Methods and devices for extracting feature descriptors for a video, the video having a sequence of pictures. The method includes identifying a first key picture and a second key picture later in the sequence than the first key picture; extracting a first set of feature descriptors from the first key picture and a second set of feature descriptors from the second key picture; identifying a set of pairs of feature descriptors, where each pair includes one descriptor from the first set and one descriptor from the second set; generating motion information describing the motion field between the first key picture and the second key picture; and filtering the set of pairs of feature descriptors based on correlation with the motion information to produce and output a subset of persistent descriptors.