A method that may include receiving or generating multiple versions of an input image, wherein the multiple versions differ from each other by resolution; feeding the multiple versions of the input image to multiple branches of an object detector; wherein the multiple branches comprise multiple shallow neural networks that are followed by multiple region units; calculating, by the multiple branches, candidate bounding boxes that are indicative of candidate objects that appear in the multiple versions of the input image; wherein the calculating comprises feeding intermediate results from shallow neural networks of lower resolution branches to shallow neural networks of higher resolution branches; and selecting bounding boxes out of the candidate bounding boxes, by a selection unit that follows the multiple branches
OBJECT DETECTOR HAVING SHALLOW NEURAL NETWORKS