Image Details
Caption: Figure 2.
Example architecture of the D4-equivariant shape measurement model (D4CNN). The input galaxy image is transformed over the full D4 orbit (four rotations and their mirrored counterparts), and we forward the CNN 8 times on each of the eight transformed variants to produce a set of features. These features are then mapped back to the original reference frame and combined through a weighted average to construct a D4-equivariant feature representation. Finally, an unbiased odd MLP preserves the sign of this equivariant feature, ensuring the output shape transforms with the desired equivariance under D4 symmetry operations.
© 2026. The Author(s). Published by the American Astronomical Society.