MobileNet-SSD with adaptive expansion of receptive field

With its lightweight structure and acceptable accuracy loss, MobileNet-SSD has been widely used in embedded system. The defect of multi-scale detection structure in the original SSD algorithm makes it insufficient in detecting small targets. In this paper, SKBlock structure is used to adaptively expand the receptive field of SSD shallow feature map to improve its detection ability for small targets. Experiments show that it can effectively improve the target detection ability, and does not increase the computational burden.