RT-DETRv2 Explained in 8 Illustrations

Abstract: Object detection architectures are notoriously difficult to understand, often more so than LLMs. While RT-DETRv2 represents an important advance in real-time detection, most existing diagrams do little to clarify how its components actually work and fit together. In this article, we explain the architecture of RT-DETRv2 through a series of eight carefully designed illustrations, moving from the overall pipeline down to critical components such as the encoder, decoder, and multi-scale deformable attention. Our goal is to make the existing one genuinely understandable. By visualizing the flow of tensors and unpacking the logic behind each module, we hope to provide researchers and practitioners with a clearer mental model of how RT-DETRv2 works under the hood.