MobileNet SSD v2 vs YOLOv4

MobileNet SSD v2 is a lightweight object detection model developed by Google Research, released in January 2018. It combines the MobileNetV2 backbone with the Single Shot MultiBox Detector (SSD) framework to produce a model optimized for inference on mobile and edge devices. MobileNetV2 introduces inverted residuals and linear bottlenecks to reduce computation while maintaining representational capacity compared to its predecessor.

MobileNet SSD v2 is designed for real-time on-device detection, making it suitable for mobile apps, embedded systems, and IoT devices. It performs object detection across a fixed set of categories and can be fine-tuned on custom datasets. It trades peak accuracy for reduced inference cost and model size relative to larger two-stage detectors.

YOLOv4 is an object detection model developed by Alexey Bochkovskiy, Chien-Yao Wang, and Hong-Yuan Mark Liao at Academia Sinica, released in April 2020 via the Darknet framework. It combines a CSPDarknet53 backbone, PANet neck, and YOLOv3 detection head with a large set of training improvements — Bag of Freebies and Bag of Specials — that improve accuracy with minimal inference cost increase.

YOLOv4 achieves 43.5% AP on COCO at 65 FPS on a Tesla V100 GPU. The Darknet implementation is the original version, distinguishing it from subsequent PyTorch-based reimplementations. It remains a widely referenced detection architecture and a supported training target in Roboflow Inference.