Spatial Visual Attention for Novelty Detection: A Space-based Saliency Model in 3D Using Spatial Memory

Saliency maps as visual attention computational models can reveal novel regions within a scene (as in the human visual system), which can decrease the amount of data to be processed in task specific computer vision applications. Most of the saliency computation models do not take advantage of prior spatial memory by giving priority to spatial or object based features to obtain bottom-up or top-down saliency maps. In our previous experiments, we demonstrated that spatial memory regardless of object features can aid detection and tracking tasks with a mobile robot by using a 2D global environment memory of the robot and local Kinect data in 2D to compute the space-based saliency map. However, in complex scenes where 2D space-based saliency is not enough (i.e., subject lying on the bed), 3D scene analysis is necessary to extract novelty within the scene by using spatial memory. Therefore, in this work, to improve the detection of novelty in a known environment, we proposed a space-based spatial saliency with 3D local information by improving 2D space base saliency with height as prior information about the specific locations. Moreover, the algorithm can also be integrated with other bottom-up or top-down saliency computational models to improve the detection results. Experimental results demonstrate that high accuracy for novelty detection can be obtained, and computational time can be reduced for existing state of the art detection and tracking models with the proposed algorithm.