serialized_pool

Pooling and upsampling driven by point cloud serialization codes.

Classes:

SerializedPool –

Grid pooling driven by the serialization code: points sharing a coarser code are reduced to one.
SerializedUpsample –

Undoes a SerializedPool step: scatters the pooled features back and adds the projected skip.

SerializedPool ¶

SerializedPool(
    in_channels: int,
    out_channels: int,
    stride: int = 2,
    bias: bool = True,
    act: Union[str, Callable, None] = None,
    norm: Union[str, Callable, None] = None,
    act_kwargs: Optional[Dict[str, Any]] = None,
    norm_kwargs: Optional[Dict[str, Any]] = None,
    reduce: Literal["sum", "mean", "min", "max"] = "max",
)

Bases: Module

Grid pooling driven by the serialization code: points sharing a coarser code are reduced to one.

Truncating the serialization code by \(3 \cdot \log_2(\text{stride})\) bits is exactly a grid subsampling, so no neighbor search is needed. Features are projected then reduced, positions are averaged, and the coarsened code is returned so the next stage can pool again.

Parameters:

in_channels (int) –

Input channel count.
out_channels (int) –

Output channel count.
stride (int, default: 2 ) –

Downsampling factor along each axis. Must be a power of \(2\).
bias (bool, default: True ) –

Whether the projection has a bias term.
act (Union[str, Callable, None], default: None ) –

Activation, name resolved by create_act. None disables.
norm (Union[str, Callable, None], default: None ) –

Normalization, name resolved by create_norm. None disables.
act_kwargs (Optional[Dict[str, Any]], default: None ) –

Extra kwargs for the activation.
norm_kwargs (Optional[Dict[str, Any]], default: None ) –

Extra kwargs for the normalization.
reduce (Literal['sum', 'mean', 'min', 'max'], default: 'max' ) –

Reduction applied within a cell: "sum", "mean", "min", or "max".

SerializedUpsample ¶

SerializedUpsample(
    in_channels: int,
    skip_channels: int,
    out_channels: int,
    norm: Union[str, Callable, None] = None,
    act: Union[str, Callable, None] = None,
    act_kwargs: Optional[Dict[str, Any]] = None,
    norm_kwargs: Optional[Dict[str, Any]] = None,
    bias: bool = True,
)

Bases: Module

Undoes a SerializedPool step: scatters the pooled features back and adds the projected skip.

Both branches get their own projection, normalization and activation before being summed.

Parameters:

in_channels (int) –

Channel count of the pooled features.
skip_channels (int) –

Channel count of the skip connection.
out_channels (int) –

Output channel count.
norm (Union[str, Callable, None], default: None ) –

Normalization, name resolved by create_norm. None disables.
act (Union[str, Callable, None], default: None ) –

Activation, name resolved by create_act. None disables.
act_kwargs (Optional[Dict[str, Any]], default: None ) –

Extra kwargs for the activation.
norm_kwargs (Optional[Dict[str, Any]], default: None ) –

Extra kwargs for the normalization.
bias (bool, default: True ) –

Whether the projections have a bias term.