Spatiotemporal cue fusion-based saliency extraction and its application in video compression

Extracting salient regions plays an important role in computer vision tasks, e.g., object detection, recognition and video compression. Previous saliency detection study is mostly conducted on individual frames and tends to extract saliency with spatial cues. The development of various motion feature further extends the saliency concept to the motion saliency from videos. In contrast to image-based saliency extraction, video-based saliency extraction is more challenging due to the complicated distractors, e.g., the background dynamics and shadows. In this paper, we propose a novel saliency extraction method by fusing temporal and spatial cues. In specific, the long-term and short-term variations are comprehensively fused to extract the temporal cue, which is then utilized to establish the background guidance for generating the spatial cue. Herein, the long-term variations and spatial cues jointly highlight the contrast between objects and the background, which can solve the problem caused by shadows. The short-term variations contribute to the removal of background dynamics. Spatiotemporal cues are fully exploited to constrain the saliency extraction across frames. The saliency extraction performance of our method is demonstrated by comparing it to both unsupervised and supervised methods. Moreover, this novel saliency extraction model is applied in the video compression tasks, helping to accelerate the video compression task and achieve a larger PSNR value for the region of interest (ROI).