1. A method comprising: receiving first data defining a first bounding box for a first image of a sequence of images, wherein the first bounding box corresponds to a region of interest including a tracked object; receiving object tracking data for a second image of the sequence of images, the object tracking data defining a second bounding box, wherein the second bounding box corresponds to the region of interest including the tracked object in the second image; determining a similarity metric for first pixels within the first bounding box and search pixels within each of multiple search bounding boxes, wherein search coordinates of each of the search bounding boxes correspond to second coordinates of the second bounding box shifted in one or more directions; and determining a modified second bounding box based on the similarity metric.