The invention discloses an unconstrained in-video 
salient object detection method combined with an objectness degree. The unconstrained in-video 
salient object detection method specifically comprises the steps of: (1) inputting an original 
video sequence F={F<1>, F<2>, ..., F<M>}, wherein a t-th frame in the sequence is referred to as F<t>; (2) adopting a video saliency model and an objectiveness 
object detection algorithm for the video frame F<t>, so as to obtain an initial rectangular region for 
salient object detection; (3) updating an objectness degree probability graph and an object probability graph through iteration for the video frame F<t>, and adjusting the size of the rectangular region for salient 
object detection continuously, so as to obtain a single-frame salient 
object detection result; (4) and utilizing a dense 
optical flow method 
algorithm to obtain a 
motion vector field of pixel points of the video frame F<t>, and calculating the overlapping degree of the rectangular regions for salient object detection of the adjacent frames, so as to obtain a final salient object detection result. The unconstrained in-video salient object detection method updates the objectness degree probability graph and the object probability graph through iteration, enhances the precision of 
spatial domain salient object detection results, improves time consistency through sequence-level refining, and can detect 
salient objects in a video more accurately and completely.