4-way formation skydiving image dataset (formations A–F)

Image dataset of 4-way formation skydiving formations (classes A–F) for formation recognition research. Contains 1,753 training/validation images, the original 60-image test set (test/), the same 60 images recropped to 720x720 (test_resized/), and an extended test set of 639 images from five outdoor and indoor competitions 2024–2026 (test_extra/). Used in "Two-step distance-based skydiving formation recognition" (Image and Vision Computing, 2026) and "Graph neural network-based recognition of skydiving formations".