A method for providing local change detection in video comprising: determining, for a current frame of a video sequence, a plurality of keypoints and associated local image descriptor values; determining (706, 901) one or more current frame inlier keypoints and one or more current frame outlier keypoints in the current frame based on previous frame inlier keypoints in previous frames of the video sequence, the current frame inlier keypoints being consistent with a global motion estimation and the current frame outlier keypoints being inconsistent with the global motion estimation; detecting (708, 902) a region of local change in the video sequence based on the current frame outlier keypoints in the current frame and previous frame outlier keypoints in the previous frames of the video sequence; and providing (709, 903) an indicator of local change based on the detected region of local change in the video sequence, -wherein determining (706, 901) one or more current frame inlier keypoints and one or more current frame outlier keypoints in the current frame based on previous frame inlier keypoints in previous frames of the video sequence further comprises: warping the previous frame inlier keypoints to coordinates associated with the current frame based on the global motion estimation; determining, for a first keypoint of the plurality of keypoints, matches, if any, with one or more inlier keypoints from each of the previous frames based on spatial and descriptor value distances between the first keypoint and the warped inlier keypoints from the previous frames, the matching inlier keypoints, warped to the current frame, being within a spatial neighbourhood of the first keypoint and having a descriptor value distance less than a threshold, wherein the warped inlier keypoints are from different frames of the previous frames; determining, for the said first keypoint, a matching score based on the determined matches, if any, between the said first keypoint and the one or more inlier keypoints from the previous frames and importance weights for the previous frames, wherein importance weights are greater for more recent frames; and comparing the matching score to a threshold to categorize the first keypoint as a current frame inlier keypoint or a current frame outlier keypoint. determining, for a current frame of a video sequence, a plurality of keypoints and associated local image descriptor values; determining (706, 901) one or more current frame inlier keypoints and one or more current frame outlier keypoints in the current frame based on previous frame inlier keypoints in previous frames of the video sequence, the current frame inlier keypoints being consistent with a global motion estimation and the current frame outlier keypoints being inconsistent with the global motion estimation; detecting (708, 902) a region of local change in the video sequence based on the current frame outlier keypoints in the current frame and previous frame outlier keypoints in the previous frames of the video sequence; and providing (709, 903) an indicator of local change based on the detected region of local change in the video sequence, -wherein determining (706, 901) one or more current frame inlier keypoints and one or more current frame outlier keypoints in the current frame based on previous frame inlier keypoints in previous frames of the video sequence further comprises: warping the previous frame inlier keypoints to coordinates associated with the current frame based on the global motion estimation; determining, for a first keypoint of the plurality of keypoints, matches, if any, with one or more inlier keypoints from each of the previous frames based on spatial and descriptor value distances between the first keypoint and the warped inlier keypoints from the previous frames, the matching inlier keypoints, warped to the current frame, being within a spatial neighbourhood of the first keypoint and having a descriptor value distance less than a threshold, wherein the warped inlier keypoints are from different frames of the previous frames; determining, for the said first keypoint, a matching score based on the determined matches, if any, between the said first keypoint and the one or more inlier keypoints from the previous frames and importance weights for the previous frames, wherein importance weights are greater for more recent frames; and comparing the matching score to a threshold to categorize the first keypoint as a current frame inlier keypoint or a current frame outlier keypoint. warping the previous frame inlier keypoints to coordinates associated with the current frame based on the global motion estimation; determining, for a first keypoint of the plurality of keypoints, matches, if any, with one or more inlier keypoints from each of the previous frames based on spatial and descriptor value distances between the first keypoint and the warped inlier keypoints from the previous frames, the matching inlier keypoints, warped to the current frame, being within a spatial neighbourhood of the first keypoint and having a descriptor value distance less than a threshold, wherein the warped inlier keypoints are from different frames of the previous frames; determining, for the said first keypoint, a matching score based on the determined matches, if any, between the said first keypoint and the one or more inlier keypoints from the previous frames and importance weights for the previous frames, wherein importance weights are greater for more recent frames; and comparing the matching score to a threshold to categorize the first keypoint as a current frame inlier keypoint or a current frame outlier keypoint.