on complex synthetic benchmarks and provide examples of applications to real-world traffic videos.

Autoencoder-based background reconstruction and foreground segmentation with background noise estimation

Even after decades of research, dynamic scene background reconstruction and foreground object segmentation are still considered as open problems due various challenges such as illumination changes, camera movements, or background noise caused by air turbulence or moving trees. We propose in this paper to model the background of a video sequence as a low dimensional manifold using an autoencoder and to compare the reconstructed background provided by this autoencoder with the original image to compute the foreground/background segmentation masks. The main novelty of the proposed model is that the autoencoder is also trained to predict the background noise, which allows to compute for each frame a pixel-dependent threshold to perform the background/foreground segmentation. Although the proposed model does not use any temporal or motion information, it exceeds the state of the art for unsupervised background subtraction on the CDnet 2014 and LASIESTA datasets, with a significant improvement on videos where the camera is moving.