Converter 
A converter applies a succession of transformations on the data

CoordinateSystem 
The class defines coordinate systems in terms of the
operations needed to transform the standard coordinate
system (currently J2000) to the coordinate system
associated with the object.

Deprojecter 
This class deprojects a point from a projection plane
onto the celestial sphere.

DepthSampler 
This class handles sampling in the depth dimension

Distorter 
This class defines a nonlinear distortion in the image plane.

Position 
This class represents a position in the sky.

Projecter 
This class is the parent class for Transformers that project a point from the celestial sphere
to a projection plane.

Projection 
This class implements projection algorithms to/from a projection
plane and the unit sphere.

Rotater 

Sampler 

Scaler 
This class does 2D scalings, rotations and linear transformations.

SphereDistorter 
This class defines a nonlinear distortion in the image plane.

Transformer 
The Transformer class is the superclass
for a variety of classes that transform positions
represented in one frame to another.

Util 

WCS 
A World Coordinate System defines a translation between celestial and pixel
coordinates.
